D R A F T
DOE Solar Energy Technologies Program FY2009

Annual Report
 

Table of Contents 

D R A F T

Introduction.............................................................................................................................................................
 

Photovoltaics...........................................................................................................................................................
 

Exploratory Research...................................................................................................................................................
 

Next Generation Photovoltaic Devices & Processes...............................................................................................
 

Minority University Research Associates Solicitation .............................................................................................
 

Commercialization Cooperative Research & Development Agreements ...............................................................
 

Seed Fund ...............................................................................................................................................................
 

Conversion Devices......................................................................................................................................................
 

Wafer Silicon...........................................................................................................................................................
 

Film Silicon ..............................................................................................................................................................
 

Copper Indium Gallium Selenide ............................................................................................................................
 

Cadmium Telluride..................................................................................................................................................
 

Concentrating Photovoltaics...................................................................................................................................
 

Organic Photovoltaics .............................................................................................................................................
 

Sensitized Solar Cells...............................................................................................................................................
 

Cross-Cutting Transparent Conducting Oxides .......................................................................................................
 

Theory & Computational Science ...........................................................................................................................
 

Measurements and Characterization..........................................................................................................................
 

Analytical Microscopy .............................................................................................................................................
 

Electro-Optical Characterization.............................................................................................................................
 

Surface Analysis ......................................................................................................................................................
 

Cell and Module Performance ................................................................................................................................
 

Process Development and Integration Laboratory......................................................................................................
 

PDIL Hardware Development, Software Integration, & Management ...................................................................
 

Photovoltaic Systems Development ............................................................................................................................
 

Technology Pathway Partnerships..........................................................................................................................
 

University Process & Product Development Partnerships......................................................................................
 

Photovoltaic Component Development.......................................................................................................................
 

Photovoltaic Technology Incubator ........................................................................................................................
 

Industry Thin Film Partnerships ..............................................................................................................................
 

Technology Evaluation.............................................................................................................................................
 

Evaluation, Validation, & Analysis...............................................................................................................................
 

Systems Performance Modeling .............................................................................................................................
 

Systems Analysis .....................................................................................................................................................
 
Reliability Research & Development ......................................................................................................................
 

Test & Evaluation ....................................................................................................................................................
 

Regional Experiment Stations .................................................................................................................................
 

Grid Integration...........................................................................................................................................................
 

Photovoltaic Grid Integration Support....................................................................................................................
 

Solar Energy Grid Integration Systems Industry Projects .......................................................................................
 

D R A F T

Resource and Safety R&D............................................................................................................................................
 

Solar Radiometry & Metrology ...............................................................................................................................
 

Solar Resource Characterization.............................................................................................................................
 

Environmental Health & Safety/Lifecycle Research................................................................................................
 

Market Transformation ...........................................................................................................................................
 

Codes & Standards ......................................................................................................................................................
 

Solar America Board for Codes & Standards ..........................................................................................................
 

Codes & Standards Laboratory Support .................................................................................................................
 

Workforce Development .............................................................................................................................................
 

Photovoltaic Installer Certification .........................................................................................................................
 

Solar Outreach & Communications.........................................................................................................................
 

Technical Assistance....................................................................................................................................................
 

Technical Assistance Provider and Tiger Team Integrator......................................................................................
 

Laboratory Support.................................................................................................................................................
 

Solar America Cities ................................................................................................................................................
 

Solar America Showcases........................................................................................................................................
 

Government Solar Installer Program ......................................................................................................................
 

Technical Outreach......................................................................................................................................................
 

State & Utility Outreach..........................................................................................................................................
 

Photovoltaic Cost Trends ........................................................................................................................................
 

Concentrating Solar Power ......................................................................................................................................
 

Parabolic Trough R&D .................................................................................................................................................
 

Trough Solar Field ...................................................................................................................................................
 

Parabolic Trough Industry Projects.........................................................................................................................
 

Dish/Stirling R&D.........................................................................................................................................................
 

Dish Engine R&D .....................................................................................................................................................
 

Dish Industry Projects .............................................................................................................................................
 

Thermal Storage Project..............................................................................................................................................
 

Storage Systems......................................................................................................................................................
 

Advanced Heat Transfer Fluids Development ........................................................................................................
 

CSP Storage Industry Projects.................................................................................................................................
 

CSP Industry Projects - Storage/Heat Transfer Fluids .............................................................................................
 

Advanced CSP Concepts ..............................................................................................................................................
 

Advanced Materials & Concepts.............................................................................................................................
 
Power Tower R&D...................................................................................................................................................
 

Advanced CSP Concepts Industry Projects..............................................................................................................
 

CSP Market Transformation ........................................................................................................................................
 

Southwest Stakeholder Outreach...........................................................................................................................
 

CSP Resource Assessment.......................................................................................................................................
 

Market Analysis & Grid Integration ........................................................................................................................
 

Solar Advisor Support .............................................................................................................................................
 

Programmatic Support for Environment Impact Study ..........................................................................................
 

D R A F T

Operations and Planning .........................................................................................................................................
 

Program Management................................................................................................................................................
 

PV Program Management.......................................................................................................................................
 

CSP Program Management.....................................................................................................................................
 

New West Technologies Programmatic Support ....................................................................................................
 

Sentech Programmatic Support..............................................................................................................................
 

Equipment and Facilities .............................................................................................................................................
 

CSP Capital Equipment & Facilities .........................................................................................................................
 

Communications & International ................................................................................................................................
 

Communications .....................................................................................................................................................
 

International ...........................................................................................................................................................
 

Planning, Budget, and Analysis Crosscut.....................................................................................................................
 

DOE Crosscut ...............................................................................................................................................................
 

Small Business Innovation Research.......................................................................................................................
 

Congressional Earmarks ..............................................................................................................................................
 

Solar Congressional Earmarks.................................................................................................................................
 
 

 

 

 

 

 

 

 

 

 

Photovoltaic Subprogram Overview
 

The mission of the Solar Energy Technologies Program (SETP) is to accelerate the development 

and large-scale deployment of solar technologies in the United States and to ensure that solar 

power is a viable and economic source for the nation’s power needs. The near-term goal of the 

photovoltaic (PV) subprogram is to help the domestic PV industry achieve grid parity by 2015 

through a program of research and development in PV materials, devices, and manufacturing 

technologies. 

D R A F T

The PV industry has seen dramatic changes over the past several years. In 2009, First Solar 

became the first PV manufacturer to ship more than 1 GW of modules a year. SunPower 

achieved notable performance advances with their back contacted cells. These advances 

however, provide only a backdrop to the more dramatic changes in the industry concerning 

pricing. PV module prices have continued to fall and appear likely to fall significantly below $2/W 

in 2010. The program’s 2015 grid parity goal, though challenging, is within reach with continued 

focus on the key cost drivers. However, to sustain a healthy domestic industry, the subprogram’s 

effort to advance technology ahead of the cost curve requires that it maintains and continuously 

sharpens focus to reach these goals. While module prices continue to fall, the PV subprogram 

must ensure that domestic manufacturers can improve performance and reduce costs quicker 

than the rate of price erosion. 

Subprogram funds were allocated among projects in critical PV research and development areas 

(R&D). Applied Research supports scientific research and development of materials, devices, and 

process technologies. Systems Development supports the development and transition of 

laboratory proven technologies into manufacturing. Within these two major areas fall projects that 

span from early-stage, applied R&D through market-oriented product and process development: 

•	 Next-Generation Research projects investigate high-risk/high-payoff PV device and 

process concepts. 

•	 Seed Fund projects at the national labs develop new ideas that upon maturity can 

develop into a cooperative research and development agreement (CRADA) or become a 

core lab research project. 

•	 Conversion Technologies Research projects focuses on deepening our understanding of 

materials and device physics of commercial and near commercial semiconductors 

including: wafer silicon, film silicon, cadmium telluride (CdTe), copper indium gallium 

diselenide (CIGS), organic photovoltaics (OPV), and SSC, as well as cross cutting 

research into Transparent Conducting Oxides (TCOs). 

•	 University PV Process and Product Development projects leverage the knowledge of 

universities to bring technology from laboratory to marketplace. 

•	 PV Pre-Incubator and PV Technology Incubators develop promising module technologies 

that have been successfully demonstrated on a small scale. 

•	 Supply Chain projects funded through the American Recovery and Reinvestment Act of 

2009 (ARRA) supports innovative companies developing cross-cutting technologies that 

provide leverage across supply chain. 

•	 Technology Pathway Partnerships (TPPs) are industry-led, public-private partnerships. 

The partnerships bring together key players across the supply chain to focus on 

innovations that reduce total installed systems costs. 

The PV subprogram continuously monitors and tracks performance of all of these funded 

activities to ensure that they are in alignment with program goals and the mission of the U.S. 

Department of Energy (DOE). 
 

D R A F T

Fig. 1 This graphic captures the projects that are funded to help the domestic solar industry 

achieve grid parity by 2015. 
 

 

 

D R A F T

Applied Research Highlights 

Applied Research and Development advances the performance of photovoltaic (PV) 

cells and modules through a process that deepens our understanding of the theory, 

materials science, device physics, and manufacturing technology of solar cells. It is a 

major part of the PV subprogram’s goals. Applied Research is broken down into four 

major research categories, each with their own specific focus along the research, 

development, demonstration, and deployment pipeline. 

Applied Research comprises the following areas: 

•	 Exploratory Research: early stage research at national labs and academia that 

bridges Basic Energy Sciences research and Applied Research 

•	 Conversion Devices: core research into PV materials and devices at the national 

labs 

•	 Measurement and Characterization: M&C infrastructure support at the national 

labs to support government and industry as well as research and development 

(R&D) into new techniques to advance our understanding of PV materials and 

devices 

•	 Process Development and Integration Laboratory Development and Utilization: 

new research facility with multiple cluster tools to enable rapid prototyping and 

development of new PV devices 

•	 Operations and Planning 

Applied Research 

Exploratory Research 

Conversion Devices 

Measurement and Characterization 

Process Development and 

Integration Laboratory 

Development and Utilization 

Operations & Planning 

NREL 

Total $K 

SNL 

Total $K 

Other 

Total $K 

Solar 

Total $K 

31855 

4604 

14234 

10025 

997 

510 

250 

0 

10303 

7249 

0 

0 

43190 

12363 

14484 

10025 

2692 

300 

0 

237 

0 

3054 

2692 

3626 
 

 

 

 

 

 

 

 

D R A F T

Exploratory Research Summary 

The fiscal year 2009 Budget for Exploratory Research encompasses Next Generation 

Photovoltaic (PV) devices and processes, Minority University Research Associates (MURA) 

solicitation, industry cooperative research and development agreements (CRADAs), and seed 

funds. The Solar Program supports exploratory research in solar energy by the nation’s best 

researchers from national laboratories, industry and universities for the purpose of discovering 

the next generation of PV technologies. 

The Next Generation PV Devices and Processes projects represent innovative, revolutionary, and 

highly disruptive next-generation PV technologies. The NREL-MURA Project provides scientific 

and technical research opportunities for minority undergraduate students working on various solar 

energy technology projects through partnerships with minority universities. The 

Commercialization CRADAs project accelerates growth of partnerships with industry to move 

more SETP technology into production faster. Seed Funds provide temporary funding for 

exploration of new ideas, including new materials, devices, or processes that have not reached 

the proof-of-concept stage. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Exploratory Research 4604 510 7249 12363 

Next Generation PV Devices 

and Processes 0 0 7233 7233 

MURA Solicitation 397 0 16 413 

Industrial CRADAs 1967 0 0 1967 

Seed Funds 2240 510 0 2750 
 

 

 

 

____________________________________________________________________________________ 

 

____________________________________________________________________________________ 

 

 

 

 

 

Next Generation PV Devices & Processes 

D R A F T

Performing Organizations:	 Arizona State University (ASU); California Institute of Technology (CIT); 

Massachusetts Institute of Technology (MIT); Mayaterials, Inc.; 

Pennsylvania State University (Penn State); Rochester Institute of 

Technology (RIT); Solexant Corporation; Soltaix LLC; Stanford 

University (Stanford); University of California, Davis (UC Davis); 

University of California, San Diego (UC San Diego); University of 

Colorado (CU); University of Delaware (UD); University of Florida (UF); 

University of Illinois; University of Michigan (U-M); University of South 

Florida (USF); University of Washington (UW); Voxtel, Inc.; Wakonda 

Technologies, Inc. 

Key Technical Contacts:	 Carolyn Elam (DOE/GO, Primary Contact), 303-275-4953, 

carolyn.elam@go.doe.gov 

Joe Lucas (DOE/GO), 303-275-4849, joe.lucas@go.doe.gov 

Jim Payne (DOE/GO), 303-275-4756, jim.payne@go.doe.gov 

Brad Ring (DOE/GO), 303-275-4930, brad.ring@go.doe.gov 

Holly Thomas (DOE/GO), 303-275-4818, holly.thomas@go.doe.gov 

DOE HQ Technology Manager:	 Marie Mapes, 202-586-000, marie.mapes@hq.doe.gov 

FY 2009 Budget:	 $7,200K 

Objectives 

•	 Make solar electricity from photovoltaics (PV) cost-competitive with conventional forms 

•	 Address long-term technological and scientific challenges for improved performance, lower cost, 

and improved reliability of PV components and systems. 

Accomplishment 

•	 Reviewed Phase 1 critical milestones and grants approved to proceed to Phase 2 research 

evaluating advanced semiconductor materials. 

Future Direction 

•	 Evaluate progress of critical milestones and decide at the end of the each project’s remaining 

Phases 2 or Phase 3 from FY 2009 and extending into FY 2011. 

1. Introduction 

The Next Generation PV Devices and Processes 

projects represent innovative, revolutionary, and 

highly disruptive next-generation PV technologies. 

These PV R&D activities are expected to produce 

prototype PV cells or processes by 2015, with full 

commercialization by 2030. 

2. Technical Approach 

The selected projects each received additional 

funding in FY 2009. The recipients are listed in the 

following table, and the specific accomplishments 

and future plans are summarized for each 

recipient in Section 3. 

Institution, PI, and FY 2009 Funding $K 

ASU; John Kouvetakis; Advanced 

Semiconductor Materials for PV 

359 

CIT; Harry Atwater; Abundant Cells from 

Earth-Abundant Semiconductors) 

360 

MIT; Vladimir Bulovic; Colloidal Nanocrystal 

Quantum Dot PV Devices 

241 

MIT; Emanuel Sachs; Recrystallization of 

Silicon Wafers in Thin Film Capsules 

360 

Mayaterials, Inc.; Richard Laine; Solar 

Grade Silicon from Ag By-Products 

310 

Penn State; Joan Redwing; High Aspect 

Ratio Semiconductor Heterojunction Cell 

210 

Penn State; Harry Allcock; Improved 

Electrodes and Electrolytes for Dye-Based 

Solar Cells 

285 

RIT; Seth M. Hubbard; High Efficiency 

Nanostructured III-V Cells for PV 

Concentrators 

219 

Solasta, Inc.; High Efficiency Power via 

Separated Photo and Voltaic Pathways 

220 Institution, PI, and FY 2009 Funding $K 

ASU; Mark van Schilfgaarde; II-IV-V Based 

Thin Film Tandem PV Cell) 

261 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

Institution, PI, and FY 2009 Funding $K 

Solexant Corporation; Alison Breeze; High 

Efficiency Quantum Dot Cells Based on 

Multiple Exciton Generation 

359 

Soltaix LLC; Mehrdad Moslehi; Ultra-HighEfficiency, Thin-Film, Crystalline Silicon 

Solar Cells 

360 

Stanford; Yi Cui; Culn(Ga)Se2 (CIGS) 

Nanowire Solar Cells 

364 

Stanford; Peter Peumans; Nanostructured 

Materials for Solution-Processed PV 

356 

UC–Davis; Adam Moule; Functional MultiLayer Solution Processable Polymer Solar 

Cells 

122 

UC–San Diego; Edward T. Yu; Highefficiency PV Based on Semiconductor 

Nanostructures 

364 

CU; Josef Michl; Exciton Fission for an UltraHigh Efficiency, Low Cost Solar Cell 357 

UD; William Shafarman; Novel Approaches 

to Wide Bandgap CuInSe2 Based Absorbers 

285 

UF; Jiangeng Xue; High Efficiency Hybrid 

Organic-Inorganic PV Cells 

360 

University of Illinois; John Rogers; Transfer 

Printed Microcells with Micro-Optic 

Concentrators) 

285 

U-M; Stephen Forrest; Crystalline Organic 

PV Cells 

276 

USF; Christos Ferekides; Next Generation 

CdTe Technology: Substrate Foil-Based 

Cells 

343 

UW; Alex Jen; Interfacial Engineering for pConjugated Polymer-Based Heterojunction 

Devices 

358 

Voxtel, Inc.; David Schut; Optimization of 

Impact Ionization in Composite Nanocrystal 

Devices 

222 

Wakonda; Leslie Fritzemeier; Novel 

Manufacturing of Flexible III-V Thin Films 

207 

3. Accomplishments and Future Directions 

3.1 II-IV-V Based Thin Film Tandem PV Cell 

(ASU—Schilfgaarde) 

Accomplishments 

•	 Grew thin films of ZnGeAs2 and ZnSnP2 using 

pulsed-laser deposition and ZnGeAs films by 

sputtering 

•	 Made p-n junctions from these films on 

different substrates, including Si, GaAs, CdS, 

and SnO and measured many optical and 

electrical device properties 

•	 Detailed experimental study of the 

thermodynamics and kinetics of ZnGeAs2 

growth by vapor phase epitaxy 

•	 Combined density functional calculations with 

thermodynamic theory to interpret the 

experimental findings. 

Future Directions 

•	 Using strategies developed to mitigate Zn 

volatility, a key challenge in the synthesis of 

the II-IV-V CPV (ZnK cells have been installed 

to facilitate Zn incorporation), determine 

optimum growth conditions and family of II-IVV CPV by combining new systematic growth 

and annealing studies with theory 

•	 Perform further theoretical calculations to 

clarify the mechanics of growth conditions in 

ZnGeAs2 and the entire family of II-IV-V to 

narrow the possible materials systems to 

explore. 

3.2 Advanced Semiconductor Materials for PVs 

(ASU—Kouvetakis) 

Accomplishments 

•	 Fully developed SiGeSn ternaries (grown 

lattice matched on Ge buffered Si) exhibiting 

direct band gaps in the desired 1-1.2 eV range 

required for the fabrication of hybrid IV/III-V 

cells 

•	 Fabricated GeSn p-i-n diodes sensitive in the 

IR spectral range not accessible to 

conventional Ge-based solar cells 

•	 Fabricated low-dark current Ge on Si PIN 

diodes deposited via a low temperature 

approach providing high quality material 

directly on Si 

•	 Produced device-quality InGaAs layers on 

ASU's Ge-buffered Si for large-scale solar cell 

integration (partner Epiworks). 

Future Directions 

•	 Fabricate and characterize GeSn/Si solar cell 

structures on Si; Ge solar cell structures 

based on ASU's Ge-buffered Si and p-n 

junction devices; and InGaAs solar cells on 

ASU's Ge-buffered Si in collaboration with 

industrial partner Epiworks 

•	 Determine band offsets between GeSiSn and 

Ge to provide critical parameters to design 

tunnel junctions in multiple-junction solar cells. 

•	 Transition the deposition chemistry used for 

the ASU Ge-on-Si and GeSiSn technologies to 

ASM America, Inc. 

3.3 Solar Cells from Earth-Abundant 

Semiconductors (CIT—Atwater) 

Accomplishments: 

•	 Achieved first room-temperature 

photoluminescence in Zn3P2; used 

photoluminescence and ellipsometry to 

definitively measure the bandgap in Zn3P2 

•	 Fabricated Mg-doped Zn3P2 junction solar 

cells with Voc = 560 mV (new record) 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Fabricated thin film a-Si solar cells with 

plasmon-enhanced light absorption, enabling 

30% enhancement in Jsc over flat reflector. 

Future Directions: 

•	 Fabricate Mg-doped Zn3P2 junction solar cells 

with high fill factor and low contact resistance 

D R A F T

•	 Optimize junction profile in Zn3P2 cells for high 

open circuit voltage 

•	 Optimize enhanced light absorption in 

plasmonic a-Si thin film solar cells. 

3.4 Colloidal Nanocrystal Quantum Dot PV 

Devices (MIT—Bulovic) 

Accomplishments 

•	 Demonstrated Schottky-junction quantum dot 

(QD) PVs using PbS (lead sulfide) QD thin 

films 

•	 Demonstrated heterojunction QD PVs using 

PbS QDs 

•	 Demonstrated the highest Voc and FF for any 

published colloidal QD PV structure using the 

heterojunction QDs 

•	 Demonstrated the first lateral heterojunction 

photodetector consisting of a metal-oxide 

charge transport layer and a colloidal QD 

charge-generation layer, to examine function 

of the heterojunction 

•	 Demonstrated a spray-coating method for 

deposition of colloidal QDs in a PV structure, 

which dramatically reduces use (and waste) of 

the QD materials during deposition 

•	 Demonstrated the influence of oxidative and 

plasma treatments on QD PV performance, 

using the results to develop a model for device 

operation. 

Future Directions 

•	 Continue to investigate the mechanism of 

operation of QD PV, focusing on the observed 

Voc/Isc tradeoffs 

•	 Continue to improve the QD film quality and 

assess the influence of chemical treatments 

on QD film performance, e.g., layered 

structures 

•	 Fabricate additional all-metal-oxide PVs. 

3.5 Recrystallization of Silicon Wafers in Thin Film 

Capsules (MIT—Sachs) 

Accomplishments 

•	 Achieved very large grain recrystallizations 

(grain size > 2 cm2

) on larger 25x100 mm 

format 

•	 Achieved proof of concept of a single crystal 

recrystallization on 25x100 mm format 

•	 Measured minority carrier lifetimes of 10 

microseconds 

•	 Fabricated 4 cm2 solar cell with active area 

efficiency of 15.0% 

•	 Invented method of in situ temperature 

measurement based on diffusion of implanted 

n- and p-type dopants 

•	 Gained understanding of super cooling 

allowed by different capsule materials using 

differential scanning calorimetry 

•	 Improved fabrication of capsules to ensure 

release from substrates as well as provide low 

nucleation surface to silicon. 

Future Directions 

•	 Modify recrystallization parameters, especially 

cooling profiles, to further reduce dislocation 

density and support growth with an inclined 

interface 

•	 Support above effort with in situ temperature 

measurement and with modeling 

•	 Continue to improve cell efficiency. 

3.6 Solar Grade Silicon from Agricultural ByProducts (Mayaterials—Laine) 

Accomplishments 

•	 Converted high purity silica and carbon 

obtained from agricultural by-products into 

silicon metal with impurities at or below 10 

ppm total, 99.999% purity 

•	 Converted high purity silica and carbon 

obtained from agricultural by-products into 

submicron-sized silicon carbide 

•	 Scaled up of the production of SiC to 20 g 

batches; scale-up of silicon production is still 

under way. 

Future Directions 

•	 Increase scale of Si production 

•	 Remove as much of remaining impurities as 

possible from silica before conversion. 

3.7 High Aspect Ratio Semiconductor 

Heterojunction Cells (Penn State—Redwing) 

Accomplishments 

•	 Developed processing technology to fabricate 

Si pillar/wire array samples on Si substrates 

with controlled diameters and spacing using 

both deep reactive ion etching (DRIE) and 

vapor-liquid-solid (VLS) growth 

•	 Performed reflectivity measurements on Si 

wire/pillar array samples and demonstrated a 

~40% reduction in reflectivity as the wire 

diameter was reduced from 32 to 1 μm 

•	 Photoelectrochemical characterization of VLSgrown Si wire arrays grown with gold and 

copper catalysts and DRIE-etched Si pillars. 

The photovoltage of the VLS-grown Si wire 

arrays varied over the range from 0.32 to 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.45V and was lower than that obtained for the 

DRIE-etched Si pillars and planar Si 

substrates (0.6V), most likely due to surface 

defects resulting from the metal-catalyzed 

growth technique 

•	 Developed processing technology to fabricate 

radial p-n junction Si wire array structures 

using dopant diffusion and low pressure 

chemical vapor deposition (LPCVD); initial 

studies of amorphous Si coating deposited by 

plasma-enhanced chemical vapor deposition 

(PECVD) indicated that a uniformly thick, 

conformal coating was obtained on the high 

aspect ratio wire structures 

D R A F 

•	 

geometry is effective at improving solar cell 

efficiency for material with short minority 

radial n

Demonstrated higher efficiency (~9%

deep reactive ion etching and dopant diffusion 

compared to comparable planar samples 

(~4%), 

+

confirm

-p+ Si pillar solar cells fabricated by 

ing that the radial junction 

) for 

T

carrier diffusion length 

•	 Developed a cleaning procedure to remove 

excess metal from the surface of VLS-grown 

Si wire arrays; demonstrated 2.3% efficiency 

in radial n+-psolar cells fabricated using goldcatalyzed Si wire arrays grown by vapor-liquidsolid growth on Si substrates and dopant 

diffusion to form the junction. 

Future Directions 

•	 Experimentally investigate effect of Si pillar 

diameter, spacing, and length on the optical 

properties and efficiency of radial n+-p+ 

junction solar cells and determine optimum 

device design 

•	 Develop in situ p-type doping process for VLSgrown Si wire arrays and demonstrate radial 

n+-p+ junction devices on Si substrates 

•	 Develop processing technology for VLS 

growth of Si wire arrays on glass substrates 

•	 Demonstrate radial junction devices formed 

using lower temperature LPCVD and PECVD 

deposition processes. 

3.8 Improved Electrodes and Electrolytes for DyeBased Solar Cells (Penn State—Allcock) 

Accomplishments 

•	 Formulated liquid/gel electrolytes based on 

mixture of phosphazene electrolyte materials 

and organic liquid additives; performed 

electrochemical experiments and assembled 

test cells for efficiency evaluation; analyzed 

thermal stability of above electrolyte-additive 

mixtures 

•	 Identified ease or difficulty of penetration of 

polymeric compounds into various nanoporous 

/nanotubular/nanocolumn electrodes under 

different infiltration conditions; examined 

difference in interfacial interactions for 

electrodes fabricated through different 

procedures 

•	 Continued to test assembly of various 

phosphazene-based electrolytes with 

nanoporous and nanowire electrodes with 

additional results related to difference in 

assembly methods and component 

combinations. 

Future Directions 

•	 Continue work of the last 2 years to optimize 

cell fabrication of existing electrolyte/electrode 

pairs 

•	 Synthesize and test ionic-liquid based 

phosphazene electrolyte materials with 

optimal molecular structures 

•	 Explore additives to formulate cost-effective, 

thermally stable gel/liquid electrolytes, 

focusing on mass transport and dielectric 

effects 

•	 Fabricate electrodes with surface-modified 

nanopatterns and assembly and test 

corresponding dye cells 

•	 Study fabrication procedures to improve cell 

performance and viability of mass production. 

3.9 High Efficiency Nanostructured III-V Cells for 

PV Concentrators (RIT—Hubbard) 

Accomplishments 

•	 Grew QD enhanced solar cells using 5-20­

stacks of InAs QD inserted within the i-region 

of a GaAs p-i-n solar cell and observed 

significant enhancement in one sun AM1.5; 

Jsc under concentration, with QD cell 

efficiency exceeding the baseline by 1% 

absolute at 400 sun concentration 

•	 Developed modified continuum elasticity 

theorem to model strain balancing in QD 

superlattice (SL), which correlated well with 

XRD values for QD-SL samples; used model 

to predict best GaP strain compensation 

thickness 

•	 Developed gold electroplating process to 

increase gold grid finger thickness at reduced 

cost; incorporated approach into a typical 

concentrator solar cell fabrication process; 

achieved peak efficiencies >400 suns and a 

corresponding drop in series resistance of the 

device 

•	 Produced electroluminescence results that are 

experimental evidence of wavefunction 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

overlap in strain-balanced QD solar cell 

devices 

•	 Developed and verified a new module for 

modeling software NanoTCAD incorporating 

solar illumination on a standard GaAs solar 

cell 

D R A F T

•	 Modeled temperature and dot-size 

dependence of thermal conductivity of QD 

structures to use to thermally optimize 

nanostructured solar cells (UC– Riverside). 

Future Directions 

•	 Investigate effect of QD “tuning” on triple 

junction solar cells under concentration; 

characterize QD-enhanced InGaP/GaAs 

tandem solar cells 

•	 Continue optimizing QD growth and uniformity 

by MOCVD 

•	 Develop model to predict QD incorporation 

effects in multijunction solar cells 

•	 Incorporate best concentrator design 

principles into the QD solar cells using 

developed models 

•	 Continue investigation into graphene as 

transparent conductive coatings (UC– 

Riverside).. 

3.10 High Efficiency Power via Separated Photo 

and Voltaic Pathways (Solasta—Naughton) 

•	 Work was discontinued on this grant when 

Solasta was awarded a subcontract under the 

NREL PV Incubator Program. 

3.11 High Efficiency QD Cells Based on Multiple 

Exciton Generation (Solexant—Breeze) 

Accomplishments 

•	 Synthesized PbS/CdS core/shell materials for 

improved surface state passivation 

•	 Demonstrated atomic layer deposition process 

for SnSx films via liquid metal-organic 

precursor 

•	 Tested conformal atomic layer deposition of 

Cu2S using new precursor materials 

•	 Continued optimizing mesoporous template for 

high surface area QD solar cells 

• Incorporated buffer layers in QD solar cells. 

Future Directions 

•	 Characterize temperature dependence of QD 

solar cells and apply insights to improve the 

device design 

•	 Optimize QD film deposition and ligand 

exchange treatment 

•	 Incorporate new ALD hole transport layers into 

QD devices 

•	 Develop inorganic ligands as alternate hole 

transport layer deposition techniques and 

incorporate into devices 

•	 Optimize back-contact electrode 

•	 Perform numerical simulations of QD solar 

cells. 

3.12 Ultra-High-Efficiency, Thin-Film, Crystalline 

Silicon Solar Cells (Soltaix—Moslehi) 

Accomplishments 

•	 Demonstrated multiple reuses of the silicon 

template by improving the various process 

•	 Developed a porous Si process enabling 

successful release of substrates with low 

defect densities 

•	 Developed an epitaxial substrate release 

techniques and a laser scribe technique to 

replace manual scribe to help minimize 

chipping and cracking of the released 

substrates, thus increasing release yield 

•	 Improved bulk minority carrier lifetime with 

world-class defect densities on both flat cell 

and 3-D cell structures 

•	 Demonstrated multiple reuses on 3-D and on 

flat templates 

•	 Demonstrated low defect density on 3-D cell 

structure and on flat cell 

•	 Demonstrated front-to-back contact cell on 

156 X 156 mm released thin film substrate 

with 15.8% efficiency 

•	 Optimized cell architecture, metal coverage, 

doping profiles, and ARC layer thickness using 

modeling. 

Future Directions 

•	 Continue focus to increase the number of 

reuses on flat substrates and improve cell 

efficiency on flat substrates and the quality of 

epitaxial thin film substrates 

•	 Further improve bulk minority carrier lifetime 

and defect density and improve efficiency by 

incorporating texture process on flat cells, 

optimizing substrate thickness. 

3.13 Culn (Ga) Se2 (CIGS) Nanowire Solar Cells 

(Stanford —Yi Cui) 

Accomplishments 

•	 Successfully synthesized a family of Cu-In-GaSe nanowire materials, including GaSe, 

In2Se3, In2-xGaxSe3, and CuInSe2 

•	 Understood the structure evolution during 

CuInSe2-CdS junction formation 

•	 Developed a facile new method in forming 

CuInSe2.nanowires by using In2Se3 

nanowires as template 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Collected data on single CuInSe2 nanowire 

transport 

•	 Fabricated single nanowire solar cells and 

study their property 

•	 Designed the antireflection and light trapping 

within nanocone and nanodome to be applied 

in CIGS cells 

D R A F T

•	 Developed the rolling process for producing 

nanocone substrates to be applied to CIGS 

solar cells. 

Future Directions 

•	 Perform CIGS nanostructure solar cell 

fabrication and measurement 

•	 Develop roll-to-roll nanostructure fabrication 

process. 

3.14 Nanostructured Materials for SolutionProcessed PV (Stanford—Peumans) 

Accomplishments 

•	 Demonstrated tandem organic solar cells with 

Ag nanowire as transparent electrodes 

•	 Produced CuInS2 nanoparticles as solar 

absorbers and demonstrated bandgap tuning 

by doping 

•	 Incorporated ZnO nanowires in bulk 

heterojunction cell, leading to increased shortcircuit current 

•	 Achieved control over ZnO nanostructure 

shapes during synthesis (nanowires, 

nanoparticles, nanoparticle assemblies of 

various size and roughness) 

•	 Demonstrated outstanding light trapping ability 

(haze > 0.3 at 1200 nm) of ZnO nanoparticle 

films 

•	 Built and qualified spray-coater to coat 

uniformly large area (30x30 cm) with Ag 

nanowires or ZnO nanostructures 

•	 Demonstrated Ag nanowire/conducting 

polymer composite transparent conductors 

with reduced roughness adequate for highperformance thin-film photovoltaics. Cell 

performance shown to be equivalent to 

conventional metal oxide (indium tin oxide, 

ITO) transparent conductors 

•	 Demonstrated a bending radius < 2 mm on 3­

mil-thick Mylar foil 

•	 Demonstrated sheet resistances approaching 

1 Ohm/sq for Ag nanowire mesh films under 

pressure 

•	 Demonstrated large-area deposition of Ag 

nanowire mesh films using spray coating. 

and transparencies > 90% by a combination of 

pressure and annealing 

•	 Continue to improve sheet resistance of ZnO 

nanowire electrodes 

•	 Fabricate nanocrystal solar cells with Ag and 

ZnO nanowires as transparent electrodes 

•	 Develop large-area deposition of uniform films 

of ZnO and Ag nanowires with controlled 

density 

•	 Measure scattering properties of ZnO 

nanostructures as a function of shape, size, 

density, and processing conditions 

•	 Analyze industrial-scale manufacturing. 

3.15 Functional Multi-Layer Solution Processable 

Polymer Solar Cells (UC-Davis—Moule) 

Accomplishments 

•	 Developed a multiple layer deposition method 

and test to make sure layers don’t mix 

•	 Determined that material layers mix upon heat 

tempering and the electrical consequences 

•	 Developed a method for using mixed 

electrode-active layer interlayer to fix work 

function 

•	 Perform optical and electrical measurements 

of organic electrode materials from Plextronics 

•	 Determine kinetic difference between various 

fullerene acceptors 

•	 Determine that PCBM crystallization is 

controlled by trace solvents and that the 

nonsolvent additives can be used to increase 

the stability of polymer/fullerene morphology 

•	 Investigated published methods for making bilayer devices from solution 

•	 Determined that the ligand size on the 

fullerene, not the reduction potential, 

determines the lifetime of the chargeseparated state using UC–Davis ultra-fast 

spectroscopy measurements of recombination 

with four different functionalized fullerenes. 

Future Directions 

•	 Use multiple layer technique to fabricate 

devices to make the process more generally 

applicable 

•	 Develop predictive optical and electrical 

modeling tools. 

3.16 High-efficiency PV Based on Semiconductor 

Nanostructures (UC San Diego—Yu) 

Accomplishments 

•	 Demonstrate 5–7% increased power 

Future Directions	 conversion efficiency in GaInAsP/InP 

•	 Improve performance of silver nanowire quantum-well solar cells compared to InP 

electrodes to sheet resistances < 5 ohm/sq homojunction solar cells 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Demonstrated ~17% increased power 

conversion efficiency in quantum-well solar 

cells incorporating nanostructure scattering 

effects relative to quantum-well solar cells 

without nanostructured scatterers 

•	 Demonstrated PV power conversion in 

nanowire-based solar cells consisting of nInAs nanowires on p-Si substrates 

D R A F T

•	 Demonstrated extended wavelength response 

in quantum well/QD solar cells. 

Future Directions 

•	 Integrate scattering-based engineering of 

photon propagation in waveguide modes of 

thin-film heterostructure devices with 

antireflection coatings for high power 

conversion efficiency 

•	 Fabricate and characterize semiconductor 

nanowire heterostructures for high-efficiency 

PV devices. 

3.17 Exciton Fission for an Ultra-High Efficiency, 

Low Cost Solar Cell (CU—Michl) 

Accomplishments 

•	 Prepared thin layers of a model chromophore, 

1,3-diphenylisobenzofuran, and demonstrated 

triplet quantum yields up to 160% by direct 

triplet-triplet absorption measurement 

•	 Produced nanocrystals of 1,3­

diphenylisobenzofuran 

•	 Discovered that in polar solvents, singlet 

fission proceeds by a new two-step 

mechanism via a charge-transfer state. 

Future Directions 

•	 Improve understanding of the competition 

between one-step and two-step singlet fission 

as a function of chromophore coupling and the 

relation to the difference in fission rates in 

crystals and covalent dimmers 

•	 Optimize covalent dimer structure for high 

triplet yields from singlet fission. 

3.18 Novel Approaches to Wide Bandgap CuInSe2 

Based Absorbers (UD—Shafarman) 

Accomplishments 

•	 Demonstrated a (AgCu)(InGa)Se2 cell with 

VOC = 0.89 V and efficiency = 13% by 

implementing a three-stage evaporation 

process, superior to the performance of other 

wide bandgap CuInSe2-based solar cells 

•	 Determined optical bandgaps for the complete 

(AgCu)(InGa)Se2 composition space and 

optical bowing parameters for fixed relative 

Group I or Group III composition 

•	 Showed that (AgCu)(InGa)Se2 lattice 

parameters determined from XRD 

measurements had a general fit to a plane 

described by Vegard’s law, showing linear 

behavior with respect to both Group I and 

Group III alloying and with no evidence of 

phase miscibility that has been reported in 

ingot samples 

•	 Showed laser/film annealing treatments that 

modify the Cu(InGa)Se2 surface and provide 

partial melting or recrystallization of the films 

to be insufficient for improved VOC in wide 

bandgap solar cells 

•	 Measured transient photocapacitance in 

(AgCu)(InGa)Se2 devices, showing that a 

defect band centered at 0.8 eV above the 

valence band is unchanged by Ag alloying; 

This may play a critical role in the 

recombination that limits VOC 

•	 Determined differences in the metastabilities 

of (AgCu)(InGa)Se2 devices after light soaking 

compared to Cu(InGa)Se2 devices; these may 

be a change in the recombination states 

limiting VOC. 

Future Directions 

•	 Quantify effects of evaporation process 

modifications and relative Ag content in wide 

bandgap (AgCu)(InGa)Se2 films with respect 

to materials properties and device behavior 

•	 Use current-voltage-temperature and 

capacitance-based characterization of 

(AgCu)(InGa)Se2 devices to develop basis 

and guide for improving these devices. 

3.19 Very High Efficiency Hybrid OrganicInorganic PV Cells (UF—Xue) 

Accomplishments 

•	 Developed ternary Zn1-xCdxSe nanospheres 

and nanorods with variable composition and a 

minimum bandgap of 1.8 eV 

•	 Synthesized PbSe nanospheres with bandgap 

of 1.5–1.1 eV 

•	 Synthesized phenylene, ethynylene, and 

thiophene-based oligomers with phosphonic 

acid end groups and bandgaps between 2.9 

and 1.9 eV 

•	 Demonstrated photoluminescence quenching 

between reactive oligomer and CdSe 

nanocrystals 

•	 Demonstrated alignment of CdSe nanorods in 

a matrix of P3HT with external electric field 

•	 Enhanced the efficiency and lifetime of hybrid 

PV devices by incorporating a ZnO 

nanoparticle layer 

•	 Demonstrated hybrid PV devices based on 

low gap polymer with efficiency of 3.3%. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Future Directions 

•	 Synthesize ternary nanorods with bandgap of 

1.5–1.8 eV 

•	 Optimize morphology of hybrid thin films and 

align nanorods assisted by an external field 

•	 Fabricate hybrid PV cells based on 

functionalized oligomer/polymers and ternary 

nanocrystals and study effect of ternary 

composition on Voc in these devices. 

D R A F T

3.20 Transfer Printed Microcells with Micro-Optic 

Concentrators (University of Illinois—Rogers) 

Accomplishments 

•	 Perfected design, transfer printing, and 

module-level integration of dual junction GaAs 

microcells 

•	 Designed and fabricated two-stage high 

concentration optics (> 1000X) 

•	 Fabricated more than 20 full modules using 

dual stage 1000X concentrator optics and dual 

junction GaAs/GaInP solar cells 

•	 Completed validating benchmarking 

measurements at NREL and Sandia National 

Laboratory on second generation modules 

•	 Completed optimized cell epi design for high 

concentration performance 

•	 Installed, certified, and initiated operations of 

tracking module platform test facility 

•	 Developed semi-automated testing and sorting 

tools. 

Future Directions 

•	 Develop prototype quad-junction inks 

•	 Model designs to boost cell performance at 

concentration ratios exceeding 1000X 

•	 Improve materials and integration schemes for 

devices integrated on lightweight, flexible 

substrates. 

3.21 Crystalline Organic PV Cells (U-M—Forrest) 

Accomplishments 

•	 Established the relationship between 

crystalline order and the exciton diffusion 

length in organic semiconductors, indicating 

the advantage of crystalline tandem 

architectures 

•	 Extended range of high-efficiency donor 

materials for tandem subcell incorporation with 

variable absorption into near infrared (NIR) 

through squaraine and phthalocyanine 

derivatives 

•	 Demonstrated high-efficiency (>2.5%) inverted 

OPV architectures for incorporation on low 

cost flexible substrates where avoiding glass 

substrates could significantly reduce overall 

cost FOM 

•	 Demonstrated 4.3% efficient cells based on 

polycrystalline squaraine donors 

•	 Demonstrated scaling capability of organic 

vapor phase deposition for large area (Gen 6) 

solar cell production 

•	 Modeled tandem performance for a range of 

subcell configurations to optimize power 

efficiencies > 6.5%. 

Future Directions 

•	 Design high-efficiency organic tandem cell 

using diffusion lengths and absorption 

characteristics of a range of crystalline and 

polycrystalline organic materials 

•	 Fabricate and characterize nanocrystalline 

tandem cells using optimized materials and 

growth conditions 

•	 Complete reliability testing of packaged single 

junction and tandem cells 

•	 Characterize key degradation mechanisms in 

various high-performance planar, bulk, 

nanocrystalline, and crystalline junctions and 

determine optimal routes to long-lifetime cells. 

3.22 Next Generation CdTe Technology: 

Substrate Foil-Based Cells (USF—Ferekides) 

Accomplishments 

•	 Established baseline process for substrate foilbased CdTe cells with efficiencies in the 6+% 

range 

•	 Demonstrated highest VOC for substrate foil 

cells: above 700 mV; baseline VOC: 650 mV 

•	 Demonstrated high spectral response, 

equivalent to substrate cells, indicating that 

collection in substrate foil cells is not key 

factor in limiting performance 

•	 Highest efficiency measured to-date in-house 

approx 6.5–7.0%; this is not corrected for 

reflection losses, which are higher than the 

typical glass superstrate CdTe cell 

•	 Continued to investigate various back-contact 

materials. 

Future Directions 

•	 Focus on factors limiting VOC and FF 

•	 Continue to develop and investigate back 

contact materials and model solar cell 

behavior to better understand performancelimiting mechanisms 

•	 Investigate heterojunction formation process 

and window layer properties to advance VOC to 

800+ mV 

•	 Investigate impact of front transparent 

electrode configuration, and optimize for 

maximum performance. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.23 Interfacial Engineering for p-Conjugated 

Polymer-Based Heterojunction Devices (UW— 

Jen) 

Accomplishments 

•	 Developed new low bandgap polymers based 

on alternating donor-acceptor backbone for 

high performance OPVs (power conversion 

efficiency= 6.4% with potential to go beyond 

7% after optimization) 

D R A F T

•	 6.4% with potential to go beyond 7% after 

optimization) 

•	 Developed chromophore-containing side-chain 

conjugated polymers with easily tunable 

absorption and energy levels for systematic 

optimization of OPV devices 

•	 New polymer in the inverted cells tested, with 

a record PCE as high as 5.4% 

•	 Developed new thermally crosslinkable 

fullerene derivatives with tunable crosslinking 

conditions and electron-transporting properties 

•	 Achieved complete control over the externally 

initiated synthesis of region-specific 

conjugated polymer P3HT, which shows 100% 

initiation with an extremely narrow 

polydispersity 

•	 Developed metal grids/conducting polymer 

transparent electrode with sheet resistance 

and transparency similar to those of 

commercial ITO conducting glass. Inverted 

OPV cell fabricated on the new hybrid 

transparent electrode shows similar PCE 

compared to that fabricated from ITO 

•	 Developed PCBM derivatives as new 

acceptors to improve morphological stability 

and lifetime of BHJ devices. 

Future Directions 

•	 Develop n-type materials with good isotropic 

charge transporting properties to replace C60 

•	 Optimize the ITO replacement electrode to 

ensure low-cost fabrication of OPVs 

•	 Combine material development and SAMmediated interface engineering to improve 

charge transport, selection, and collection 

•	 Use theory-guided synthesis to systematically 

optimize both electrical and optical properties 

of conjugated polymers. 

3.24 Optimization of Impact Ionization in 

Composite Nanocrystal Devices (Voxtel—Schut) 

Accomplishments 

•	 Performed in situ synthesis of Janus Type II 

nanocrystalline QDs (J2NQD) on ITO/TiO2 

substrates 

•	 Observed fluorescent quenching on ligand 

substitution of PbS(oleic acid) with bifunctional 

ligands. Ligand dimmers and oligomers 

reduced the quantum confinement effect 

•	 Studied the performance of PbS NQDs with 

various ligands with different types of hole 

transfer layer materials or electrolytes for best 

performance 

•	 Investigated the performance of several 

different types of TiO2 to determine best 

substrate upon which to place the PbS(ligand) 

NQDs; hybrid of hydrothermally generated 

TiO2 covered with nanoparticle-sintered TiO2 

gave the best results 

•	 Observed that smaller PbS NQDs were more 

effective at injecting charge than smaller PbS 

NQDs. 

Future Directions 

•	 Continue to analyze performance and 

characterize J2NQDs 

•	 Increase fill factor with J2NQDs and PbS 

NQDs in general. 

3.25 Novel Manufacturing of Flexible III-V Thin 

Films (Wakonda—Fritzemeier) 

Accomplishments 

•	 Reengineered virtual single crystal (VSC) 

substrate for mechanical and physical 

properties matched to compound 

•	 Improved projected manufacturing costs to 

< $0.50/Wp at module level 

•	 Extended VSC substrate applicability to II-VI 

materials, demonstrating epitaxial CdTe cells. 

Future Directions 

•	 Optimize large-area processes for 

performance and manufacturability 

•	 Increase cell performance to high commercial 

levels 

•	 Demonstrate ability to scale to production 

volumes at competitive costs. 

4. FY 2009 Special Recognitions, Awards, and 

Patents 

CIT 

Best Poster Award, 34th IEEE Photovoltaics 

Specialists Conference, June 7-9, 2009 

Philadelphia PA, “Modeling, Synthesis, and 

Characterization of Thin Film Copper Oxide for 

Solar Cells,” D.E. Darvish and H.A. Atwater. 

MIT 

Patent application filed; US, PCT, and others: 

“Recrystallization of Semiconductor Wafers in a 

Thin Film Capsule and Related Processes,” E. 

Sachs, J. Serdy, and E. Hantsoo. 

Mayaterials, Inc. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Patent filed for “Low Cost Routes to High Purity 

Silicon and Derivatives Thereof.” 

Penn State 

Joan Redwing co-organizer of the symposium 

“Semiconductor Nanowires: Growth, SizeDependent Properties and Applications,” at the 

2009 Spring Meeting of the Materials Research 

Society (MRS). 

D R A F T

Solexant 

Provisional patent filed by Glenn Alers and Qiaoer 

Zhou: “Atomic Layer Deposition of Tin Sulfide 

Films Using Dibutyl-Tin-Diacetate and Hydrogen 

Sulfide as Precursors” (61/212727). 

University of Colorado 

J. Michl elected vice-president of the International 

Academy of Quantum Molecular Sciences. 

University of California-San Diego 

E.	 Yu invited to give talks at a LANL functional 

materials workshop, and two international 

conferences on semiconductor devices. E. Yu 

appointed to Swearingen Regents Chair in 

Engineering at U of Texas at Austin. 

Wakonda 

Wakonda received request from U.S. Army to 

develop packaging solutions for high-efficiency 

flexible PV. 

5. Major FY 2009 Publications 

ASU 

T.J. Peshek, Z. Tang, L. Zhang, R.K. Singh, B. To, 

N. Newman, T.A. Gessert, T.J. Coutts, and M. 

van Schilfgaarde, “Suitability of ZnGeAs2 Thin 

Films for Photovoltaics,” Proc., 34th IEEE 

Photovoltaic Specialists Conference, 2009. 

CIT 

G.M. Kimball, A.M. Muller, N.S. Lewis, and H.A. 

Atwater, “Photoluminescence-based 

Measurements of the Energy Gap and Diffusion 

Length of Zn3P2,” Appl. Phys. Lett, 95, 11 (2009). 

MIT 

A.	 Appapillai and E. Sachs, “The Effect of 

Substrate Material on Nucleation Behavior of 

Molten Silicon for Photovoltaics,” Conference of 

the American Association on Crystal Growth and 

Epitaxy, August 2009. 

Penn State University 

Y. Ke, X.J. Weng, J.M. Redwing, C.M. Eichfeld, 

T.R. Swisher, S.E. Mohney, and Y.M. Habib, 

“Fabrication and Electrical Properties of Si 

Nanowires Synthesized by Al Catalyzed Vaporliquid-solid growth,” Nano Lett. 9, 4494 (2009). 

Rochester Institute of Technology 

C. Bailey, S.M. Hubbard, D. Forbes, and R. 

Raffaelle, "Evaluation of Strain Balancing Layer 

Thickness for InAs / GaAs QD Arrays Using 

HRXRD and Photoluminescence," Appl. Phys. 

Lett. 95, 203110 (2009). 

Stanford (Cui) 

H. Peng, X.F. Zhang, R.D. Twesten, and Y. Cui, 

“Vacancy Ordering and Lithium Ion Insertion in 

In2Se3 Nanowires,” Nano Res. 2, 327 (2009). 

D.T. Schoen, H. Peng, and Y. Cui, “Anisotropy of 

Chemical Transformation of In2Se3 to CuInSe2 

Nanowires through Solid State Reaction,” J. Am. 

Chem. Soc. 131, 7973 (2009). 

Stanford (Peumans) 

H. Peng, C. Xie, D.T. Schoen, and Y. Cui, “Large 

Anisotropy of Electrical Properties in LayerStructured In2Se3 Nanowires,” Nano Lett. 8, 

1511 (2008). 

C.-M. Hsu, S.T. Connor, M. Tang, and Y. Cui, 

“Wafer-Scale Silicon Nanopillars and Nanocones 

by Langmuir-Blodgett Assembly and Etching,” 

Appl. Phys. Lett. 93, 133109 (2008). 

L. Goris, R. Noriega, M. Donovan, G. J. Kusinski, 

J. R. Jokisaari, and A. Salleo, “Al and Ga Doped 

ZnO Nanowires for Transparent Electrodes,” J. 

Electron. Mater. 38, 586 (2009). 

R. Devan, M. Marinkovic, R. Noriega, S. Phadke, 

A. Salleo, and D. Knipp, “Light Trapping in Thin 

Film Silicon Solar Cells with Periodic Pyramid 

Texture,” Optics Express 17, 23058 (2009). 

W.	 Gaynor, J.-Y. Lee, and P. Peumans, “Fully 

Solution-Processed Inverted Polymer Solar Cells 

with Laminated Nanowire Electrodes,” ACS 

Nano, Article ASAP (2009). 

University of California, Davis 

B.V. Andersson, D.M. Huang, A.J. Moulé, and O. 

Inganäs, “An Optical Spacer Is No Panacea for 

Light Collection in Organic Solar Cells,” Appl. 

Phys. Lett. 94, 043302 (2009). 

University of California, San Diego 

C.O. McPheeters, C.J. Hill, S.H. Lim, D. Dekacs, 

D.Z. Ting, and E.T. Yu, “Improved Performance 

of In(Ga)As/GaAs Quantum Dot Solar Cells via 

Light Scattering by Nanoparticles,” J. Appl. Phys. 

106, 056101 (2009). 

University of Colorado 

E.C. Greyson, J. Vura-Weis, J. Michl, and M. A. 

Ratner, “Singlet Fission in Organic Dimers: 

Maximizing the Triplet Yield within the Regime of 

Localized Excitation and Fast Coherent Electron 

Transfer”, J. Phys. Chem. B (2010, in press). 

University of Florida 

Y.	 Zheng, R. Bekele, J. Ouyang, and J. Xue, 

“Organic Photovoltaic Cells with Vertically 

Aligned Crystalline Molecular Nanorods,” 

Organic Electron. 10, 1621 (2009). 

University of Illinois 

B.Y. Ahn, E.B. Duoss, M.J. Motala, X. Guo, S.I. 

Park, J. Yoon, and R.G. Nuzzo, “Direct-write 
 

 

 

 

 

 

2009 

D R A F T

Assembly of Flexible, Spanning, and Stretchable 

Silver Microelectrodes for Printed Electronics,” 

J. A. Rogers, J.A. Lewis Science 323, 1590-1593. 

University of Michigan 

N. Li and S.R. Forrest, “Tilted Bulk Heterojunction 

Organic Photovoltaic Cells Grown by Oblique 

Angle Deposition," Appl. Phys. Lett., 95, 123309 

(2009). 

R.R. Lunt, N.C. Giebink, A.A. Belak, J.B. Benziger, 

and S.R. Forrest, "Exciton Diffusion Lengths of 

Organic Semiconductor Thin Films Measured by 

Spectrally Resolved Photoluminescence 

Quenching," J. Appl. Phys. 105, 053711 (2009). 

Voxtel 

T. Novet, T. Allen, G. Williams, D.R. Tyler, J. 

Sambur, B. Parkinson, and D.M. Schut, “Dipole 

Induced Carrier Extraction Mechanisms in 

Nanocrystal Sensitized Solar Cells,” 

Presentation at the Center for Green Materials 

and Chemistry Symposium, Bend, OR. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

Northwestern University 

Mark Ratner 

Evanston, IL 

ratner@chem.northwestern.edu 

quantum chemical calculations 

for singlet fission sensitizers 

NREL 

Art Nozik and Justin Johnson 

Golden, CO 

Arthur.Nozik@nrel.gov time-resolved spectroscopy 

Rochester Institute of Technology 

Dr. Ryne Raffaelle 

Rochester, NY 

rprsps@rit.edu 

GaAs cell analysis and 

optimization 

Research Triangle Institute 

Dr. Rama Venkatasubramanian 

Research Triangle, NC 

rama@rti.org 

GaAs junction growth and 

optimization 

Ahura Scientific 

Dr. Chris Pinzone 

Wilmington, MA 

cjpinzone@ahurascientific.com GaAs junction growth 

University of South Florida 

Prof. Chris Ferekides 

Tampa, FL 

ferekide@eng.usf.edu 

CdTe cell processing and 

analysis 

University of Delaware 

Brian McAndless 

Newark, DE 

bem@udel.edu CdTe doping and analysis 
 

 

 

_______________________________________________________________________________________________________ 

 

 

 

 ________________________________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

Minority University Research Associates Solicitation 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Fannie Posey-Eddy (NREL), 303-384-6773, fannie.eddy@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budgets: $397K (NREL), $16K (DOE/GO) 

Objectives 

•	 Provide scientific and technical research opportunities for minority undergraduate and graduate 

students in solar technologies via the Minority University Research Associates (MURA) project. 

•	 Facilitate the creation of a diverse and competent workforce for existing and developing solar 

technologies. 

Accomplishments 

•	 Presented MURA student research findings at the Renewable Academic Partnership (REAP) 

Conference in conjunction with the 19th Workshop on Crystalline Silicon Solar Cells: Materials 

and Processes, August 9-12, 2009, in Vail, Colorado. 

•	 Supported Merit Review Committee (MRC) meeting for the SETP Funding Opportunity 

Announcement (FOA): MURA Program (MURA) 

Future Directions 

•	 MURA Program activities have been transferred and will be coordinated through the DOE Golden 

Field Office. 

•	 Continue to assist DOE Golden Field Office (DOE/GO) in monitoring the MURA project. 

•	 Facilitation of the REAP2010 Summer Program. 

1. Introduction 

The NREL-MURA Project (1995-2009) provided 

scientific and technical research opportunities for 

minority undergraduate students working on 

various solar energy technology projects through 

partnerships with minority universities. The 

universities performed subcontracted research 

under NREL’s University and Exploratory 

Research Project. During the school year, 

undergraduate and graduate students are involved 

in solar technology-related research at the 

universities. The students are awarded internships 

in industry or at national laboratories such as 

NREL during the summer. The program helps 

retain minority students in the science and 

technology areas and enables many students to 

reach their educational and career goals. Through 

these sub contracts, the MURA program continues 

to contribute to the development of a diverse and 

competent workforce ready to supply the nation’s 

growing energy industries. 

2. Technical Approach 

The MURA project consists of eight individual 

university faculty/student research programs which 

focus on solar energy technologies. All of the 

current sub contracts have been completed and 

are closed. 

Agreement Tasks FY 2009 

Budget ($K) 

Minority University Research 

Associates Program 397 

DOE-GO 16 

TOTAL $413 

3. Results and Accomplishments 

3.1 North Carolina A&T State University: 

Several students continued their research project 

on “Synthesis and Characterization of Photovoltaic 

(PV) Active Polymer Nanocomposites.” Students 

designed a 1 KW PV system to be installed on the 

roof of Biological Engineering Building at NCA&T 

SU. 

3.2 Fisk University: Eight undergraduate and 

graduate students compose the team. Two MURA 

students received graduate degrees in physics last 

semester. The Fisk-MURA Team was published 

in three refereed journals and gave 11 

presentations at professional workshops and 

conferences. 

3.3 Central State University: A 3-week 

introductory energy laboratory course was 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

provided for 12 undergraduate students majoring 

in engineering and natural sciences; Central State 

was an active affiliate of the University Clean 

Energy Alliance of Ohio (UCEAO). 

3.4 University of Texas Brownsville: The 

Tonatiuh software was extended to model 

reflective systems, such as CPC collectors, 

hyperbolic mirrors, parabolic trough, solar tower, 

dish/Stirling systems and refractive systems, such 

as none-imagine Fresnel lenses. The following 

web sites have been enhanced and include video: 

www.tonatiuh.googlecode.com 

www.youtube.com/user/TonatiuhRaytracer. 3.5 Southern University: Successfully organized 

eight renewable energy education and curriculum 

development workshops for science teachers in 

East and West Baton Rouge parishes for 

implementing and integrating renewable energy 

content in the high school physical science and 

environmental science courses. Two MURA 

graduates secured positions in the California 

solar energy industry while attending graduate 

education. The SUBR-MURA Team published 12 

papers in peer reviewed journals. 

3.6 North Carolina Central University: The 

computationally efficient effective potential model 

developed earlier at NCCU was extended to 

model InxGa1-xAs QDs with significant Ga 

fractions. This work was featured in the 

September, 2009 issue, NASA Tech Briefs. 

3.7 University of Texas El Paso: MURA 

students presented papers at IEEE, ACS and the 

International Materials Congress conferences in 

2009. 

3.8 Howard University: A module for the Energy 

Conversion course was designed. It focuses on a 

rigorous introduction to various Renewable Energy 

technologies and associated technologies as well 

as their applications. 

4. Planned FY 2010 Activities 

A new solicitation was issued in the summer of 

2009 by the DOE Golden Field Office. NREL will 

continue to assist GO in the management of the 

new sub contracts to be awarded in 2010. 

Organization/ 

Principal Investigator Location/E-mail Description/Title/Research Activity FY 2009 ($K) 

Southern University/R. Bobba Baton Rouge, LA 

rambabu@cox.net 

"Energy Conversion and Storage 

Devices: Solar Energy Research and 

Education." 

26 

15* 

University of Texas at El 

Paso/Gregory Lush 

El Paso, TX 

lush@ece.utep.edu 

"Fabrication, Characterization and 

Modeling of Solar Cells." 

15 

15* 

Fisk University/Richard Mu Nashville, TN 

rmu@fisk.edu 

"Development of Quantum-DotSensitized ZnO and TiO2 Nanorod-Array 

Solar Cells." 

70 

15* 

Howard University/J. Momoh Washington, DC 

jmomoh@howard.edu 

"PV and Renewable Energy 

Research/Training for Optimal Power 

Management and Distribution.” 

53 

North Carolina Central 

University/J.Dudda & Mn Wu 

Durham, NC 

mwu@nccu.edu 

"Investigation of Photovoltaic and 

Thermoplastic Semiconductors." 

49 

15* 

University of Texas 

Brownsville/Manuel Blanco & 

William Berg 

Brownsville, TX 

wberg@utb.edu 

"Design, Development, and 

Implementation of Simulation Tools for 

Analysis of Solar Concentrating 

Systems." 

48 

15* 

North Carolina A&T State 

University/G. Shahbazi 

Greensboro, NC 

ash@ncat.edu 

“Performance Testing and Utilization of 

Photovoltaic Energy in Residential 

Environments.” 

10 

15* 

Central State University/Clark 

Fuller 

Wilberforce, OH 

cfuller@prodigy.net "Renewable Energy Technology and 

Technology Transfer in Developing 

Countries." 

34 

10* 

5. University and Industry Partners
 

The following organizations partnered in the project’s research activities during FY 2009.
 

* Funded with prior year (FY 2008) funds 
 

 

 

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D R A F T

Commercialization Cooperative Research & Development Agreements 

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: John Benner (NREL), 303-384-6496, john.benner@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,967K (NREL) 

Objectives 

•	 Apply program funding to advance technologies to a state ready for industrial collaborations 

•	 Reduce financial and administrative barriers impeding the development of substantial industry 

partnerships. 

Accomplishments 

•	 Solicited internal proposals, selecting three for award starting in February 2009: 

o	 Coincident epitaxy for high performance multijunctions (Phase 0) 

o	 Crystalline CdTe multijunctions of silicon (EPIR Phase 2) 

o	 Ink precursors for copper indium gallium selenide (CIGS) (HelioVolt Phase 3) 

•	 Conceived the Innovation by Design project and developed concept with DOE (01/09) 

•	 Selected Nucleated Innovation by Design teams (04/09) 

•	 Reviewed five proposals (selected members of NREL’s Venture Capital Advisory Board, 06/09) 

•	 With DOE review and concurrence (07/09), started the leading team with a project to develop 

20% efficient thin-film solar cells with low-cost fabrication. 

Future Directions 

•	 Explore potential for privately funded cost share for 2010 Innovation by Design project 

•	 Open pathways to launch new photovoltaics (PV) business derived from licensing a suite of 

NREL-generated intellectual property protecting a complete, new product. 

1. Introduction 

The commercialization cooperative research and 

development agreements (CRADAs) project 

accelerates growth of partnerships with industry to 

move more NREL-developed technology into 

production faster. The project lowers 

administrative and financials barriers to 

partnerships for both the NREL scientist and 

prospective industry at all phases of engagement, 

including finding, forming, funding, and expanding 

the collaborative development of products and 

processes that incorporate NREL technology. 

2. Technical Approach 

Transferring our technologies to industry is the 

culmination of years of research. This is also 

perhaps the most difficult stage of development. 

Although NREL can point to numerous examples 

of successful tech transfer, including many patents 

that have been licensed, the majority of our 

contributions have occurred “under the radar.” 

Vast amounts of know-how, measurements, data, 

sample exchange, and joint experiments have 

transformed industry processes and products 

without visible agreements. This has contributed to 

blunders from both sides of the partnership. Our 

planning has instances of terminating support for 

research tied to a partner’s interest. Equally 

damaging, we have experienced apparently 

effective collaborations instantly evaporating as 

corporate senior management redirects all 

technical resources to the new, most pressing 

problem. These result in a large waste of 

resources. The remedy is to raise the visibility of 

the interaction through formalizing the agreement 

in a Technical Services Agreement (TSA) or 

CRADA. The attention of management of the 

partnering companies is particularly enhanced 

when they have their own resources on the line. 

The nature of the PV business has fundamentally 

changed the way that NREL must interact with 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

industry. As private funding has rocketed past 

federal support and the total investments move 

toward $2 billion annually, companies have 

become much more concerned and savvy in their 

approach to collaborating to gain outside help. 

Moreover, there are many more companies 

seeking access to our resources. This change 

again drives us toward using a coordinated 

process to select partners and manage the 

success of each partnership. 

Finally, the opportunity to leverage program 

support to bring in increasing amounts of private 

investment at NREL helps maintain and expand 

our capabilities to meet the growing demands from 

the very rapidly growing U.S. industry. 

3. Results and Accomplishments 

This project was conceived in 2008 and has 

realized its primary objective of increasing the 

number and size of technology partnership 

agreements. Because of the business-sensitive 

nature of these partnerships, a comprehensive 

listing of these agreements is inappropriate for a 

public report. Some partners, however, are 

pleased to have their associating with NREL 

highlighted. For example, our research with 

HelioVolt Corporation to develop processes using 

deposition from liquid sources to form precursors 

for their proprietary FASST process resulted in 

receipt of an R&D 100 award. 

Perhaps the most significant accomplishment of 

2009 is the creation of a new mode for developing 

core intellectual property to stimulate partnerships 

of a far larger scale. NREL’s largest CRADAs 

were generated by the potential to develop an 

entirely new product by cooperative development 

around a suite of inventions. The project called 

Innovation by Design has the primary objective of 

creating a product concept. Modeled after 

commercial methods for structuring the process of 

innovation, the project requires participation from 

interdisciplinary teams—teams of investigators 

who do not work together routinely. Seeded with 

common background reading in fruitful topics, the 

team meets in facilitated sessions to explore 

potential technology significance. Where a new PV 

product is conceived, the team then carries out a 

search on relevant intellectual property (IP) and 

develops an IP strategy. This strategy is then used 

to establish experiments planned to deliver data 

needed to support the patent applications. At this 

stage, the team develops a proposal that is 

evaluated on both a technical and a business 

basis, with a team selected to receive funding to 

complete investigations on an initial schedule of 

12 months. Five teams entered the competition in 

2009, and NREL’s Venture Capital Advisory Board 

reviewed their proposals. The winning project will 

seek to prove that highly crystalline GaAs can be 

grown epitaxially faster than 200 nm/minute to 

deliver a low-cost pathway to a 20% efficient thinfilm module. 

4. Planned FY 2010 Activities 

As in 2009, in 2010 the project funding will be split, 

with roughly equal portions used to support the 

original concept of reducing barriers to creation of 

industry partnerships and to the newer idea of 

launching a new product. The major new 

challenge will be to determine it is possible to 

engage cost-sharing with venture capital 

investment at this early stage of product 

development in a national laboratory. If so, we 

would initiate two new Innovation by Design teams 

in 2010. 
 

 

 

 

 

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Seed Funds 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Sandia National Laboratories (SNL) 

Key Technical Contacts: Sarah Kurtz (NREL, Primary Contact), 303-384-6475, 

sarah.kurtz@nrel.gov 

Vipin Gupta (SNL, Primary Contact), 505-844-5876, 

vpgupta@sandia.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budgets: $2,240K (NREL), $510K (SNL) 

Objectives 

•	 Provide temporary funding for exploration of new ideas, including new materials, devices or 

processes that have not reached the proof-of-concept stage 

•	 Facilitate the Solar Energy Technologies Program (SETP) mission of transitioning 

exploratory/discovery-stage research to applied research and development to provide a stream of 

next-generation photovoltaic (PV) technology options. 

Accomplishments 

•	 Demonstrated lift-off of 14-μm-thick c-Si cell with a measured 14.9% efficiency 

•	 Synthesized p-type amorphous Zn-Co-O thin films by sputtering deposition 

•	 Demonstrated lift-off of 2.7-μm-thick backside-contact III-V cell with a measured 10% efficiency 

•	 Evaluated feasibility of silicon quantum dots (QDs) as novel solar cell absorber material 

•	 Reduced water vapor transport rates (WVTR) even with evaporated metal thin films by five orders 

of magnitude (i.e., ~10-4 g/m2

-day) compared to standard TCO materials, giving clear indication 

that the metal layer improves WVTRs by more than 10-fold 

•	 Developed a solution deposition method for NiO hole transport layers and demonstrated greatly 

enhanced performance in high Voc polymer solar cell systems relative to PEDOT:PSS 

•	 Demonstrated 3.1% efficiency for hybrid organic photovoltaics (OPV) cell. 

Future Directions 

•	 Explore new self-assembly approaches to make PV modules from micro-PV cells 

•	 Explore III-V PV on a low-cost substrate and TCOs deposited by hot-wire CVD 

1. Introduction 

SETP funds research to develop commercially 

attractive PV technologies. In general, these 

efforts support national lab in-house R&D (e.g., 

NREL), universities, and existing industry or new 

companies. These efforts may last for multiple 

years and can be most successful with stable 

funding of a sustained effort. It is also useful for 

SETP to fund temporary R&D that explores new 

ideas. If the new concepts reach the proof-ofconcept stage, the efforts may be expanded; if 

they are unsuccessful in reaching their goals or 

reach a successful negative conclusion, then they 

are terminated to free those funds for new 

projects. Success of an individual project is not 

necessarily defined by continued funding or 

transition into the core program. Rather, success 

of an individual project could be an unequivocal 

answer to a question about the practicality of a 

new concept. The goal of the aggregate of 

projects in the Seed Fund is to seed the core PV 

conversion technology effort with innovation. 

Collaboration with other elements of the program 

is encouraged to facilitate transfer of projects that 

demonstrate the feasibility of a concept. 

2. Project Details 

Thirteen projects were funded in 2009, executed 

within the calendar year to facilitate the start of 

new projects. The approach, accomplishments, 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

and plans are described in a single section to 

facilitate presentation of the 13 projects. 

Agreement Title FY 2009 

Budget ($K) 

1. Doped polymeric molecular 

semiconductor p-n junction OPV 

300 

2. Carbon nanotube architectures 

for low cost and high efficiency 

300 

3. Incorporation of third generation 

mechanisms into OPV devices 

200 

4. Thin III-V cells 168 SNL/ 55 

NREL 

5. Novel nanocrystal-based solar 

cell to exploit MEG 

300 

6. Ultra-thin c-Si cells 315 SNL/ 44 

NREL 

7. Multifunctional TC and selfhealing impermeable barriers 150 

8. Si quantum dot solar cells 300 

9. Amorphous oxide 

semiconductors for ambient 

temperature deposited PV 

221 

10. New absorber materials for 

thin-film PV beyond 1 TW 

140 

11. Hole transport layers for 

excitonic solar cells 

40 

12. Flexible OPV made by 

lamination 

40 

13. Massive parallel assembly for 

low-cost modules 

27 

Task #1: Doped polymeric molecular 

semiconductor p-n junction OPV; PI: Brian 

Gregg 

Purpose: Investigate new approach to creating a 

stable OPV cell by using a class of materials that 

has been extensively engineered for automobile 

paints. This approach is qualitatively different from 

other approaches in that it adds specific functional 

groups to create both n- and p-type material. 

Potential impact: OPV has the potential to achieve 

very low costs because of its low materials usage 

combined with the potential to use very low cost 

deposition techniques. To date, the OPV cells 

have achieved efficiencies of only ~7% and this 

efficiency often decreases to <3% when the 

sample is exposed to air. Very little is understood 

about the wealth of materials that could be used 

and the hope of this new approach is that it will 

reveal a pathway to higher efficiency as well as be 

insensitive to air. 

Milestone: 

•	 Preparation and characterization of new type 

of OPV cell, >4% efficiency. 

Accomplishments: 

•	 A new n-type perylene diimide material was 

developed that has twice the absorption 

coefficient of the original polymer and absorbs 

much more sunlight (being black versus red). 

•	 Improved photostability was demonstrated. 

Task #2: Carbon nanotube architectures for 

low-cost and high-efficiency photovoltaics; PI: 

Jeff Blackburn 

Purpose: Leverage the expertise already developed at NREL in synthesizing carbon nanotubes 

(CNTs) to determine their utility for use in photovoltaic devices. CNTs have the potential to be low 

cost, can be applied with high-speed solution 

phase processing at low temperatures, have high 

thermal stability, and may have performance (conduction and transmission) properties competitive 

with conventional transparent conductors. 

Potential impact: Carbon nanotubes may be an 

enabling technology for any of the thin-film approaches. Implementing CIGS in a flexible form 

factor is currently limited by the sensitivity of zinc 

oxide (the most commonly used transparent 

conductor) to moisture. Similarly, the PEDOT used 

for hole transport in OPV cells is commonly 

considered to be a contributor to the instability of 

OPV. In addition, if CNTs are successfully implemented, they may reduce the cost of the thin-film 

cells or enable configurations that could not be 

achieved with transparent conductors deposited at 

higher temperatures. 

Milestone: 

•	 Use sprayed SWNT films as electrodes in PV 

devices and evaluate system performance, 

e.g., stability and efficiency, relative to 

conventional TCOs. Journal publication of 

results. 

Accomplishments: 

•	 Demonstrated spray process of SWNT TCOs 

with carboxymethyl cellulose inks and acid postprocessing step applied to OPV devices with efficiencies > 3.0% 

•	 Certified 2.6%-efficient OPV device on SWNT 

TC with no PEDOT:PSS (ITO control <1%) 

•	 Developed method to remove CMC matrix 

without acid post-processing step and applied to 

CdTe devices with efficiencies ~8% 

•	 Developed preliminary inks with no surfactants 

that require no post-processing treatment. 

Task #3: Incorporation of third-generation 

mechanisms into OPV devices; PI: David Ginley 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Purpose: Explore using third-generation concepts 

such as multijunction, QDs, and other quantumconfined structures with conjugated polymers to 

create solar cells with high efficiencies. This work 

focuses specifically on implementing a 

multijunction polymer solar cell, incorporating 

colloidal semiconductors into conjugated 

oligomers, polymers, and dendrimers. 

D R A F T

Potential impact: Although OPV solar cells have 

the potential to deliver very-low-cost solar cells, to 

date OPV has not surpassed 7% efficiency. This 

approach has the potential to improve the efficiency while retaining the low cost. 

Milestones: 

•	 Demonstrate enhanced Voc to at least 600 

mV with a ZnO/QD/P3HT structure 

•	 Demonstrate additive photoresponse to 700 

nm for a P3HT/QD hybrid cell. 

Accomplishments: 

•	 Demonstrated 3.1% efficiency for hybrid OPV 

cell. 

Task #4: Thin III-V solar cells; PI: Greg Nielson 

Purpose: Epitaxial lift-off (ELO) has been explored 

for a number of years as a means to reduce the 

cost of multijunction III-V cells. Challenges have 

been identified in both handling the lifted-off layers 

and avoiding the creation of interlayer cracks. We 

are exploring ELO and other lift-off techniques to 

create small-area cells (<1 cm2

). 

Potential impact: We anticipate multiple cost 

benefits for flat panel or coarse tracking CPV systems resulting from this work. The ability to remove the grown cell structure from the underlying 

substrate and reuse that substrate for subsequent 

epitaxial growth represents a significant cost 

savings over the current III-V cell technique, which 

requires a new substrate for each growth. Further, 

we expect that going to smaller cell sizes should 

reduce interlayer cracking, leading to improved 

performance and better yields. Within a 

concentrator module based on small cell sizes, 

additional benefits include simplified tracking, fluidbased assembly techniques, and easier thermal 

management. 

Milestone: 

•	 Demonstrate lift-off of single-junction III-V 

cells. 

Accomplishments: 

•	 Demonstrated lift-off of 2.7-μm-thick backsidecontact III-V cells with confinement layers and 

a measured efficiency of 10% 

•	 Modified the material stack to improve 

handling for testing purposes and enhance 

device performance. 

Task #5: Novel nanocrystal-based solar cell to 

exploit MEG; PI: Matt Beard 

Purpose: Demonstrate that multiple excitons can 

be collected within a solar cell. Specifically, if QDs 

are used to enhance the probability that multiple 

excitons are generated from absorption of a single 

high-energy photon (this has already been 

demonstrated), can multiple electrons/photon be 

collected in an external circuit? Cells with 

efficiencies > 2% have already been 

demonstrated. 

Potential impact: If the multiple-exciton process 

can be used efficiently, a single-junction solar cell 

may be able to achieve efficiencies exceeding the 

Shockley-Queisser limit. 

Milestone: 

•	 4% cell with area ≥ 1 cm 2

; demonstrate collection of more than one electron per photon at 

short wavelengths; spectroscopic 

demonstration of MEG in device-quality film 

under bias. 

Accomplishments: 

•	 Successfully inverted the device design so 

that the high-energy photons are absorbed 

within the active region of the solar cell. The 

resulting new solar cell design achieves a 

higher Voc and a higher efficiency. Achieved 

an efficiency of ~ 3.8%. 

Task #6: Ultra-thin c-Si solar cells; PI: Greg 

Nielson 

Purpose: This project seeks to develop a method 

that creates c-Si cells on a standard c-Si substrate, then lifts off the 10–20-μm-thick c-Si cells 

from the substrate. The substrate is then reused to 

create additional layers of cells. These cells have 

a small area (<1 cm2

), which allows for further 

system-level cost savings. 

Potential impact: This project manufactures cells 

in a material-conserving manner with the c-Si cell 

thickness optimized for minimal cost/watt. The 

small cell size further allows other system-level 

cost savings, including fluidic parallel assembly 

methods that can create large modules at high 

rates and low cost. Other benefits include the 

ability to use low temperature and flexible substrates for the c-Si cells, increasing the utility and 

lowering costs, perhaps allowing new types of 

building integrated solar devices. The method also 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

produces a flat concentrator module with simple 

tracking and heat management. 

Milestone: 

•	 Demonstrate lift-off of thin c-Si cells with 12% 

efficiency. 

D R A F T

Accomplishments: 

•	 Demonstrated lift-off of 14-μm-thick c-Si cell 

with a measured 14.9% efficiency 

•	 Created high-quality (ohmic) contacts with 

metallization process. 

Task #7: Multifunctional transparent conducting and self-healing impermeable barriers; 

PI: Lin Simpson 

Purpose: Develop a multilayer coating grown with 

low-temperature (<80°C) deposition techniques, 

resulting in a coating that is highly transparent with 

high electrical conductance, low water-vapor 

transmission, and lower cost than ITO. 

Potential impact: This new barrier could reduce 

the cost of thin-film cells by using lower cost processes/materials than typically used for transparent 

conductors. A barrier that achieves very low watervapor permeability may enable flexible CIGS 

modules and be especially useful for OPV. 

Milestone: 

•	 Demonstrate scalable low temperature 

processing to form TCO/metal/TCO structures 

and improve impermeability (<10-4 g/m2

/day). 

Accomplishments: 

•	 Reduced the WVTR, even with evaporated 

metal thin-films, by five orders of magnitude 

(i.e. ~10-4 g/m2

-day) compared to standard 

TCO materials. More conformal film 

processing should improve WVTR 

performance further. These results indicate 

that the metal layer improves WVTRs by > 10 

fold. 

•	 Demonstrated transparent conducting 

materials with ~5 Ω/sq resistivities and >90% 

transmission. This exceeds the conductivity 

(<10 Ω/sq.) and light transmission (>80%) 

performance goals. 

•	 Improved structural integrity/enhanced cyclic 

loading durability and strain tolerance. 

•	 Demonstrated the potential to reduce TCO 

and barrier layer costs by more than 100X. 

This type of cost reduction enables substantial 

market penetration increases for new 

technologies, not only reducing PV 

manufacturing costs by 10% to 25% but also 

enabling other technologies that ultimately 

could reduce energy usage by ~40%. 

Task #8: Si quantum dots; PI: Pauls Stradins 

Purpose: Explore using Si QDs in solar cells as a 

way of tuning the optical properties while retaining 

use of an abundant, high-performance material 

(silicon). 

Potential impact: Create disruptive technology by 

exceeding 30% efficiency with a third-generation, 

nanostructured Si solar cell. 

Milestone: 

•	 Use quantitative analysis of Si QDs as PV 

material to identify structure that can achieve 

adequate absorption. 

Accomplishments: 

•	 Si nanoparticles synthesized and 

characterized structurally and optically 

•	 Theory simulations showed that good PV Si 

QD material requires densely packed, closely 

spaced, uniform size Si nanoparticles; 

quantum confinement is preserved 

•	 Optical studies show that adequate optical absorption in Si QD absorber layers is achieved 

with a thickness in the micrometer range 

•	 Nanoparticle synthesis reported in MRS 2009 

Fall Meeting. 

Task #9: Amorphous oxide semiconductors for 

ambient temperature deposited PV; PI: John 

Perkins 

Purpose: Demonstrate a metal-oxide-based, thinfilm heterojunction solar cell that can be deposited 

at ambient temperature. 

Potential impact: A thin-film cell that could be 

lower cost than today’s thin-film devices. If successful, this could form a whole new class of thinfilm photovoltaic devices. Appropriate n-type 

amorphous oxides (e.g., a-InZnO) are known. The 

clear initial challenge is to develop an appropriate 

p-type amorphous oxide absorber. Candidates 

include a-ZnCuO, a-CuNiO, and a-ZnCoO. 

Milestone: 

•	 Publish paper on Zn-Cu-O system in peerreviewed journal. 

Accomplishments: 

•	 Amorphous ZnCuO and ZnCoO thin films 

synthesized by sputtering 

•	 a-ZnCoO demonstrated to be p-type as 

desired 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Optical absorption in a-ZnCuO and a-ZnCoO 

determined to be too weak for application as 

PV absorber material. Decision made to bring 

current work to publication and wrap up this 

project in FY 2010. 

Task #10: New absorber materials for thin-film 

photovoltaics beyond 1 TW; PI: Jennifer Leisch, 

Glenn Teeter 

D R A F T

Purpose: Develop new thin-film PV absorber 

materials that are abundant. 

Potential impact: Extend the vision of CdTe and 

CIGS to the TW scale. 

Milestone: 

•	 Synthesize thin-film Cu2ZnSnS4 or 

Cu2ZnSnSe4 or both. 

Accomplishments: 

•	 Developed capability to deposit uniform or 

combinatorially graded thin-film samples 

•	 Performed in situ thermal-desorption mass 

spectrometry to quantify the thermal stability of 

Cu-Zn-Sn thin films. 

Task #11: Inorganic hole-transport layers for 

excitonic solar cells; PI: Dana Olson, Joe Berry 

Purpose: Develop inorganic hole transport layers 

to replace PEDOT in OPV cells. 

Potential impact: Would be an enabling technology 

for OPV cells. Currently, PEDOT is the most 

commonly used material, and it shows problems 

with respect to morphology, chemistry, stability, 

and scalability. Thus, successful implementation of 

this project would increase the chances of developing a low-cost, high-reliability, high-performance 

OPV cell. 

Milestone: 

•	 Validate NiO results and optimize deposition 

conditions for enhanced current extraction; 

use the optimized NiO material to enable OPV 

devices using ZnO-based TCOs. 

Accomplishments: 

•	 Established equivalent performance of PLD 

and sputtered NiO HTL materials on OPV 

devices made on ITO and Ga-doped ZnO 

transparent conducting oxides 

•	 Developed a solution deposition method for 

NiO HTL and demonstrated similar 

performance after processing to vacuum 

deposited NiO materials 

•	 Demonstrated enhanced performance of high 

Voc polymer electron donor compared to 

PEDOT:PSS—5.6% PCE for solution NiO 

compared to 3.5% PCE for PEDOT:PSS. 

Task #12: Flexible OPV made by lamination; PI: 

Nikos Kopidakis 

Purpose: Explore the possibility of assembling an 

OPV cell by laminating a coating on a flexible 

substrate with a second coating. 

Potential impact: This assembly technique could 

open new possibilities for OPV cell fabrication by 

allowing control of the structure of the active layer, 

allowing fabrication of structures when the processes for the different layers are incompatible, 

providing access to interfaces, providing the encapsulation in the same step as the cell assembly, 

avoiding the problems with the metal contact 

evaporation directly onto the active layer, and providing for a means of using nontransparent substrates by avoiding the need to use a high-temperature process to apply a transparent, conducting contact. 

Milestone: 

•	 Demonstrate an inverted OPV device with 

laminated PEDOT/ITO top contact; 

demonstrate rectifying behavior in J-V curves 

of that device and evaluate its photoresponse. 

Accomplishments: 

•	 Fabricated a 3% efficient OPV device with 

laminated top contact. This efficiency equals 

the efficiency of similar devices in the literature 

with an evaporated-metal top contact. 

•	 Routinely demonstrated better fill factor, 

indicating that avoiding hot metal deposition is 

beneficial to certain OPV architectures. 

•	 As an example of alternative electrodes for 

flexible OPV, laminated a CNT flexible 

electrode (in collaboration with task #2) to 

complete an OPV device with 1.7% efficiency. 

This was achieved with an unoptimized 

nanotube electrode. 

•	 Presented “Hot Press Lamination of Inverted 

Organic Photovoltaic Devices” at the MRS Fall 

09 meeting in Boston. 

Task #13: Massive parallel assembly for lowcost modules; PI: Greg Nielson 

Purpose: Develop a method to handle small and 

thin c-Si and III-V PV cells that will allow assembly 

of many of these cells at once to create large-area 

modules. 

Potential impact: If successful, this project will leverage the successes of the ultra-thin c-Si and III-V 

cell projects to develop a method to create large 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

modules of the thin and small chips rapidly using 

parallel manufacturing concepts. The arrays of thin 

and small PV cells can be formed in either dense 

arrays for one-sun modules or in sparse arrays for 

concentrator modules. This manufacturing technique may be implemented in a commercial process as a roll-to-roll process. In addition to lowering 

the costs of assembling modules, this method 

allows the use of low-temperature and flexible 

substrates. This may further create benefits by 

enabling building-integrated PV concepts. 

D R A F T

Milestone: 

•	 Explore a variety of methods for parallel 

assembly of small, thin PV cells onto 

inexpensive substrates. 

Accomplishments: 

•	 Developed three distinct concepts for fluidic 

self-assembly of small, ultrathin PV cells onto 

substrates. 

3. FY 2009 Special Recognitions, Awards, and 

Patents 

Patent application #11/933,438 filed with claims on 

microsystem-enabled PV design, manufacturing, 

and operation. 

Submitted PCT patent entitled “Multi-functional 

Transparent Conducting & Self-Healing 

Impermeable Barriers.” 

4. Major FY 2009 Publications 

M. Beard, A. Midgett, M. Law, O. Semonin, R. 

Ellingson, and A. Nozik, “Variations in the 

Quantum Efficiency of Multiple Exciton 

Generation for a Series of Chemically Treated 

PbSe Nanocrystal Films,” Nano Lett. 3, 836 

(2009). 

J. Berry, N. Widjonarko, B. Bailey, A. Sigdel, D. 

Ginley, and D. Olson, “Surface Modification of 

NiO Hole Transport Layers for Organic Solar 

Cells,” J. Selected Topics Quantum Electron. (in 

press). 

J. Chesin, K. Steirer, N. Widjonarko, J. Berry, A. 

Miedaner, D. Ginley, and D. Olson, “Solution Deposited NiO Thin-films as Hole Transport Layers 

in Organic Photovoltaics,” Adv. Mater. 

S. Dayal, N. Kopidakis, D. Olson, D. Ginley, and 

G. Rumbles, “Direct Synthesis of CdSe 

Nanoparticles in Poly(3-hyxylthiophene),” J. Am. 

Chem. Soc. 131, 17726 (2009). 

S. Dayal, N. Kopidakis, D. Olson, D. Ginley, and 

G. Rumbles, “Photovoltaic Devices with a Low 

Band Gap Polymer and CdSe Nanostructures 

Exceeding 3% Efficiency,” Nano Lett. 10, 239 

(2010). 

Duenow et al., Proc. IEEE 2009. 

H. Hillhouse and M. Beard, “Solar Cells from 

Colloidal Nanocrystals: Fundamentals, Materials, 

Devices, and Economics,” Current Opinion 

Colloidal & Interface Sci. 14, 245 (2009). 

B. Jariwala, P. Stradins, J. Beach, R. Collins, P. 

Taylor, J. Radziszewski, S. Williams, J. Cheng, 

J. Fields, K. Kiriluk, C. Ciobanu, and S. Agarwal, 

“Next-Generation Photovoltaics Devices Based 

on Silicon Nanocrystals,” Mater. Res. Soc. Fall 

Meeting, Boston, Nov. 2009. 

Z. Liang, R. Cormier, A. Nardes, and B. Gregg, 

“Air Stable and Solution Processable n-type 

Perylene Diimide Polymers,” Macromolecules 

(submitted). 

G.	 Nielson, M. Okandan, P. Resnick, J. CruzCampa, P. Clews, M. Wanlass, W. Sweatt, E. 

Steenbergen, and V. Gupta, “Microscale PV 

Cells for Concentrated PV Applications,” 24th 

European PVSEC, 2009. 

G.	 Nielson, M. Okandan, P. Resnick, J. CruzCampa, T. Pluym, P. Clews, E. Steenbergen, 

and V. Gupta, “Microscale c-Si (C)PV Cells for 

Low-Cost Power,” 34th IEEE PVSC, 

Philadelphia, PA, 2009. 

R. Tenent, T. Barnes, J. Bergeson, A. Ferguson, 

B. To, L. Gedvilas, M. Heben, and J. Blackburn, 

“Ultrasmooth, Large-Area, High-Uniformity, 

Conductive Transparent Single-Walled-CarbonNanotube Films for PV Produced by Ultrasonic 

Spraying,” Adv. Mater. 21, 3210 (2009). 

M. Woodhouse, C. Perkins, M. Rawls, R. Cormier, 

and B. Gregg, “Photophysical and Electronic 

Properties of a New Class of Polymers for 

Organic Photovoltaics,” J. Phys. Chem C 

(submitted). 
 

 

 

 

5. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

D R A F T

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of Research Activity 

FY 

2009 

($K) 

Cost 

Share 

($K) 

University of Florida/ 

P. Holloway 

Gainesville, FL 

pholl@mse.ufl.edu 

Fundamental research on growth of ptype mixed metal oxide thin films for PV 

absorber application 

30 0 

University of 

Minnesota 

Minneapolis, MN 

kakalios@umn.edu 

Si nanoparticle synthesis and embedding 

into various matrices for material 

characterization at NREL for PV potential 

30 0 

University of Toledo/ 

R. Ellingson 

Toledo, OH 

randy.ellingson@utoledo.edu 

Novel nanocrystal-based solar cell to 

exploit multiple exciton generation 110 20 
 

 

 

 

 

 

D R A F T

Conversion Devices Summary 

Conversion Devices research at the national laboratories is the primary effort for 

materials and device research to advance the performance of photovoltaic (PV) devices. 

Research at the national labs explores new and novel device processing techniques with 

the potential for much wider industrial impact. The primary topic areas include: 

•	 Wafer Silicon: advancement of wafer silicon (c-Si and mc-Si) cell processing 

techniques for higher efficiency silicon cells 

•	 Film Silicon: develop silicon film growth and cell fabrication techniques on 

inexpensive substrates 

•	 Copper Indium Gallium Diselenide (CIGS): work closely with industry to close the 

efficiency gap between best National Renewable Energy Laboratory (NREL) cell 

result and industrial production efficiency 

•	 Cadmium Telluride (CdTe): increase understanding of efficiency limiters in CdTe 

fabrication processes 

•	 Concentrating Photovoltaics (CPV): advance Inverted Metamorphic Multi-junction 

(IMM) CPV cell architecture and processing 

•	 Organic Photovoltaics (OPV): develop state of the art active layers, contacts, and 

understanding of degradation mechanisms 

•	 Sensitized Cells: screen cell materials and configurations for environmental stability 

•	 Transparent Conducting Oxide (TCOs): cross-cutting research aimed at reducing 

transparent conductor sheet and contact resistance for the semiconductor absorbers 

listed above 

•	 Theory and Computational Science: scientific modeling and prediction for novel 

materials to accelerate development as a PV absorber material. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Conversion Devices 14234 250 0 14484 

Wafer Silicon 1775 0 0 1775 

Film Silicon 3225 0 0 3225 

Copper Indium Gallium 

Diselenide 1835 0 0 1835 

Cadmium Telluride 1226 0 0 1226 

Concentrating Photovoltaics 1860 0 0 1860 

Organic Photovoltaics 1751 250 0 2001 

Sensitized Cells 694 0 0 694 

Transparent Conducting Oxide 618 0 0 618 

Theory & Computational 

Science 915 0 0 915 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

Wafer Silicon 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Qi Wang (NREL), 303-384-6681, qi.wang@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,775 K (NREL) 

Objectives 

•	 Develop a low-cost and high-efficiency cell process to meet U.S. Department of Energy (DOE) goal of 

levelized cost of energy (LCOE).The 2015 targets for residential, commercial, and utility markets are 

8–10, 6–8, and 5–7¢/kWh, respectively. 

•	 Help U.S. solar industry. 

Accomplishments 

•	 Achieved 16.8% conversion efficiency in nanopore black silicon (Si) approach. 

•	 Demonstrated Si heterojunction solar cells for low concentrator and developed 5-in.Si wafer cells. 

•	 Completed the installation of the CZ crystal grower. 

•	 Achieved more than 10% heterojunction BIC c-Si solar cell and solve the S-shape of JV curve. 

•	 Achieved conductive narrower line of 30–40 μm at 10 μm thick using ink-jet printing. 

•	 Produced and delivered strong conference presentation and publications. 

Future Directions 

•	 Establish quick evaluation of solar Si feedstock. 

•	 Develop high-efficiency Si heterojunction solar cells on thin wafers. 

•	 Develop novel materials for better surface passivation. 

1. Introduction 

Wafer Si solar cells and modules are welldeveloped and the leading technology in 

photovoltaic (PV) production—about 90% of all PV 

production in 2008 was wafer Si. To keep the 

leading position of wafer Si and meet DOE goal of 

LCOE in 2015, many laboratories and PV 

industries focus their R&D on low-cost Si 

feedstock, selective emitters, thinner wafers, epiSi wafers, laser assisted doping and contacts, 

simplified processes for high efficiency solar cells, 

advanced diagnostic techniques, and improved 

reliability. 

2. Technical Approach 

This project will focus on accelerating solar Si 

feedstock evaluation, high-efficiency c-Si solar 

cells, next-generation surface and bulk 

passivation, novel front contacts, and advanced 

light management. A summary of the project is 

itemized as the following: 

• Crystal growth 

- Growth and evaluation of Si feedstock 

• High-efficiency solar cells 

- Heterojunction solar cells 

- Heterojunction BIC solar cells 

- Novel light trapping 

- Surface and bulk passivation materials 

• Si solar cell process development 

- Novel metal contact processing 

- New metallization schemes. 

Table I. Task list of wafer-Si agreement in FY 

2009 

Wafer Si FY 2009 

Budget ($K) 

CZ grower 194 

Silicon heterojunction solar cells 654 

Passivation of mc-Si 216 

Heterojunction BIC solar cells 260 

Black Si 151 

Direct writing contact 200 

Fire-through metallization 100 

Total 1775 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Results and Accomplishments 

We completed assembly of the CZ crystal Si 

grower in Figure 1 in early 2009. After it passed 

the acceptance test at the factory, the system was 

delivered and installed at NREL at the end of 

2009. This system can grow 3–4 in. diameter Si 

ingot up to 10 in. long or 4.9 kg per load. It also 

has a capability of vacuum bake-out at 10-6 Torr. 

We are bringing this system on-line. In FY 2010, 

we expect the CZ puller to start growing solar Si 

feedstock, and we will evaluate the feedstock. We 

expect to complete the TSA with a few PV 

companies that have shown interest. 

D R A F T

Fig. 1. Czochralski crystal growth chamber and 

grown Si crystal. 

We made continual progress in the silicon 

heterojunction solar cell task in FY 2009. The 

summary report was published in APL (Wang et 

al., 2010). In that publication, we described our 

research on p-type wafers with the highest reported 

efficiency of 19.3% and the understanding of how the 

Si heterojunction cell works. We also studied the Si 

heterojunction cells under concentrated light to 

understand the heterojunction and the possibility of 

their use in concentrator applications. Figure 2 

shows the cell performance under light intensity up to 

50 suns. We found the p-type based heterojunction 

solar cell performance to be better than the n-type 

based under intensive illumination. This work was 

submitted to APL as well. 

Fig. 2. Solar cell performance of Voc and efficiency 

of silicon heterojunction cells on p-type wafers 

under low concentrated light. Solid symbol = Voc, 

open symbol = efficiency, circle = cell at 1 cm2

, 

and square = cell with dense front grid at 0.1 cm2. 

A wafer-sized Si heterojunction solar cell was 

developed in the newly installed Si cluster tool in 

the Process Development and Integration 

Laboratory. We successfully tested a-Si:H films 

and indium tin oxide (ITO) in the Si cluster tool. 

We also developed a wafer final cleaning process 

before a-Si:H deposition and JV measurement up 

to 10 A for high current, large solar cells. About 10 

wafer-size Si heterojunction cells were made to 

optimize the i/p/ITO junction. More reports about 

HJ solar cell are expected in FY 2010. 

Work under the black Si task aims to archive highefficiency silicon solar cells with a better antireflection with a 

Fig. 3. Photograph at tilted angle of silicon wafers 

with industrial micron-scale texture (left), micronscale texture combined with an interference 

coating (right), and after our black silicon antireflection (center). 

simpler process. It has been known for decades 

that lower reflection can be achieved with a 

density-graded surface. Such density-graded anti­
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

reflection also suppresses reflection across a 

wider range of wavelengths and for light incident 

at any angle. Techniques of fabricating such 

“black silicon” have been expensive, however, and 

the best solar cells based on density-graded antireflection, without interference layer coatings, 

previously reached only 13.9% efficiency. 

D R A F T

In FY 2009, the NREL team has developed an 

inexpensive, nanocatalyzed liquid etch to make 

nanotextured black silicon that reflects less than 

2% of light across the entire usable solar spectrum 

(see Fig. 3). We also fabricated a confirmed 

16.8% efficient black silicon solar cell (see Fig. 4). 

This advance goes far beyond our FY 2009 

milestone of a 15% efficient demonstration cell. 

Except for the advanced anti-reflection strategy, 

our cell is made with standard silicon processes 

used to make more than 80% of today’s solar 

cells. We also demonstrated 14.9% efficient black 

silicon cells on a less-expensive multicrystalline 

silicon wafer. Because our nanocatalyzed etch is 

likely to be less expensive than present antireflection coatings, a start-up company is now 

licensing the technology from NREL to spearhead 

commercialization efforts. Equally important, our 

work demonstrates the practicality of densitygraded anti-reflection in solar cells and may 

inspire applications of this anti-reflection principle 

to other photovoltaic materials and solar energy 

devices. 

Direct writing contact uses inkjet printers to make 

fine conductive lines on c-Si cells. In FY 2009, we 

reduced the printed line width to 30–40 μm at 10 

μm thick; reduced contact resistance to values 

below those of screen printed contacts (<2 

Fig. 4. Independently confirmed IV curve of our 

16.8% efficient black silicon solar cell. 

mOhm cm2

) by continued development of 

proprietary inkjet printable burn-through material; 

reduced resistivity of printed nickel and copper 

(both at 5x bulk); developed dopant inks for 

deposition of doped contacts and tested contacts 

on both n-type and p-type wafers with promising 

results; and installed an Atmospheric Processing 

Platform (APP) for scaling of printed contacts to 

full 156 x 156 mm wafers. The APP also includes 

full wafer thermal processing capabilities; we 

added aerosol spray to deposition techniques as 

an alternative to inkjet printing. Deposited material 

properties are similar to those of inkjet. 

The fire-through process task is using an optical 

furnace to develop a process for mc-Si solar cells 

that will yield cell performance equal to or 

exceeding that of the commercial vendor. We are 

working with two solar cell manufacturers, who 

supply us with unfired screen-printed cells. The 

firing of the cells is done at NREL and cell 

performance is compared with the performance of 

cells from the respective vendor. 

In FY 2009, we successfully changed the firing 

profile. First, we designed a unique procedure to 

create a uniform aluminum (Al) melt on Si by 

altering the wetting properties of the Si surface 

using diffusion of Si into Al during a firing process. 

Next, we determined that in most practical cases, 

the thickness of the back surface field (BSF) is 

limited by the growth rate of the epitaxial layer 

from the Si-Al melt (rather than the melt thickness 

itself). Hence, the BSF is typically controlled by the 

cooling rate between the peak temperature and 

about 600°C. 

With these changes we were able to make cells 

that exceeded the Voc and Jsc values obtained by 

the conventional firing cycles. This work was 

presented at the IEEE meeting and more recently 

at the MRS 2009 Fall meeting. We will continue to 

apply the new firing profile and make 

improvements such that can be used for the 

commercial cells. 

In August 2009, the 19th c-Si workshop was held 

in Vail, CO. It was a successful meeting, where we 

discussed solar-grade Si and the future of monoand multicrystalline Si. Many university, national 

lab, and solar industry representatives attended 

the conference. 

4. Planned FY 2010 Activities 

In FY 2010, we will work on many projects, but we 

will focus on the following areas: 

•	 Operationalize the CZ-crystal grower 

•	 Develop efficient 5-in. heterojunction solar 

cells 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Study the surface and bulk passivation with aSi layers and hydrogenation 

•	 Develop interdigitated solar cells using 

heterojunction a-Si:H layer 

•	 Work on black Si solar cells and technology 

transfer. 

D R A F T

•	 Study direct writing contact 

•	 Examine efficient furnace and fire-through 

metal contact. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

ROI 09-10V: V.E. Yost, H.-C. Yuan, M.R. Page, “AntiReflection Black-Etching Technique for Deep n-type 

Dopant (phosphorus) Diffused Silicon Wafers Using 

Anionic/Organic and Inorganic Wet Chemistry.” 

6. Major FY 2009 Publications 

Kh.A. Abdullin, B.A. Beketov, G.N. Chumikov, B.N. 

Mukashev, M.F. Tamendarov, Т.S. 

Turmagambetov, M.R. Page, and D.M. Kline, 

“Compensated Silicon Crystals and Monosilane 

by Metallurgy Route,” to appear in Proc. 24th 

European Photovoltaics Solar Energy Conf. and 

Exhibition, Hamburg, Germany. 

H.M. Branz, V.E. Yost, S. Ward, K.M. Jones, B. 

To, and P. Stradins, “Nanostructured Black 

Silicon and the Optical Reflectance of GradedDensity Surfaces,” APL 94, 231121 (2009). 

B.N. Mukashev, Kh.A. Abdullin, M.F. Tamendarov, 

T.S. Turmagambetov, B.A. Beketov, M.R. Page, 

and D.M. Kline, “A Metallurgical Route to 

Produce Upgraded Silicon and Monosilane,” Sol. 

Energy Mater. Sol. Cells (2009). 

B. Sopori, V. Mehta, D. Guhabiswas, R. Reedy, H. 

Moutinho, B. To, A. Shaikh, and A. Rangappan, 

“Formation of a Back Contact by Fire-through 

Process of a Screen Printed Silicon Solar Cell,” 

Proc. 34th IEEE PVSC, Philadelphia, June 7–12, 

2009, 1963–1968. 

B. Sopori, V. Budhraja, P. Rupnowski, S. 

Johnston, N. Call, H. Moutinho, M. Al-Jassim, 

“Defect Clusters in Multicrystalline Silicon: Their 

Nature and Influence on the Solar Cell 

Performance,” Proc. 34th IEEE PVSC 

Philadelphia, June 7–12, 2009, 1969. 

B. Sopori, P. Rupnowski, V. Mehta, V. Budhraja, S. 

Johnston, N. Call, H. Mountinho, M. Al-Jassim, 

Aziz Shaikh, M. Seacrist, and D. Carlson, 

“Performance Limitations of mc-Si Solar Cells 

Caused by Defect Clusters,” ECS Trans. 18(1), 

1049–1058 (2009). 

M.F.A.M. van Hest, C.J. Curtis, A. Miedaner, R.M. 

Pasquarelli, J. Kreuder, P. Hersh, and D.S. 

Ginley, “Inkjet Printed Contacts for Use in 

Photovoltaics,” IEEE PVSC Philadelphia, June 

2009. 

Q.	 Wang, “High-Efficiency Hydrogenated 

Amorphous/Crystalline Si Heterojunction Solar 

Cells,” Philosophical Magazine, Prof. Walter E. 

Spear Commemoration Issue, 89, 2587 (2009). 

Q. Wang, M. Page, E. Iwaniczko, Y. Xu, and F. 

Hasoon, “Light Management for Efficient 

Crystalline Si Heterojunction Solar Cells,” in 

Proc. 216th ECS , Vienna, Austria, October 

2009. 

Q. Wang, M.R. Page, E. Iwaniczko, Y.-Q. Xu, L. 

Roybal, A. Duda, F. Hasoon, S. Ward, P.R. Yu, 

and Dong Wang, “

Amorphous/Crystalline Silicon 

Heterojunctions under Intensive Illumination,” 

submitted to APL. 

Q. Wang, M.R. Page, E. Iwaniczko, Y. Xu, L. Roybal, 

R. Bauer, B. To, H.-C. Yuan, A. Duda, F. Hasoon, 

Y.F. Yan, D. Levi, D. Meier, H.M. Branz, and T.H. 

Wang, “Efficient Heterojunction Solar Cells on ptype Crystal Silicon“ APL 96, 013507 (2010). 

H.-C. Yuan, V.E. Yost, M.R. Page, P. Stradins, 

D.L. Meier, and H.M. Branz, “Efficient Black 

Silicon Solar Cell with a Density-Graded 

Nanoporous Surface: Optical Properties, 

Performance Limitations, and Design Rules,” 

APL 95, 123501 (2009). 
 

 

____________________________________________________________________________________ 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

Film Silicon 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Howard Branz (NREL), 303-384-6694, howard.branz@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $3,225K (NREL) 

Objectives 

•	 Develop cost-effective wafer-replacement film crystal silicon materials and devices as prototypes 

for a PV module technology that can be manufactured for $0.50/W 

•	 Improve growth rates and quality of lowgap thin-film silicon alloys for amorphous silicon
 

mulitjunction solar cells
 

•	 Transfer technology and support industrial partners manufacturing thin-film and film crystal silicon 

Accomplishments 

•	 Fabricated 6.3% hot-wire chemical vapor deposition (HWCVD) epitaxial test solar cell on wafer, 

with open-circuit voltage of 570 mV achieved in October 2009 

•	 Grew HWCVD epitaxial silicon (Si) at low temperature with dislocation density less than 2 x 105 

cm-2 and minority-carrier diffusion length of 14 μm 

•	 Demonstrated submicron control of doping in device structures 

•	 Led Si material research and photovoltaic (PV) device design efforts through a cooperative 

research and development agreement that contributed to Ampulse Corporation’s successful 

raising of $8 million in Series A venture capital 

•	 Published first-principles modeling of structure and electronic properties of promising γ-Al2O3/Si 

heteroepitaxial interface for film c-Si applications 

•	 Fabricated 10.1%-efficient a-Si:H solar cell in the new 6-in. Process Development and Integration 

Laboratory (PDIL) cluster tool, exceeding 9% milestone. 

•

Future Directions 

•	 Deposit efficient epitaxial Si solar cells on oriented seed layers on display glass 

•	 Fabricate efficient high deposition rate VHF-CVD nanocrystalline Si solar cells that minimize 

capital costs. 

1.	 Introduction 

Silicon is abundant, nontoxic, well-understood, 

and accepted in the marketplace. There is a highly 

developed industrial base in all forms of Si, and an 

enormous, rapidly growing scientific literature. Si 

PV costs must be reduced, however, to reach the 

U.S. Department of Energy (DOE) 2020 goal of 

$0.06/kWh PV electricity. This requires module 

costs well below $1/W. Today, the Si feedstock 

contract cost alone is greater than $50/kg and is 

unlikely to fall further. Even with utilization 

improving to 8 g/W, wafer materials costs alone 

will top $0.40/W, making it unlikely that wafer Si 

can reach the 2020 Roadmap goals of about 

$0.50/W. 

However, films of crystalline Si could reach this 

goal by using silane to grow Si films, rather than 

feedstock, and by leveraging the existing crystal Si 

and amorphous Si industrial infrastructure from 

PV, displays, and computer chips. Although the 

basic physics of Si semiconductors are quite well 

understood, considerable materials, defect, and 

device research is needed to enable a low-cost PV 

technology using low-cost forms of Si. 

This film Si project addresses key research 

problems toward near-term expansion of the thinfilm Si industry based on amorphous silicon (aSi:H) and allied materials and midterm creation of 

a wafer-replacement crystalline film Si technology. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Technical Approach 

The NREL PDIL is a unique platform for vacuum 

transfer of PV materials and devices among 

deposition and advanced characterization tools 

without breaking vacuum. Our new robotic-transfer 

silicon cluster tool is now operating in the PDIL, 

giving us the ability to deposit 157-mm thin-film aSi:H, a-SiGe:H, nanocrystalline solar cells and to 

collaborate with industrial partners on these larger 

devices. The tool is a unique system for studying 

and developing thin-film Si technologies for PV 

applications. For thin-film Si process development, 

the Si cluster tool has six plasma-enhanced CVD 

chambers and an HWCVD chamber; a sputter tool 

deposits transparent conduction oxides for 

contacts. In FY 2009, we tested all chambers in 

the system and worked to optimize the layers and 

test devices. 

D R A F 

To assess HWCVD for wafer-replacement c-Si film 

T

PV, we grew high-quality epitaxial layers on 

heavily doped “dead” c-Si wafers and designed, 

modeled in PC1D, and fabricated test solar cells to 

see how well the epitaxial Si performs on an ideal 

seed layer. In addition, we improved the epitaxial 

quality at low T and performed gas-to-solid phase 

modeling that suggests viable paths to epitaxial 

growth rates higher than the 300 nm/min we have 

so far achieved (corresponding to 6 minutes for a 

2-μm cell). Finally, we collaborated closely with 

industry partners who develop low-cost seed 

layers and worked to develop new types of seed 

layers ourselves by laser-assisted thermal 

crystallization, by microwave seeding, and by ionbeam assisted deposition of oxide layers matched 

to c-Si on glass. 

3. Results and Accomplishments 

Our PC1D simulations clearly show that film c-Si 

cells have the potential to approach wafer-based 

PV device efficiencies with Leff orders of 

magnitude below the millimeter range required of 

200–300 μm wafer cells. A 5 μm thick c-Si 

absorber needs Leff ~ 5–10 μm to reach 10% 

efficiency, and adding 5X to 10X light trapping 

(i.e., the optical path length is 5 to10 times the 

absorber thickness) would increase JSC and 

improve the efficiency to greater than 15%. The 

simulations also suggest that defective absorbers 

with short Leff can be thinned to capitalize on a 

gain in VOC, as long as the surface recombination 

remains low. 

Figure 2 displays the JV characteristics of three 

representative epitaxial devices grown at different 

T, along with their corresponding plan-view 

electron beam induced current (EBIC) images 

revealing threading dislocations. The VOC and 

efficiency improvement in the devices grown at 

higher T correspond to a marked decrease in Nd in 

the absorber; clearly dislocation density 

determines cell performance. The highest VOC is 

570 mV. As we reduce dislocation densities at 

lower T on display-glass substrates and 

hydrogenate the defects, our design goal of 610 

mV should be achievable. 

Fig. 1. (top) Schematic of the test device structure 

on “dead” c-Si wafers. (middle) J-V curves and 

parameters of epitaxial Si test solar cells, 

correlated with (bottom) EBIC dislocation 

densities, for a range of substrate temperatures. 

We developed an analytic model that explains the 

insensitivity of our very thin PV cells to impurities 

(and other point defects). Minority carrier bulk 

lifetime, τbulk

, scales inversely with the 

concentration, N, of the most recombination-active 

impurity or defect, and therefore the carrier 

diffusion length, Leff = (Dτbulk)

1/2, scales as 

because of the random walk that minority carriers 

undergo before recombining. Here D, the minority 

carrier diffusion coefficient, is assumed weakly 

dependent on N. For efficient carrier collection at 

N-1/2 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the surface of an absorber of thickness d, Leff must 

be about 3 times d, as described below. 

Consequently, the maximum impurity density a 

cell can tolerate depends on thickness as Nmax ∝

d-2 . Compared to the bulk impurity concentration 

that can be accommodated in a 200-μm thick 

wafer cell [20], the impurity or defect concentration 

in a 2-μm cell can be 104 times higher without 

performance degradation; i.e., metal impurity 

levels of at least 1017 cm-3 can be tolerated. 

Secondary ion mass spectrometry (SIMS) reveals 

~1017 cm-3 of both O and C throughout our 

absorber layers. In our growth chamber, W (from 

the hot filament) and Ni are present; the 

concentration of each in the epitaxial layers is 

comparable to the 1014–1015 cm-3 noise of the 

SIMS measurement, but T-dependent EBIC shows 

that the impurities do not limit performance. In 

wafer cells, randomly distributed metal 

contaminant concentrations of only 1013–1014 cm-3 

would be sufficient to degrade wafer cell 

performance. 

D R A F T

When limited by highly recombination-active 

dislocations, three length scales control the 

relationship between material quality and film c-Si 

device performance: Leff, d, and the characteristic 

distance between dislocations, ld ~ Nd

-1/2. Our IQE 

measurements (not shown) show that the red 

response of a 2-μm cell reaches ideal behavior at 

4 μm < Leff < 8 μm, experimental confirmation of 

our simulated results that Leff ~ 3d is required for 

efficient carrier extraction. This relationship applies 

because minority carriers do not drift directly to the 

junction but, instead, reverse direction frequently 

during their random walk to the emitter. Second, 

correlation of EBIC and IQE measurements 

indicates that Leff ~ ld/2. With equal probability of 

traveling in any direction, recombination at a 

dislocation naturally limits Leff to about half of ld. 

Thus, our experiments suggest that ld ≥ 6d for 

efficient film Si cells. For example, our 2-μm cell 

requires a dislocation density ≤ 5 x 105 cm-2 for 

efficient carrier collection, but a 5-μm cell would 

require an unpassivated dislocation density of 1 x 

105 cm-2 and a higher-current 10-μm cell would 

require 3 x 104 cm-2. More dislocations could be 

tolerated if they are well-passivated by 

hydrogenation. 

In the Si cluster tool, we optimized a-Si:H film 

uniformity, deposition rate, dark and light 

conductivity, bandgap, and activation energy of 

both intrinsic and doped films. We varied substrate 

temperature, process gas flow rate, gases 

mixtures, and radio frequency power. We also 

optimized the indium tin oxide and ZnO:Al 

transparent conducting oxide (TCO) layers to 

achieve film transmittance > 85% and sheet 

resistance < 10 Ω/square.

Figure 2 shows the J-V curve and performance 

parameters of a 10.15% cell on Asahi U-type glass 

coated with surface-textured SnO:F TCO. The cell 

structure is glass/TCO/p-i-n/Ag, the cell area is at 

0.5 cm2

, and the i-layer thickness is about 350 nm. 

The cell stabilizes at 8% after 1000 hours of light 

soaking. The 10.15% initial efficiency exceeds the 

FY 2009 milestone of 9% and allows us to assist 

industrial partners with cell development in the 

PDIL. 

Fig. 2. Light and dark J-V of a 10.15% efficient 

a-Si:H solar cell fabricated in the Si cluster tool. 

We also identified key parameters for a p-layer 

that supports high cell efficiency by eliminating “Sshaped” J-V curves that we linked to poor 

electrical contact between the TCO and p-layer 

that reduces fill factor (FF). By controlling p-layer 

bandgap, dopant concentration, and thickness, we 

were able to eliminate the S-shape. The best FF of 

our cells reached 73%. 

4. Planned FY 2010 Activities 

In FY 2010, we will apply our experience with 

devices on wafers to solar cells on inexpensive 

templated-coated substrates such as display glass 

and metal foil. Goals include improved low-T 

epitaxial layer quality, hydrogenation-passivated 

dislocations, and increased deposition rate. As we 

improve our own novel seed layers on glass, we 

will measure grain sizes and orientation and will 

deposit and characterize Si epitaxial layers and 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

devices to assess PV potential. We will also 

demonstrate nc-Si solar cells for use as a lowgap 

partner to a-Si:H in tandem cells and increase 

growth rates in the Si cluster tool. Milestones 

include: 

D R A F T

D.L. Young, H.M. Branz, F. Liu, R. Reedy, and Q. 

Wang, “Electron Transport and Structure in 

Highly-Conducting P-doped Polycrystalline Si 

Thin Films,” J. Appl. Phys. 105, 33715 (2009). 

I.T. Martin, H.M. Branz, P. Stradins, D.L. Young, 

K.M. Jones, R.C. Reedy, and C.W. Teplin, 

“Doping of High-Quality Epitaxial Silicon Grown 

by Hot-Wire Chemical Vapor Deposition near 

700°C,” Thin Solid Films 517, 3496-3498 (2009). 

C.W. Teplin, K. Alberi, M. Shub, C. Beall, I.T. 

Martin, M.J. Romero, D.L. Young, K.M. Jones, R. 

Reedy, P. Stradins, and H.M. Branz, 

“Mechanisms Controlling the Phase and 

Dislocation Density in Epitaxial Silicon Films 

Grown from Silane below 800°C,” submitted to 

Appl. Phys. Lett. 

K. Alberi, I.T. Martin, M. Shub, C.W. Teplin, M.J. 

Romero, E. Iwaniczko, A. Duda, P. Stradins, 

H.M. Branz, and D.L. Young, “Material Quality 

Requirements for Efficient Epitaxial Film Silicon
 

Solar Cells,” Appl. Phys. Lett., in press (2010).
 

M.S. Dabney, P.A. Parilla, L.M. Gedvilas, A.H. 

Mahan, and D.S. Ginley, Appl. Phys. Lett. 95, 

251902 (2009). 

A.H. Mahan, M.S. Dabney, P.A. Parilla, and D.S. 

Ginley, “The Effect of the Film H Content on the 

Crystallization of Laser Processed and Thermally 

Annealed HWCVD a-Si:H,” Phys. Stat. Solidi, in 

press (2010). 

A.H. Mahan, T. Su, D.L. Williamson, L.M. 

Gedvilas, S.P. Ahrenkiel, P.A. Parilla, Y. Xu, and 

D.A. Ginley, “Identification of Nucleation Center 

Sites in Thermally Annealed Hydrogenated 

Amorphous Silicon,” Adv. Funct. Mater. 19, 2338 

(2009). 

Liu, F., K.M. Jones, Y. Xu, W. Nemeth, J. Lohr, J. 

Neilson, M.J. Romero, M.M. Al-Jassim, and D.L. 

Young, “Ultra-High Crystalline-Quality Silicon 

Pillars Formed by Millimeter-Wave Annealing of 

Amorphous Silicon on Glass,” Adv. Mater. 21, 

3002 (2009). Cover story. 

Project scientists delivered more than 25 

conference and workshop presentations in 

FY2009, including 9 invited talks. 

•	 Publish paper on quality of epitaxial Si on 

seed layers on inexpensive substrates. (9/30) 

•	 Fabricate solar cell device on wafer with opencircuit voltage above 560 mV. (8/31) 

•	 Demonstrate 2% absolute improvement in epiPV efficiency by hydrogenation. (03/10) 

•	 Publish effect of film thickness on grain size in 

thermal annealing of a-Si after subthreshold 

laser crystallization. (8/31) 

•	 Fabricate 7% baseline nc-Si solar cell in PDIL 

Si Cluster Tool (09/10). 

5. FY 2009 Awards and Patents 

Charles Teplin received an NREL Outstanding 

Performance Staff Award for his PV work with 

Ampulse. In addition, we filed for 4 U.S. patents: 

A Photovoltaic Cell with Back-Surface Reflectivity 

and Scattering, filed 08/06/09, US12/537,185 

Back Contact to Film Silicon on Metal for 

Photovoltaic Cells filed 08/07/09,US 12/537,152 

Crystal Silicon Processes and Products, filed 

02/12/09, US PCT/US09/33937 

Epitaxial Growth of Silicon for Layer Transfer, filed 

08/21/08 US and World: PCT/US08/73834. 

We submitted 4 new Records of Invention. 

6. Major FY 2009 Publications 

I.T. Martin, C.W. Teplin, H.M. Branz, and P. 

Stradins, “Silicon Epitaxy Rate Optimization and 

Modeling for Hot-Wire Chemical Vapor 

Deposition from 600 to 800°C,” J. Applied 

Physics, in press (2010). 

H.J. Xiang, J.L.F. Da Silva, H. M. Branz, and S.-H. 

Wei, “Heteroepitaxial Interface without Defects or 

Gap States: Single Crystal Si on Al2O3,” Phys. 

Rev. Lett. 103, 116101 (2009). 

P. Stradins, C.W. Teplin, and H.M. Branz, “Phase 

Evolution in Nanocrystalline Silicon Films: 

Hydrogen Dilution and the Cone Kinetics Model,” 

Phil. Mag. 89, 28, 2461-2465 (2009). 

7. University and Industry Subcontracted Partners 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Jeff Neilson, 

Lexam Research 

10 Black Fox Way, 

Redwood City, CA 94062 

jeff@lexamresearch.com 

Microwave wave optical design 

assistance 6 0 
 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

Copper Indium Gallium Diselenide 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Ingrid Repins (NREL), 303-384-7678, ingrid.repins@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,835K (NREL) 

Objectives 

•	 Assist with development of goals and metrics associated with copper indium gallium diselenide 

(CIGS) Technology Roadmaps, including those related to stability, in situ sensors, device 

physics, decreased cost, and enhanced module efficiency 

•	 Support the needs of the expanding CIGS photovoltaics (PV) industry 

•	 Install vacuum components of CIGS Process Development and Integration Laboratory (PDIL) 

platform to enhance capabilities for both industrial support and research 

•	 Expand intellectual property related to CIGS PV. 

Accomplishments 

•	 Completed ES&H and facilities requirements for full functionality of equipment in Science and 

Technology Facility (STF) at NREL 

•	 Finished installation of vacuum components for CIGS PDIL platform, brought them into 

compliance with NREL ES&H regulations, and commenced operation
 

•	 Gathered data on industrial and laboratory samples showing minority carrier lifetime to be a 

useful metric of CIGS quality 

•	 Quantified the damp heat reliability of various transparent conductors used in the CIGS device; 

identified possible strategies to mitigate sensitivities. 

Future Directions 

•	 Develop processes in each component of the PDIL CIGS platform and proceed with industrial 

collaborations, state-of-the-art CIGS devices, and characterization. 

•	 Adapt minority carrier lifetime as an in situ metric of CIGS quality, suitable for installation on 

manufacturing deposition equipment. 

•	 Test success of identified strategies to improve resistance of CIGS device to damp heat. 

1. Introduction 

The research undertaken by the Polycrystalline 

Thin Film Devices Group is directed at thin-film 

semiconductor materials, device properties, and 

fabrication processes to improve the efficiency, 

stability, and cost of photovoltaic solar energy 

conversion. This research can be broadly placed 

into three categories: application of capabilities to 

assist industry in addressing current problems; 

exploration of specific techniques and processes 

to develop and transfer technology improvements 

that industry will soon need; and understanding 

that builds a solid technical foundation for 

continuing improvement of thin-film PV products. 

Within this framework, the FY 2009 project 

supported thin-film technologies related to the 

substrate, Mo, CIGS, and transparent conducting 

oxide (TCO) components of the thin-film 

technology. Activities and time frames are 

consistent with those identified in the DOE Solar 

Program Multi-Year Technical Plan and related 

Technology Roadmaps. 

NREL’s CIGS technologies continue to lead the 

world in demonstrated cell performance, and our 

innovations related to high-quality TCO 

technologies are being rapidly assimilated into the 

thin-film industry. Because thin-film PV can 

generate lower-cost PV electricity than many 

historical alternatives (in $/watt), thin-film PV is the 

fastest growing segment of the PV market. 

Providing new innovations and a technical 

foundation for this rapidly expanding industry is at 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the heart of the efforts of the NREL Polycrystalline 

Thin-Film Group. 

2. Technical Approach 

The project involves research on CIGS device 

development. FY 2009 activities were funded via 

four agreements, as listed next. 

D R A F T

evaporation tool, the DC sputtering chamber (for 

Mo back contact and related materials), the RF1 

sputtering chamber (for the ZnO bi-layer top 

contact and related materials), the RF2 sputtering 

chamber (for sputtered buffer layers and related 

materials), the central robot chamber, which 

moves samples between the different processes, 

and the system load lock. Figure 1 is a photo of 

the CIGS platform. 

Task Title FY 2008 

Budget ($K) 

PDIL 900 

Sensors 500 

TCO 250 

Reliability 185 

These research tasks are detailed as follows: 

•	 PDIL—This task enables numerous near-term 

to long-term research activities at NREL using 

the PDIL (http://www.nrel.gov/pv/pdil/ 

about_pdil.html). The task involves the 

installation, acceptance, verification, 

integration, and commissioning of the CIGS 

platform, followed by demonstration of the 

deposition and fabrication of state-of-the-art 

CIGS solar cells. 

•	 Sensors—Achieving rapid transfer of the 

essential characteristics of 20.0% small-area 

devices to manufacturing environments 

requires real-time measurements (sensors) of 

the important qualities of each device layer. 

Such measurements enable higher yields and 

real-time process optimization, as well as 

enhance the understanding of the device. This 

task seeks to develop these measurements. 

•	 TCOs—Advances in TCOs can help improve 

device performance, decrease materials costs, 

increase reliability, and enable a wider variety 

of encapsulants (through increased damp heat 

stability). 

•	 Reliability —Improving the quality of CIGS PV 

products requires reliability and stability 

studies. Of particular interest to this task is 

identifying the failure mechanisms caused by 

environmental activity on the cell. Such 

reliability studies could have a direct impact on 

improving the environmental tolerance of 

CIGS solar cells and therefore produce 

reliable and useful long life products. 

3. Results and Accomplishments 

3.1 PDIL 

In FY 2009, we installed, operated, and integrated 

all vacuum components of the CIGS platform in 

the PDIL. These components are the CIGS 

Fig. 1. CIGS platform installed and functioning in 

PDIL. 

Additionally, a large-area prototype for bathdeposited CdS, the baseline process for high 

efficiency devices, was designed, tested, and 

proven successful. Equipment specifications were 

written for such a tool, in a form compatible with 

the PDIL’s mechanical interfaces and high degree 

of automation. 

3.2 Sensors 

During FY 2009, a correlation between lifetime 

measured on CIGS films and subsequent device 

voltage was demonstrated. This correlation was 

shown to be valid for samples made in the 

laboratory and those originating from a 

manufacturing line, and agrees approximately with 

results expected from basic physics. The sample 

set included a wide range of efficiencies, carrier 

densities, Ga gradings, and CIGS deposition 

temperatures. The correlation is shown in Figure 

2. The measurement technique, time-resolved 

photoluminescence, is therefore likely to be 

successful as a diagnostic tool for process 

monitoring, control, and optimization. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• 0.80

0.75

D R A F T

0.40

0.45

0.50

0.55

0.60

0.65

0.70

GSE

NREL

0 20 40 60 80

Lifetime, τ2 

Fig. 2. Measured Voc as a function of lifetime for 

samples from NREL (x) and Global Solar Energy 

(o), and comparison with prediction from basic 

device physics (solid line). 

3.3 TCO 

Progress in the area of TCOs proceeded in two 

areas: ZnMgO replacement of the resistive i-ZnO 

layer, and application of protective metal oxides. 

Using a ZnMgO layer to replace the i-ZnO layer 

can create CIGS devices with equal or better 

device performance. The importance of limiting 

sputtering power in this layer that is very close to 

the junction was demonstrated. The results are 

important for understanding the constraints on 

processing layers near the junction during 

manufacture, enabling wide bandgap CIGS 

devices with correct band alignment at the 

junction, and decreasing absorption losses in the 

TCO. 

Second, preliminary data indicate success in 

improving the moisture-resistance of the CIGS 

device via application of a protective transparent 

metal oxide (PTMO) film. Initial experiments show 

that, with the sputtering-deposited PTMO layer, 

the degradation rate of the AZO window layer is 

reduced by four to five orders of magnitude and 

the degradation rate of CIGS device is four to five 

times. The PTMO may therefore enable a wider 

family of lower-cost and flexible encapsulants. 

3.4 Reliability 

FY 2009 accomplishments under the reliability 

agreement include the following: 

•	 Expanded the lab/test capability with 

acquisition, installation, and operation of a 

new ESPEC environment chamber. 

•	 Evaluated/ranked the damp-heat (DH) stability 

of a number of TCOs for CIGS, verified that 

InZnO and ITO are the most DH-stable. 

Verified the usefulness of a simple wetchemical process to protect the bi-layer ZnO. 

3.5 Summary of Milestones Achieved 

The accomplishments described satisfy the 

following milestones from the FY 2009 annual 

operating plan: 

•	 Complete installation and operation readiness 

of PDIL CIGS evaporation module (02/09). 

•	 Integrate PDIL central robot chamber with 

other modules (08/09). 

•	 Demonstrate correlation between device 

performance and ex situ noncontact 

characterization for sensor use (06/09). 

•	 Fabricate ZnMgO films with electro-optical 

properties similar or exceeding those of ZnO 

(03/09). 

•	 Assess the performance and reliability of 

ZnMgO in the CIGS device (09/09). 

4. Planned FY 2010 Activities 

The group’s mission and the accomplishments 

described suggest the following activities for FY 

2010: 

•	 Tune processes in each component of the 

PDIL CIGS platform such that film properties 

are consistent with high-efficiency CIGS 

devices. 

•	 Assess whether CdS deposition in the PDIL 

should be performed via sputtering (existing 

tool, significant process development required) 

or chemical bath (existing process, wet tool 

required). 

•	 Adapt lifetime measurement to small, 

inexpensive instrumentation that can be used 

as an in situ sensor for CIGS. 

•	 Quantify benefits of identified strategies for 

moisture-hardening of CIGS device. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

One of the group’s papers, “19.9%-efficient 

ZnO/CdS/CuInGaSe2 Solar Cell with 81.2% Fill 

Factor,” was identified by Research Trends in 

October 2009 as the most highly cited 2008– 

2009 paper in the field of energy research. 

F.J. Pern was an invited speaker and served in the 

organizing committee at the SPIE Solar Energy 

and Tech. Conf. (08/09). 

F.J Pern was a co-chair and invited speaker at the 

APP International PV Reliability workshops 

(December 2008, 07/09). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

I.L. Repins was an invited speaker at the IEEE 

PVSC (06/09). 

I.L. Repins was an invited speaker at the SPIE 

Solar Energy and Tech. Conf. (08/09). 

M. Contreras was chair of	 “Symposium M: ThinFilm Compound Semiconductors,” at the MRS 

Spring Meeting (04/09). 

M.	 Contreras was an organizer of the 18th 

International Material Research Congress 

(08/09, Mexico). 

X. Li was a committee member for OPTOmism 

conference (05/09). 

Record of invention filed with DOE. “Fiber fed time 

resolved photoluminescence for CIGS quality 

control,” IR10-04. I.L. Repins. 

Record of invention	 filed with DOE. “Protective 

metal oxides for CIGS thin-film solar cells,” ROI 

09-70. X. Li, J Pern, S. Glick. 

6. Major FY 2009 Publications 

FY 2009 publications for which the first author 

worked in the CIGS group are listed. 

M.A. Contreras, I.L. Repins, W. Metzger, M. 

Romero, and D. Abou-Ras, “Se Activity and its 

Effect on CIGS PV Thin-Film Materials,” Phys. 

Stat. Solidi A – App. Mater. Sci. 206(5), 1042– 

1048 (2009). 

X. Li, A. Kanevce, J.V. Li, and I. Repins, “Impact of 

Front Contact ZnO:Al/Zn1-xMgxO Layer on CIGS 

Thin-Film Solar Cells,” Phys. Stat. Solidi C 

(2009). 

X. Li, I. Repins, B. Egaas, J.V. Li, and A. Kanevce, 

“The Impact of Zn1-xMgxO on CIGS Thin Film 

Solar Cells,” Proc. IEEE PVSC 34 (2009). 

J.R. Mann, N. Vora, and I. Repins, “In Situ 

Thickness Materials of CBD CdS,” accepted Sol. 

En. Mater. Solar Cells (2009). 

F.J. Pern, B. Egaas, B. To, C.-S. Jiang, Jian V. Li, 

S. Glynn, and C. DeHart, “A Study on the 

Humidity Susceptibility of Thin-Film CIGS 

Absorber,” 34th IEEE PVSC, 2009. 

F.J. Pern, S.H. Glick, X. Li, C. DeHart, T. Gennet, 

M. Contreras, and T. Gessert, “Stability of TCO 

Window Layers for Thin-Film CIGS Solar Cells 

upon DH Exposures—Part III,” Rel. of PV Cells, 

Mod., Comp., and Sys.—2009 Solar Conf. 

F.J. Pern, R. Jones, L. Gedvilas, and T. Gessert, 

“Preliminary Evaluation of Conductive Adhesive 

Tapes as Potential Interleafing Connects for 

Flexible Thin-Film PV Applications,” MRS Spring 

Meeting, 2009. 

Repins,	 S. Glynn, J. Duenow, T.J. Coutts, W. 

Metzger, and M.A. Contreras, “Required 

Materials Props. for High-Efficiency CIGS 

Modules,” SPIE Solar Energy Technol. 7409, 

74090M (2009). 

I.L. Repins, W.K. Metzger, C.L. Perkins, J.V. Li, 

and M.A. Contreras, “Measured Minority-Carrier 

Lifetime and CIGS Device Performance,” Proc. 

IEEE PVSC 34, 2009. 

R. Sundaramoorthy, F.J. Pern, C. DeHart, T. 

Gennett, F.Y. Meng, M. Contreras, and T. 

Gessert, “Stability of TCO Window Layers for 

Thin-Film CIGS Solar Cells upon DH 

Exposures—Part III,” Rel. PV Cells, Mod., 

Comp., Sys.—2009 Solar Conf. 

R. Sundaramoorthy, I.L. Repins, T. Gennett, Jian 

V. Li, D. Albin, F.J. Pern, C. DeHart, S. Glynn, J. 

Perkins, D. Ginley, and T. Gessert, “Comparison 

of a-InZnO and PX ZnO:Al as a Conductive 

Layer for CIGS PV Solar Cells, Proc. IEEE 

PVSC 34 (2009). 

N. Vora, I. Repins, S. Robbins, J. Mann, H. 

Castenada, B. Armstrong, and D. Weber, 

“Large-Area Chemical Bath Deposition of CdS 

on CIGS,” MRS Proc. 1165 (2009), doi 1165-

M05-05. 

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of Research Activity FY 2009 

($K) 

Cost 

Share 

($K) 

Optony 825 E. Evelyn Ave., Suite 339; 

Sunnyvale, CA 94086 

Development of thin film CIGS solar cells 

for concentrator applications 15 15 

Dupont Harland.l.tate@usa.dupont.com Evaluation of novel substrates for CIGS 

solar cells. 180 0 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. Cost share for 

Optony was provided through the NREL Technology Transfer Office. Cost share for DuPont was provided 

through a National Center for Photovoltaics entrepreneurial CRADA. 
 

____________________________________________________________________________________ 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

Cadmium Telluride 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Tim Gessert (NREL), 303-384-6451, tim.gessert@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,226K (NREL) 

Objectives 

•	 Complete contract, legal, and vendor review necessary to release cadmium telluride (CdTe) 

Process Development and Integration Laboratory (PDIL) tool request for quotes (RFQ) 

•	 Test process sequence for all-dry CdTe and establish baseline design 6”x6” close spaced 

sublimation (CSS) source 

•	 Expand research staff and lab facilities needed for expanded cooperative research and 

development agreement (CRADA) requests
 

•	 Expand NREL intellectual property (IP) for novel transparent conducting oxides (TCOs) for use in 

thin-film CdTe photovoltaics (PV) 

•	 Develop new techniques for rapid assessment of CdTe cell-level reliability 

•	 Assist with developing goals and metrics associated with CdTe Technology Roadmaps, including 

coordinating PDIL platform designs. 

Accomplishments 

•	 Benchmarked 14% efficient CdTe devices using all-dry processing 

•	 Confirmed 3”x3” CSS design with improved uniformity, established 6”x6” design for PDIL 

•	 Established TCO/soda-lime glass processes and 3”x3” CTO/ZTO/CdS:O hardware for CRADAs 

•	 Expanded NREL IP related permittivity control of TCO for PV applications 

•	 Published reports on using transient CV for analyzing mechanisms of CdTe junction stability 

•	 Published report on increase in minority carrier lifetime during Cu diffusion into CdTe. 

Future Directions 

•	 Finalize procurement of CdTe PDIL tool. Expect delivery of some components in fiscal year (FY) 

2010 

•	 Expand IP base in TCO permittivity control, CTO, ZTO, CdS, and moisture-tolerant TCOs 

•	 Develop techniques to assess rapidly intrinsic CdTe cell-level reliability 

•	 Expand Cu/lifetime studies to differentiate various layers (space-charge vs. quasi-neutral) 

•	 Initiate partnerships with commercial companies to accelerate CdTe PV-product development. 

1. Introduction 

The research undertaken by the CdTe Technology 

Area studies semiconductor materials, device 

properties, and fabrication processes to improve 

the efficiency, stability, and cost of PV solar 

energy conversion using CdTe thin-film devices. 

This research can be broadly placed into three 

categories: applying capabilities to assist industry 

in resolving current problems; exploring specific 

techniques and processes to develop and transfer 

technology improvements that industry will soon 

need; and providing understanding that builds a 

solid technical foundation for continuing 

improvement of thin-film PV products. Within this 

framework, the FY 2009 activity supported glass, 

TCO, CdS, CdTe, and back-contact thin-film 

technologies. Activities and time frames are 

consistent with those identified in the DOE Solar 

Program Multi-Year Technical Plan and related 

Technology Roadmaps. 

NREL’s CdTe technology leads the world in 

demonstrated cell performance, and our 

innovations related to high-quality TCO 

technologies are being rapidly assimilated into the 

thin-film industry. Because thin-film PV can 

generate lower-cost PV electricity than many 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

historical alternatives (in dollars/watt), thin-film PV 

is the fastest growing segment of the PV market. 

Further, CdTe PV is rapidly achieving (or possibly 

has achieved) grid parity in some markets. 

Creating innovations and a technical foundation 

for this rapidly expanding industry is at the heart of 

the efforts of the CdTe Technology Area. 

D R A F T

2. Technical Approach 

The CdTe Research Activity focuses on research 

associated with CdTe device-level development 

and understanding. In FY 2009, efforts in CdTe 

cell-level reliability were moved back into the CdTe 

Research Activity from the Module Reliability 

Activity. Additional FY 2009 support that directly 

benefited the CdTe Research Activity was from 

the Industrial Program Funds managed within the 

National Center for Photovoltaics. These funds 

were targeted to accelerate research in certain 

NREL IP to enable licensing potential and 

establish background IP to enhance success for 

CRADAs (i.e., Redlen Inc., Solexant, and EPIR 

Technologies). 

•	 Perform studies needed for CdTe PDIL tool. 

o	 All-dry CdTe device processing 

o	 Uniform CdTe on 3”x3” substrates 

o	 Thermal modeling for 6”x6” substrates. 

•	 Establish infrastructure for industry 

collaborations. 

o	 High-quality SnO2:F on soda-lime glass 

o	 3”x3” sputter deposition of Cd2SnO4, 

ZnSnxOy, and CdS:O. 

•	 Develop new TCO materials using NREL IP 

related to permittivity engineering. 

•	 Re-establish CdTe cell-level reliability within 

CdTe Research Activity. 

•	 Advance understanding of defect evolution 

during Cu contacting. 

3. Results and Accomplishments 

This NREL CdTe Research Activity leads the 

world in developing CdTe thin-films and related 

materials for use in high-performance and stable 

single-junction solar cells. The project objectives 

support near-term manufacturing, build the 

knowledge and technology base for future 

manufacturing improvements, allow for training of 

the next generation of CdTe PV device 

technologists, and sustain innovation that supports 

progress toward the future and the long-term Solar 

Program goal of 15%-efficient commercial 

modules. Over the past decade, we have steadily 

improved the quality of the layers in the CdTe 

device and achieved a world-record efficiency of 

16.5%. The following represent highlights from FY 

2009 CdTe research activities. 

The capital procurement of the CdTe PDIL tool 

proceeded on schedule, with all the required 

documentation cleared by the NREL Contracts 

and NREL Legal Offices by September 2009. The 

RFQ was submitted in October 2009. Because this 

particular type of tool has not been commercially 

constructed, the final design specification required 

a patent filing ([Record of Invention]ROI-09-08, 

Provisional Patent filed 3/09). To test that the 

components identified in the design are likely to 

perform as expected, we demonstrated 14% 

devices using the all-dry process steps specified in 

the RFQ. These results were reported in Duenow 

et al. (2009b). We also conducted foundational 

studies of the thermal and mass transport 

characteristics through computer simulation 

(ComSol Program). Simulation results were 

confirmed by producing an actual 3”x3” CdTe CSS 

source for an existing test system. Results of this 

testing are a foundation for the final 6”x6” PDIL 

source design. Simulation studies will be 

presented at the 35th IEEE PVSC meeting. 

The number of requests for assistance from the 

PV industry increased rapidly in FY 2009. To 

respond to these requests, we 

designed/constructed/established infrastructure 

consistent with the industry requirements. 

Specifically, we began a project to produce TCOcoated glass consistent with the 3.2-mm soda-lime 

commercial product. This allows production of 

CdTe devices onto any new TCO or glass options 

to be compared directly to NREL baseline devices. 

Similarly, we modified a system to sputter 

Cd2SnO4, ZnSnxOy, and CdS:O (i.e., CTO, ZTO, 

CdS) films on 3”x3” substrates. This required 

building much larger equipment designed for toxic 

material use (i.e., Cd-containing). 

We expanded studies to engineer permittivity 

control into our next generation of TCO materials 

(ROI]-#09-30). Specifically, we added Zr into 

SnO2:F to produce a SnZrO2 alloy that shifts the 

plasma edge 200–600 nm farther into the infrared. 

If adopted by the glass industry, this should allow 

CdTe modules to produce more current and thus 

higher performance. We also filed an ROI that 

allows for production of a Cd2SnO4-like material at 

temperatures consistent with soda-lime glass 

(ROI-08-28). We also continued studies to 

improve the electrical performance of TCOs using 

multiple improved dopant design. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Our understanding of new methods to study CdTe 

cell-level reliability was advanced by capacitancevoltage analysis to monitor transient effects of 

potentially mobile charges in CdTe PV devices. In 

FY 2009, reports were presented where the CV 

transients were observed and linked to CdTe 

device stability. These studies were reported in 

Albin and del Cueto (2009) and Albin et al. (2009a, 

2009b). 

D R A F T

Studies continued to improve our under-standing 

of the effect of minority-carrier lifetime in typical 

CdTe devices. FY 2009 studies included lowtemperature photoluminescence to probe the 

defect functionality that ultimately limits Cuinduced lifetime improvements. These were 

reported in Gessert et al. (2009a). 

4. Planned FY 2010 Activities 

In FY 2010, efforts will continue to expand from 

producing small and medium-sized devices and 

related films toward larger devices required to 

establish operations in the CdTe PDIL laboratory. 

Efforts will also be expanded for CdTe-related 

CRADAs. This and other planned activities are 

outlined below. 

•	 Finalize procurement of CdTe PDIL tool. 

Expect delivery of some components in FY 

2010. 

•	 Expand IP base in TCO permittivity control, 

CTO, ZTO, CdS, and moisture-tolerant TCOs. 

•	 Expand techniques to assess rapidly intrinsic 

CdTe cell-level reliability. Determine if 

transients are caused by mobile charges or 

defect variations 

•	 Expand Cu/lifetime studies for CdTe layers. 

•	 Initiate partnerships with commercial 

companies to accelerate development of CdTe 

PV-specific products. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

ROI-08-28. “Transparent Conducting Oxide Films 

Produced by CVD,” X. Li, T. Burst, T.A. Gessert. 

Discuss to file as non-provisional. 

ROI-09-08. “Research-Scale CdTe Device 

Development Platform,” T.A. Gessert, T. Barnes. 

ROI Submitted 11/08. Provisional Patent Filed 

03/09. 

ROI-09-30. “SnO2 Films with High Permittivity,” X. 

Li, J. Burst, T.A. Gessert, ROI Submitted 

03/02/09. 

ROI-09-63. “TCO Films with Improved Properties,” 

T.A. Gessert, X. Li, T.M. Barnes, S.E. Asher, C.L 

Wyse. ROI Filed 07/09. 

ROI-09-70. “Protective Metal Oxides for CIGS 

Thin-Film Solar Cells,” X. Li, F.J. Pern, S. Glick, 

R. Noufi. ROI Filed 08/09. 

ROI-09-71. “Fluorine Compounds for Doping 

Conductive Oxide Thin Films,” T.A. Gessert, S. 

Li, T. M. Barnes, R. Torres, C.L. Wyse. ROI Filed 

09/09. 

ROI-09-72. “Growth of CuInSe2- Based Solar Cells 

Using Close-Spaced Sublimation of Highly 

Volatile Cu Precursors,” D. Albin. ROI Filed 

09/09. 

6. Major FY 2009 Publications 

D.S. Albin, R.G. Dhere, S.C. Glynn, J.A. del 

Cueto, and W.K. Metzger, “Degradation and 

Capacitance-Voltage Hysteresis in CdTe 

Devices,” SPIE Solar Energy + Technology 

Conference, San Diego, CA (2009a). NREL 

Conference Paper NREL/CP-520-46304. Invited 

paper. 

D.S. Albin, R.G. Dhere, S.C. Glynn, and W.K. 

Metzger, “The Direct Correlation of CdTe Solar 

Cell Stability with Mobile Ion Charge Generation 

During Accelerated Lifetime Testing”, Proc. 34th 

IEEE Photovoltaics Specialists Conf. (2009b). 

D. Albin and J. del Cueto, “New Diagnostic Tool to 

Assess Thin-film Solar Cell Reliability,” SPIE 

Newsroom Item. DOI 10.1117/2.1200908.1790. 

http://spie.org/x36691.xml?Articleid=X36691, 

(2009). Invited Paper. 

J.M. Burst. S. Choi, M.G. Scott, X. Li, T.J. Coutts. 

T.A. Gessert, S.M. Weiss, and B.R. Rodgers, 

“Permittivity-Engineered TCOs: Optimizing 

Optical Properties of SnO2:F,” Proc. 34th IEEE 

Photovoltaics Specialists Conf. (2009). 

R.G. Dhere, J.N. Duenow, A. Duda, S.E. Asher, 

W.K. Metzger, H.R. Moutinho, and T.A. Gessert, 

“Recent Results for All-Dry-Processed 

CdTe/CdS Solar Cells,” MRS Symp. Proc. 1165 ( 

2009a).
 

R. Dhere, B. Fluegel, A. Mascarenhas, J. Duenow, 

and T.A. Gessert, “Investigation of Effects of 

Processing and Impurities on the Properties of 

CdTe Using Microscopic 2D PL Imaging 

Technique,” Proc. 34th IEEE Photovoltaics 

Specialists Conf. (2009b). 

J.N. Duenow, T.M. Barnes, R.G. Dhere, J.D. 

Bergeson, B.A. Larson, J.L. Blackburn, A. Duda, 

G. Teeter, and T.A. Gessert, “Comparison of 

Transparent Back Contacts for CdTe Top Cells 

in Tandem Thin-Film Photovoltaic Devices,” 

Proc. 34th IEEE Photovoltaics Specialists Conf. 

(2009a). 
 

 

 

 

 

 

 

 

 

D 

 

R A F T

J.N. Duenow, R.G. Dhere, J. Li, W.K. Metzger, A. 

Duda, and T.A. Gessert, “Development of ZnTe 

Contacts for Cd1-xMgxTe Thin-Film Solar Cells 

for Tandem Applications,” MRS Symp. Proc. 

1165 (2009b). 

T.A. Gessert, W.K. Metzger, P. Dippo, S.E. Asher, 

R.G. Dhere, and M.R. Young, “Dependence of 

Carrier Lifetime on Cu-Contacting Temperature 

and ZnTe:Cu Thickness in CdS/CdTe Thin Film 

Solar Cells,” Thin Solid Films 517, 2370–2373 

(2009a). 

T.A. Gessert, Y. Yoshida, C. Fesenmaier, and T.J. 

Coutts, “High Transparency Sputtered In2O3 and 

ITO Films Containing Zirconium,” J. Appl. 

Physics, 105 pp. 083547.1-6 (2009b). 

T.A. Gessert, Y. Yoshida, C.C. Fesenmaier, and 

T.J. Coutts, “TCO Films with Permittivity 

Control,” MRS Symp. Proc. 1165, (2009c). 

Selected as one of the most influential papers 

presented at the symposium. 

X. Li, J. Pankow, and Y. Yan, “Impurity Study of 

Optical Properties in Fluorine-Doped Tin Oxide 

for Thin-Film Solar Cells,” MRS Symp. Proc. 

1165, (2009). 

T.J. Peshek, Z.Z. Tang, L. Zhang, R.K. Singh, B. 

To, N. Newman, T.A. Gessert, T.J. Coutts, and 

M. van Schilfgaarde, “Suitability of ZnGeAs Thin 

2 

Films for Photovoltaics,” Proc. 34th IEEE 

Photovoltaics Specialists Conf. (2009). 

C. Wyse, R. Torres, T. Barnes, M. Scott, M. 

Young, and X. Li, “Sulfur Hexafluoride (SF6) as a 

Dopant Precursor for Production of Fluorine 

Doped Tin Oxide Films by MOCVD,” Proc. 34th 

IEEE Photovoltaics Specialists Conf. (2009). 

. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of 

Research Activity 

FY 2009 

($K) 

Cost 

Share ($K) 

Primestar Solar 

Fred Seymore 

Wheatridge, CO 

fred.seymour@primestarsolar.com 

Broad assistance with startup company, CdTe devices to 

module reliability 

100* 

869** 

969*** 

5* 

20*** 

Eikos 

Paul Glatkowski 

Lexington, MA 

pglatkowski@eikos.com Development of materials and 

devices for carbon nanotubes 

50* 

410** 

560*** 

0 

Phase A Industry 

Development 

(Redlen) 

Glenn Bindy 

Canada 

Glenn.bindy@redlen.com 

Competitive solicitation for 

“Research on Low-Cost, 

High- Efficiency Organic Solar 

Cells” 

0 50* 

Phase A Industry 

Development (TCO) TBD Testing of new CdTe source materials in actual devices 0 150* 200** 

Matheson Tri Gas 

Rob Torres 

Longmont, CO 

RTorres@Matheson-Trigas.com 

Development of CVD 

precursors for advanced TCO 

materials 

75* 

75** 

90*** 

5 

Solexant 

Craig Liedholm 

San Jose, CA 

Craig.liedholm@solexant.com 

Development of superstrate 

CdTe PV devices for 

alternative Substrates. 

50* 

100** 

50* 

100*** 

St. Gobain 

Frank Gromball 

Herzogenrath, Germany 

Frank.Gromball@satinGobain.com 

Development of CdTe 

devices on St. Gobain 

glass/TCO materials 

110* 

110** 

229*** 

0 

EPIR 

Chris Grien 

Bolingbrook, IL 

grein@epir.com 

Fundamental research on 

new semiconductor materials 

150† 

1,150†*** 

20* 

150*** 

Corning 

Mark Taylor 

Sullivan Park, NY 

TaylorMP@Corning.com 

Development of high 

temperature CdTe devices 

and TCOs 

250† 20† 

Abound Solar 

Kurt Barth 

Fort Collins, CO 

Kbarth@abound.com 

Lectures at Abound and 

discussions of Abound 

process 

100† 0† 

* Approximate amount spent in 2009 ; ** approximate total amount spent to date; ***total amount of activity planned, 

† award pending. 
 

____________________________________________________________________________________ 

____________________________________________________________________________________ 

 

 

 

Concentrating Photovoltaics 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Dan Friedman (NREL), 303-384-6472, daniel.friedman@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budgets: $1,860K (NREL) 

Objectives 

•	 Evaluate use of back surface reflector (BSR) in inverted metamorphic (IMM) triple-junction cells, 

targeting higher efficiency and decreased cell thickness, which translates to lower cost 

•	 Identify environmental contributors to AlInP window-layer degradation 

•	 Initiate a study of the stability of lattice-mismatched solar cells 

•	 Strengthen scientific underpinnings of effects of growth conditions on mismatch epitaxy 

•	 Test and validate advanced tool for the simulation of multijunction cells. 

Accomplishments 

•	 Demonstrated VOC gain in 1 eV metamorphic junctions thinned for BSR implementation 

•	 Quantified advantages of sub-gap infrared rejection to heat load caused by BSR 

•	 Demonstrated that AlInP degradation is enhanced by the photoelectrochemical effect 

•	 Developed high-power laser-based degradation capability to study cell stability 

•	 Demonstrated a low defect density GaAsP virtual substrate for growth of high bandgap GaInP, 

used for both solar cells and ordering studies 

•	 Compared graded layers in both compression and tension and both continuous and step-graded 

structures 

•	 Expanded our full three-dimensional circuit model of a multijunction solar cell to enable batch 

processing and better visualization of the input and output 

•	 Applied our 2D simulation model successfully to the operation of a GaInP/GaAs dual junction 

solar cell with nonuniform irradiance. 

Future Directions 

•	 Compare degradation in InGaAs cells with different amounts of strain and defect density 

•	 Extend study of graded structures to different materials and structures 

•	 Develop the capability to simulate nonisothermal effects in multijunction III-V solar cells 

•	 Add functionality to the SPICE model: variable temperature, perimeter recombination, and 

possibly a nonlinear tunnel junction resistance; extend application to U.S. Department of Energy 

and cooperative research and development agreement (CRADA) tasks. 

1. Introduction	 developments are in strong demand by CRADA 

partners and the CPV industry. 

The Concentrating Photovoltaics (CPV) group will 

further the high-efficiency multijunction cell 2. Technical Approach 

technology, with a continued emphasis on the 

inverted lattice-mismatched (LMM) approach The project approach included tasks oriented at 

introduced by NREL in 2005. This approach has cell development; reliability; studies of 

proven very fruitful and provides a number of semiconductor materials for cell applications; and 

promising paths for future developments in advanced cell modeling for application in realefficiency, heat management, and cost, giving a world systems. 

clear path to significantly improved levelized cost 

of energy (LCOE) for CPV systems. These 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Results and Accomplishments 

3.1 Task 1: Three-Junction IMM Cell Development 

In FY 2009, we explored practical issues and 

advantages of the triple-junction IMM solar cell 

design. Previously, we had demonstrated higher 

room temperature efficiencies of triple-junction 

designs with two metamorphic junctions (40.8%, a 

world record at the time) than the original design 

with one metamorphic junction, but device 

modeling indicates that the advantages of this 

more complicated device are much diminished at 

the higher temperature most likely typical in real 

life operation. We therefore focused on the original 

IMM structure with lattice matched GaInP and 

GaAs top junctions and a single metamorphic 1­

eV InGaAs junction. We developed an improved 

understanding of doping in the tunnel junction and 

contact layers, allowing us to routinely achieve 

peak efficiencies around 300 suns with limiting 

series resistance from the top sheet resistance 

rather than the tunnel junction. We furthermore 

developed improved process control that allows us 

to reproducibly achieve 106 defects/cm2 in 

metamorphic 1-eV InGaAs. 

D R A F T

Because of the extremely thin nature of the IMM 

solar cell, it is well suited to selectively absorbing 

only the light that is needed for producing electric 

energy while rejecting much of the infrared (IR) 

light that contributes only to heating. The IR light in 

the direct solar spectrum below 1.0 eV makes up 

almost 16% of the total power flux, most of which 

can be rejected from the IMM by a BSR to reduce 

the heat load. A simple gold BSR reflects at least 

80% of this power from the cell. We also 

demonstrated an Al2O3/Al BSR that has the 

Fig. 1. Dependence of VOC and JSC on junction 

thickness, compared for different BSRs. 

potential to reduce the amount of the IR power 

absorbed within the device by a factor of two 

compared to the simple gold BSR, at a cost of 

some increased complexity of the processing and 

resistive losses at the back grid. By comparing 

IMM bottom junctions with a BSR to IR transparent 

devices, we showed that the BSR allows the 

bottom junction to be thinned somewhat without a 

large current loss. The VOC does increase slightly 

as shown in Figure 1, but only at small 

thicknesses (about 0.5 μm) incur too much current 

loss for current matching. These results indicate 

good interface recombination velocities with 

(SbLb/Db) ~ 1 or less, where Sb is the base surface 

recombination velocity and Db/Lb is the bulk 

recombination velocity of minority carriers. Given 

the current quality of the metamorphic InGaAs 

junction and its interfaces, we therefore find that 

thinning cannot be used to increase the Voc. 

These findings fulfill a major FY 2009 milestone. 

3.2 Task 3: Cell Reliability 

In FY 2009 we completed our experiment on the 

oxidation of AlInP window layers and began 

experiments to probe the degradation of latticemismatched concentrator cells. Testing the 

hypothesis that the oxidation of AlInP is enhanced 

by the photoelectrochemical effect, we 

investigated the degradation of the AlInP layers 

with varying levels of n-type and p-type doping 

under different conditions of temperature, 

humidity, and light exposure. The data suggest 

that n-type window layers are more susceptible to 

oxidation than p-type layers. Without the inclusion 

of ultraviolet (UV) light, the oxidation proceeds at a 

slower rate equivalent to established damp heat 

oxidation rates for AlInP, which may indicate the 

need for UV filtering in field-deployed concentrator 

cells. We mentored an ACTS summer intern who 

was trained to use the weatherometer and 

assisted with data collection. A publication is 

under preparation. 

In accordance with our FY 2009 milestone, we 

began investigating degradation in LMM InGaAs 

solar cells by evaluating changes in performance 

after operation under high forward-bias currents. 

Preliminary experiments showed very slight 

decreases in Voc, Jsc, and shunt resistance with 

accumulating bias time. To better probe the 

degradation of these cells operating at high 

currents, we developed a high power laser-based 

degradation system, which will be used to both 

degrade the cell and monitor the electrical 

characteristics of the cell during degradation. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.3 Task 4: Science of Dislocations 

The study of LMM epilayers and graded layers in 

both compression and tension was continued. In 

accordance with our milestones; our work this year 

has led to a publication and multiple submitted 

manuscripts. We completed installation of an in 

situ wafer curvature sensor on our molecular 

beam epitaxy growth system and developed its 

usage for 2D analysis. We used this technique to 

measure the anisotropy between the strain 

relaxation in different crystal directions of InGaAs 

epilayers. Varying the growth condition changes 

various relaxation properties, including the onset 

of relaxation, the initial direction of relaxation, the 

rate of relaxation, and the final strain state after 2 

μm of epilayer growth. Thus, control over these 

aspects of relaxation is demonstrated; a 

manuscript on this work is under review. 

Relaxation of GaAsBi epilayers was also studied 

using the wafer curvature technique. In 

comparison with InGaAs, the relaxation of GaAsBi 

occurs at a slower rate and is less complete. 

D R A F T

We studied graded layers of GaAsP in tension by 

varying the grading rate, stress profile, mismatch 

per step, and total number of steps. Optimization 

of these properties achieved growth of low-defectdensity, high bandgap GaInP. We varied the alloy 

ordering in this material using Sb surfactant and 

published this work in the Journal of Applied 

Physics. Additionally, a high bandgap GaInP cell 

using these grades was grown and characterized. 

A manuscript on this work is under review. We 

studied continuously graded and step-graded 

layers in compression. Almost no difference in the 

in situ relaxation behavior and dislocation density 

was observed between step grades and 

Fig. 2. Total current flowlines for a dual junction 

cell illuminated with a beam of light centered on 

the top contact. Local irradiance is 3000 suns; 

average irradiance is 600 suns. Peak tunneling 

current for this device is about 800 suns. 

continuously varied grades with the same total 

thickness and average grade rate. 

3.4 Task 6: Advanced Cell Modeling 

SPICE circuit analysis: We expanded our full 

three-dimensional circuit model of a multijunction 

solar cell to enable batch processing and better 

visualization of the input and output. The limits of 

performance were also tested and expanded to 

264 (x) by 24 (y) nodes for a three-junction cell (z 

direction). We performed a study of the effect of 

chromatic aberration and nonuniform irradiance on 

a GaInP/GaAs/Ge triple-junction cell for one of our 

CRADA partners. 

As a benchmark for this work, a calculation 

demonstrated that our three-dimensional results 

(Fig. 1) are consistent with a prior one-dimensional 

study. This figure quantifies how the sheet 

resistance of a lateral current-spreading layer 

between the top and bottom subcells affects the 

performance of a GaInP/GaAs tandem cell under 

chromatic aberration. If the typical sheet 

resistance value of 200–1000 ohm/square could 

be reduced significantly, chromatic aberration from 

lower-quality (less-expensive) optics could be 

mediated. This sort of three-dimensional modeling 

helps quantify the performance compromises 

inherent to a CPV module. 

Simulation of III-V multijunction solar cells: During 

the validation work, we found that although both 

the Silvaco and the Crosslight codes could 

simulate well the performance of single-junction 

GaInP and GaAs solar cells and stand-alone 

tunnel junctions, only Crosslight could adequately 

handle a GaInP/GaAs dual-junction solar cell with 

tunnel junction interconnect (TJIC). As a result, we 

ended the work on the Silvaco code. 

We successfully simulated the two-dimensional 

operation of a dual-junction GaInP/GaAs (with 

TJIC) under uniform and nonuniform highirradiance conditions. For uniform irradiance, we 

demonstrated the expected gradual (then abrupt) 

roll-off of fill factor (FF) and efficiency as the 

photocurrent Jsc approaches (then exceeds) the 

peak tunneling current Jpeak of the GaAs tunnel 

junction interconnect. For Jsc > Jpeak, the 

simulated IV of the tandem device reflects the IV 

curve of the embedded tunnel junction. For 

nonuniform irradiance, we can now simulate 

current spreading in the vicinity of the tunnel 

junction as shown in Figure 2, as well as the 

accelerated fall-off of efficiency and FF with 

average irradiance, relative to the case of uniform 

irradiance. 
 

 

 

 

 

 

 

 

 

D R A F T

3.5 Milestones Achieved 

•	 Evaluate use of BSR in IMM triple-junction 

cells (level 3; achieved 09/09). 

•	 Improve understanding of growth effects on 

LMM cell growth (level 4, achieved 09/09). 

4. Planned FY 2010 Activities 

5. FY 2009 Special Recognitions and Awards 

2009 Federal Laboratory Consortium Award for 

Excellence in Technology Transfer, for the 

development and transfer of the inverted 

metamorphic multijunction solar cell. 

•	 Design 3J IMM cell for high-temperature 

operation, and initiate temperature-dependent 

measurement (09/10). 

•	 Develop diffusion barriers for enhanced 

tunnel-junction manufacturability (09/10). 

•	 Measurement of degradation-induced change 

in cell parameters as a function of misfit / 

defect density (09/10). 

•	 Use in-situ characterization techniques to 

characterize strain relaxation mechanisms as 

a function of III-V materials compositions 

(09/10). 

•	 Extend numerical modeling to include nonuniform illumination and non-uniform heating 

of multijunction solar cells (09/10). 

6. Major FY 2009 Publications 

M.A. Steiner, L. Bhusal, J.F. Geisz, A.G. Norman, 

M.J. Romero, W.J. Olavarria, Y. Zhang, and A. 

Mascarenhas, “CuPt Ordering in High Bandgap 

GaxIn1-xP Alloys on Relaxed GaAsP Step 

Grades,” J. Appl. Phys. 106, 063525 (2009). 

J.F. Geisz and D.J. Friedman, “Engineering the 

World's Most Efficient Solar Cells,” SPIE 

Newsroom 1645 (2009). doi: 

10.1117/2.1200906. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 2009 

($K) 

Cost Share 

($K) 

RF Micro Devices Greensboro, 

NCrfmd.com 

IMM technology transfer / highvolume, low-cost production 

* Funds-in 

Dupont-DARPA Wilmington, DE 

James.McCambridge@ 

usa.dupont.com 

DARPA VHESC-Very High 

Efficiency Solar Cell Program 

* 

Funds-in 

Several additional 

industry partners 

Varied IMM technology transfer and CPV 

development 

* Funds-in 

*TOTAL: >$2.5M 
 

 

____________________________________________________________________________________ 

____________________________________________________________________________________ 

Organic Photovoltaics 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contacts: Dave Ginley (NREL, Primary Contact), 303-384-6573, 

david.ginley@nrel.gov 

Dana Olson (NREL), 303-384-6575, dana.olson@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,751K (NREL) 

Objectives 

•	 Develop state-of-the-art active layer materials using modeling and synthesis to improve
 

absorption and open circuit voltage, thus improving conversion efficiency and lifetime.
 

•	 Develop contact materials with tailored properties for carrier selectivity and low contact resistance 

for a variety of active layer materials to optimize device performance. 

•	 Investigate degradation mechanisms in organic photovoltaic devices and develop materials as 

well as device architectures that improve device lifetime. 

•	 Demonstrate scalable processes to organic solar cell fabrication. 

Accomplishments 

•	 Demonstrated 5% conversion efficiency for organic solar cell on 1-cm2 device area. 

•	 Completed initial degradation and lifetime studies on organic solar cells using the NRELdeveloped combinatorial degradation system.
 

•	 Demonstrated greatly enhanced device lifetime in inverted devices versus traditional devices that 

use low work function metal cathodes. 

•	 Demonstrated the active layer is very stable if proper encapsulation is employed. 

•	 Enhanced the electric field and charge extraction at the anode interface in hybrid solar cells 

through gradient doping of the ZnO electron transport layer material with Ga or Li. 

•	 Assembled a materials design and synthesis team that proposed new materials with enhanced 

absorption and band alignment for enhanced conversion efficiency. 

•	 Developed solution-deposited multilayer inorganic barrier films with barrier properties >1 order of 

magnitude better than current industrial food packaging barriers. 

•	 Maintained Cooperative Research and Development Agreements (CRADA) interactions with 

Konarka, Plextronics, and TDA Research; started CRADA work with Luna Innovations; and 

initiated CRADA interactions with Solarmer, Nano-C, and ConocoPhillips. Collaborating with 

ECN, Stanford, and University of Queensland. 

•	 Published more than 20 papers, gave more than 30 invited talks, and helped organize 

international conferences based on these efforts.
 

Future Directions 

•	 Design and synthesize new absorber materials to improve light absorption and band offset in 

organic photovoltaic (OPV) devices. 

•	 Continue to develop new contact layers for optimized charge extraction from new donor/acceptor 

materials systems as well as continued improvement in device lifetime. 

•	 Explore further degradation mechanisms in OPV devices, including studies on the contribution of 

contacts and active layer lifetime. 

•	 Develop next-generation encapsulation with processes scalable to roll-to-roll processing. 

1. Introduction	 The OPV effort develops new materials and 

device architectures needed to improve 

conversion efficiency and lifetime in organic solar 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

cells. It supports the industry directly through 

CRADA interactions and through research on new 

active layer and contact materials. Our OPV 

program has gained national and international 

attention because of our integrated approach to 

new acceptor and donor development coupled 

with our developments in new process technology, 

new characterization tools specific to OPV, and 

initial results to improve the lifetime (intrinsic and 

extrinsic) of OPV devices. 

D R A F T

2. Technical Approach 

•	 Develop next-generation OPV devices and 

investigate scalability and lifetime. 

•	 Design and synthesize new donor/acceptor 

systems to improve performance and lifetime. 

•	 Develop a program to understand and 

optimize hybrid interfaces in OPV devices. 

•	 Improve contacts by collaborating with the 

TCO program to develop OPV devices using 

non-ITO TCOs. 

•	 Support our CRADAs with Konarka, 

Plextronics, TDA, Luna Innovations. 

3. Results and Accomplishments 

We continued to develop the infrastructure and 

assembled a team with the skills and tools to 

design and synthesize high performance 

donor/acceptor materials. This effort is producing 

materials by design, which allows a downselection of target systems prior to synthesis. New 

IP has already resulted from this approach. This 

allows for a focused and efficient program for new 

organic materials development. 

Previous work focused on developing the phenylcored thiophene-based dendrimers as electron 

donors in OPV devices. They often have the 

lowest unoccupied molecular orbital (LUMO) 

localized on the core, which likely hinders photoinduced electron transfer to the fullerene acceptor 

and in turn the performance in BHJ devices. As 

such, we designed several new materials that tune 

the bandgap and band offset to fullerene 

acceptors used in OPV devices. One donor 

system is based on triphenylamine, known for 

excellent hole-transport properties. It employs a 

benzothiadiazole moiety shown to decrease the 

LUMO, thereby reducing the bandgap of the 

material as well as the energy lost in the electron 

transfer process from donor to acceptor. This 

results in increased absorption without loss in VOC 

and the LUMO localized on the arms to facilitate 

electron transfer (Fig. 1). 

Fig. 1. DFT-calculated HOMO (top) and LUMO 

(bottom) orbitals of 1-arm molecule. The remaining 

arms show degenerate states equal in energy and 

electron density. 

The calculations allow us to reasonably predict the 

material properties before the time- and resourceintensive synthesis process. These methods are 

being used to develop conjugated polymer donor 

systems as well based on novel chromophores 

that allow for tailoring the band structure of the 

donor material. Predicted values indicate that 

these materials are capable of very high 

absorption coefficients, bandgaps near 1.4 eV, 

and VOC greater than 0.8 V. Such systems are 

being prepared, and productivity in materials 

preparation will accelerate soon with the 

completion of the new synthesis lab for OPV 

materials scheduled to be open in a few weeks 

time. This capability coupled to our ability to make 

new materials is unique and can serve the solar 

community. 

Fig. 2. J-V curves for inverted OPV devices with 

different dopants incorporated into the ZnO 

electron transport layer. 

Work in developing new contact materials for OPV 

devices continued on ZnO-based inverted device 

architectures because of their potential for 

improved stability. We developed a lowtemperature solution deposition method that 

results in very high quality ZnO films after 

processing at only 100  ̊C. This allows for 

processing on flexible substrates and eliminates 

any dependence of device performance on the 

underlying TCO material (Fig. 2). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We demonstrated that doping gradients in the ZnO 

electron contact enhance the field at the front 

interface with the active layer. Gradients in carrier 

concentrations were achieved using both gallium 

and lithium doping. This results in enhanced diode 

quality, fill factor, and efficiency in inverted OPV 

D R A F T

devices (Fig. 3). 

Fig. 3. J-V curves for inverted ITO/doped 

ZnO/P3HT:PCBM/Ag devices with different 

dopants incorporated into the ZnO layer. 

As we had determined, electrode materials 

selection is critical for determining the lifetime of 

OPV devices. We showed that inverted device 

architectures dramatically improve the shelf life of 

devices in the dark in air without encapsulation. 

The completed combinatorial degradation system 

allows us to evaluate 360 devices concurrently. 

We used this system to evaluate the performance 

of unencapsulated inverted devices under 

continuous illumination. In Figure 4 we show the 

current density (JSC) versus illumination time. The 

VOC and fill factor remain constant during this time, 

and therefore the efficiency mirrors the JSC. We 

also demonstrate that the lifetime can be 

dramatically improved by increasing the Ag metal 

electrode thickness. When the electrode thickness 

is increased, T80 is not yet reached after 1500 

hours of light soaking in air for unencapsulated 

inverted devices. 

Fig. 4. Current density vs. time curves for four 

inverted OPV devices with 100-nm Ag anode 

thickness (left), and with 100-nm Ag + 100-nm Al 

electrode (right). 

Although we made progress on understanding and 

reducing OPV device degradation, the intrinsic 

stability of the active layer upon illumination will 

determine the ultimate stability limit. We used 

characterization methods specific for OPV to 

evaluate the intrinsic stability of the active layer 

under 1 sun intensity for 1000 hours without 

contacts or electrodes in both inert atmosphere 

(N2-filled glove box) and ambient conditions. 

Under inert atmosphere, we observed no photoinduced degradation after 1000 hours of 

illumination. In contrast, some devices did degrade 

under inert atmosphere, indicating that it can be 

largely attributed to other components of the 

device, such as interfaces with electrical contacts. 

Fig. 5. (A) The product of the yield for free carrier 

generation times the mobility of free carriers 

(extracted from the photoconductivity data) vs. 

degradation time in air, for a P3HT:PCBM blend 

under illumination (red squares) and a control 

sample that was kept in the dark (black squares). 

Same results shown for a pure P3HT film in air 

and in the dark. (B) Absorbance of the films from A 

at 500 nm. 

Under ambient conditions, strong bleaching or 

pure P3HT was observed under illumination. The 

presence of PCBM in the bulk heterojunction, 

however, stabilized the polymer and strongly 

mitigated the bleaching (Fig. 5B). The 

photoconductivity of the blend decreased by 

almost two orders of magnitude, despite the 

apparent stability of the polymer (Fig. 5A). The 

results in Figure 5 indicate that a photo-induced 

structural change of PCBM may be present that 

has an adverse effect on the mobility of electrons 

in the blend. We performed TOF-MALDI 

experiments to probe the species present in a 

degraded P3HT:PCBM film. This leads to new 

efforts to develop new acceptors. 

This is the first complete study that effectively 

combines contactless photoconductivity, structural 

characterization, and theory to identify the 

dominant mechanisms for degradation in organic 

bulk heterojunctions. A manuscript has been 

submitted to Nature Materials; it is the first in a 

series of studies to identify general mechanisms of 

degradation and to design mitigation schemes. 

The methods developed here can also serve as a 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

screening tool for candidate materials from our 

CRADA partners. 

We accomplished these milestones: 

•	 Achieved 5.0% OPV device with 1-cm2 device 

area (Fig. 6; 9/09). 

•	 Dramatically enhanced device lifetime and 

understanding of degradation mechanisms in 

OPV devices (8/09). 

•	 Established and employed models with 

synthesis for developing new donor/acceptor 

systems. 

These accomplishments have the potential for 

tremendous impact on enhancing OPV device 

performance and lifetime. 

Fig. 6. Current density–voltage curves for 5% 

OPV devices with 1 cm2 device area. 

4. Planned FY 2010 Activities 

•	 Develop state-of-the-art active layer materials 

to improve absorption properties, enhance 

open circuit voltage, and thus improve 

conversion efficiency (09/10). 

•	 Develop contact materials with tailored 

properties for carrier selectivity and low 

contact resistance to a variety of active layer 

materials to optimize device performance 

(09/10). 

•	 Investigate degradation mechanisms at play in 

organic solar cells and develop materials as 

well as device architectures that improve 

device lifetime (09/10). 

5. FY 2009 Special Recognitions and Awards 

David Ginley will serve as president of the MRS in 

2010. 

David Ginley is editor of a Springer book on TCOs 

to be published this year. Dana Olson is a 

chapter author. 

David Ginley was organizer for MRS symposia on 

combinatorial materials. 

Dana Olson was co-chair of Organic Photovoltaics 

2009, held in Philadelphia. 

Dana Olson was chair of Organic Photovoltaics 

Summit 2009, held in Boston. 

David Ginley is a co-chair of the 3rd Intl. Summit 

on OPV Stability. 

More than 15 invited talks on OPV in 2009. 

6. Major FY 2009 Publications 

Lloyd et al., “Impact of Contact Evolution on the 

Shelf Life of Organic Solar Cells,” J. Mater. 

Chem. 19, 7638 (2009). 

Lloyd et al., “Improved Efficiency in Poly(3-

hexylthiophene)/Zinc Oxide Solar Cells via 

Lithium Incorporation,” J. Phys. Chem. C 113, 

17608 (2009). 

Reese et al., “Photoinduced Degradation of P3HT 

and P3HT:PCBM Active Layers for Organic 

Photovoltaic Devices,” submitted to Nature 

Materials. 

White, M.S. et al., Control of Charge Separation 

by Electric Field Manipulation in Polymer-Oxide 

Hybrid Organic Photovoltaic Bilayer Devices, 

Physica Status Solidi A (2009). 

doi:10.1002/pssa.200925591. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 

2009 

($K) 

Cost 

Share 

($K) 

Konarka Technologies 

Russel Gaudiana 

Lowell, MA 

rgaudiana@konarka.com 

Development of solution deposited 

inorganic multilayer barriers for roll-toroll processing 400 100 

Plextronics 

Darin Laird 

Pittsburgh, PA 

dlaird@plextronics.com 

Research on contacts, TCOs, and 

lifetime of OPV devices 150 150 

TDA Research 

Michael Diener 

Wheat Ridge, CO 

mikee@tda.com 

Development of new fullerene acceptors 

for OPV devices 105 42 

Luna Innovations 

Steven Joslin 

Danville, VA 

joslins@lunainnovations.com 

Research on carbon nanosheets as 

electrodes in OPV devices 150 
 

 

 

 

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Sensitized Solar Cells 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Arthur Frank (NREL), 303-384-6262, Arthur.Frank@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $694 K (NREL) 

Objectives 

•	 Develop next-generation sensitizers, architectures, and charge-conducting phases for improved 

device stability and performance. 

•	 Identify promising cell materials and configurations for highest device durability and efficiency. 

•	 Develop assembly procedures and cell-sealing techniques to increase device stability. 

•	 Obtain detailed understanding of fundamental processes that affect device stability and 

performance in collaboration with DOE/OS/BES.
 

Accomplishments 

•	 Demonstrated 5.8% efficient device with <10% power loss over 1000 hours under light soaking. 

•	 Developed a process for forming inorganic p-type semiconductors in n-type nanotube (NT) 

arrays. 

•	 Developed a general synthetic approach for preparing transparent TiO2 NT films on transparent 

conducting oxide (TCO). 

•	 Established a characterization tool set to study degradation of devices under light soaking. 

•	 Demonstrated use of atomic layer deposition (ALD) for preparing an inorganic semiconductor 

sensitized solar cell (SSC). 

Future Directions 

•	 Demonstrate devices with improved efficiency and durability under continuous light soaking. 

•	 Develop nonvolatile charge-conducting phases for solid-state devices. 

•	 Demonstrate performance of devices with newly developed charge-conducting phases and film 

architectures. 

•	 Investigate principal fundamental parameters governing device stability and efficiency. 

1. Introduction 

This agreement applies to SSCs, covering both 

liquid/solid and solid/solid electron- and holeconducting materials. Both dyes and inorganic 

semiconductor nanostructures are used as lightabsorbing materials. Our primary objectives are to 

evaluate cell stability at different performance 

levels, to identify the causes of efficiency loss, and 

to develop more effective cell materials and 

configurations for improved device durability and 

efficiency. 

2. Technical Approach 

This project focused on designing and developing 

photoelectrode architectures, solid/liquid chargeconducting phases, and assembly/sealing 

techniques for enhancing device stability and 

performance. A significant fraction of the research 

effort was aimed at developing photoelectrodes 

with oriented nanostructured architectures (e.g., 

NT arrays) having enhanced charge-collection and 

light-harvesting capabilities compared with 

conventional nanostructured architectures. 

Another aspect of this work was to increase cell 

stability by developing more robust and effective 

charge-conducting phases. 

3. Results and Accomplishments 

•	 Demonstrated 5.8% efficient device with 

<10% power loss over 1000 hours under light 

soaking (09/09). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We made major upgrades to our diagnostic setup 

to improve the reliability of long-term 

measurements of cell stability and performance. 

Using a low volatile ionic electrolyte, we 

demonstrated a 5.8% efficient device with less 

than 10% degradation (power loss) over 1,000 

hours under simulated AM 1.5 light soaking (Fig. 

D R A F T

1). 

Fig. 1. Stability test of TiO2 nanoparticle (NP)-

based dye-sensitized solar cells (DSSCs). 

•	 Developed a process for forming inorganic ptype conducting phase in n-type NT arrays 

(11/08). 

We constructed an ordered sensitized 

heterojunction using a novel, low-cost bottom-up 

electrochemical synthesis approach. p-CuInSe2 

was grown within the nanopores (pore diameters < 

100 nm) of electrically conducting n-type TiO2 NT 

and NP films. Such solid-state film architectures 

could potentially extend operating temperatures 

and increase the stability and efficiency of SSCs. 

•	 Developed a general synthetic approach for 

preparing transparent TiO2 NT films on TCO 

(09/09). 

High solar conversion efficiency in oriented TiO2 

NT-based DSSCs requires that the incident light 

enters the cell from transparent electron-collecting 

substrates. There are technological challenges 

with current methods for depositing NT films on 

TCO. We discovered that adding a special thin 

layer between Ti metal and TCO enables 

reproducible fabrication of transparent NT films on 

TCO. This approach is applicable to preparing 

other metal oxide electrodes on TCO. 

•	 Developed characterization tool set to study 

degradation effects of devices under light 

soaking (09/09). 

We developed a characterization tool set to study 

the energy losses owing to electron dynamics. The 

initial studies based on time- and frequencyresolved electro-optical techniques showed that 

the charge-collection efficiency exhibits a simple 

but nontrivial correlation with light soaking. Such 

studies will provide important insight into the 

effects of long-term light soaking on the 

degradation of SSCs. 

•	 Demonstrated the use of ALD for preparing 

inorganic semiconductor SSCs (08/09). 

We developed (with Steven George at CU 

Boulder) an ALD route for fabricating inorganic 

semiconductor SSCs. This approach is applicable 

to a variety of semiconducting materials. 

4. Planned FY 2010 Activities 

•	 Develop 6.5% efficient device with <10% 

power loss over 1,000 hours under continuous 

light soaking. 

•	 Develop nonvolatile, charge-conducting 

phases for solid-state devices. 

•	 Demonstrate performance of devices with 

newly developed charge-conducting phases 

and film architectures. 

•	 Investigate principal fundamental parameters 

governing device stability and efficiency. 

5. FY 2009 Special Recognitions and Patents 

K. Zhu, et al. Nano Lett. 2007, 7, 69 on NT based 

DSSCs has become the eighth most cited paper 

in chemistry from 2007 <http://sciencewatch.com/ana/hot/che/09mayjun-che/>. 

Provisional patent (Frank, Neale, Zhu) “Nanowire 

Sensitized Solar Cells,” filed 2008. 

6. Major FY 2009 Publications and 

Presentations 

A.J. Frank, “Science, Technology and the Future 

of Sensitized Solar Cells,” Beijing National 

Laboratory for Condensed Matter Physics, 

Institute of Physics, Beijing, P.R. China, January 

7, 2009. 

A.J. Frank, “Recent Advances in Sensitized Solar 

Cells,” WOLEDs and Organic Photovoltaics 

Workshop, University of Hong Kong, January 8– 

11, 2009. 

Q. Wang, K. Zhu, N.R. Neale, and A.J. Frank, 

“Constructing Ordered Sensitized 

Heterojunctions: Bottom-Up Electrochemical 

Synthesis of p-Type Semiconductors in Oriented 

n-TiO2 Nanotube Arrays.” Nano Lett. 9, 806 

(2009). 
 

_________________________________________________________________________________ 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

Cross-Cutting Transparent Conducting Oxides 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contacts: Dave Ginley (NREL, Primary Contact), 303-384-6573, 

dave.ginley@nrel.gov 

John Perkins (NREL), 303-384-6606, john.perkins@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $618K (NREL) 

Objectives 

•	 Develop new transparent conducting oxides (TCOs) for improved PV performance 

•	 Use and improve combinatorial methods to accelerate materials advances for TCOs 

•	 Develop solution-based processes and precursors to enable functional TCOs synthesized at 

atmospheric pressure. 

Accomplishments 

•	 Increased conductivity of amorphous In-Zn-O (a-IZO 25% to 3,750 S/cm by mixed RF/DC 

sputtering; environmentally stable at 85°C, 85% relative humidity (RH) for >40 days; a-IZO 

finished copper indium gallium selenide (CIGS) solar cell with 16.4% efficiency; first 

demonstration of a-IZO finished silicon heterojunction cell 

•	 Provided new deposition systems on line (Process Development and Integration Laboratory 

[PDIL]) with in situ diagnostics resulting in large area uniform coating for IZO and ZnO to other 

photovoltaic (PV) groups at NREL and externally 

•	 Gave significant support to the organic photovoltaics (OPV) effort through materials and interlayer 

development 

•	 Improved conductivity of Ga-doped ZnO (GZO) to > 3,000 S/cm by sputtering; also improved JSC 

in OPV by 75%using GZO interfacial layer. 

•	 Used atmospheric pressure synthesis to produce smooth, dense a-IZO with conductivity >30S/cm 

•	 Developed sputtered SnO2:F with conductivity of 1,000 S/cm (subject of two records of invention). 

Future Directions 

•	 Increase conductivity of a-IZO to 4,000–5,000 S/cm 

•	 Optimize a-IZO TCO top contact for CIGS PV and Si heterojunction PV 

•	 Research high conductivity, sputtered, SnO2-based TCOs 

•	 Develop TCOs with functionally independent control of conductivity and work function 

•	 Transfer new TCO technologies to PV manufacturers. 

1. Introduction	 High-throughput discovery and optimization are 

coupled with very controlled single composition 

Nearly every solar technology uses TCOs. deposition to optimize TCO material properties. 

Because the needs are commensurate, an We used newly developed tools to incorporate 

integrated approach to TCO development with these TCOs into prototype PV devices, resulting in 

high-throughput methods is employed to rapidly fundamentally new materials science and 

develop materials for internal and external optimized materials for PV applications. 

partners, specifically with Si, a-Si, CIGS, and 

OPV.	 3. Results and Accomplishments 

2. Technical Approach	 Using combinatorial approaches, we determined 

that high conductivity transparent a-IZO can be 

made with indium content down to 60%, 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

significantly less than the industry standard of 

84%. 

D R A F 

(Fig. 1) is being optimized for and incorporated in 

Fig. 1. 

of maximum conductivity. 

Using our new mixed RF/DC sputtering capability

we improved conductivity of a

3,000 to 3,750 S/cm (world best). The TCO 

Absorption in a-IZO. Dashed line is contour 

-IZO by 25%, from 

a-IZO 

, T

CIGS PV applications. Also, we accomplished the 

first demonstration of an a-IZO finished Si 

heterojunction cell. In addition, we increased the 

conductivity of sputtered Ga-doped ZnO by a 

factor of 10 to 3,200 S/cm for OPV applications. 

We are now testing a-IZO TCOs as the top TCO in 

CIGS PV with the NREL CIGS team and Heliovolt 

because of the improved stability of this material. 

The TCO a-IZO is being optimized for CIGS and 

HIT cell PV, and GZO is being optimized for OPV; 

a-IZO has demonstrated optical and electrical 

stability in damp heat (85°C, 85% RH) for 40 days. 

4. Planned FY 2010 Activities 

•	 State-of-the-art TCO materials: Develop a-IZO 

with conductivity > 4,000 S/cm; Zn(Ga, Mg, Cu) 

for TCOs with independent bandgap, work 

function, and conductivity control; high 

conductivity sputtered SnO2. 

•	 TCOs for PV technologies: Optimize a-IZO for 

CIGS and Si heterojunction PV; Zn(Ga, Mg, 

Cu)O for OPV. 

•	 Scale up new TCO materials to large-area 

deposition (using PDIL): Atmospheric pressure 

synthesis of TCOs from liquid precursors. 

5. FY 2009 Special Recognitions and Patents 

Project staff are active in leading professional 

organization activities, conference symposia 

organization (5), invited talks (8), and book 

chapters (3). 

Completed TCO book now at Springer for 

publication. 

Three records of invention (one joint with Corning). 

6. Major FY 2009 Publications 

M.P. Taylor et al., “The Remarkable Thermal 

Stability of Amorphous In-Zn-O Transparent 

Conductors,” Adv. Funct. Mater. 18, 3169 

(2008). 

J.D. Perkins et al., “Conductivity and 

Transparency in Amorphous In-Zn-O 

Transparent Conductors,” M.F.A.M. van Hest, 

M.P. Taylor, and D.S. Ginley, Int. J. 

Nanotechnol., 6, 850 (2009). 

J.D. Perkins et al., “Transparent Conducting 

Oxides for Advanced Photovoltaic Applications,” 

Photovoltaics International, 3rd edition, First 

Quarter, 94 (2009). 

J.D. Perkins et al., “Optical Absorption and 

Electrical Conductivity in Amorphous In-Zn-O: A 

New TCO for CIGS PV,” Proc. 34th IEEE PVSC 

(2009). 

T. Gennett et al., “Humidity-Resistant HighConductivity Amorphous-InZnO Transparent 

Conductors,” Proc. 34th IEEE PVSC (2009). 

R.	 Sundaramoorthy et al., “Comparison of 

Amorphous InZnO and Polycrystalline ZnO:Al as 

a Conductive Layer for CIGS PV Solar Cells,” 

Proc. 34th IEEE PVSC (2009). 

R.	 Pasquarelli et al., “Solution Deposition of 

Amorphous IZO Films by Ultrasonic Spray 

Pyrolysis,” Proc. 34th IEEE PVSC (2009). 

7. University and Industry Partners 

Organization/PI Location/E-mail Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

University of Colorado 

Prof. Charles Rogers 

Boulder, CO 

Charles.Rogers@colorado.edu 

Properties of sputtered 

amorphous InZnO TCOs 80 0 

Colorado School of 

Mines 

Prof. Ryan O’Hayre 

Golden, CO 

rohayre@mines.edu 

Deposition of InZnO TCO from 

liquid precursors 40 0 

Heliovolt Austin, TX 

leldada@heliovolt.com 

Development of improved TCO 

for CIGS 75 25 

Plextronics Pittsburgh, PA 

DLaird@plextronics.com 50 30 
 

 

 

 

 

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Theory & Computational Science 

D R A F T

Performing Organization:	 National Renewable Energy Laboratory (NREL) 

Key Technical Contacts:	 Bill Tumas (NREL, Primary Contact), 303-384-7955, bill.tumas@nrel.gov 

Suhuai Wei (NREL), 303-384-6666, suhuai.wei@nrel.gov 

Alex Zunger (NREL), 303-384-6672, alex.zunger@nrel.gov 

Angelo Mascarenhas (NREL), 303-384-6608, 

angelo.mascarenhas@nrel.gov 

Wesley Jones (NREL), 303-275-4070, wesley.jones@nrel.gov 

DOE HQ Technology Manager:	 Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget:	 $915K (NREL) 

Objectives 

•	 Enhance and accelerate advances in photovoltaic (PV) technology; perform fundamental 

research to establish the basic knowledge infrastructure of PV materials using state-of-the-art 

computational tools; explain experimental results, give guidance for future experimental 

investigation, and predict properties of novel materials that are potential candidates for future PV 

applications 

•	 Accelerate the pace of PV materials and device understanding and development using data 

management systems, advanced data analyses with data mining, and statistical optimization 

approaches to guide experiments. 

Accomplishments 

•	 Systematically searched possible quaternary chalcogenides for potential PV absorber; gave 

theoretical insights about suitability of these materials for PV applications 

•	 Explained why IZO has good optical and transport properties even in the amorphous phase 

•	 Proposed new quantum dots for potential hybrid organic-inorganic solar cell applications 

•	 Produced physical insights on growing covalent Si on ionic oxides with clean interfaces 

•	 Gave insight about the suitability of (Mg, Zn, Cd)Te alloys for tandem solar cell applications 

•	 Proposed new approaches to overcome doping difficulty in wide gap semiconductors 

•	 Advanced theory and models for solar energy materials, both foundational and applied, leading to 

new capabilities for accurate prediction of PV materials properties and to results directly relevant 

in materials of current solar cell technologies 

•	 Demonstrated the capability of the ultrafast measurement of defect study 

•	 Developed informatics-aided methods for maximally extracting quantitative processing-structureproperty relationships 

•	 Initiated data modeling and development of data aggregation systems for correlation, querying, 

and analysis of multiple local repositories of deposition records 

•	 Implemented a new data aggregation tool into the silicon data system for the P-System. 

Future Directions 

•	 Compare the electronic and defect properties of quaternary chalcogenides (Cu2ZnGeSe4, 

Cu2ZeSnS4, and CuGa(Sn□)Se4) with CIGS to investigate their suitability as PV absorbers 

•	 Study physical properties of homologous IZO, GZO, and AZO for low-cost TCO applications 

•	 Understand impurity diffusion and related stability issue in CdTe-based solar cell 

•	 Search oxide substrate that has the optimal interface properties for growth of c-Si 

•	 Understand the crystal structures and passivation mechanism of c-Si/a-Si heterojunction 

•	 Search new nano materials for SSC and hybrid OPV applications 

•	 Establish collaboration between BES-sponsored Energy Frontier Research Center (EFRC) at 

NREL and the Solar Energy Technologies Program (SETP) 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

•	 Predict doping and carrier transport properties in TCOs used in current PV technologies 

•	 Predict effect of defects on performance of In-free solar cells absorbers from Cu2(II,IV)VI4 family 

and ways to overcome them 

•	 Initiate data aggregation, analysis and mining for CIGS reliability testing 

•	 Develop informatics tools to integrate, correlate, and visualize composition spread, crystalline and 

amorphous phases, property, and performance for future p-type TCO 

•	 Enhance collaborations with groups concerning advanced characterizations 

•	 Develop new reliability-testing methods for PV modules and devices (CIGS and encapsulation). 

1. Introduction 

This agreement integrates PV-related crosscutting NREL capabilities in computational, 

theoretical, and fundamental materials studies at 

the Basic Science directorate. These capabilities 

are (1) theory of PV materials, (2) solid state 

theory, (3) ultrafast imaging of defects in PV 

materials, and (4) PV materials informatics. This 

agreement plays a key role in building a strong link 

between fundamental study and applied 

technologies. 

2. Technical Approach 

The Theory of PV Materials task applies state-ofthe-art computational methods such as density 

functional theory, molecular dynamics, and Monte 

Carlo simulation to study critical issues in design 

and development of novel PV materials. The 

studies are done in close collaboration with NCPV 

experimental groups. 

The hallmarks of the SST work are that we use 

state-of-the-art, quantum-mechanical theoretical 

methods to address contemporary translational 

materials challenges in Type II PV; (we leverage 

methods developed under our BES programs; and 

we work primarily with PV experimentalists at 

NCPV as well as SETP subcontractors. 

The ultrafast measurement is based on a new PL 

mapping direct-imaging technique in which the 

entire two-dimensional sample surface can be 

imaged onto an electron-multiplying-CCD camera. 

In PV Informatics, we build sophisticated data 

management models and multivariant analysis 

tools to relate deposition, characterization, and 

process data and enable mining of related data. 

We apply state-of-the-art material informatics 

techniques to design experiments and optimization 

techniques in collaboration with researchers. 

3. Results and Accomplishments 

•	 Searched systematically quaternary 

compounds for PV absorber applications using 

sequential atomic mutation approach. 

Suggested that Cu2ZnGeSe4 in the kesterite 

structure may be the best quaternary PV 

absorber material (Chen et al. 2009a, 2009b; 

Walsh et al. 2009a) . 

•	 Demonstrated and explained that ternary 

oxides formed from zinc and indium 

compounds (IZO) have good electrical and 

optical properties even in the amorphous 

phase (Walsh et al. 2009b, 2009c). 

•	 Predicted that zincblende (Mg, Zn)Te [(Mg, 

Cd)Te] alloys have accessible direct band 

gaps in the ranges of 2.39(1.48)–3.25(3.02) 

eV, suitable for tandem solar cell applications 

(Yang et al. 2009). 

•	 Calculated electronic structures of polymers. 

Suggested that InSb quantum dots or 

quantum wires could be good materials for 

hybrid organic-inorganic solar cells 

applications (Arantes et al. 2009, Xiang et al. 

2009b). 

•	 Explained why Si and Al2O3 can form clean 

interface. Provided criterion on searching 

optimal oxide substrate for growth of c-Si 

(Xiang et al. 2009a). 

•	 Suggested new approaches such as 

surfactant-enhanced doping to overcome 

doping difficulty in PV materials (Gai et al. 

2009, Zang et al. 2009). 

•	 Performed first theoretical study of n-type 

doping by transition metals in the currently 

used TCOs ZnO and In2O3 (Raebiger et al. 

2009). 

•	 Developed and applied a novel method to 

predict quantitatively hole binding energies of 

acceptors in p-type TCO, useful for multiple 

PV applications. Applied this method to all 

metal-site acceptors in ZnO, In 2O3, and SnO2, 

and showed that the acceptor levels are too 

deep to produce p-type conductivity, contrary 

to previous claims based on conventional 

theories (Lany and Zunger 2009). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Developed and tested computational method 

needed for calculating defects in complex PV 

materials (Lany and Zunger 2008). 

•	 Measured glass/SnO2/CdS/CdTe samples, 

showing that after treatment a higher 

concentration of the Te-rich CdSxTe1-x alloy 

exists in the grain-boundary region and that 

CdCl2-treatment can reduce nonradiative 

recombination at the grain boundary (Dhere et 

al. 2009). 

D R A F T

•	 Initiated and continued work in data 

aggregation, analysis, and mining (i.e., 

informatics). Began developing data models 

for integrating local data aggregation systems 

into a common platform. 

•	 Implemented a new data aggregation tool into 

the silicon data system for the P-System. It is 

focused on a user-friendly data entry and 

record display (Jones et al. 2009). 

•	 Continued updates and support for the data 

aggregation tool for FTIR characterization 

focusing on data access and reporting. 

•	 Demonstrated an effective way of screening 

and visualizing myriad information by 

providing the effect of composition of Co of 

Co:ZnO thin films on the structural properties 

and linked it processing conditions. 

•	 A new accelerated reliability testing technique 

was developed in terms of experimental 

economics and statistical accuracy. 

4. Planned FY 2010 Activities 

The PV Materials Theory project will continue its 

work on critical issues related to PV materials. In 

FY 20110, the focus will be on studying the 

electronic and defect properties of quaternary 

chalcogenides (Cu2ZnGeSe4, Cu2ZeSnS4, and 

CuGa(Sn□)Se4) to investigate their suitability as 

PV absorber materials; studying crystalline and 

amorphous phases of homologous GZO and AZO 

for low-cost TCO applications; and understanding 

impurity diffusion and related stability issues in 

CdTe-based solar cells. If funding permits, we will 

also extend our study to include searching an 

oxide substrate for growth of c-Si and 

understanding the passivation mechanism of the 

c-Si/a-Si heterojunction. 

The SST research activity will further address ptype doping in TCOs and wide-gap 

semiconductors. We will also apply our unique 

capabilities to predict doping and carrier transport 

properties in TCOs of current technologies, like 

TiO2, to identify and resolve bottlenecks on the 

basis of an accurate theory. We further plan to 

investigate the impact of defects on In-free 

Cu2ZnSnS4 absorber materials, and to identify the 

trade-offs for optimal performance. If funding 

permits, we will further study charge separation 

mechanisms in Si nanowire based solar cell, and 

the design of intermediate band solar cells. 

The Ultrafast Measurement activity will use and 

perfect the apparatus for the study of defects in 

thin-film solar cell and build new apparatus to 

extend the current capabilities. We apply this 

technique to understand the relationship of the 

microstructure and individual defects to optical 

behavior of thin-film PV materials. 

The PV Materials Informatics task will initiate new 

and continued data aggregation activities with film 

silicon, OPV, thin films, TCOs, and measurements 

and characterization researchers. It will begin 

collaborations on applying state-of-the-art material 

informatics techniques with PV program 

researchers. We will begin data aggregation, 

analysis, and mining for CIGS reliability testing. 

We will review requirements and maintain 

capability compatible with DOE requirements for 

scientific and technical data access and 

distribution. We will enhance collaborations with 

groups concerning advanced characterizations 

such as auger electron spectroscopy and X-ray 

photoelectron spectroscopy for elemental and 

chemical mapping for CIGS devices and PDIL. 

5. FY 2009 Special Recognitions and Awards 

S.-H. Wei, “First-Principles Design of Functional 

Materials for Energy Applications,” Arizona 

Workshop for Renewable Energy, Tempe, AZ, 

November 2008. 

S.-H. Wei, “Overcoming the Doping Asymmetry 

Problem in Wide Gap Semiconductors,” CECAM 

Workshop on Electronic Structure Method for the 

Study of Defects, Lausanne, Switzerland, June 

2009. 

S.-H. Wei, “Computational Study of Material 

Properties of Metal Oxides,” International 

Conference on Materials for Advanced 

Technologies, Singapore, July 2009. 

S.-H. Wei, “First-Principles Investigation of 

Unusual Materials Properties of Oxides,” 

CECAM Workshop on Computer Simulation of 

Oxides, Dublin, Ireland, September 2009. 

S. Lany, “Theory of Doping, Defects, and Nonstoichiometry in Transparent Conducting 

Oxides,” 2nd Intl. Symp. Transparent Conductive 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Oxides, Hersonissos, Crete, Greece, October 

2008. 

S. Lany, “Predicting p-orbital Hole-polarons in DFT 

Supercell Calculations,” CECAM Workshop on 

Electronic Structure Method for the Study of 

Defects, Lausanne, Switzerland, June 2009. 

D R A F T

S. Lany, "Material-intrinsic efficiency limitations in 

CIGS absorbers due to metastable defects," 

MRS Spring Meeting, San Francisco, CA, April 

2009. 

A. Zunger, Invited talk on novel PV materials in 

MRS. 

A. Zunger, Invited talk on theory applications to PV 

at BES panel. 

6. Major FY 2009 Publications 

J.T. Arantes, S.-H., Wei, et al., “Effects of Side 

Chain and Electron Correlation on the Band 

Structure of Perylene Diimide Liquid Crystals: A 

Density Functional Study,” J. Phys. Chem. B 

113, 5376 (2009). 

S. Chen, S.-H. Wei, et al., “Crystal and Electronic 

Band Structure of Cu2ZnSnX4 (X = S and Se) 

Photovoltaic Absorbers: First-Principles 

Insights,” Appl. Phys. Lett. 94, 041903 (2009a). 

S. Chen, S.-H. Wei, et al.,	 “Electronic Structure 

and Stability of Quaternary Chalcogenide 

Semiconductors Derived from Cation CrossSubstitution of II-VI and I-III-VI2 Compounds,” 

Phys. Rev. B 79, 165211 (2009b). 

R. Dhere, A. Mascarenhas, et al., “Investigation of 

Effects of Processing and Impurities on the 

Properties of CdTe Using Microscopic 2D PL 

Imaging Technique,” Proc. 34th IEEE PV 

Specialists Conf. Philadelphia, PA, 2009. 

Y. Gai, S.-H. Wei, et al., “Design of Shallow 

Acceptors in ZnO through Compensated DonorAcceptor Complexes: A Density Functional 

Calculation,” Phys. Rev. B 80, 153201 (2009). 

W.B. Jones, et al., “Tools for Aggregating, 

Analyzing and Mining Combinatorial Data,” 

Mater. Res. Soc. Symp. Proc. 1159, G03-08 

(2009). 

D. Korytina, W.B. Jones, et al., “Ad hoc Structured 

Search over Complex, High-Throughput Data 

Sets, Expressed in a Restructurable, Integrated 

Form,” Proc. IKE 2009 143 (2009). 

S. Lany and A. Zunger, “Assessment of Correction 

Methods for the Band Gap Problem and for 

Finite-Size Effects in Supercell Defect 

Calculations: Case Studies for ZnO and GaAs,” 

Phys. Rev. B 78, 235104 (2008). 

S.	 Lany and A. Zunger, “Polaronic Hole 

Localization and Multiple Hole Binding of 

Acceptors in Oxide Wide-Gap Semiconductors,” 

Phys. Rev. B 80, 085202 (2009). 

H. Raebiger, S. Lany, and A. Zunger, “Electronic 

Structure, Donor and Acceptor Transitions, and 

Magnetism of 3d impurities in In2O3 and ZnO,” 

Phys. Rev. B 79, 165202 (2009). 

A. Walsh, S.-H. Wei, et al., “Design of Quaternary 

Chalcogenide Photovoltaic Absorbers through 

Cation Mutation,” Proc. 34th IEEE PV Specialists 

Conf., Philadelphia, PA, 2009a. 

A. Walsh, S.-H. Wei, et al., “Electronic and Optical 

Analysis of Ternary In2O3(ZnO)n Transparent 

Conducting Oxides,” Phys. Rev. B 79, 073105 

(2009b). 

A.	 Walsh, J.L.F. Da Silva, and S.-H. Wei, 

“Interplay between Order and Disorder in the 

High Performance of Amorphous Transparent 

Conducting Oxides,” Chem. Mater. 21, 5119 

(2009c). 

H.J. Xiang, J.L.F. Da Silva, H.M. Branz, and S.-H. 

Wei, “Understanding the Clean Interface 

between Covalent Si and Ionic Al2O3,” Phys. 

Rev. Lett. 103, 116101 (2009a). 

H. Xiang, S.-H. Wei, and X. G. Gong, “Identifying 

Optimal Inorganic Nanomaterials for Hybrid 

Solar Cells,” J. Phys. Chem. C 113, 18968 

(2009b). 

J.-H. Yang, S.-H. Wei, et al., “Electronic Structure 

and Phase Stability of MgTe, ZnTe, CdTe and 

their Alloys in the B3, B4 and B8 Structures,” 

Phys. Rev. B 79, 245202 (2009). 

L. Zhang, Y. Yan, S.-H. Wei, “Enhancing Dopant 

Solubility via Epitaxial Surfactant Growth,” Phys. 

Rev. B 80, 073305 (2009). 
 

 

 

 

 

D R A F T

Measurement & Characterization Summary 

The Measurements and Characterization (M&C) project supports the Solar Energy Technology 

Program (SETP) through the development and application of measurement and analysis 

techniques to solve scientific and technical problems that arise in the development and 

commercialization of photovoltaic (PV) technologies. Our expertise and capabilities facilitate 

research, development, and test and evaluation (T&E) in support of each of the PV technology 

roadmaps. 

The M&C project consists of four closely integrated core competency groups: Cell and Module 

Performance, Analytical Microscopy, Electro-Optical Characterization, and Surface Analysis. 

Each group utilizes a wide array of state-of-the-art measurements and characterization 

techniques and has highly trained staff with a combined total of more than 450 years of 

experience in PV materials and device characterization. This extensive PV experience base, 

coupled with the breadth of our capabilities, sets us apart from other organizations throughout the 

world (a summary of our analytical capabilities can be found at www.nrel.gov/pv/measurements). 

The M&C project focuses its efforts in three complementary areas: support, collaborative R&D, 

and technique development, as shown in Figure 1. M&C Support focuses on providing routine 

and specialized measurement and characterization support for the PV community through rapid 

and direct response to requests. M&C support also includes test and evaluation (T&E) and stagegate review activities in support of the SETP supported PV companies. Collaborative R&D 

focuses on contributing to and leading collaborative research projects to address critical issues 

and problems in PV technologies. Technique and Diagnostic Development focuses on developing 

and implementing new and specialized measurement techniques in response to specific needs in 

PV R&D and manufacturing. This work is done within the context of supporting all DOE-supported 

technologies and technology partners. 

The M&C project is designed to help the SETP meet their 2015 targets. Research activities span 

a broad range of tasks that are focused on addressing technology-specific priorities. A summary 

includes: 

•	 T&E services in support of the subcontracted program and stage-gate reviews 

•	 Rapid-turnaround manufacturing process and device problem solving R&D 

•	 Process development and device optimization R&D 

•	 Cell failure analysis R&D 

•	 Module failure analysis R&D 

•	 New measurement techniques that address challenging material and device problems for 

mature and emerging PV technologies 

•	 T&E protocols to accurately measure the performance of novel cell and module 

structures
 

•	 Measurements and characterization consulting for industry and university partners. 

NREL SNL Solar 

Total $K Total $K Total $K 

Measurement & Characterization 10025 0 10025
 

Analytical Microscopy 2545 0 2545
 

Electro-Optical Characterization 2590 0 2590
 

Surface Analysis 1800 0 1800
 

Cell and Module Performance 2200 0 2200
 

M&C Management 890 0 890
 
 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

Analytical Microscopy Characterization 

Performing Organization: National Renewable Energy Laboratory (NREL) 

D R A F T

Key Technical Contact: Mowafak Al-Jassim (NREL), 303-384-6602, mowafak.aljassim@nrel.gov 

DOE HQ Technology Manager: John Lushetsky, 202-586-8064, john.lushetsky@hg.doe.gov 

FY 2009 Budget: $2,545K 

Objectives 

•	 Provide routine and specialized measurement and characterization support for photovoltaics (PV) 

program research and industry teams 

•	 Lead and contribute to collaborative research that addresses critical issues in PV technologies 

•	 Develop and implement novel measurement techniques that enhance the ability to understand 

and advance fundamental PV research and development. 

Accomplishments 

•	 Provided extensive analytical microscopy support to our industrial partners, including preincubator, incubator, and Technology Pathway Partnership projects; maintained cutting-edge 

support and acceptable turnaround time despite the large increase in sample volume 

•	 In support of the Process Development and Integration Laboratory (PDIL) operation, 

commissioned and further developed a scanning probe microscope and a scanning electron 

microscope with environmental control and pod compatibility 

•	 Studied the reliability of CdTe/CdS solar cells, investigated the effects of stress on these cells, 

and studied the influence of Cu on their electrical properties 

•	 Investigated surface electronics of CIGS thin films and role in junction formation of solar cells 

•	 Developed a scanning luminescence microscopy technique to investigate exciton transport in 

organic solar cells 

•	 Studied the reliability of III-V solar cells and the relaxation behavior and atomic ordering behavior 

in lattice mismatched III-V layer structures 

•	 In collaboration with in-house black Si project, investigated the microstructure, chemistry, and 

electronic properties of the porous Si oxide layer before and after thermal treatment 

•	 In collaboration with in-house Si heterojunction project, investigated microstructure, chemistry, 

and electronic properties of a-Si/c-Si interface of initial SHJ cells grown on industrial Si cells 

•	 In collaboration with in-house CdTe project, investigated barrier layer for Na diffusion from soda 

lime glass. 

Future Directions 

•	 Provide priority analytical microscopy support to our industrial partners 

•	 Investigate the influence of the deposition rate on the defect physics in copper indium gallium 

diselenide (CIGS) films 

•	 Investigate the amorphous/crystalline Si interface in industrial Si heterojunction cells 

•	 Develop a better understanding of the role of grain boundaries and intragrain defects in affecting 

transport properties of CdTe films 

•	 Continue the studies of the degradation of multijunction cells 

•	 Investigate defect type, density, and distribution as a function of casting conditions of upgraded 

metallurgical grade Si wafers. 

1. Introduction	 for the National Photovoltaics Program. It supports 

all PV material technologies and involves broad 

The Analytical Microscopy Team provides collaborations with external research partners in 

measurement and analysis support and research university and industry laboratories, PV 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

manufacturers, and internal research groups. 

Each year this project assists clients with the 

analysis of thousands of materials and device 

samples, helping them understand and direct work 

on their research and commercial product 

development. We also serve as one of the test 

and evaluation facilities used to evaluate 

subcontract and stage-gate deliverables for 

preincubator and incubator projects. 

These activities address one or more of the three 

areas crucial to meeting the EERE goal of 

reducing the levelized cost of energy for PV to 

$0.06/kWh by 2015. The three areas are (1) 

improving device and module performance, (2) 

reducing manufacturing costs, and (3) improving 

device/module reliability. This is accomplished by 

selecting projects that address key issues for a 

broad spectrum of technologies, including c-Si, aSi, thin Si, copper indium diselenide (CIS), CdTe, 

III-Vs, organic photovoltaics (OPV), and other 

future-generation materials. 

2. Technical Approach 

We use a wide variety of microscopy-based 

techniques to characterize PV materials and 

devices. Electron probe microanalysis (EPMA) 

makes compositional measurements using either 

energy dispersive or wavelength dispersive X-ray 

analysis. We use transmission electron microscopy 

(TEM) and high resolution scanning transmission 

electron microscopy (STEM) to perform structural 

and defect analyses. Scanning electron microscopy 

(SEM) in its various modes, such as secondary 

electron imaging, cathodoluminescence (CL), and 

EBIC imaging, provides wide support for measuring 

the topographical, luminescent, and microelectrical 

properties of PV materials and devices. 

Additionally, this task gives extensive support to 

the PV program in the nanoscale characterization 

area. Atomic force microscopy (AFM)-based 

techniques examine the morphology, surface 

structure, and electrical properties on the 

nanoscale of semiconductor and PV materials and 

devices. 

3. Results and Accomplishments 

Supporting our SETP industrial partners: 

The highest priority in FY 2009 was supporting the 

PV industry projects. Considerable time and 

resources were devoted to supporting 

preincubator, incubator, and TPP projects. Such 

projects resulted in a significant increase in our 

workload from the previous year. Despite this 

dramatic increase in analysis volume, we supplied 

state-of-the-art measurements at an acceptable 

turnaround time. The industry work falls into three 

categories: measurement support, verification of 

deliverables, and research support. An example of 

the last is the light-induced degradation study of Si 

cells. 

PDIL tool development: 

In support of the PDIL, we finished installing and 

testing the scanning probe microscopy (SPM) 

system for large-area samples and 

environmentally controlled measurements. The 

sample transfer station was tested with the pod 

and achieved the expected performance. Further, 

the glove box was installed, tested, and approved. 

We demonstrated the benefits of the glove box by 

analyzing Si samples by C-AFM in air and in the 

controlled ambient of the glove box. We also 

finished commissioning the large-sample 

environmental SEM and its sample transfer station 

in the PDIL. We applied these new 

environmentally controlled and vacuum 

capabilities to characterizing several solar cell 

materials and devices. One example is 

investigating the electrical potential profiles on the 

junction of III-V devices. We previously studied the 

potential profile in air, and demonstrated a surface 

Fermi-level pinning on cross-sections of the 

device. This Fermi-level pinning made the 

measured potential value smaller than that of the 

bulk, a crucial parameter in device performance. 

With cleaving the device in the glove box, we 

demonstrated clean surface and a minimal effect 

of surface Fermi-level pinning. 

Investigation of light-induced degradation in UMG 

mc-Si cells: 

We studied the reliability of upgraded metallurgical 

grade (UMG) Si cells. Light-induced degradation 

(LID) in these cells was the main degradation 

mechanism observed. LID in these UMG mc-Si 

cells was investigated using I-V, QE, diffusion 

length, and lifetime measurements. A meta-stable 

regenerated state with finite time factor was further 

investigated for the UMG cells. Eff, Voc, and Jsc 

degraded logarithmically with time, and the Jsc is 

the dominant factor for the efficiency degradation. 

QE measurements showed that the Jsc 

degradation happened mainly in the long 

wavelength range, indicating the degradation is in 

the bulk absorber. Diffusion length maps (Fig. 1a) 

as deduced from light-beam induced current 

(LBIC) show grain structures with degradation at 

grain boundaries and intragrain defects. The 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

diffusion length is longer on the [111]-oriented 

grains than in other orientations. With LID, the 

diffusion length on the defect-free regions was 

significantly reduced (Fig. 1b), regardless of the 

grain orientations. The diffusion length on the 

defects, however, did not change significantly with 

LID, indicating that the recombination of carriers 

on the defects is dominated by the defects 

themselves. Lifetime measurements by microphotoconductance decay (u-PCD) also showed 

overall decrease consistent with the LBIC and QE 

measurements. All these measurements indicate 

that LID induces defects that are dispersed in the 

bulk absorber with micro- or atomic scales. 

D R A F T

0 

4 

8 

1 

1 

2 

5 10 15 20 25 30 35 

Anneale 

LI 

diffusion length 

Percentage 

(a) 

(b 

Fig. 1. (a) A diffusion length map of a UMG mcSi cell, and (b) histograms of the diffusion length 

of a cell at the annealed and LID states. 

Resolution of the nanoscale exciton transport in 

organic solar cells by a new SPM: 

We observed excitonic luminescence from P3HT 

blended with PCBM in tunneling luminescence 

measurements based on AFM. The plasmon 

excitation confined to the metallic tunneling gap at 

the tip is responsible for the large enhancements 

in the intensity of the molecular luminescence. 

This effect allows for dramatic improvement in the 

detection sensitivity and, in combination with AFM, 

the acquisition of photon intensity images of the 

excitonic luminescence with nanometer resolution. 

For a series of P3HT:PCBM annealed at different 

temperatures, we found excellent correlation 

between the nanoscale morphology and the 

predicted exciton transport properties reflected in 

the photon intensity images of the molecular 

luminescence. This scanning luminescence 

microscopy can thus be applied to investigating 

the exciton transport, dissociation across donoracceptor interfaces, and evaluation of the exciton 

diffusion length, all with nanometer resolution. 

Developing such a powerful technique will produce 

critical information on the performance of OPV 

devices. 

Defect physics in CIGS thin films: 

Defect physics includes the study of atomic 

structure, chemical composition, electrical 

potential, and recombination behaviors of point 

defects and their complexes, grain boundaries, 

dislocations, stacking faults, twins, and interfaces. 

In FY 2009 we focused on surface defects, which 

are long thought to be a fundamental aspect of 

CIGS films that is critically involved in the 

formation of the junction of the solar cell. We 

developed a luminescence spectroscopy based on 

the STM, in which tunneling electrons are 

responsible for the excitation of luminescence. 

Such tunneling luminescence is excited at the 

surface and, consequently, the tunneling 

luminescence spectrum reveals the electronic 

states near the surface. In combination with 

cathodoluminescence, the transition from the grain 

interior to the surface can be investigated. We 

observed a red-shift in the emission spectrum at 

the surface of the CIGS that can be explained by 

the distinct defect structure of the surface caused 

by its deviations in stoichiometry. The <112> 

orientation is a special case in which there is no 

discontinuity at the surface. The surface 

electronics is controlled by the relative Cu 

deficiency, and most of the time is spatially more 

uniform than the underlying CIGS. We applied 

these measurements to CIGS thin films with 

different selenium regimes (from deficiency to 

overpressure) and investigated the electron 

transport across individual grain boundaries for 

films with increasing <Se>/<M> ratios. This 

technique produced much needed information on 

the characteristics of our best-efficiency CIGS 

cells and the key to achieving the 20% efficiency. 

The influence of grain misorientation on grain 

boundary recombination in thin-film Si cells: 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The film silicon roadmap puts a high priority on 

developing large-grained c-Si films on low-cost 

substrates that must be high quality to be used in 

15% solar cells. The effects of residual grain 

boundaries (GBs) and dislocations must be 

understood, and it is a roadmap priority to develop 

passivation techniques for them. This project 

aimed to develop the fundamental understanding 

and needed techniques for imaging GBs and for 

evaluating the recombination activity of GBs and 

dislocations and the efficacy of passivation 

techniques. In collaboration with the in-house thin 

film Si project, we studied seed/epitaxy Si films to 

understand which grain boundaries dominate the 

recombination statistics. We (1) mapped the 

misorientation of various GBs over selected areas 

on prepatterned films using electron backscattered 

diffraction (EBSD); (2) measured selected areas 

with the multiple techniques from AFM and SEM; 

and (3) selected specific grain boundaries in the 

focused ion beam (FIB) and examined the atomic 

structure of the boundaries by TEM. We observed 

(Fig. 2) that (1) carrier concentrations are lower 

around the GBs than on center regions of the 

grains; (2) the depletion width at the GBs varies 

considerably, between 0 and 100 nm, depending 

on individual GBs; and (3) intragrain carrier 

depletion existed at point and line defects. Directly 

measuring the carrier depletion on the GBs 

demonstrates that the GBs in Si thin films indeed 

create charged gap states. The nonuniformity of 

the carrier depletions suggests that the gap states 

depend on specific GB structures, which should 

relate directly to the grain orientations and grain 

facets adjacent to the GB. The depletion around 

the intragrain defects indicates that the defects are 

charged and can be recombination centers and, 

thus, harmful to device performance. 

D R A F T

Fig. 2. Scanning capacitance image (left) and 

EBSD image (right) of GBs in thin-film Si solar cell. 

4. Planned FY 2010 Activities 

•	 Provide priority analytical microscopy support 

to our SETP industrial partners 

•	 Investigate shunting in industrial Si cells 

•	 Study the reliability of UMG Si cells and 

modules 

•	 Complete the reliability study of CdTe/CdS 

cells, investigate the effects of stress on these 

cells, and study the influence of Cu on their 

electrical properties 

•	 Continue the studies of the degradation of III-V 

multijunction cells 

•	 Develop further understanding of the 

interfaces of Si heterojunction cells on large Si 

wafers. 

5. FY 2009 Special Recognitions and Awards 

One NREL Staff Award and several NREL 

Directors Awards. 

6. Major FY 2009 Publications 

C.-S. Jiang, A. Ptak, B. Yan, H.R. Moutinho, J.V. 

Li, and M.M. Al-Jassim, “Microelectrical 

Characterizations of Junction in Solar Cell 

Devices by Scanning Kelvin Probe Force 

Microscopy,” Ultramicroscopy 109, 952 (2009). 

H. Moutinho, R. Dhere, C.-S. Jiang, and M. AlJassim, “Scanning Kelvin Probe Microscopy of 

CdTe Solar Cells Measured Under Different Bias 

Conditions,” MRS Proceedings 1165, M08-28 

(2009). 

A.G. Norman, “Defects and Strain Relaxation 

Behavior in Compositionally Step Graded Layer 

Structures for High Efficiency, Metamorphic, 

Multi-junction Solar Cells,” invited talk at the 17th 

American Conference on Crystal Growth and 

Epitaxy, Lake Geneva, WI, August 2009. 

M.J.	 Romero, M.A. Contreras, I. Repins, C.-S. 

Jiang, and M.M. Al-Jassim, “Recent Advances in 

the STM-based Luminescence Microscopy of 

Cu(In,Ga)Se2 Thin Films,” MRS Proceedings 

1165, M09-11 (2009). 

M.J. Romero, A.J. Morfa, T.H. Reilly III, J. van de 

Lagemaat, and M.M. Al-Jassim, “Nanoscale 

Imaging of Exciton Transport in Organic 

Photovoltaic Semiconductors by Tip-enhanced 

Tunneling Luminescence,” Nano Lett. 9, 3904 

(2009). 
 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

Electro-Optical Characterization 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Dean Levi (NREL), 303-384-6605, dean.levi@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $2,590K (NREL) 

Objectives 

•	 Help SETP subcontractors succeed by giving top priority support through collaborative R&D 

projects, technique development, and standard measurements 

•	 Bring six new PDIL tools to full operational capability, including vacuum-integrated spectroscopic 

ellipsometry, vacuum-integrated minority carrier lifetime, vacuum-integrated photoluminescence 

imaging, PV reflectometer, optical processing furnace, and wafer processing station 

•	 Continue ongoing advancement of measurement techniques, including imaging of lifetime and 

cell performance, minority carrier lifetime, minority carrier diffusion length, and fundamental PV 

device properties 

•	 Help NREL in-house PV technology projects succeed through collaborative R&D projects, 

technique development, and standard measurements. 

Accomplishments 

•	 Gave priority support for numerous SETP-supported companies, including 1366 Technologies, 

Innovalight, Solexel, Abound (formerly AVA) Solar, Calisolar, MicroLink Devices, PrimeStar Solar, 

SoloPower, BP Solar, Dow Chemical, General Electric, Miasole, Nanosolar, and United Solar 

Ovionic 

•	 Achieved substantial completion of all PDIL tools, including vacuum-integrated spectroscopic 

ellipsometry, vacuum-integrated minority carrier lifetime, vacuum-integrated photoluminescence 

imaging, PV reflectometer, optical processing furnace, and wafer processing station 

•	 Made significant advances in imaging techniques for solar cell diagnostics, including electroluminescence imaging, forward and reverse bias dark lock-in thermography, and illuminated lockin thermography 

•	 Transferred NREL-developed technology to two industrial partners through CRADAs: GT Solar 

ha developed the GT Fabscan 6000 based on NREL’s PV reflectometer technology, and 2) 

Applied Optical Sciences developed a highly efficient optical processing furnace for PV 

applications based on NREL’s cavity-type optical furnace 

•	 Developed a robust computational model of triple-junction PV devices that included the first 

accurate simulation of tunnel junctions; used this model to study the effects of concentration and 

provided a new explanation for fill factor drop at high concentrations 

•	 Developed a transient ion drift measurement using slow capacitance transients to study dopant 

migration in CdTe, CIGS, and organic photovoltaic (OPV) devices. 

Future Directions 

•	 Give top priority support for SETP subcontractors through collaborative R&D projects, technique 

development, and standard measurements 

•	 Integrate six new PDIL tools into collaboration and support projects. Seek opportunities to partner 

with PV industry and in-house NREL research groups using these new capabilities 

•	 Continue ongoing advancement of measurement techniques for minority carrier lifetime, minority 

carrier diffusion length, thin film optical properties, and fundamental PV device properties 

•	 Determine the viability of time-resolved photoluminescence (TRPL) as an online diagnostic for PV 

manufacturing (contingent on capital equipment funding) 

•	 Initiate studies of CIGS material growth using real-time spectroscopic ellipsometry 
____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• Support NREL in-house PV technology projects through collaborative R&D projects, technique 

development, and standard measurements. 

1. Introduction 

The Electro-Optical Characterization agreement 

supports SETP by developing and applying 

measurement and analysis techniques to solve 

scientific and technical problems that arise when 

developing and commercializing PV technologies. 

Our expertise and capabilities cut across all 

technologies to facilitate research, development, 

and T&E in support of the PV technology 

roadmaps: wafer-silicon, film-silicon, concentrator 

PV, CIGS, CdTe, OPV, intermediate-band PV, 

D R A F 

2. Technical Ap

s

m

olar 

ultiple

cells, and 

-excitonrgeneration PV, 

eliability. 

proach 

dye-sensitized 

T

We bring extensive experience and advanced 

experimental capabilities to solving technical 

challenges in PV R&D. Our technical staff are 

experts in applying and interpreting a wide range 

of electro-optical measurement techniques. A 

major focus area is developing and applying 

methods for measuring minority carrier lifetime 

(MCL) and diffusion length. Experimental 

techniques for characterizing MCL include TRPL, 

resonantly coupled photoconductivity decay 

(RCPCD), microwave photoconductive decay (uwPCD), infrared free-carrier absorption (FCA), 

photoluminescence imaging (PLI), and infrared 

carrier density imaging (CDI). We are developing 

advanced capabilities for rapid imaging of MCL. 

We apply several spectroscopic techniques: 

photoluminescence spectroscopy; spectroscopic 

ellipsometry; near-, mid-, and far-infrared 

spectroscopy; and diffuse reflectance 

spectroscopy. We use several electrical device 

characterization methods to determine defect 

properties and fundamental junction parameters: 

deep level transient spectroscopy (DLTS), 

capacitance-voltage (C-V), admittance 

spectroscopy (AS), drive-level capacitance 

(DLCP), and in-plane impedance spectroscopy. 

We also have expertise in 2D and 3D computer 

modeling of solar cell structures, including 

modeling the measurements themselves, enabling 

our scientists to “look inside” the measurement 

process to gain greater insight and understanding 

of the measurement results. 

3. Results and Accomplishments 

•	 Supported SETP subcontractors at the highest 

level possible 

•	 Achieved significant advances in imaging 

techniques for solar cell diagnostics. 

Support for solar companies comprises a major 

portion of our work. In FY 2009 we performed 

hundreds of measurements and analyses for 14 

different SETP-supported companies. One 

emphasis for our group in recent years has been 

developing advanced imaging metrology 

techniques for the PV industry. We began to 

extensively use these techniques to support SETP 

contractors, e.g., our collaboration with an SETPsupported company to help optimize their 

multicrystalline Si wafer processing. The company 

was concerned with cell series resistance. We 

used a modified version of our standard PL 

imaging (PLI) technique, where a CCD camera is 

used to image the PL emission from a Si wafer 

that is excited using an 810-nm laser diode. In this 

case the mc-Si PV cell is connected through a 

resistive load while illuminated by 810-nm light. 

Areas of high resistance show up brighter in the 

image because of higher carrier densities resulting 

from poor carrier collection. Figure 1 shows an 

image of one of their cells where the crosshatched 

pattern in the lower left matched the pattern of a 

belt furnace used in wafer processing. The 

company was then able to modify the furnace to 

eliminate this problem and produce higher 

efficiency cells. We also made significant 

advances using dark lock-in thermography to 

image shunts, began applying imaging techniques 

to CIGS solar cells, and transferred the technical 

knowledge for imaging to multiple SETPsupported companies. 

•	 Achieved substantial completion of six new
 

PDIL tools
 

•	 Transferred NREL-developed technology to 

two industrial partners.
 

The electro-optical characterization group was 

unique among NREL agreements responsible for 

tool development in the PDIL in terms of the 

number and complexity of tools that fell within its 

agreement. Of the six PDIL tools we were 

responsible for in FY 2009, only one was an “off 

the shelf” unit from an outside vendor. The rest 

were completely custom designed and 

constructed at NREL, designed at NREL and 

built by an outside contractor, or based on 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NREL-developed IP and designed and 

constructed under a CRADA with a commercial 

partner under license with NREL. In FY 2009 we 

substantially completed all six PDIL tools: 

vacuum-integrated spectroscopic ellipsometry, 

vacuum-integrated minority carrier lifetime, 

vacuum-integrated photoluminescence imaging, 

PV reflectometer, optical processing furnace, and 

wafer processing station. 

D R A F T

Fig. 1. PL image of a multicrystalline silicon solar cell 

under load showing areas of high resistance (bright 

areas) that correlated to the pattern of a belt furnace. 

Two of these tools, the PV reflectometer and the 

optical processing furnace, or OPF, are excellent 

examples of technology transfer from NREL to the 

PV industry. Both are based on NREL intellectual 

property and licensed to a commercial partner. 

The PV reflectometer and OPF now in the PDIL 

are the first commercial prototypes, and were 

designed and assembled by our commercial 

partners in collaboration with NREL scientists 

under a CRADA agreement. The PV 

reflectometer, or GT-Fabscan 6000, as it is now 

known, is based on a patented measurement 

concept developed at NREL. It uses reciprocal 

optics to rapidly acquire the diffuse reflectance 

spectrum of a large-area sample. It can also use 

spectrally filtered images to produce parameter 

maps. This capability is illustrated in Figure 2, 

which shows a dislocation density map of an mcSi wafer. We made extensive use of this capability 

to help several PV wafer suppliers better 

understand and optimize their ingot growth 

process. In addition to dislocation density, the 

reflectometer can measure wafer thickness, grain 

orientation maps, grain size distribution, texturing 

etching, antireflection coating thickness, front 

metallization (metal height and metallization area), 

and back reflectance. Because GT-FabScan 6000 

can make measurements very rapidly (typically in 

< 40 ms) and without physically contacting the 

wafer, it can be used to monitor various process 

steps in the commercial production of solar cells. 

This tool is now available to NREL and visiting 

industry researchers to help understand and 

optimize their solar cell processing. 

Fig. 2. Dislocation density in mc-Si wafer mapped by
 

NREL’s GT Fabscan. This map is acquired in 10 ms.
 

•	 Developed a robust computational model of triple 

junction PV devices and applied it to understand 

device performance under high concentration. 

One of the goals in concentrating photovoltaics 

(CPV) is operating at very high levels of 

concentration (500–1000x). This reduces the 

amount of expensive semiconductor required in a 

CPV module and also increases the conversion 

efficiency of the triple-junction solar cell. It has 

been experimentally shown that device efficiency 

increases with concentration but saturates as 

concentration exceeds 300x. 

We have been working for the past 2 years to 

develop robust computational models of the 

GaInP/GaAs/Ge triple-junction solar cells that are 

used in CPV modules. In FY 2009 we succeeded 

in achieving convergence of these highly complex 

models and used them to study the effects of 

concentration on triple-junction solar cell 

performance. Our simulations found that the fillfactor reaches a peak near 300x and then starts 

decreasing. Because of the fill-factor decrease, 

the efficiency saturates at high concentrations. 

These are the same trends observed 

experimentally, but not fully explained so far. 

In addition to the commonly accepted explanation 

that the impact of series resistance on device 

performance increases under concentration, the 

simulations pointed to an additional effect. The 

valence-band offset (VBO) at the GaAs/GaInP 

interface for the GaAs middle cell back contact 

creates a barrier for majority holes. To study the 

impact of this barrier, we performed simulations on 

an isolated GaAs middle cell. Under high 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

concentration, the high density of photogenerated 

minority electrons will cause the recombination 

rate at the barrier to increase, reducing the density 

of holes to values below the levels needed to 

produce high photocurrents through the tunnel 

junction. It follows that a lower VBO at the 

GaAs/GaInP interface will reduce the FF drop at 

high concentrations. Figure 3 illustrates this 

concept, showing FF dependence on 

concentration for three different VBOs. For a VBO 

of 0.35eV, the FF drop significantly decreased, 

and our simulations show that efficiency keeps on 

increasing with concentration beyond 1000x. It 

follows that the FF decrease can be eliminated by 

substituting GaInP with other materials. A 

research group in Spain used 

AlxGa1-xAs (0.2 < x < 0.3) instead of Ga0.5In0.5P, 

and obtained peak efficiency at higher 

concentrations, essentially confirming the results 

of our calculations. 

D R A F T

Fig. 3 Calculated fill factor as a function of 

concentration X for three different values of the 

valence band offset at GaInP/GaAs interface. 

4. Planned FY 2010 Activities 

See “Future Directions” section on first page. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

PV workshops 

•	 Organized the 19th Crystal Silicon Workshop 

August 5-9, 2009 in Vail, CO; very well 

attended and successful; 184 PV specialists 

attended 

•	 Organized symposium “Materials and 

Manufacturing Issues in Photovoltaics” at the 

MRS 2008 Fall Meeting. MRS has requested 

that we organize a 3.5-day, annual workshop 

of the same title for next 5 years. 

Invited talks 

•	 Bhushan Sopori, “Limitations of 

Multicrystalline Si Solar Cells: Potential 

Approaches to Reach Monocrystalline Si 

Efficiencies,” TMS Annual Meeting, San 

Francisco, CA (02/09) 

•	 Steve Johnston, extended oral presentation: 

“Applications of Imaging Techniques for Solar 

Cell Characterization,” IEEE PVSC 

Philadelphia, PA, (06/09) 

•	 Bhushan Sopori, “Limitations of 

Multicrystalline Solar Cells Caused by Defect 

Clusters,” ECS-Asia, Shanghai, China, (03/09) 

•	 Bhushan Sopori and Przemyslaw Rupnowski, 

“Breakage Mechanism(s) of Photovoltaic 

Silicon Wafers: Theory and Experiment,” 

International Photovoltaic Reliability 

Conference II, Tempe, AZ, (07/09). 

Awards 

•	 B. Sopori, V. Budhraja, P. Rupnowski, S. 

Johnston, N. Call, H. Moutinho, and M. AlJassim, “Defect Clusters in Multicrystalline 

Silicon: Their Nature and Influence on the 

Solar Cell Performance,” IEEE PVSC 

Philadelphia, PA June 2009, Best Poster 

Award. 

Invention disclosures 

•	 B. Sopori, Optical technique for measurement 

of Pt content in PMEA electrodes. 

•	 B. Sopori, A new chuck for cross sectioning 

wafer silicon solar cells. 

6. Major FY 2009 Publications 

R.K.	 Ahrenkiel and S.W. Johnston, “An Optical 

Technique for Measuring Surface Recombination 

Velocity,” Solar Energy Mater. Solar Cells 93(5) 

645 (2009). 

D.S.	 Albin, R.G. Dhere, S.C. Glynn, and W.K. 

Metzger, “Direct Correlation of CdTe Solar Cell 

Stability with Mobile Ion Charge Generation 

During Accelerated Lifetime Testing,” 34th IEEE 

PVSC, June 2009, Philadelphia, PA. 

S.W.	 Johnston, N.J. Call, B. Phan, and R.K. 

Ahrenkiel, “Applications of Imaging Techniques 

for Solar Cell Characterization,” 34th IEEE 

PVSC, June 2009, Philadelphia, PA. 

A.	 Kanevce and W.K. Metzger, “The Role of 

Amorphous Silicon and Tunneling in 

Heterojunction with Intrinsic Thin Layer (HIT) 

Solar Cells,” J. Appl. Phys. 105 (9) 094507 

(2009). 

I.L. Repins, W.K. Metzger, C.L. Perkins, J.V. Li, 

and M.A. Contreras, “Measured Minority Carrier 

Lifetime and CIGS Device Performance,” 34th 

IEEE PVSC, June 2009, Philadelphia, PA. 
 

 

 

 

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____________________________________________________________________________________ 

Surface Analysis 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contacts: Sally Asher (NREL, Primary Contact), 303-384-6450, 

sally.asher@nrel.gov 

Peter Sheldon (NREL), 303-384-6533, peter.sheldon@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,800K (NREL) 

Objectives 

•	 Take routine and specialized measurements of surfaces and interfaces to support advancement 

of photovoltaic (PV) program research and industry partners 

•	 Lead and contribute to collaborative research on critical issues in understanding surfaces and 

interfaces in PV technologies 

•	 Develop and implement novel measurement techniques that enhance the ability to understand 

surface chemistry and physics of materials to advance fundamental PV R&D. 

Accomplishments 

•	 Gave surface analysis measurement support to researchers and manufacturers funded by the 

Solar Energy Technologies Program (SETP) 

•	 Completed development of thermodynamics-based models describing impurity migration and 

surface/interfacial segregation in PV materials and heterostructure devices under processing and 

field-deployed conditions 

•	 Completed installation and acceptance tests of the Process Development and Integration 

Laboratory (PDIL) measurements and characterization sample transfer robot
 

•	 Completed installation and acceptance tests of the large-platen AES tool in PDIL; demonstrated 

large-area mapping capabilities 

•	 Completed installation of the large-platen XPS tool and flipping station in PDIL 

•	 Installed and integrated into program activities a new, state-of-the-art, dynamic secondary ion 

mass spectrometer (SIMS) 

•	 Developed unique capabilities for synthesizing and studying the novel thin-film PV absorber 

material Cu2ZnSnS4 (CZTS) 

•	 Developed methods using XPS and dynamic contact angle to establish glass-washing protocols, 

screening methods for clean glass, and metrics for glass cleanliness of substrates intended for 

Mo deposition for subsequent CIGS device fabrication. 

Future Directions 

•	 Give high level surface analysis support to SETP-supported PV companies and researchers, 

making all reasonable attempts to maintain maximum 2-week turn-around time for requests 

•	 Examine textured crystalline silicon surfaces intended for heterojunction cells; explore surface 

composition as a function of the conditions used for texturing; and relate the findings to the 

resultant electronic properties of finished cells 

•	 Investigate the chemical interactions occurring at interfaces of organic semiconductors 

•	 Measure CIGS thermal decomposition and equilibrium vapor pressure; compare results with 

process conditions used in various NREL CIGS deposition systems 

•	 Map uniformity of ink jet printed top contacts and underlying metal contact/adhesion layer or 

metal contact/AR coating interface using the PDIL XPS tool 

•	 Develop combinatorial mapping capabilities for the large-platen AES and XPS tools. 

•	 Enhance existing capabilities of the STF 140 Surface Analysis cluster tool by developing the 

ability to deposit one or more layers of a typical organic photovoltaic (OPV) device. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Introduction 

The Surface Analysis project advances the 

understanding of PV materials and devices by 

employing surface science practices and 

techniques to investigate surface and interfacial 

properties of materials. Project scientists are 

active in three main areas: (1) giving analytical 

support to SETP research participants, conversion 

technology researchers, and researchers in 

reliability; (2) collaborating and leading research 

on the chemistry and physics of surfaces and 

interfaces of PV materials; and (3) advancing the 

utility and understanding of our measurements by 

improving analytical methods and by developing 

new tools for in situ study of surface and interface 

properties. 

D R A F 

This project uses best practices to obtain 

2. Technical Approach 

T

information about surfaces and interfaces of PV 

materials and devices. The specifications for the 

major pieces of analytical equipment we use in our 

work are detailed at 

www.nrel.gov/pv/measurements/surface 

_analysis.html. The group received three new 

pieces of equipment in FY 2009, adding significant 

new capabilities for surface science research: a 

small-spot XPS/UPS, a large-platen Auger, and a 

low-energy depth profiling dynamic SIMS. The 

group was also responsible for the M&C PDIL 

sample transfer robot. 

During FY 2009, we continued our focus on 

activities related to supporting DOE SETP funded 

partners, and to our collaborative interactions with 

in-house PV conversion technology researchers. 

We also worked with multiple instrument 

manufacturers to ensure all four of our new tools 

were installed safely, and that they met the 

performance specifications listed in the contracts. 

This included suggesting and testing modifications 

to the new equipment when it did not to perform to 

specification. We also spent significant time 

integrating these new tools into program activities. 

Finally, we continued to conduct research leading 

to better understanding of various PV materials, 

and also work that improved our analytical results. 

3. Results and Accomplishments 

3.1 Support for DOE SETP Funded Partners 

•	 CaliSolar—We continued work described in FY 

2008 report developing their process for 

upgraded metallurgical silicon. 

•	 1366 Technologies—We studied phosphorous 

depth distribution on and between contact 

regions on silicon solar cells; produced 

scanning ion image maps of the surface 

showing contact regions; and also provided 

depth profile analysis for light element 

contaminants. 

•	 Innovalight—We studied phosphorous depth 

distribution on and between contact regions on 

silicon solar cells; produced scanning ion image 

maps of the surface showing contact regions; 

and also provided depth profile analysis for light 

element contaminants. 

•	 United Solar—We studied nanocrystalline cell 

structures grown under various conditions; we 

also produced light element and dopant depth 

distributions. 

•	 MicroLink—We studied III-V high-efficiency cell 

structures and compared inverted and 

noninverted cell structures; we used depth 

profile analysis to look for diffusion of dopants, 

matrix elements, and light element 

contaminants. 

•	 GA Tech—We collaborated with GA Tech 

researchers to study phosphorous and boron 

diffusion in belt furnace fired silicon solar cells; 

performed depth profiles to study metallic and 

light element contamination; and used SIMS to 

perform trace element analysis of gold 

remaining after black silicon texturing. 

•	 We also collaborated with PrimeStar Solar, 

Ampulse, Plextronics, Global Solar Energy, and 

EPV Solar. 

3.2 Chemical	 Interactions of Organic 

Semiconductors and Contact Materials 

•	 Using ultraviolet photoelectron spectroscopy, 

we determined the band alignments for the 

components in a solar cell based on a new 

perylene-based polymer synthesized by Gregg 

and coworkers. The work is a key part of an 

article submitted to Chemistry of Materials. 

•	 Collaboration with Plextronics led to a better 

understanding of chemical interactions between 

their cathode materials and active layers and 

resulted in changes in some of their deposition 

processes. 

•	 An innovation report was filed describing a 

completely new class of cathode materials for 

devices based on organic semiconductors. 

3.3 Surface Modification of Oxides for Improved 

Dye-Sensitized Cells 

•	 We quantitatively compared molecular linking 

schemes used in dye-sensitized cells and in 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPV devices that use ZnO using XPS, contact 

angle measurements, and a new technique 

based on a homebuilt quartz crystal 

microbalance-based flow reactor. 

•	 A novel means of using ammonium chloride 

as a probe of self-assembled monolayer 

quality was introduced and used in this study. 

D R A F T

•	 The phosphonic acid moiety was found to be 

substantially superior to the thiol group for 

linking organic molecules to the ZnO surface. 

A manuscript detailing this work was published 

9/09. 

3.4 Studies of Cu2ZnSnS4, a Novel Thin-Film 

Absorber Material for TW-level PV 

•	 We initiated a project funded by the NCPV 

Seed-Fund Program to synthesize and study 

CZTS, a material that has recently attracted a 

great deal of interest because of its potential 

as a thin-film absorber based on abundant 

elements. 

•	 We developed experimental capabilities that 

include the ability to deposit either uniform or 

combinatorially graded thin-film samples, and 

to perform in situ thermal-desorption mass 

spectrometry (TDMS) studies of 

thermodynamics and growth kinetics. We used 

TDMS quantify the thermal stability of thin 

films in the Cu-Zn-Sn ternary system, which 

might be used for CZTS synthesis via 

precursor sulfurization. 

•	 In addition, we deposited a series of 

combinatorially graded Cu-Zn-Sn thin-film 

precursor library films in preparation for 

sulfurization and baseline device-processing 

studies. 

3.5 Installation and Testing of New Surface 

Analysis Tools 

•	 We installed and tested the new large-platen 

PDIL Auger tool, and discovered errors in the 

stage motion and locating routines. We 

discussed problems and potential solutions 

with DCA, leading to removal and repair of the 

stage. After its return and reinstallation on the 

tool, we were able to produce large-area maps 

using the tool. 

•	 Major issues reading data files into existing 

NREL processing software were finally 

resolved with the help of the software 

manufacturer, CasaXPS. The Auger is 

currently connected to the CIGS cluster tool 

and is awaiting growth activities to begin on 

this tool. 

•	 Installed and tested the new small-spot PDIL 

XPS/UPS tool with flipping station. 

Unfortunately there have been numerous 

problems with the installation and integration of 

these two tools, and the XPS has still not reached 

levels of performance necessary to attain 

acceptance by NREL. Most issues involve either 

the base pressure in the sample chamber or the 

reliable handling of platens. In addition, there are 

difficulties with the flipping/transfer station that limit 

the ability to move platens easily from one system 

to the other. Both manufacturers have worked with 

NREL to solve most of the problems; however, 

further redesigns will probably be necessary to 

fully resolve the issues. 

•	 We installed and tested the new dynamic 

SIMS instrument. The installation was smooth 

and the tool was accepted after the 

specification tests were concluded. 

Subsequent, more thorough testing by NREL 

staff, however, revealed a significant problem 

with primary optics focusing under certain 

analytical conditions. The manufacturer 

acknowledged an unforeseen design flaw 

existed, after NREL brought the problem to 

their attention. They have been cooperating 

with NREL staff to reach a workable solution. 

Fig. 1. Combinatorially graded Cu-Zn-Sn metal 

precursor films. 

4. Planned FY 2010 Activities 

The Surface Analysis team will focus on several 

activities. Many of these activities will employ the 

new PDIL tools to relate changes in surface 

chemistry and composition across a large area to 

variations in material quality or device 

performance or both. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Give Surface Analysis support to DOE SETP 

supported PV companies and researchers; 

make all reasonable attempts to maintain 

maximum two-week turn-around time for 

analytical requests 

•	 Examine textured crystalline silicon surfaces 

intended for heterojunction cells to explore 

optimal surface preparation as a function of the 

conditions used for texturing, and relate the 

findings to the resultant electronic properties of 

finished cells 

D R A F T

•	 Investigate the chemical interactions occurring 

at interfaces of organic semiconductors 

•	 Measure CIGS thermal decomposition and 

equilibrium vapor pressure. Time permitting, 

compare results with process conditions used 

in various NREL CIGS deposition systems 

•	 Map uniformity of ink jet printed top contacts 

and underlying metal contact/adhesion layer or 

metal contact/AR coating interface using PDIL 

XPS tool 

•	 Develop combinatorial mapping capabilities for 

large-platen AES and XPS tools 

•	 Enhance existing capabilities of STF 140 

Surface Analysis cluster tool by developing 

ability to deposit one or more layers of a typical 

OPV device. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

NREL Innovation Report #IN 09-19 was filed 

describing a completely new class of cathode 

materials for devices based on organic 

semiconductors. 

NREL is developing terms for “license to 

technology” with industrial partner and coinventor Beneq. The license will guarantee 

royalty income to NREL from ALD tools built by 

Beneq that use our joint invention for production 

of moisture barriers. 

6. Major FY 2009 Publications 

T.A. Gessert, W.K. Metzger, P. Dippo, S.E. Asher, 

R.G. Dhere, and M.R. Young, “Dependence of 

Carrier Lifetime on Cu-Contacting Temperature 

and ZnTe:Cu Thickness in CdS/CdTe Thin Film 

Solar Cells,” Thin Solid Films 517(7), 2370 

(2009). 

C.S. Jiang, H.R. Moutinho, R. Reedy, M.M. AlJassim, and A. Blosse, “Two-Dimensional 

Junction Identification in Multicrystalline Silicon 

Solar Cells by Scanning Kelvin Probe Force 

Microscopy,” J. Appl. Phys. 104(10), Article No. 

104501 (2008). 

X. Li, J. Pankow, and Y. Yan, “Impurity Study of 

Optical Properties in Fluorine-Doped Tin Oxide 

for Thin-Film Solar Cells,” Materials Research 

Society Symposium Proceedings (Thin-Film 

Compound Semiconductor Photovoltaics), 2009. 

C.L.	 Perkins, “Molecular Anchors for SelfAssembled Monolayers on ZnO: A Direct 

Comparison of the Thiol and Phosphonic Acid 

Moieties,” J. Phys. Chem. C 113, 18276 (2009). 

C.L. Perkins, B. Egaas, I. Repins, and B. To, 

“Quantitative Analysis of Graded Cu(In1-

x,Gax)Se2 Thin Films by AES, ICP-OES, and 

EPMA,” submitted to Surface and Interface 

Analysis. 

I. Repins, W.K. Metzger, C.L. Perkins, J.V. Li, and 

M.A. Contreras, “Measured Minority-Carrier 

Lifetime and CIGS Device Performance,” Proc. 

34th IEEE Photovoltaics Specialists Conference, 

Philadelphia, PA, June 7-12, 2009. 

G. Teeter, “A Model for Bulk-Diffusion-Coupled 

Surface Segregation Kinetics and Equilibria,” to 

be submitted. 

G.	 Teeter, “A Model for Dopant or Impurity 

Migration in Device Heterostructures,” to be 

submitted. 

D.L. Young, H.M. Branz, F. Liu, R. Reedy, B. To, 

and Q. Wang, “Electron Transport and Band 

Structure in Phosphorus-Doped Polycrystalline 

Silicon Films,” J. Appl. Phys. 105(3), Article No. 

033715 (2009). 

G.D. Yuan, Z.Z. Ye, J.Y. Huang, L.P. Zhu, C.L. 

Perkins, and S.B. Zhang, “X-ray Photoelectron 

Spectroscopy Study of Al- and N- Co-doped ptype ZnO Thin Films,” J. Crystal Growth 311(8), 

2341 (2009). 

M. Woodhouse, C.L. Perkins, M.T. Rawls, R.A. 

Cormier, Z. Liang, A.M. Nardes, and B.A. Gregg, 

“Non-Conjugated Polymers for Organic 

Photovoltaics: Physical and Optoelectronic 

Properties of Poly(perylene diimides),” submitted 

J. Phys. Chem. C. 
 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

Cell and Module Performance 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Keith Emery (NREL), 303-384-6632, keith.emery@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $2,200K (NREL) 

Objectives 

•	 Support contact technical monitors, SETP partners, and the photovoltaic (PV) industry by
 

furnishing accurate traceable efficiency, peak watt, quantum efficiency (QE), and I-V 

measurements with respect to standard reporting conditions
 

•	 Maintain ISO 17025 accreditation for cell and module calibrations 

•	 Maintain primary reference cell calibrations 

•	 Transfer I-V and QE measurement technology to solar partners and the PV community 

•	 Maintain and advance the state of the art in I-V and QE cell and module measurements 

•	 Continue with International Electrotechnical Commission (IEC) and American Society for Testing 

and Materials (ASTM) standards development. 

Accomplishments 

•	 Gave measurement support in cell and module performance to more than 260 PV research 

partners in industry, academia, and NREL; even more groups were supported via phone 

conversations, emails, and visits detailing all aspects of cell and module PV I-V and QE 

measurement technology 

•	 Assisted Newport in becoming a certified secondary cell calibration facility 

•	 Gave site visit and tutorials to UL to assist in PV testing procedures at their San Jose, CA, plant; 

continue to support, at highest possible level, all current and future U.S. based certified cell and 

module testing groups 

•	 Maintained ISO 17025 accreditation for primary and secondary cell and module calibrations 

•	 Chaired the November 2008 ASTM E44.09 PV standards meetings, and served as the secretary 

for the E44 main committee as well as the chair of the PV technical subcommittee; member of 

IEC TC82 working groups 2 and 7; active in writing, shepherding, and developing the technical 

basis for all ASTM and IEC standards related to cell and module performance evaluation 

•	 Supported the U.S. terrestrial PV community by transferring performance measurement 

technology via emails, tours, day-long technical visits at NREL, visits to partner sites, phone 

conversations, and publications. 

Future Directions 

•	 Continue to support SETP subcontracted program at the highest possible priority and level 

•	 Continue to support the U.S. terrestrial PV community by transferring performance measurement 

technology and furnishing cell and module performance measurements and calibrations 

•	 Enhance capabilities to determine the energy part of the levelized cost of energy for PV
 

technologies from flat-plate to low-X to high concentration
 

•	 Bring newly procured simulators to an operational status and use them to determine energy 

delivered with respect to a reference year and spectral sensitivity of multijunction technologies 

•	 Maintain ISO 17025 accreditation for primary and secondary cell and module calibrations. 

1. Introduction	 terrestrial PV community since 1980. We have 

kept that community “on the same page” in 

This agreement has been performing PV terms of performance ratings and efficiency 

performance measurements for the U.S. measurements by providing these groups with 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

calibrations upon request. PV performance 

measurement technology relating to algorithms, 

procedures, and equipment capabilities and 

limitations have been routinely transferred to 

academia, PV cell and module manufacturers, 

and equipment suppliers. This project has 

supported, directly or indirectly, nearly all EERE 

activities relating to PV cell and module 

development. This project has advanced the 

state of the art in performance characterization 

in many areas, and has been active in ASTM 

and IEC PV standards development. 

D R A F 

simulator based current versus voltage test beds 

illuminated by different light sources 

different but complementary capabilities 

evaluating prototype cells, concentrator cells, 

commercial cells, flat plate modules

This 

2. Technical Approach 

agreement employs six different solar 

, 

with 

and 

for 

T

concentrator modules of any conceivable size 

and technology. The test beds are designed to 

be able to evaluate performance with respect to 

standard reporting conditions defined by total 

irradiance (1-sun = 1000 Wm-2), spectral 

irradiance (IEC 60904-3 / ASTM G173), and 

temperature (25°C). The group has two outdoor 

test beds for taking single-point measurements 

on flat plate modules and for evaluating 

performance of concentrator modules over time. 

The unique contributions of the project include 

giving PV manufacturers and research labs 

accurate certified PV performance calibrations; 

offering extensive consulting on performance 

measurement procedures, equipment, and 

software; and developing the measurement 

science and methods that allow for state-of-theart cell and module performance 

characterization. For example, we have led the 

community in multijunction measurement 

procedures and procedures to evaluate highefficiency, multijunction concentrator cells and 

modules. 

The major scientific and technical issue is that, 

despite being the most capable PV performance 

characterization lab in the world, our 

measurement uncertainties are still too large for 

some customers. 

3. Results and Accomplishments 

•	 Furnish routine and specialized measurement 

and characterization support for PV program 

research and industry teams: 

During FY 2009, the team evaluated numerous 

contract deliverables and stage-gate milestones 

at the cell and module level. We evaluated 

stage-gate milestones consistently in less than 1 

week from arriving in the lab (2 weeks for 

concentrator cells) by giving these requests the 

highest possible priority at the expense of other 

requests in the queue. During FY 2009, 

independent efficiency measurements and 

reference cell and module calibrations were 

performed on 2,631 cells and modules for 261 

groups. There were 5,140 cell I-V, QE, and 

linearity measurements on 1,496 samples, and 

3,839 I-V measurements on 905 modules. All of 

these measurements were subjected to the 

team’s rigorous ISO 17025 quality system of 

data collection and review. The team also 

performed on-site stage-gate measurements on 

a prototype concentrator module following 

ASTM E2527 for the Skyline Solar PV-Incubator 

subcontract. The prototype concentrator module 

test bed took 78,618 I-V curves on nine 

modules, including SAI partners Amonix, 

Boeing, Solfocus, and Spectrolab. Multijunction 

prototype concentrator modules from Semprius 

Solar, Greenvolts, Daido Steel, and Fraunhofer 

ISE were also evaluated. 

To improve the calibration accuracy and 

traceability of key DOE partners, the team 

calibrated 10 primary reference cells with formal 

ISO 17025 accredited calibration certificates for 

Sandia and FSEC. 

We completed internal and external audits by 

A2LA to verify the team’s compliance with ISO 

17025 requirements regarding our quality 

system, equipment calibrations, software, and 

documentation. This is critical for other DOE 

labs like Sandia, industry, and research partners 

to have an accurate and formal calibration 

traceability path so the peak watt rating for PV is 

a useful rating. This lab is the only one in the 

nation that has formal primary reference cell 

calibration capability. The other three labs 

worldwide are PTB in Germany, AIST in Japan, 

and The EU Joint Research Center in Italy. 

Intercomparisons with these labs are conducted 

annually to document how the team’s 

calibrations compare with values from around 

the world. 

• In-House Support and Collaborative R&D: 

In support of the NCPV, the team maintained 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

user facilities for IV and QE measurement 

calibrations and trained users in procedures to 

minimize measurement errors. We also 

maintained our 35-year-old simulator and 15­

year-old test bed, which required frequent 

maintenance, and updated system software to 

meet changing research requirements. The inhouse reliability program was also supported 

with the highest possible priority measurements 

to minimize the time the samples are not being 

stressed. During FY 2009, we evaluated more 

than 1,320 modules in support of the reliability 

group, as well as hundreds of samples of all cell 

technologies for in-house groups for 

independent efficiency measurements reported 

on samples fabricated at NREL. 

D R A F 

• Large

Installation and Certification: 

-Area Module Solar Simulator 

T

Fig. 1. The Spire 4600 long pulse solar 

simulator was delivered in May 2008. 

After acceptance testing and development of the 

software to meet the team’s standards, the Spire 

4600 long pulse solar simulator was certified as 

operational and customers’ samples were being 

measured beginning in August 2009. Several 

significant software issues in Spire's code were 

identified and communicated to Spire. The 

spatial nonuniformity of the simulator meets 

ASTM and IEC guidelines for a Class A 

simulator but meets only class C non-uniformity 

specifications for small pixel sizes complicating 

the procedures and uncertainty analysis. The 

manufacturer was alerted that this issue could 

be a serious problem for thin-film modules 

where the cells are long and narrow. This is also 

being discussed in the standards arena because 

the uniformity specification in the IEC and ASTM 

simulator standard did not account for a 

simulator with large uniformity differences as the 

pixel area changes from 4 to 100 or 200 cm2

. 

•	 Multisource Concentrator Solar Simulator 

Development: 

The Spectrolab THIPSS spectrally adjustable 

concentrator solar simulator purchase order was 

placed on October 2008, and the unit is 

scheduled to be delivered May 2010. The 

delivery was delayed for several reasons, 

including expanded range and software 

capabilities required to meet the needs of the PV 

concentrator community. 

•	 Multisource 1-Sun Solar Simulator 

Development: 

Fig. 2. Photo showing fiber optic bundle 

delivering light in nine spectrally adjustable 

bands to the test plane. 

A new multisource 1-sun solar simulator, 

designed by Sphere Optics (now Labsphere), 

was delivered in July 2008, four months behind 

schedule. The unit failed to meet multiple critical 

performance criteria detailed in the 

specifications, including beam size (15 x 15 cm), 

ability to match the reference spectrum in 

selected bands, and failure of the Xe lamps to 

operate at Denver's elevation. We are working 

closely with Labsphere, and they are devoting 

significant resources to resolve these problems. 

Before this purchase, the largest fiber optic 

based simulators (research or commercial) had 

beam sizes of only a few square centimeters 

and were not spectrally adjustable. This unique 

simulator will be able to map out the spectral 

sensitivity at or below 1-sun for any conceivable 

multijunction technology. The data acquisition 

system, probe station, and temperaturecontrolled plates were purchased and installed. 

The software was written and debugged to the 

extent possible without a working simulator. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4. Planned FY 2010 Activities	 K. Emery, Uncertainty Analysis of Certified 

•	 Furnish routine and specialized 

measurement and characterization support 

for PV program research and industry 

teams; support subcontractors (Technology 

Pathway Partnerships and PV Incubator) at 

the highest level possible 

D R A F T

•	 Maintain full ISO 17025 accreditation for 

primary reference cell, secondary reference 

cell, and secondary module calibrations 

•	 Continue active membership and 

participation in ASTM and IEC WG2 and 

WG7 PV cell and module standards 

activities 

•	 Include the SPI4600 long pulse simulator in 

the team’s scope of ISO 17025 accreditation 

•	 Resolve the failures to meet specifications 

and bring the spectrally adjustable 1-sun 

simulator to an operational status 

•	 Accept delivery of concentrator multisource 

simulator, verify that the unit meets 

performance specifications, and bring to an 

operational status. 

5. FY 2009 Special Recognitions and Awards 

NCPV received the 2009 Colorado Governor's 

Award for Research Impact in the area of 

renewable energy for its work on thin film solar 

cells; gave presentation showcasing the team’s 

contribution to this award. 

6.	 Major FY 2009 Publications 

A. Barnett, D. Kirkpatrick, C. Honsberg, D. 

Moore, M. Wanlass, K. Emery, R. Schwartz, D. 

Carlson, S. Bowden, D Aiken, A. Gray, S. 

Kurtz, L. Kazmerski, M. Steiner, J. Gray, T. 

Davenport, R. Buelow, L. Takacs, N. Shatz, J. 

Bortz, O. Jani, K. Goossen, F. Kiamilev, A. 

Doolittle, I. Ferguson, B. Unger, G. Schmidt, E. 

Christensen, and D. Salzman, “Very High 

Efficiency Solar Cell Modules,” Prog. 

Photovoltaics Res. Applicat. 17, 75 (2009). 

J.A. del Cueto, C.A. Deline, D.S. Albin, S.R. 

Rummel, and A. Anderberg, “Striving for a 

Standard Protocol for Preconditioning or 

Stabilization of Polycrystalline Thin Film 

Photovoltaic Modules,” SPIE 2009 Conference 

7412, San Diego, CA, Aug. 2009. 

K. Emery, "Cell and Module Level Testing 

Procedures and Intercomparisons," 

International Photovoltaic Reliability Workshop 

II, Tempe, AZ, July 29-31, 2009. 

Photovoltaic Measurements at the National 

Renewable Energy Laboratory, NREL/TP-520­

45299, Golden, CO: NREL (August 2009). 

M.A. Green, K. Emery, Y. Hishikawa, and W. 

Warta, “Solar Cell Efficiency Tables (version 

33),” Prog. Photovoltaics Res. Applicat. 17, 85 

(2009). 

M.A.	 Green, K. Emery, Y. Hishikawa, and W. 

Warta, “Solar Cell Efficiency Tables (version 

34),” Prog. Photovoltaics Res. Applicat. 17, 

320 (2009). 

A. Kimber, T. Dierauf, L. Mitchell, C. Whitaker, 

T. Townsend, J. NewMiller, D. King, J. 

Granata, K. Emery, C. Osterwald, D. Myers, B. 

Marion, A. Pligavko, A. Panchula, T. Levitsky, 

J. Forbess, and, F. Talmud, “

Improved Test 

Method to Verify the Power Rating of a 

Photovoltaic (PV) Project,” Proc. 24th IEEE 

PVSC, Philadelphia, PA, June 8–12, 2009. 

M.A. Steiner, M.W. Wanlass, J.J. Carapella, A. 

Duda, J.S. Ward, T.E. Moriarty, and K.A. 

Emery, "A Monolithic Three-Terminal 

GaInAsP/GaInAs Tandem Solar Cell," Prog. 

Photovoltaics Res. Applicat. 17, 587 (2009). 

X.	 Wang, N. Waite, P. Murcia, K. Emery, M. 

Steiner, F. Kiamilev, K. Goossen, C. 

Honsberg, and A. Barnett, "Improved Outdoor 

Measurements for Very High Efficiency Solar 

Cell Sub-modules," Proc. 24th IEEE PVSC, 

Philadelphia, PA, June 8–12, 2009. 

7. University and Industry Partners 

The group partnered with more than 250 groups, 

including measurement technology transfer and 

PV cell and module calibration services. 
 

 

 

 

D R A F T

PDIL Development & Integration Laboratory Summary 

The Process Development and Integration Laboratory (PDIL) is a collaborative facility that 

provides specially designed and unique research tools to accomplish the following vision for the 

U.S. Solar Program: 

•	 Shorten the time necessary to transfer a PV technology from the laboratory to pilot 

production by facilitating an improved understanding of process integration issues that 

are critical to successfully scaling a technology. 

•	 Assist the U.S. industry by providing access to state-of-the-art capabilities and scientific 

expertise in the areas of materials deposition, processing, and characterization. 

•	 Facilitate the development of next-generation PV technologies by providing a dynamic 

research capability that encourages innovation and helps develop the scientific 

foundation necessary to commercialize a new technology. 

The PDIL will provide the largest known collection of integrated PV-specific capabilities 

supporting multiple PV technologies. It is operated as a collaborative facility between research 

partners and core NCPV research staff. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

PDIL Development & Utilization 2692 0 0 2692 

PDIL Hardware Development 1692 0 0 1692 

PDIL Software Integration 660 0 0 660 

PDIL Project Management 340 0 0 340 
 

____________________________________________________________________________________ 

 

 

 

 

D R A F T

Process Development and Integration Laboratory Hardware Development,
 

Software Integration, & Management
 

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Brent Nelson (NREL), 303-384-6407, brent.nelson@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-0565, scott.stephens@hq.doe.gov 

FY 2009 Budget: $1,692K (NREL) 

Objectives 

Hardware Development 

•	 Ensure hardware standards are followed in equipment design and implementation. 

•	 Ensure DOE and NREL EHS requirements are followed 

•	 Coordinate acquisition, site preparation, equipment installation, and optimization 

•	 Install hardware into the Process Development and Integration Laboratory (PDIL). 

Software Integration 

•	 Furnish the necessary file structures and database schema supporting the PDIL data products 

•	 Create a data technology bridge allowing PDIL researchers to access the high-level analysis tools 

of the Computational Sciences Center (CSC) 

•	 Develop or improve automation systems for sample handling, data acquisition, and equipment 

diagnostics 

•	 Develop intuitive user interfaces to access raw data, derive logical data sets, and support
 

knowledge extraction
 

•	 Furnish security to ensure that the PDIL network is protected and monitored and that all data 

products are encrypted, transferred, and stored securely. 

Management 

•	 Give financial (acquisition) guidance to the core groups and tool owners 

•	 Furnish project management support for tool installations 

•	 Communicate PDIL capabilities to the photovoltaics (PV) community at large 

•	 Continue ongoing management of the physical assets of the PDIL 

Accomplishments 

Hardware Development 

•	 Delivered and installed the CIGS cluster tool 

•	 Delivered and installed the Atmospheric Processing Platform (APP) 

•	 Enhanced the thin-film silicon cluster tool with VHF capabilities 

•	 Designed and specified the silicon wafer replacement tool (thin crystal silicon film). 

•	 Designed and specified the CdTe cluster tool 

•	 Installed the Auger electron spectroscopy (AES) tool. 

•	 Installed the X-ray photoelectron spectroscope (XPS) 

•	 Installed the scanning electron microscope (SEM) 

•	 Installed the atomic force microscope (AFM) 

•	 Installed the wet chemistry processing station 

•	 Installed the reflectance spectroscopy tool 

•	 Installed the spectroscopic ellipsometry tool. 

Software Integration 

•	 Completed a PDIL network, file structure, and database schema 

•	 Established a data interface and strong personnel working relationship with the CSC, giving us 

access to their high-end analysis tools 

•	 Made the PDIL data infrastructure fully DOE cyber security compliant 

•	 Gave data access at project level need-to-know and controlled by project PIs 
 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

•	 Created software development process to monitor changes and documentation 

•	 Developed methods and techniques of PV informatics to be used on actual PDIL data. 

Management 

•	 Gave financial (acquisition) guidance to the core groups and tool owners 

•	 Furnished project management support for tool installations 

•	 Communicated PDIL capabilities to the PV community at large 

•	 Continued ongoing management of the physical assets of the PDIL. 

Future Directions 

Hardware Development 

•	 Furnish hardware support to optimize tool operation 

•	 Install the optical processing furnace 

•	 Oversee fabrication of the silicon wafer replacement tool 

•	 Oversee fabrication of the CdTe cluster tool 

•	 Fully integrate the resonance-coupled photoconductive decay (RC-PCD) tool on the 

measurements and characterization (M&C) vacuum robot
 

•	 Fully integrate the photoluminescence (PL) imaging on the M&C vacuum robot 

•	 Fully integrate the sputtering / plasma etching tool on the M&C vacuum robot 

•	 Fully integrate the plasma-enhanced chemical vapor deposition (PECVD) tool on the M&C 

vacuum robot. 

Software Integration 

•	 Automate scientific and process data extraction so that researchers have access to meta- and 

derived data on the atmospheric processing tool and the CIGS cluster tool important to science 

•	 Integrate arrays of spectral data for extracting information to surface analysis and analytical 

microscopy tools in the PDIL, especially related to CIGS data 

•	 Continue to integrate PDIL data, via applied informatics, into a PV Informatics Toolkit. 

Management 

•	 Give financial (acquisition) guidance to the core groups and tool owners 

•	 Furnish project management support for tool installations 

•	 Communicate PDIL capabilities to the PV community at large 

•	 Continue ongoing management of the PDIL physical assets 

1. Introduction 

The PDIL is a unique collaborative facility where 

industry and universities can work closely with 

NREL scientists on integrated equipment to 

answer pressing questions related to PV material 

and device development. It is the only fully 

integrated R&D laboratory dedicated to resolving 

the unique challenges of PV applications. The 

facility includes complementary deposition, 

processing, and characterization tools that can 

share 157 x 157 mm (~6-inch) samples in a 

controlled atmosphere. We work with a wide range 

of PV materials from wafer silicon to organics, 

including the various thin films (e.g., crystalline Si, 

amorphous Si, microcrystalline Si, copper indium 

gallium diselenide, and cadmium telluride). 

Integrated characterization techniques allow us to 

probe chemical compositional, morphological, and 

structural properties of materials and interfaces 

immediately after material growth without exposing 

a surface to air. The ability to transport a device 

part way through cell fabrication, in a controlled 

ambient environment, to a large number of 

characterization tools, and then return the sample 

to complete the device, allows us to gain 

knowledge about how material properties and 

interface characteristics affect cell performance. 

2. Technical Approach 

The PDIL directly supports industrial 

collaborations as well as in-house research. 

Support for the PV industry presents unique 

challenges. Although essentially all PV devices 

share a common circuit design (one or more p-n 

junctions in series), an immense range of 

materials and processes are manufactured and 

investigated. It is useful to compare the associated 

challenges with the microelectronics industry, 

which shared a single material and geometry 

(round silicon wafers). This commonality greatly 

facilitated cooperation between manufacturers, 

equipment fabricators, material suppliers, and 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

researchers. In contrast, the PV industry lacks 

standardization or even standard product sizes. To 

have an integrated toolset, we implemented a 

size, geometry, and transfer standard that enables 

cooperation but is flexible enough to 

accommodate the unique needs of multiple PV 

technologies. The standard chosen consists of a 

178 x 178 mm (7 x 7 in.) frame, or platen, capable 

of handling samples up to 157 x 157 mm. The 

PDIL Hardware Agreement supports the efforts of 

the core groups in developing their PDIL tool sets. 

Fig. 1. The CIGS cluster tool in Bay 1 of the PDIL. 

3. Results and Accomplishments 

Hardware 

The central robot and three sputtering chambers 

for ZnO, CdS, and Mo were added to the CIGS 

MBE chamber and are installed in PDIL Bay 1 

(Fig. 1). This cluster tool gives the PDIL the 

functionality to fabricate a full CIGS device with all 

dry processes. 

Fig. 2. The APP in Bay 2 of the PDIL. 

The APP was installed in PDIL Bay 2 (Fig. 2); it 

consists of both a spray-jet and an ink-jet printer 

for depositing metals, semiconductors, transparent 

conducting oxides, and other solar cell materials. 

These deposition capabilities are in controlled 

ambient glove boxes and supported by a rapid 

thermal annealer, XRF, and XRD, also in glove 

boxes. The platform also has a vacuum robot to 

interface to the PDIL intertool transport pod and 

evaporation and sputtering capabilities. Added to 

the existing M&C tools during FY 2009 were the 

SEM, XPS, and reflectance spectrometer in PDIL 

Bay 5 (Fig. 3). 

Fig. 3. Standalone M&C equipment in Bay 5 of the 

PDIL. 

Much of the integrated M&C cluster tool was 

installed in PDIL Bay 6: the central vacuum robot 

(Fig. 4), the spectroscopic ellipsometer tool 

(Fig. 5), the RC-PCD, and PL imaging tools 

(Fig. 6). 

For complete details of PDIL capabilities, see 

(http://www.nrel.gov/pv/pdil/capabilities.html). The 

intertool mobile transport pods underwent several 

design changes in FY 2009 because of 

inconsistencies in floor levelness from tool to tool. 

This project is behind schedule, but is a top priority 

for FY 2010. 

Software 

The necessary file structures and database 

schema was developed; it is the key architecture 

for proper archiving and data handling for PDIL 

tools. This was a level 4 milestone for FY 2009. It 

supports the creation of automated data pipelines 

for the heterogeneous PDIL assets, methods for 

system monitoring, and automated acquisition of 

the data products across the network. 

Significantly, it also is the infrastructure for moving 

and storage of the data to the CSC data archives 

by establishing data formats and files structures 

that work in concert with their advanced parallel 

computing systems and analysis codes. A file 

download portal was added to facilitate the 

scientists’ ability to download their files. 
 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F 

integrated M&C cluster tool in Bay 

Fig. 4. Central robot and load lock on the 

6 of the PDIL. 

T

Fig. 5. Spectroscopic ellipsometer tool on the 

integrated M&C cluster tool in Bay 6 of the PDIL. 

The PDIL group continued integrating PDIL data 

products into the established infrastructure. An 

intuitive user interface was developed to access 

the raw data, derive logical data sets, and furnish 

knowledge extraction capabilities to researchers in 

the PDIL. We also wrote a data user manual to 

educate users on how to use these tools. This 

interface will undergo continuous improvement 

based on feedback from data generators and data 

analysis collaborators. 

The PDIL software architecture was expanded to 

include a fully compliant web and application 

server on the NREL moderate enclave, separating 

test and development systems from production 

systems. The development process was then 

enhanced to include software path-to-production 

concepts, enabling future development in a robust, 

industry-standard methodology, where new 

software and database concepts are fully tested 

and processed through change control procedures 

before being moved to production. 

Fig. 6. Photoluminescence imaging tool on the 

integrated M&C cluster tool in Bay 6 of the PDIL. 

The PDIL data infrastructure was made fully DOE 

cyber security compliant, protecting proprietary 

data products from inadvertent and targeted 

losses. 

4. Planned FY 2010 Activities 

Hardware 

The PDIL group will continue to support acquiring 

and installing the thin-crystal silicon film (a.k.a., 

silicon wafer replacement) cluster tool, the CdTe 

cluster tool, and both the sputtering/plasma 

diagnostic and PECVD chambers on the 

integrated M&C cluster tool. 

Software 

This task will fully integrate the operational 

equipment of the PDIL into the automated data 

services of the PDIL. This includes the CIGS, 

atmospheric processing, silicon cluster, TCO, 

SEM, AFM, XPS, Auger, reflectometer, and 

ellipsometry. It will ensure that the acquisition and 

data system of the CdTe and Si-wafer 

replacement tools is compatible with PDIL data 

standards. It will also automate the actual 

operation of the electro-optical and surface 

analysis tools on the M&C central robot. This task 

continues work to develop a data technology 

bridge to the CSC. 
 

 

 

 

 

D R A F T

Systems Development Highlights 

A significant portion of the photovoltaic (PV) subprogram R&D budget falls into the Systems 

Development category. The goal of Systems Development is to rapidly advance the maturity and 

performance of commercial and near commercial PV manufacturing technologies. 

Systems Development comprises the following areas: 

• PV Systems Development 

• PV Component Development 

• Operations and Planning. 

Within PV Systems Development is a major program initiated in 2007. Technology Pathway 

Partnerships (TPPs) are industry-led projects that emphasize the development, testing, 

demonstration, validation, and interconnection of new PV components, systems, and 

manufacturing equipment. TPPs focus on technologies at the more advanced stage of maturity 

that are closer to the market but still face significant technological hurdles that can be overcome 

through partnership based research and development. TPPs are developed with clear levelized 

cost of energy (LCOE) metrics that helps focus awardees to address Total System Costs. TPPs 

have a minimum cost share requirement of 50%. 

Within the PV Component Development area is an innovative program that supports small 

companies in the development of new PV technologies. The PV Incubator Program supports the 

transition of verified PV devices to prototype products and early pilot production by leveraging 

National Renewable Energy Laboratory (NREL) R&D resources and mitigating risk through fixed 

firm pricing contracts. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Systems Development 15204 591 50522 66342 

PV Systems Development 964 200 45450 46614 

PV Component Development 13726 50 0 13776 

Operations & Planning 514 341 5072 5952 
 

 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

Technology Pathway Partnerships 

Performing Organizations: Amonix; The Boeing Company; BP Solar, Inc.; 

D R A F T

Dow Chemical Company; GE Global Research; GreenRay, Inc.; 

Konarka Technologies, Inc.; Nanosolar, Inc.; Soliant Energy, Inc.; 

Sunpower, Inc.; United Solar Ovonic LLC, National Renewable Energy 

Laboratory (NREL); Sandia National Laboratories (SNL) 

Key Technical Contacts:	 Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953, 

carolyn.elam@go.doe.gov 

Leon Fabick, DOE/GO, 303-275-4958, leon.fabick@go.doe.gov 

Jim Payne, DOE/GO, 303-275-4756, jim.payne@go.doe.gov 

Holly Thomas, DOE/GO, 303-275-4818, holly.thomas@go.doe.gov 

DOE HQ Technology Manager:	 Scott Stephens, (202) 586-0565, Scott.Stephens@ee.doe.gov 

FY 2009 Budgets:	 $42,339K TPP Recipients, $964K (NREL), $200K (SNL) 

Objectives 

•	 Bring better products to market and enable new applications. Develop modular, turnkey 

photovoltaic (PV) systems that offer residential and commercial customers a complete solution 

and attractive value proposition (e.g., enabling building-integrated PV [BIPV]and zero-energy 

homes). Develop designs and supply chains for large-field PV installations to service large 

commercial and utility renewable-generating requirements. Help U.S. companies leapfrog global 

competition with the best-designed, lowest-cost solar-energy solutions. 

•	 Foster development of the domestic PV industry. Catalyze collaboration across the value chain to 

(1) eliminate costs at the system level; (2) better optimize PV-system design; and (3) ensure 

superior performance and reliability. Demonstrate novel manufacturing processes that provide 

U.S. industry with a cost advantage and facilitate manufacturing scale-up. 

•	 Increase the effect of PV energy on the U.S. energy economy with results, including accelerate 

development of U.S.-produced PV systems so that PV-produced electricity reaches parity with 

the cost of electricity in grid-tied markets across the nation by 2015; enable expansion of the 

annual U.S. production capacity of PV systems from 240 MW in 2005 to as much as 2,850 MW 

by 2010, representing a tenfold increase; and foster research that will lower the cost of PVgenerated electricity to $0.05 to $0.10 per kWh by 2015 in residential, commercial, and utility 

markets. 

Accomplishments 

•	 Continued 11 Technology Pathway Partnership (TPP) awards into FY 2009 

•	 Assessed TPP Program Progress against objectives; Evaluated technology viability and ability to 

meet program critical criteria for 2010 objectives 

•	 Completed six Phase I Stage-Gate Reviews and three Phase II Stage Gate Reviews in FY 2009; 

remaining reviews anticipated for FY 2010 completion. 

Future Directions 

•	 Develop PV systems that by 2015 produce electricity at parity with the cost of electricity in select 

grid-tied target markets across the nation and expand the U.S.-installed domestic capacity of PV 

systems to 5 to 10 GW. 

1. Introduction	 of partnering with entities in the industry to 

accelerate commercialization of PV system R&D 

The TPP is an integral part of the Solar Energy to meet ambitious cost and installed-capacity 

Technologies Program (SETP). The TPP goals. 

represents a significant enhancement of the U.S. 

Department of Energy’s (DOE’s) business strategy 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

The TPP program will accelerate 

commercialization of solar PV systems by 2015. 

The specific goals of the 9-year TPP mission are: 

•	 Accelerate development of U.S.-produced PV 

systems substantively, so that PV-produced 

electricity reaches parity with the cost of 

electricity in select grid-tied target markets 

across the nation (see Table 1) 

•	 Expand the U.S.-installed domestic capacity of 

PV systems to 5 to 10 GW. 

The cost basis of electric energy in these markets 

is the kilowatt hour; therefore the TPP program 

uses targets for PV systems based on the 

levelized cost of energy (LCOE) delivered by 

these systems. This key metric is defined as the 

measure of total lifetime costs of a PV system 

divided by expected lifetime energy output, with 

appropriate adjustments for such factors as time 

value of money. Table 1 lists the overall cost goals 

for the TPP projects. 

Table 1. Cost Targets for Grid-Connected PV 

Systems in Key Market Sectors 

Market 

Sector 

Current 

U.S. 

Market 

Range 

(¢/kWh)1,2 

Solar Electricity Cost— 

Current and Projected 

(¢/kWh)1 

Benchmark Target 

2005 2010 2015 

Residential3 5.8–16.7 23–32 13–18 8–10 

Commercial3 5.4–15.0 16–22 9–12 6–8 

Utility4 4.0–7.6 13–22 10–15 5-7 1 Costs are based on constant 2005 dollars.
 2 Current costs are based on electric generation with conventional sources.
 3 Cost to customer (customer side of meter).
 4 Cost of generation (utility side of meter).
 

2. Program/Technical Approach 

The TPP program focuses on developing new and 

better PV solutions for the grid-tied electric power 

markets, including: 

•	 Residential rooftop market. Systems are 

typically mounted on rooftops and range from 

less than 1 kW to 10 kW, most commonly 3 

kW to 4 kW. These systems are connected to 

the grid on the retail (customer) side of the 

utility meter, and can be retrofitted for existing 

homes or integrated into new construction 

through BIPV designs. 

•	 Commercial rooftop market. Systems are 

typically mounted on the large flat roofs of 

commercial, institutional, and industrial buildings, and range in size from less than 10 kW 

to 500 kW and connected on the retail side of 

the utility meter. Retrofits and BIPV are 

possible applications in this market as well. 

•	 Utility market. These are large-scale (multimegawatt) systems displacing conventional 

utility-generated intermediate load electricity 

(e.g., natural gas CCT plants) for wholesale. 

Utility systems typically are ground-mounted 

and range in size from 1 to 100 MW, although 

much larger systems are being developed. 

Designs include both fixed and tracking 

configurations. 

The following approaches are designed to meet 

goals for these markets. 

•	 Industry-led: Applicants formulate all technical 

details regarding approach, timelines, 

milestones, and system integration. The 

national laboratories give critical support to 

DOE in monitoring technical progress, 

conducting tests and evaluations, and directly 

supporting TPPs on specific R&D tasks. 

•	 Focused on near- and mid-term results: 

Emphasis is on technologies with the greatest 

potential for cost-competitiveness in the period 

leading up to 2015. 

•	 System focus: The primary metric for the TPP 

program is the LCOE, based on the complete 

PV system rather than any component. TPP is 

working toward novel, integrated, PV systems. 

•	 Partnerships: Industry participants are strongly 

encouraged to formulate partnerships to 

address the spectrum of possible technical 

improvements in the PV-system value chain. 

•	 Market-based: All technical objectives 

established through SETP directly affect the 

market-based goals for cost, penetration, and 

job creation.. 

Each TPP project is planned in three 3-year 

phases to progressively reduce the cost of 

commercially available PV systems and 

components to ultimately yield commercial 

products and production processes that achieve 

the LCOE goals and support 2015 installed capacity targets. 

•	 Phase 1. Demonstrate pilot production of 

lower-cost systems. R&D project duration of 3 

years (2007–2010) allows companies the 

flexibility to align projects with their targeted 

business model, technical capabilities, and 

product/process maturity. 

•	 Phase 2. Demonstrate replication of low-cost 

pilot production. Project duration of 3 years 

(2010–2012), with new entrants eligible. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Phase 3. Develop supply chain and distribution infrastructure. Reduce capital expenditure 

intensity of manufacturing scale-up through 

targeted investments in such areas as 

equipment/feedstock suppliers and distribution 

channels. 

D R A F T

The 11 awards must demonstrate the benefits of 

their project based on the LCOE and installed 

capacity measures. Each award also falls into a 

“class” of either systems or subsystems defined as 

follows: 

•	 Systems-class projects (integrated systems): 

Focus on multiple technology improvements in 

PV component and system design, integration, 

and installation 

•	 Subsystems-class projects (componentbased): Focus on component-level technology 

developments for system improvements. 

Total DOE funding available for systems-class 

awards is limited to $20 million and subsystemsclass awards are limited to $8 million per 3-year 

period and require a 50% cost share of the total 

project costs. 

The awards began in FY 2007. They are funded 

through (approximately) annual budget periods, 

which conclude with a stage-gate review 

scheduled around major technical milestones or 

decision points. After the stage-gate review, DOE 

makes a determination about the continuation of 

the project into the next budget period. 

2.1. Stage-Gate Reviews 

A stage-gate management approach facilitates 

rigorous project management and supports 

continuous assessment of the awards. 

Deliverables must demonstrate the ability of each 

recipient to meet the DOE LCOE cost targets for 

their technology. The LCOE values depend on 

system performance and manufacturing costs; 

therefore these quantities are evaluated independently (performance evaluated by NREL/Sandia 

and cost evaluated by an independent contractor 

to DOE) to ensure that they are sufficient to 

demonstrate the stage-gate criteria were met. 

DOE conducts a programmatic review and 

decision to continue to the next phase as 

proposed, continue to the next phase with 

modifications, hold the project until more 

information is available, or discontinue the project. 

Figure 1 shows the steps of the stage-gate 

process. 

Fig. 1. Stage-gate review process. 

2.2. TPP Project Management Approach 

Project monitoring and technical oversight are 

conducted by a team from the DOE Golden Field 

Office, which manages and administers the 

cooperative agreements; DOE Headquarters; and 

technical monitoring support provided by NREL 

and SNL. 

This management approach uses a technical 

monitor who is cognizant of the technology being 

developed. Technical monitors are from one of the 

National Center for Photovoltaics laboratory 

partners (NREL or SNL). Assignments are made 

based on the alignment between the skills and 

experiences of lab personnel and the R&D 

activities of the project. The technical monitors are 

an integral part of the project management team, 

and assist DOE in overseeing and assessing the 

progress of TPP projects. 

In this capacity, they give substantial technical 

assistance and guidance, facilitate interactions 

with additional technical experts as needed, and 

ensure timely access to DOE-funded laboratory 

resources when required for the project (e.g., test 

facilities). The technical monitors also perform 

technical evaluations during the stage-gate 

reviews and evaluations of technical progress 

against milestones; consult on the go/no-go 

decision points and critical success factors; and 

participate in, and make recommendations from, 

the stage-gate reviews. 

3. Results and Accomplishments 

Amonix Inc.: Fielded the Amonix 7700 Solar 

Power Generator equipped with III-V, multijunction 

solar cells. 

Boeing Co.: Increased average production lot cell 

efficiency to 28.5% and demonstrated cell 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

efficiency > 39% using experimental metamorphic 

cells; completed proof of design for CPV system 

deployed and under test at multiple locations. 

BP Solar Inc.: Demonstrated 18.35% Mono2TM top 

performing cell. 

GreenRay Inc.: Verified 50-year inverter lifetime 

with in-house stress testing. 

Konarka Technologies Inc.: Demonstrated the 

utility of adhesive fillers for stabilizing modules that 

allow > 1,000 hours of stable performance at 

65°C/85% humidity. 

Nanosolar Inc.: Completed TUV panel certification 

and also passed the requirements for a UL Class 

A fire rating. 

Soliant Inc.: Designed and built pilot plant capable 

of producing more than 1 MWp per year of 

manufactured tracking/concentrating solar panels. 

SunPower Inc.: Achieved world-record panel 

efficiency at 20.4%, as verified by NREL. 

United Solar Ovonic LLC: Obtained NRELconfirmed 11.7% stable total-area efficiency on aSi:H/nc-Si:H/nc-Si:H triple-junction device. 

3.1 Stage-Gate Reviews 

Six Phase I stage-gate reviews were completed 

during FY 2009. Results of the reviews are as 

follows. 

•	 Dow Chemical Co. (11/06/08); Hold, pending 

revised testing results of flexible roofing 

product. 

•	 GE Global Research Inc. (11/29/08); Project 

not continued. Met Phase I technical 

objectives. See OSTI database 

(http://www.osti.gov/) for detailed technical 

results. 

•	 Nanosolar Inc. (11/29/08): Pass to Phase II; 

on track to meet project targets, proceed as 

planned. 

•	 SunPower Inc. (11/30/08): Pass to Phase II, 

continue to fund project at a reduced level of 

effort. 

•	 BP Solar Inc (01/27/09): Pass to Phase II; on 

track to meet project targets, proceed as 

planned. 

•	 Soliant Energy Inc. (02/10/09): Pass to Phase 

II; on track to meet project targets, proceed as 

planned. 

Three Phase II stage-gate reviews were 

completed during FY 2009. Results of the reviews 

are as follow: 

•	 The Boeing Co. (07/15/09): Pass to Phase II; 

on track to meet project targets, proceed as 

planned. 

•	 Konarka Technologies (08/25/09): Pass to 

Phase I; on track to meet project targets, 

proceed as planned. 

•	 GreenRay Inc. (08/27/09): Pass to Phase II; 

on track to meet project targets, proceed as 

planned. 

3.2 TPP Awardee Progress 

Progress for each TPP awardee is summarized in 

this report. 

4. Planned FY 2010 Activities 

Stage gates anticipated for FY 2010 are shown in 

Table 2. 

Table 2. TPP Award Recipients, FY 2009 Funding, Stage-Gate Schedule 

TPP Recipient 

FY 2009 

Obligation Start Date 

Stage-Gate I 

Date 

Stage-Gate II 

Date 

Amonix Inc. $5,740,496 5/14/07 6/24/08 10/20/09 

The Boeing Co. $4,216,900 7/1/07 6/26/08 7/15/09 

BP Solar Inc. $3,934,505 9/1/07 1/27/09 1/26/10 

Dow Chemical Co. - 8/1/07 11/06/08 Pending 
D R A F 

T

GE Global Research Inc. $1,265,464 9/1/07 11/19/08 * 

GreenRay Inc. $1,149,515 1/1/07 6/18/08 8/27/09 

Konarka Technology Inc. $866,421 7/1/07 9/4/08 8/25/09 

Nanosolar Inc. $8,096,247 9/1/07 11/29/08 11/4/09 

Soliant Energy Inc. $1,081,928 9/1/07 2/10/09 4/10 

SunPower Corp. $9,552,817 9/1/07 11/30/08 11/5/09 

United Solar Ovonics LLC $5,434,499 4/30/07 8/27/08 11/13/09 

*Project completed 6/30/09. 
 

 

 

 

 

 

 

 

 

D 

 

R A F T

TPP Awardee: Amonix Inc. 

“Low Cost High Concentration Photovoltaic Systems for Utility Power Generation” 

Total Award Amount: $33,635,272; DOE/Recipient Share: $15,605,631/$18,029,642 

Objectives 

•	 Develop a high-volume (25 MW/year), low-cost manufacturing facility in 3 years 

•	 Redesign components of the high-concentration PV system for high-volume, low-cost
 

manufacturing and installation
 

•	 Conduct reliability testing of redesigned system components 

•	 Incorporate III-V multijunction solar cells into redesigned system. 

Accomplishments 

•	 Fielded the Amonix 7700 Solar Power Generator equipped with III-V multijunction solar cells 

•	 Developed a parameter model well correlated to more than 12 months of field performance 

•	 Compiled energy performance data for a proposed IEC energy rating specification for
 

concentrating photovoltaics (CPV)
 

•	 Conducted accelerated life tests under an NREL CRADA for validating and improving cell
 

package designs
 

•	 Sent representative test modules to UL for certification to IEC 62108 and UL 8703 

•	 TUV conducted tests on representative modules to obtain CEC listing 

•	 Sandia measurements of MegaModule performance exceeded stage-gate milestones for Phase II 

and Phase III 

•	 Completed Amonix LCOE roadmap out to 2015 with SAM results falling within LCOE goal ranges 

set out by the DOE SETP 

•	 Based on TPP accomplishments, Amonix identified a major investor for the next round of funding 

needed to commercialize Amonix’ CPV systems. 

Future Directions 

•	 Complete IEC 62108 qualification and UL 8703 safety certification 

•	 Demonstrate 25 MW/year manufacturing facility 

•	 Expand reliability studies through system deployment, compilation of reliability data, and 

investigation of lifetime determination methods.
 

1. Introduction 

The principal objectives of this project are to meet 

DOE’s LCOE goals for 2015 and enable Amonix to 

successfully compete in large-scale utility markets 

with its CPV systems. The project consists of 

tasks leading to reduced material costs, system 

performance increases, improvements in 

reliability. and, most important, cost reductions 

owing to high-volume manufacturing. 

2. Technical Approach 

Amonix expanded its production capacity to 

25MW/year by building a production line for 

automated manufacturing of all components of the 

MegaModule, including cell packages, receiver 

plate, and module structure. 

During the first phase, all effort shifted from silicon 

to III-V multijunction cells to more quickly meet the 

TPP LCOE goals. Although this shift entailed 

additional risk, a significant payoff was realized by 

incorporating these much higher efficiency solar 

cells into the Amonix MegaModules. 

During FY 2009, the project continued to develop 

all non-solar-cell components of the Amonix 

MegaModule by redesigning them for low-cost and 

high-volume manufacturing. For example, the 

MegaModule depth was reduced in the project’s 

first phase to reduce steel costs. A fast-cure 

adhesive for lens attachment was also developed 

in the project’s first phase. During Phase II, 

Amonix reviewed designs for the pedestal, drive, 

and torque tube and identified high-volume 

suppliers. The drive, controls, and installation 

processes were improved for high-volume 

installation and lower cost. Optimized III-V 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

multijunction cells were produced for field use in 

the MegaModules. The cell packages were 

adapted to accommodate the III-V Multijunction 

cells and began extensive field, qualification, and 

accelerated tests to ensure reliability. Amonix 

fabricated and tested HCPV systems, leading to 

its new 7700 product consisting of a seven 

MegaModule array on a single pedestal. 

Amonix worked with suppliers and partners for 

lens fabrication, III-V multijunction cells, and cell 

packaging; MegaModule manufacturing 

equipment, pedestals, trackers, and inverters; and 

installation, testing, and system demonstration 

with interested customers. The outcome was new 

suppliers identified that can meet the performance, 

reliability, and cost requirements for manufacturing 

Amonix’s 7700 product. 

3. Results and Accomplishments 

In March 2009, Amonix announced its latest 

product, the Amonix 7700 HCPV solar-powered 

generator. The 7700 is powered by the world’s 

most efficient III-V multijunction solar cells and is 

rated at 53 kW AC under PVUSA test conditions. 

Researchers developed a multijunction parameter 

model to predict power and energy generation of 

the Amonix systems. This model demonstrates a 

strong correlation between prediction and more 

than 12 months of energy generation. The model 

incorporates soiling as well as atmospheric 

variation using meteorological data from the TMY3 

database. The only adjustable parameter is the 

schedule for cleaning the lenses. The parametric 

model was also used to generate peak power and 

annual energy predictions for five prospective 

deployment locations. 

Daily energy (kWh) generated and plotted as a 

function of the direct normal solar radiation 

(kWh/m2

/day) shows a strong linear correlation 

over 6 months. The data were presented to IEC 

TC82 WG7 for its consideration as an IEC 

Technical Specification for CPV energy 

performance rating. 

Results from Highly Accelerated Life Testing 

(HALT) studies conducted at NREL allowed one 

major failure mode to be addressed and revealed 

a second failure mode, which led to an improved 

design. 

A set of 14 representative modules, each about 1 

m2

, was prepared and sent to UL in San Jose, CA, 

for testing to IEC 62108 (qualification standard) 

and UL 8703 (safety standard). Amonix sent a fullsize test MegaModule and control MegaModule to 

UNLV for witness testing by UL. TUV conducted 

tests on another set of representative modules to 

obtain CEC listing for the Amonix 7700 to qualify 

for California Solar Initiative programs. 

Sandia measured the performance of the Amonix 

MegaModule in September 2009. Sandia 

determined that the MegaModule surpassed the 

stage-gate review efficiency milestones for both 

Phase II and Phase III. The efficiency was 

measured to be 28.7% at STC (DNI = 1000 W/m2

, 

AM1.5D, Tcell=25°C) or 28.9% at CPV-STC (DNI = 

850 W/m2

, AM1.5D, Tcell=25°C). 

Performance projections from the Amonix power 

waterfall and the pricing assumptions from the 

business plan were used to complete the LCOE 

roadmap for Amonix through 2015. The LCOE 

projections for Amonix fall within the LCOE goal 

ranges set out by DOE’s SETP. 

Despite the difficult economy in 2009, Amonix 

found potential investors, project developers, and 

customers were quite interested in Amonix’ new 

MegaModule technology developed as a result of 

this TPP. This interest bodes well for 2010. 

4. Planned FY 2010 Activities 

•	 Demonstrate operation of 25 MW/year 

production rate in Seal Beach 

•	 Qualify MegaModule system to IEC 62108, UL 

8703 and obtain CEC listing. 

•	 Compile reliability data on deployed HCPV 

systems. 

5. Major FY 2009 Publications 

R.	 McConnell, M. Symko-Davies, and S. Kurtz, 

Conference Co-Chairs of 5th International 

Conference on Solar Concentrators, Palm 

Desert, CA, Proceedings CD, ISBN: 978-0-615­

29119-2 (November 2008) 

G. Kinsey and K. Edmondson, “Spectral Response 

and Energy Output of Concentrator Multijunction 

Solar Cells,” Prog. Photovoltaics (December 

2008) 

G. Kinsey, P. Pien, P. Hebert, and R. Sherif, 

“Operating Characteristics of Multijunction Solar 

Cells,” Solar Energy Mater. Solar Cells (June 

2009). 

R. McConnell, V. Garboushian, J. Brown, C. 

Crawford, K. Darban, D. Dutra, S. Geer, V. 
 

 

 

 

 

 

Ghassemian, R. Gordon, G. Kinsey, K. Stone, Systems II, N. Dhere, J. Wohlgemuth, and D.
 

and G. Turner, “Assuring Long-Term Reliability Ton, editors, Proc. SPIE 7412, 741208 (2009).
 

of Concentrator PV Systems,” Reliability of
 

Photovoltaic Cells, Modules, Components and
 

6. University and Industry Research Partners 

D R A F T

Organization Location Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

University of Nevada, 

Las Vegas 

Las Vegas, NV Installation and testing of Amonix 

MegaModules 247 0 

NREL Golden, CO Cooperative R&D agreement for 

HALT studies 30 0 

State Engineering 

University of Armenia Yerevan, Armenia DLC coatings 27 0 
 

 

 

 

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R A F T

TPP Awardee: The Boeing Co. “Concentrator Photo Voltaic Power System” 

Total Award Amount: $45,315K; DOE/Recipient Share:$19,981K/$25,334K 

Objectives 

•	 Develop a new CPV system, incorporating high-efficiency multijunction cells, for the utility-scale 

PV power market 

•	 Employ a novel nonimaging optical design to optimally use cell performance while addressing the 

reliability and cost of the tracker and balance of systems equipment 

•	 Increase the efficiency of production multijunction solar cells for high-concentration terrestrial 

applications from 36% to 40% by 2010 

•	 Reduce the cost of such cells by more than 50% and increase cell production capacity to 1 

GW/year by 2015 

•	 Achieve a $0.15/kWh LCOE by 2010 and $0.07/kWh by 2015. 

Accomplishments 

•	 Increased average production lot cell efficiency to 28.5% 

•	 Demonstrated cell efficiency > 39% using experimental metamorphic cells (9 months ahead of 

schedule) 

•	 Increased cell production throughput to > 20 MW/year (more if market demand warrants) 

•	 Demonstrated production of C4MJ metamorphic cells with efficiencies > 39% 

•	 Deployed one full-size panel (15 m2

) and four remote test sites with minimum two modules 

supporting life testing in real world environments 

•	 Selected site for 100-kW demonstration power plant and started construction 

•	 Demonstrated greater than 30% module active-area efficiency 

•	 Validated the cost reduction efforts required to hit the $0.15/kWh LCOE target 

•	 Started construction of a demonstration 1-2 MW/year robotic assembly factory 

•	 Completed mechanical design for a Boeing tracker 

•	 Started debugging Boeing controller software 

•	 Completed qualification of PV powered 260-kW inverter with an industry-best, 10-year warranty 

•	 Selected licensee and signed commercialization agreement ensuring the future of the products 

developed on the SETP-TPP program. 

Future Directions 

•	 Deploy C4MJ cells in real-world applications 

•	 Deploy 100 kW power plant at California State University, Northridge (CSUN) 

•	 Install Boeing trackers and controllers at the CSUN site 

•	 Design next-generation module to ensure path toward LCOE < $0.15/kWh 

•	 Investigate protective coatings for the first surface mirror and antireflective coatings for the cover 

glass and secondary lens 

•	 Continue developing relationship with licensee to ensure future commercialization of the SETPTPP developed products. 

1. Introduction	 energy, it is possible to reduce the area (and cost) of 

the semiconductor per watt of power produced. This 

Boeing has long been a leader is solar cell technology project has a dual focus: first to increase the 

through its wholly owned subsidiary, Spectrolab. The efficiency of Spectrolab’s cells while reducing cost 

Boeing TPP Concentrator PV project is intended to and second to develop the concentrator system that 

leverage this technical leadership and to expand uses those cells to produce power. 

Spectrolab’s market in terrestrial solar power. 

Spectrolab’s leadership is in multijunction (III-IV) 2. Technical Approach 

gallium arsenide solar cells. This project uses 

multijunction cells and unique optics to concentrate During FY 2009, Boeing and its team partners 

solar radiation by 700x. By concentrating the solar continued their TPP activities started in 2007. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Spectrolab continued to lead the industry with the 

development of C4MJ advanced metamorphic cells. 

Cell efficiencies > 39% have been demonstrated. 

The Boeing Research and Technology team 

completed the design of the off-axis CPV panel. One 

full-size panel and four remote test systems were 

built, each employing a minimum of two modules at 

each site. To date, the full-size panel has been on 

sun for 9 months with no measurable degradation in 

performance. Boeing also supplied one module to 

NREL for testing. That module continues to perform 

as expected. The team also pursued system 

engineering approaches to drive down LCOE in a 

verifiable manner. Team member PV Powered 

improved the reliability of its next-generation inverter 

and validated its operation through UL certification. 

The 260 kW inverter is the second inverter product to 

receive UL certification under this program. 

D R A F T

3. Results and Accomplishments 

•	 Produced 38.5% average production efficiency 

cells during the engineering confidence run for 

the production C3MJ cell design and completed 

that generation’s Final Design Review 

•	 Implemented automated tooling at Spectrolab for 

cell manufacturing and demonstrated annualized 

production rate of 20 MW/year 

•	 Completed installation of one full-size array and 

remote test systems in four locations 

•	 Demonstrated a module acceptance angle 

greater than 1.9° and measured a panel 

acceptance angle greater than 1°, within the 

expected value based on our tolerance analysis 

•	 Demonstrated active-area efficiency of greater 

than 30%. 

Fig. 2. Production module 

Two-axis array trackers were purchased and 

evaluated. The evaluation result was a decision to 

pursue a Boeing tracker solution. The mechanical 

design is complete for a new tracker and the control 

software is being tested. The tracker control algorithm 

is innovative and will offer a significant cost savings. 

Team member PV Powered obtained UL certification 

of their new 260-kW inverter. Reliability improvements 

resulting from this program allowed PV Powered to 

offer a 10-year standard warranty, the first in the 

industry, for a nominally increased cost. This should 

be viewed as a singular success for the TPP 

programs. 

•	 Completed power plant system for the initial 

deployment at CSUN, to augment the green 

energy programs already in place there 

•	 Validated the detailed LCOE model and 

established a path to meeting the $0.15/kWh 

LCOE target 

•	 Participated in various IEC WG7 standards 

committees, particularly the CPV tracker 

committee and the system energy rating 

committee. 

4. Planned FY 2010 Activities 

•	 Demonstrate production mean cell efficiency of at 

least 38.5% (06/09) 

•	 Perform module environmental test using C4MJ 

cells and criteria consistent with IEC 62108 

(06/09) 

•	 Install 100 kW capacity at CSUN 

•	 Demonstrate pilot production of inverter and 

tracker (06/09) 

•	 Begin planning for a 1–2 MW reference power 

plant to begin construction in early 2011 in 

conjunction with our licensee. 
 

 

 

 

 

 

5. FY 2009 Special Recognitions, Awards, and Presentation will be given at the Printed Electronic 

Patents USA 2009, San Jose, CA, Dec. 2–3, 2009. 

D R A F T

N.H. Karam, “Ultrahigh Efficiency Multi-junction Solar 

Two patent applications were filed in 2009: Cells for Terrestrial Applications," to be presented 

61/091,284 Flexible Thermal Cycle Test Equipment at Arizona State University, Tempe, Nov. 6, 2009. 

for Concentrator Solar Cells (provisional) R.W. Morris and J.M. Fife, “Using Probabilistic 

12/258,321 Flexible Thermal Cycle Test Equipment Methods to Define Reliability Requirements for High 

for Concentrator Solar Cells Power Inverters,” 

N. Karam, R. King, R. Jones, P. Pien, and J. Ermer, 

6. Major FY 2009 Publications	 “Recent Progress in Concentrating Photovoltaic 

Solar Cell Technology and Manufacturing,” 

“Electric Energy Generation using Concentrating presented at SPIE Conf., August 2009. 

Photovoltaic III-V Solar Cell Technology,” 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009 

Organization Location 

Description or Title of 

research FY2009 

Cost 

Share 

SPL Sylmar, CA 

Solar cell performance 

improvements $5,329,278 $2,982,321 

LPI 

Los 

Angeles/Madrid 

SP 

Optics development and parts 

for demonstration hardware $1,456,210 $458,408 

PV Powered Bend, Or Qualify 260 kW inverter $548,661 $548,661 

Comau Detroit, MI Automated factory optimization $424,108 $0 

UCI Irvine, CA 

Solar tracker mechanical 

structure study $4,500 $0 

UC-Boulder Boulder, CO Low-cost CPV tracker $65,082 $0 

CSUN Northridge, CA Conceptual design: Solar track $24,331 $0 
 

 

 

 

 

 

 

 

 

 

 

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D 

 

R A F T

TPP Awardee: BP Solar International Inc.
 “Reaching Grid Parity Using BP Solar Crystalline Silicon Technology”
 

Total Award Amount: $39,693; DOE/Recipient Share: $19,431/$20,262 

Objectives 

•	 Reduce module cost to 67% of 2006 costs by 2010 and to 50% of 2006 costs by 2015 

•	 Develop process for fabrication of solar grade silicon 

•	 Optimize and implement Mono2TM casting technology to improve material quality 

•	 Develop BIPV products designed for specific value-added applications. 

Accomplishments 

•	 Completed pilot trial of Mono2TM ingots, transferring the full process into production and producing 

650,000 wafers (1.5 MW worth) 

•	 Demonstrated contaminant reduction in the casting process 

•	 Developed process for wafering 156 mm square, 180 μm thick wafers and transitioned newer 

production saws to this process 

•	 Demonstrated 18.35% Mono2TM top performing cell 

•	 Demonstrated an advanced metallization process developed by PARC realized an efficiency gain 

of +1.0% absolute driven by Isc and FF improvements 

•	 Performed a 520 module pre-production run at BP Solar with the half-cell module design; average 

power for the modules was 245 W (module efficiency 14.5%) 

•	 Completed a pilot run of 5 kW of silicone encapsulated modules 

•	 Completed development of TPO membrane supermodule and built samples for qualification 

testing and demonstration on a roof 

•	 Demonstrated remote dispatchability of stored energy from SMUD House of the Future. 

•	 Completed fabrication of HV-MPPT charge controller prototypes and conducted full HALT- MultiEnvironment Over Stress Test (MEOST ). 

Future Directions 

•	 Demonstrate 16% cell efficiency using silicon cast with 100% solar grade material 

•	 Continue to develop the Mono2TM and demonstrate 15% module efficiency 

•	 Complete development of a roof integrated PV module and submit for certification 

•	 Define a module production process that achieves cost reductions to 67% of the 2006 BP Solar 

baseline 

•	 Verify that both the residential and commercial systems under development will meet the DOE 

LCOE 2010 target goals. 

1. Introduction	 2. Technical Approach 

BP Solar’s TPP program is based on accelerated The BP Solar program addresses all aspects of 

development of multicrystalline silicon technology the PV product chain from raw materials including 

for use in the residential and commercial markets, silicon through installation of the systems at the 

using products specifically designed for these customer site. To achieve parity with the grid and 

applications. The goals of this program are to growth to gigawatt levels of production requires 

achieve grid parity and increase production involving the entire product chain. Partners in this 

volume. To meet these goals, our objectives are to effort include: 

substantially reduce 1) module cost to 67% of the • Key materials vendors (Dow Corning for 

2006 cost by 2010 and to 50% of the 2006 costs silicon, encapsulants, and pottants; Ceradyne 

by 2015; and 2) system costs to 60% of 2006 cost for crucibles; STR for EVA; and AGC Flat 

by 2010 and to 36% of 2006 costs by 2015. These Glass North America for glass) to assist in 

are projected to result in LCOE of 8¢–10¢/kWh for lowering cost, improving quality and 

residential systems and 6¢– 8¢/kWh for performance, and ensuring that the material 

commercial systems by 2015. will be available in the volume necessary 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Equipment vendors (Komax and ATS) to 

assist in developing the next generation of 

equipment for automated production at high 

volumes 

•	 Vendors of balance of systems equipment 

(Xantrex for inverters, Comverge for energy 

dispatchability) to improve reliability, increase 

lifetime, increase volume, and lower cost 

D R A F T

•	 Universities (Georgia Tech, Arizona State 

University, North Carolina State University, 

and University of Central Florida) and a 

research laboratory (PARC) to support 

research. 

•	 A utility (SMUD) will supply customer 

interface, demonstration sites, and the utility 

prospective on the value of PV electricity. 

Key components of the program include: 

•	 Silicon purification process development of 

solar grade silicon to increase the availability 

of silicon feedstock for the PV industry 

•	 Casting: Implementation of Mono2TM 

technology (single crystal quality at multi cost) 

•	 Wafering: thinner wafers down to 160 μm in 

2010 and to 100 μm in 2015; thinner wire; 

improved slurry and slurry recycling; and 

automated demounting and singulation of 

wafers 

•	 Cell Process: Optimized design and 

processing for ultra-thin Mono2TM to achieve a 

cell efficiency of 18% in 2010 and 20% in 2015 

•	 Module: Lower material costs, products 

designed for integration into specific roof 

types, and safe operation at high voltages 

•	 Automation and process control to transition 

from hundreds of cells per hour to hundreds of 

cells per minute 

•	 Higher efficiency, increased reliability inverters 

•	 Improved low cost systems monitoring 

•	 Reduced indirect costs through organized 

deployment channels and integrated solutions. 

3. Results and Accomplishments 

Results are described by topic. 

3.1 Silicon Feedstock 

Solar grade silicon (SGS) purchased from a 

commercial vendor was mixed in a ratio of 93% 

SGS to 7% semiconductor grade Si, cast into 

multicrystalline ingots, and processed on the cell 

line. The cells from the three ingots matched the 

cell efficiency and yields of standard ingots 

processed with 100% semiconductor grade, 

except for slightly higher levels of shunt rejects. 

Ten cells, each measuring > 16% efficiency were 

delivered to DOE. 

3.2 Casting 

A large Mono2TM trial was run with 55 ingots 

produced. Process procedures were documented 

and operators trained beforehand to allow 

operation personnel to learn all production 

aspects. A total of 650,000 wafers were cut. Cell 

fabrication is now under way. Process economics 

were carefully tracked 

3.3 Wafering 

Production trials were undertaken with 120 μm 

diameter wire used to cut 160 μm wafers. The 

yields were considerably lower for the thinner 

wafers with the largest yield loss due to cleaning 

and separating after the actual cutting process. 

Improvements to the cleaning and handling 

equipment and process are necessary before 160 

μm thick wafers can be implemented in 

production. 

3.4 Cell Process 

Efforts during Phase II included implementing 

processes developed during Phase I as well as 

identifying future processes for high efficiency. 

Processes optimized on the cell line included: 

•	 Improved back print design achieving a 0.6% 

relative gain in average cell efficiency and a 

1% gain in module efficiency 

•	 Optimized SiN deposition process and co-fire, 

resulting in a 0.6% relative gain in average cell 

efficiency 

•	 Improved control over process to eliminate 

visual stains, resulting in a 2% increase in 

yield. 

Laboratory efforts to improve processing of 

Mono2TM , including texturing, selective emitter, 

diffusion/SiN optimization, and rear passivation, 

resulted in best cell efficiencies of 18.3% with a 

group average of approximately 17%. 

3.5 Module Development 

New product development included work on a 

residential roofing tile, a module that integrates 

into a commercial roofing material, a half-cell 

module that increases module efficiency, and an 

encapsulant that helps reduce module 

temperature. 

3.6 Manufacturing 

BP Solar implemented statistical process control in 

the production line to improve control and reduce 

yield loss. A new method for measuring and 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

controlling the SiN color, thickness, and index of 

refraction was implemented. 

3.7 Inverter 

Partner Xantrex completed design of a charge 

controller for high-voltage PV systems for use with 

battery storage. The full prototype design was 

successfully tested via MEOST, a new extension 

to HALT with the addition of voltage stress cycles. 

3.8 Monitoring and Control 

Partner Comverge installed a cellular gateway in 

the SMUD House of the Future and verified its 

operation via remote server. During the summer, 

web-enabled battery charging and discharging 

was successfully tested and a battery discharge 

schedule was developed that coincided with 

SMUD’s peak usage period. 

3.9 System Engineering 

The mounting system for the Generation 2 BIPV 

residential roofing product passed in-house wind 

uplift testing. The mounting design was modified to 

improve the spread of lame test results. 

3.10 System Installation and Maintenance 

A trial installation of the residential roofing product 

was completed in conjunction with ASU Design 

Center, a roof tile manufacturer, and a home 

builder. Carlisle supplied details on the installation 

procedures for roofing membranes and assisted 

BP Solar in designing an integrated PV roofing 

membrane product. 

3.11Deployment 

BP has been assessing some commercially 

available software tools designed to predict PV 

system performance. The initial results indicate 

that various tools give significantly different results 

and that they all have trouble duplicating actual 

performance under some sets of operating 

conditions. 

3.12 Collaboration 

BP participated in Solar ABCs, IEC, ASTM, and 

UL efforts in PV standards and codes 

development. 

4. Planned FY 2009 Activities 

•	 Demonstrate processes and cost model for 

lowest cost purification of UMG Si to make 

SoG Si 

•	 Demonstrate full commercial production of 

SoG Silicon 

•	 Demonstrate efficiency boost from 

contaminant reduction in casting process 

•	 Define and demonstrate process for lowest 

possible cost per kg of Mono2TM manufacturing 

•	 Complete development of equipment and 

processing with new station and make 

decision to expand capacity using this design 

•	 Demonstrate wafering, cleaning, and 

demounting of 100 μm thick wafers 

•	 Select and prototype a preferred process for 

passivated rear point contacts 

•	 Achieve 18% average cell efficiency using 

processes compatible with 160μm wafers 

•	 Complete development and qualification of 

two residential and one commercial roofing 

products and begin commercialization 

•	 Complete development and offer charge 

controller along with inverter for commercial 

sale 

•	 Complete development and testing of monitor 

and control unit and make decision to 

commercialize 

•	 Complete three residential demonstrations 

•	 Complete one commercial building 

demonstration. 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

Five disclosures related to this program were 

submitted in FY 2009. Three patent applications 

were submitted to the US Patent Office in FY 

2009. 

6. Major FY 2009 Publications 

D.W. Cunningham, D. Amin, A. Nguyen, J. Miller, 

Z. Xia, and J. Wohlgemuth, “Key Aspects of 

Module Design That Influence Energy 

Generation,” 24th European PVSEC, September 

2009. 

N.G. Stoddard, R. Sidhu, J. Creager, S. Dey, B. 

Kinsey, L. Maisano, C. Phillips, R. Clark, and J. 

Zahler, “Evaluating BP Solar’s Mono2 TM Material: 

Lifetime and Cell Electrical Data,” 34th IEEE 

PVSC, 2009. 

J. Wohlgemuth, R. Clark, J. Posbic, J. Zahler, M. 

Gleaton, D. Carlson, and D. Cunningham, 

“Reaching Grid Parity Using BP SOLAR 

Crystalline Silicon Technology,” 34th IEEE 

PVSC, 2009. 

Z. Xia, D. Cunningham, and J. Wohlgemuth, A 

“New Method for Measuring the Cross-link 

Density in Ethylene Vinyl Acetate Based 

Encapsulant,” PV International, 5th edition, 2009. 

Z.	 Xia, D. Cunningham, and J. Wohlgemuth, “A 

Non-solvent Extraction Method for Measuring the 
 

 

 

 

 

 

 

D R A F T

Gel Content of Ethylene Vinyl Acetate as PV Based Backsheet Materials,” SPIE Solar Energy 

Encapsulant,” 34th IEEE PVSC, 2009. and Technology Conference, August 2009. 

Z. Xia, J.H. Wohlgemuth, and D.W. Cunningham,  Z. Xia, J.H. Wohlgemuth, and D.W. Cunningham, 

“A Semi-empirical Method of Predicting the “Lifetime Prediction of PV Encapsulant and 

Lifetime of EVA Encapsulant and Polyester Backsheet via Time Temperature Superposition 

Principle,” 34th IEEE PVSC, 2009. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization Location Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Dow Corning Midland, MI 

Solar-grade Si feedstock for the 

casting process; develop 

alternative silicone encapsulation 

system 

1,300 1,300 

AGC Flat Glass NA Kingsport, TN Develop solar glass with AR 

coatings 75 137 

ATS-Ohio Lewis Center, OH Develop automated thin wafers 

and cells handling equipment 197 0 

Arizona State University Tempe and Mesa, AZ 

Evaluate PV module and array 

performance; monitor residential 

PV system; model power 

distribution system and advanced 

power converters; design BIPV 

products 

284 66 

Ceradyne Thermo 

Materials Clarkston, GA Develop large-area, high purity crucibles for silicon casting 152 152 

Georgia Institute of 

Technology 

Atlanta, GA Design, optimize, and fabricate 

high-efficiency solar cells on BP 

Solar cast silicon wafers 

70 0 

Komax Systems York York, PA Develop screen print and 

tabbing/stringing equipment for 

thin PV cells 

135 183 

PARC Palo Alto, CA Develop, qualify a gridline printing 

system 12 12 

BASF Wyandotte, MI Design, develop residential BIPV 

molded module frames 49 49 

Sacramento Municipal 

Utility District 

Sacramento, CA Supply utility prospective to and 

demonstration sites for residential 

and commercial PV systems 

5 

STR Enfield, CT Develop of low-cost, highperformance encapsulants 70 70 

University of Central 

Florida 

Coco, FL Study module energy collection, 

PV connector performance, and 

module leakage current 

140 0 

Xantrex Technology Inc. Burnaby, BC 

Develop high-reliability, batterybacked, grid-tie inverter power 

conversion system 

0 400 

North Carolina State 

University 

Raleigh, NC Evaluate BP cast multicrystalline 

and mono2 silicon 92 0 

Comverge Kennett Square, PA 

Development of data acquisition 

systems for PV systems with 

remote deployment of stored 

energy 

58 58 
 

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D R A F T

TPP Awardee: Dow Chemical Co. Inc. 

“Fully Integrated Building Science Solutions for
 

Residential and Commercial Photovoltaic Energy Generation”
 

Total Award Amount: $19,649; DOE/Recipient Share $9,824/$9,825 

Objectives 

•	 Reduce the total systems cost by revolutionizing the design; incorporating mass production 

module fabrication; and developing solutions that are driven by the targeted applications 

•	 By 2010, reduce LCOE for residential BIPV to $3.85/W installed. 

Accomplishments 

•	 Validated shingle design concepts with respect to decreasing installation costs 

•	 Determined materials needed in robust, long-term packaging components 

•	 Met minimum cell efficiency requirements for roadmap to meet LCOE targets. 

Future Directions 

•	 Scale up pilot line for low-cost manufacturing of shingles 

•	 Transfer residential shingle developments to commercial roofing product concepts. 

1. Introduction 

Dow is working to develop modular, turnkey PV 

systems that offer residential and commercial 

customers a complete solution and attractive value 

proposition. Dow’s approach to a complete 

solution is to reduce the total systems cost by 

revolutionizing the design, incorporating mass 

production module fabrication, and developing 

solutions that are driven by the targeted 

applications as opposed to reconfiguring or 

modifying modules that had been designed for 

alternative purposes (e.g., ground-mounted solar 

farms and other rigid applications). Dow is working 

on all components of a turnkey system through 

existing channels with the building, construction, 

and infrastructure markets. Dow has partnerships 

with home builders (Pulte Homes and Lennar 

Homes), access to balance of system components 

through Dow Wire and Cable, and channels to the 

roofing industry through the wholly owned 

subsidiary Dow Roofing Systems. 

2. Technical Approach 

Dow developed a shingle design ready for pilotscale production. A smaller version was designed 

to test interconnects, packaging materials, and 

installation techniques. Several design issues 

were resolved to be applied in the full-size shingle. 

Shingle design was affected by a change in cell 

supplier. We were able to rapidly qualify another 

CIGS manufacturer to aid our development. This 

manufacturer, Global Solar, Inc., operates two 

large-scale CIGS PV manufacturing sites, one in 

Tucson, AZ, and one in Berlin, Germany. 

Dow expended significant effort on materials 

characterization and development to design a 

CIGS PV cell package that was suitable for the 

shingle functional format. This was accomplished 

using both external products and internal 

technology under development. 

3. Results and Accomplishments 

Milestones Achieved: 

•	 Secured cell supply for prototype development 

•	 Produced working prototype shingles with 

packaging material (03/08) 

•	 Produced full-scale shingle (07/08) 

•	 Reviewed cost model with Navigant. 

Competitive Benchmarking, Cell Supply, and 

Shingle Development 

Dow worked to set a baseline for performance of 

competitive products in the market from both a PV 

cell perspective and a packaging materials 

perspective. 

System Engineering and Integration 

Dow is new to solar product development, and 

spent a considerable amount of time developing a 

BIPV material test plan to qualify the needed 

materials to ensure cell stability and long shingle 

life. They also needed to acquire and qualify 
 

 

 

 

 

 

 

 

 

 

equipment for a test lab, which is now fully 4. Planned FY 2010 Activities 

functional. 

D R A F T

Dow is developing the BIPV product materials 

structure using a multigeneration plan to ensure 

continuous progress in terms of cost reduction 

while maintaining successful product performance. 

Many different approaches to achieving adequate 

barrier performance that will enable CIGS-based 

PV shingles to perform for more than 20 years 

were experimented with, tested, and in some 

cases taken to development. Dow evaluates all 

the materials of construction with the total solution 

in mind. 

Dow is working toward a simple yet rugged and 

reliable interconnection design for the Dow Solar 

Shingle that totally eliminates all on-the-roof wiring 

and therefore the necessity of having an 

electrician or licensed solar installer do the 

installation. As part of reducing installation costs, 

Dow validated their design with a test build using 

standard roofing contractors. 

•	 Develop equipment modifications to fit product 

design (GSE; Q1) 

•	 Build pilot line and start-up (Q1) 

•	 Install turnkey systems and collect data (Q2) 

•	 Develop commercial roofing analog product 

(Q1). 

5. FY 2009 Special Recognitions, Awards, and 

Patents 

Provisional Application No. 61/098941, Connector 

Device for Building Integrated PV Device. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal 

Investigator 

Location Description/Title of Research 

Activity 

FY 2009 

($K) 

Global Solar Energy 

Jeffery Britt 

Tuscon, AZ Cell supplier 3 

Prost Construction 

Vaughn Prost Columbia, MO 

Install demonstration unit with 

Columbia Water and Light to 

initiate rate structure study for solar 

PV electricity production 

35 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

TPP Awardee: GE Global Research Inc. “A Value Chain Partnership to Accelerate U.S. PV Industry Growth” 

Total Award Amount: $21,225K; DOE/Recipient Share $9,184K/$12,041K 

Objectives 

•	 Investigate multiple technical pathways for producing modules and system components that will 

meet the TPP LCOE goals and be successful in the U.S. marketplace 

•	 Address the segments of the U.S. PV market where GE’s technical and system integration 

competencies can have the largest effect on PV system cost and performance 

•	 Deliver into the residential and commercial markets a complete system of components consisting 

of a module array, dc-ac inverter, and energy monitor 

•	 Meet LCOE targets of $0.13/kWh to $0.18/kWh by 2010 and $0.08/kWh to $0.10/kWh by 2015. 

Accomplishments 

•	 Completed the moisture-ingress-degradation model for flexible packaged CIGS devices and ran it 

for a variety of conditions, packages, and cells 

•	 Proved that modified barrier coatings for CIGS-based devices improve by ~10x the number of 

visible defects generated during damp heat testing 

•	 Built and tested mini-modules to validate the interconnect electrical model; model predictions are 

generally within 3&–6% of these measurements 

•	 Expanded the temperature/humidity test matrix for cell degradation kinetics to include 100% 

humidity testing; the results indicate some amount of electrical contact degradation combined 

with CIGS device degradation 

•	 Studied power loss for three system level interconnect strategies. 

1. Introduction 

General Electric’s (GE) DOE Solar Energy 

Technologies Program (SETP) TPP 

encompassed development in critical areas of 

the photovoltaic value chain that affected the 

LCOE for systems in the United States. This 

was a complete view across the value chain, 

from materials to rooftops, to identify 

opportunities for cost reductions to realize the 

Department of Energy’s cost targets for 2010 

and 2015. GE identified several strategic 

partners with proven leadership in their 

respective technology areas to accelerate along 

the path to commercialization. GE targeted both 

residential and commercial rooftop scale 

systems. 

During FY 2009, GE and its partners 

investigated two photovoltaic pathways that 

included low-cost multicrystalline silicon cells 

and modules and flexible thin film modules. The 

balance of system for residential and 

commercial installations were also investigated. 

GE pursued innovative system installation 

strategies as an additional avenue for cost 

reduction. 

2. Technical Approach 

GE focused on two distinct technical pathways 

for the module, as well as a technical pathway 

that addresses the inverter/balance of system 

and installation. Each pathway was selfcontained, spanned the value chain to include 

materials, solar device, and system, and 

included critical technologies and partners. An 

internal stage-gate process was used to downselect to the most favorable approach or 

partnership. 

2.1 Low-Cost Multicrystalline Silicon Module 

GE developed a solar cell based on a molded 

silicon wafer fabricated in a continuous casting 

process that eliminates the waste associated 

with conventional sawing, resulting in a wafer 

that is 2x less expensive to produce. GE also 

developed a low-cost silicon feedstock based on 

a carbothermic reduction process that would be 

easier to scale than other processes currently in 

use. This process takes advantage of GE Global 

Research’s knowledge of high-quality quartz 

manufacturing. 

2.2 Flexible Thin Film Module 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

GE worked with vendors developing technology 

for CIGS on flexible substrates as a source of 

flexible solar cells. This technology has great 

potential for low cost and the creation of unique 

building integrated products. A weakness of 

CIGS (and all other thin films using a thin 

conductive oxide) is sensitivity to moisture, 

limiting life well below that of a silicon module. 

GE developed packaging technologies for 

flexible organic light emitting diodes (OLEDs) 

that have been directly applied to the CIGS 

material. A novel multilayer SiN/organic film that 

can be directly deposited onto the solar cell or a 

polycarbonate sheet forms the basis for a 

moisture-tight package that provides four ordersof-magnitude better protection than the Teflonbased materials currently being used. 

A moisture-ingress-degradation model was 

completed and run for a variety of conditions, 

packages, and cells. Key predictions are 1) a 

barrier of WVTR < 104 g/m2

/day is required for 

20-year life in Miami; 2) 20years in Miami is 

roughly equivalent to 12,000 hours of “damp 

heat” (85°C/85%RH) for a barrier-packaged cell; 

3) cells of less-robust structure (obtained from a 

second vendor) require 25X this barrier; 4) cells 

must degrade at < 0.07X this rate to require no 

barrier; and 5) two-sided compared with onesided module heat transfer (freestanding 

compared with BIPV) has little effect on module 

degradation rate. 

2.3 Balance of System 

GE and Xantrex Technology, Inc. intend to lower 

inverter cost and improve performance by 

developing innovative new circuit designs, 

implementing high-performance components, 

and taking advantage of higher volume 

component pricing made possible by market 

growth. A large element of the cost is embedded 

in the system engineering and integration 

functions and in the installation. GE worked with 

top PV installers to identify internally driven cost 

elements related to time and materials and 

external factors such as local codes and 

regulations that influence costs nonuniformly, 

and to develop a streamlined process flow. 

Additionally, in a partnership with GAF, GE 

intends to market and develop new solar 

systems and roofing systems for residential and 

commercial customers. 

4. Major FY 2009 Publications 

D.J. Coyle, H.A. Blaydes, J.E. Pickett, R.S. 

Northey, and J.O. Gardner, “Degradation 

Kinetics of CIGS Solar Cells,” 34th IEEE PV 

Specialists Conference, Philadelphia, PA, June 

2009. 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

TPP Awardee: GreenRay Inc. ”Development of an AC Module System” 

Total Award Amount: $5,044K; DOE/Recipient Share: $2,522K/$2,522K 

Objectives 

•	 Develop a fully integrated plug-and-play PV system by integrating power electronics with a highefficiency PV module 

•	 Reduce PV system installation labor cost by half 

•	 Increase system reliability and reduce system maintenance costs by 75% 

•	 Increase system safety for installers and users 

•	 Lower the life-cycle cost of PV energy to meet DOE goals. 

Accomplishments 

•	 Began safety certification testing of inverter and AC module at UL 

•	 Stress testing in house verifies 50-year inverter lifetime 

•	 Completed AC module system demonstrations in Massachusetts, New Jersey, and Texas. 

Future Directions 

•	 Complete thorough testing of the inverter, including final safety certification 

•	 Begin pilot production and market launch. 

1. Introduction 

The market for PV systems on the roofs of homes 

and commercial buildings is growing rapidly in the 

United States. Expectations are high that growth 

will continue for the foreseeable future. To help 

foster the widespread adoption of PV, GreenRay 

is creating a true plug-and-play AC system, with 

advantages of simplicity, safety, performance and 

cost. GreenRay focuses on driving cost out of PV 

through evolution of the balance of systems and 

levels of integration. 

2. Technical Approach 

GreenRay is developing three elements for the AC 

Module System: a high-reliability inverter, a simple 

residential mounting system, and a data 

acquisition system. To achieve an integrated PV 

system that simplifies installation, GreenRay is 

eliminating many of the redundant structural 

elements in today’s systems. Prototypes of the 

mounting system were developed and evaluated 

by experienced PV installers. 

The inverter has been designed to achieve a 30­

year lifetime, to improve system reliability, and 

reduce maintenance. Consultants reviewed the 

inverter design to help GreenRay achieve its 

goals. 

The integrated data system is designed to take 

advantage of the distributed intelligence in the AC 

Module System to produce module-level 

information. 

3. Results and Accomplishments 

•	 AC Module System submitted to UL for safety 

certification (07/09) 

•	 In-house stress testing shows inverter lifetime 

greater than 50 years (08/09) 

•	 Cost projections of the AC Module System 

show the potential to achieve the targeted 

lifecycle cost of energy (08/09). 

GreenRay completed the design of its novel 

inverter in a form factor optimized for integration 

with a PV module. The beta prototype of the 

inverter operated successfully. Updated reliability 

analysis was completed using standard tools and 

methods to model the circuit. Results indicate the 

potential to achieve the targeted lifetime and 

reliability. In-house stress tests demonstrate a 

50+year lifetime for the inverter. 

Demonstration systems were completed in 

Massachusetts, New Jersey, and Texas. The 

installation labor cost savings were validated, and 

the GreenRay AC Module System is roughly half 

that of the conventional system. 

GreenRay tested and demonstrated imbedded 

data acquisition and communication capability. 
 

 

D R A F T

The user interface features were reviewed with 5. FY 2009 Special Recognitions, Awards, and 

key stakeholders and refined. Patents 

4. Planned FY 2010 Activities	 One patent was filed in FY 2009: 

•	 Modified ZVT Converter. 

•	 Complete AC module safety certification 

(04/10) Two provisional patents were advanced to the 

•	 Begin pilot production of 2,000 AC modules PCT level and filed in the United States in FY 

and launch product in market. (04/10). 2009: 

•	 AC Module Wiring Method 

•	 AC Module and Inverter Assembly. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization Location Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

SANYO Energy San Jose, CA Testing to support inverter and 

AC module development $25,062 $25,062 
 

 

 

 

 

 

 

D R A F T

TPP Awardee: Konarka Technologies Inc.

“Low Cost, Lightweight Solar Modules Based on Organic Photovoltaic Technology”
 

Total Award Amount: $8,585K; DOE/Recipient Share:$3,656K/$4,929K 

Objectives 

•	 Improve stability by using water and oxygen barriers that include barrier films, coated barrier films and 

adhesives that have barrier properties 

•	 Improve performance by creating and using n-type materials in the active layer 

•	 Improve performance and lower cost by using a highly conductive, highly transparent, printed metal grid. 

•	 Reach performance objective of 10% cell efficiency and module efficiency 7%–8% 

•	 Reach rooftop module lifetime objective of 10years and cost objective of < $0.2/kWh. 

Accomplishments 

Stability 

•	 Demonstrated the utility of adhesive fillers in stabilizing modules 

•	 Demonstrated that solution coatable barriers have potential for improving stability 

• Delineated molecular details regarding degradation.
 

Performance: n-type materials
 

•	 Produced many fullerene derivatives per specification, but none showed performance improvement over 

the standard PCBM.
 

Performance: Printed metal grids
 

•	 Developed silver grid top electrode that exhibits performance equal to a solid silver electrode 

•	 Identified silver formulation for the bottom grid electrode that has the correct set of properties and surface 

roughness. 

Future Directions 

•	 Transfer clay/adhesive formulations to manufacturing 

•	 Develop solution coatable barriers 

•	 Investigate new family of n-type fullerenes 

•	 Optimize silver formulations for the top grid and bottom grid. 

1. Introduction	 families of polymers have been developed and are 

being optimized. N-type materials, e.g., fullerene 

Konarka Technologies is dedicated to producing derivatives and new polymers, are also being 

low-cost organic photovoltaic modules that are investigated. The concept behind this investigation 

flexible, lightweight, and with low manufacturing centers on imparting better absorption properties 

costs. This can be accomplished because the and better matched device energy levels. 

modules are made using a roll-to-roll coating 

process on inexpensive polymer substrates in a Regarding the grid electrodes, the expensive ITO 

high-speed, wide-roll coating process. bottom electrode will be replaced with an electrode 

that has higher transmission, higher conductivity, 

2. Technical Approach	 and lower cost. Using a silver grid as the top 

electrode replacing the solid silver electrode also 

Konarka concentrated all work on organic lowers the cost (~10%) of the silver. 

photovoltaics. They are simultaneously creating new 

materials and investigating advanced concepts while 3. Results and Accomplishments 

pushing the best performers through development 

and into manufacturing. The latter is making Stability 

products for portable applications centered on During the second year of the program, Konarka 

battery charging. focused on devising and optimizing the formulas for 

a new adhesive/clay combination. Konarka 

Konarka is also investigating the environmental demonstrated that stability was significantly 

factors that are responsible for instability while improved when this adhesive/clay combination was 

creating, evaluating, and using new barrier used in combination with improved barrier material 

materials. films. Several examples were produced that are 

stable for several thousand hours at 65 °

C/85%RH; 

Regarding performance, researchers are 85/85 testing has begun with resultant formulations 

investigation new polymeric donors; several new being incorporated into the product line. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

NREL is developing solution coatable barriers. 

Experiments with these materials on our Research 

Test Coater pilot line have begun. 

Performance—N-Type Materials 

Konarka created two sets of fullerene derivatives: 

one set with deeper LUMOs and the other with 

shallower LUMOs relative to PCBM. Thus far these 

have not exhibited better performance than PCBM. 

Konarka continues to investigate these new 

materials from the standpoint of their effect on 

morphology. 

Performance—Grids 

We experimented with a wide variety of silver inks 

and have used various printing techniques, including 

inkjet in the December timeframe. For the bottom 

grid, upon which the active layers of the cell will be 

coated, target surface roughness is < 5nm RMS, 

and we achieved this level of roughness. In addition, 

the surface of the grids and the leveling layer are 

equal. There is still a very low density of 50–100 nm 

spikes in the silver grid, and we are working on this 

problem. We developed a grid for the top electrode, 

and modules are in development. 

4. Planned 2010 Activities 

The Konarka manufacturing line is now fully 

operational, and continued improvement of product 

performance is expected. 

Stability 

•	 Incorporate new adhesive and improved 

commercial barriers into the product line 

•	 Improve barrier properties and coat NREL’s 

solution coatable barriers. 

Performance 

•	 Demonstrate 8%–9% cell efficiency 

•	 Demonstrate 5%–6% module efficiency 

•	 Use printed silver grids in both top and bottom 

electrodes target cell efficiency equal to that of 

ITO and solid silver electrodes. 

5. FY Awards, Special Recognition, Patents 

Patent 7,622,667, Photovoltaic fibers 

Patent 7,612,367, Photovoltaic component and 

production method therefor 

Patent 7,586,035, Photovoltaic cell with spacers 

Patent 7,572,974, Gel electrolytes for dye sensitized 

solar cells 

Patent 7,572,396, Patterned photovoltaic cell 

Patent 7,544,747, Photoactive materials and related 

compounds, devices, and methods 

Patent 7,522,329, Displays with integrated 

photovoltaic cells 

Patent 7,476,278, Roll to roll manufacturing of 

organic solar modules 

6. Papers 

C.N. Hoth, S.A. Choulis, P. Schilinsky, and C.J. 

Brabec, “On the Effect of Poly(3-hexylthiophene) 

Regioregularity on Inkjet Printed Organic Solar 

Cells,” J. Mater. Chem. 19(30), 5398 (2009). 

C.N. Hoth, P. Schilinsky, S.A. Choulis, and C.J. 

Brabec, “Printing Highly Efficient Organic Solar 

Cells,” Nano Lett. 8(9), 2806 (2008). 

C.N. Hoth, R. Steim, P. Schilinsky, S.A. Choulis, 

S.F. Tedde, O. Hayden, and C.J. Brabec, 

“Topographical and Morphological Aspects of 

Spray Coated Organic Photovoltaics,” Organic 

Electron. 10(4), 587 (2009). 

M. Koppe, C.J. Brabec, S. Heiml, A. Schausberger, 

W. Duffy, M. Heeney, and I. McCulloch, “Influence 

of Molecular Weight Distribution on the Gelation of 

P3HT and Its Impact on the Photovoltaic 

Performance,” Macromolecules 42(13), 4661 

(2009). 

M.R. Lee, R.D. Eckert, K. Forberich, G. Dennler, 

C.J. Brabec, and R.A. Gaudiana, “Solar Power 

Wires Based on Organic Photovoltaic Materials,” 

Science 324(5924), 232 (2009). 

M.R. Lee, R.D. Eckert, K. Forberich, G. Dennler, C. 

Brabec, R.A. Gaudiana, P. Calvert, and A. 

Agrawal, “Optical and Electronic Properties of 

Organic Photovoltaic Wires and Fabrics,” J. 

Macromol. Sci., Part A: Pure Appl. 

Chem. 46(12), 1238 (2009). 

A. Seemann, H.-J. Egelhaaf, C.J. Brabec, and J. A. 

Hauch, “Influence of Oxygen on Semi-transparent 

Organic Solar Cells with Gas Permeable 

Electrodes,” Organic Electron. 10(8), 1424 (2009). 

R. Steim, P. Schilinsky, S.A. Choulis, and C.J. 

Brabec, “Flexible Polymer Photovoltaic Modules 

with Incorporated Organic Bypass Diodes to 

Address Module Shading Effects,” Solar Energy 

Mater. Solar Cells 93(11), 1963 (2009). 

R. Steim, S.A. Choulis, P. Schilinsky, U. Lemmer, 

and C.J. Brabec, “Formation and Impact of Hot 

Spots on the Performance of Organic Photovoltaic 

Cells,” Appl. Phys. Lett. 94(4), 043304/1 (2009). 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization Location Description/Title of 

Research Activity 

FY 2009 

($K) 

Cost 

Share 
 

D R A F 

T

($K) 

Institute for Energy 

Conversion, 

University of 

Delaware 

Newark DE 

Determination of the stability 

of modules under various 

conditions of temperature, 

humidity, and light. 

Investigation of the instability 

mechanism. 

103 76 

NREL 

Golden, CO 

Improving barrier properties 

of perimeter seals by adding 

rodlike fillers to the 

adhesives. Year 2, converted 

to solution coatable barriers. 

450 – 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TPP Recipient: Nanosolar Inc.

“Delivering Grid-Parity Solar Electricity for the Commercial Market” 

Total Award Amount: $42,616K, DOE/Recipient Share $19.991K/$22,626K 

D R A F T

Objectives 

•	 Achieve grid-parity economics for the commercial market based on an integrated suite of innovations in 

module, inverter, and mounting technology 

•	 Achieve a 2010 real LCOE target of 6.3¢/kWh and a 2015 real LCOE target of 5.5¢/kWh. 

Accomplishments 

•	 Demonstrated successful achievement of all technical milestones for Phase II of the project 

•	 Completed TUV certification for our initial panel product, and passed the requirements for a UL Class A 

fire rating 

•	 Retained more than 95% of initial power output after 200 thermal cycles, and more than 90% of power 

output after 450 thermal cycles, when Nanosolar panels were tested per standard IEC protocols . 

•	 Showed, using the Sunlink mounting system, that the installation process is highly streamlined by 

minimizing mounting components, standard tool usage, and a plug-in installation strategy. 

Future Directions 

•	 Demonstrated successful deployment of both 100-kW and 1-MW commercial rooftop systems. 

ABSTRACT 

Nanosolar optimized the manufacture of an 

inexpensive solar panel enabled by the rapid 

roll-to-roll production of solar cells, which are 

then assembled into modules in a highthroughput automated process. The economics 

of the Nanosolar cell and module production 

enables a substantial reduction in panel cost. 

The Nanosolar panel also successfully achieved 

TUV and UL certification. The panel design 

enables reduced balance of system costs for 

mounting and installation. Further, SunLink LLC, 

a Nanosolar team partner, developed an 

inexpensive and rapidly assembled mounting 

system optimized for Nanosolar panels. A test 

installation with Nanosolar panels and a Sunlink 

mounting system was deployed. 

1. Objectives 

Nanosolar developed a new generation of solar 

electricity cell technology based on a printed 

semiconductor, which permits substantially 

improved cost efficiency. To translate this cell 

advance into grid-parity PV systems economics, 

however, the panel mounting system was also 

optimally redesigned, allowing for a redefinition 

of the interfaces and component functions from 

a systems-optimized perspective. Nanosolar is 

leading a team to develop an optimized solar 

system for the key market of corporate 

customers with flat-roof commercial buildings. 

2.1 Solar Cell Technology 

Nanosolar developed proprietary technology 

based on CIGS absorber technology that allows 

printing this semiconductor material onto metal 

foil using a high-speed, high-throughput roll-toroll manufacturing process. Cells are then 

assembled and placed between two glass panes 

to form a panel. 

2.2 Mounting System Technology 

o further reduce the cost of deploying solar 

systems on rooftops, Sunlink has developed a 

low-cost and durable mechanical structure to 

rapidly assemble modules on a flat commercial 

rooftop using a system that comprises only 

seven components and requires only two 

standard tools for installation. 

Taking input from structural analysis, roof 

interface requirements, Nanosolar panel 

mounting guidelines, and typical installation 

practices, researchers designed a mounting 

system that is responsive to the needs of the 

installation crews. The system was then built 

and assessed using both wind-tunnel testing 

and mechanical load tests. 

Figure 1 shows the installation of a Nanosolar 

panel in the Sunlink mounting system, and 

Figure 2 shows an array of Nanosolar panels 

attached using a Sunlink mounting system. The 

integrated system permits rapid array assembly. 

2. Technical Approach 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Fig. 1. Installation of Nanosolar panel in Sunlink 

mounting system on simulated rooftop. Upper 

panel, placement of panel onto mounting 

structure. Lower panel, rapid plug-in installation 

into mounting system. 

3. Results 

3.1 Certification of Nanosolar Panel 

Nanosolar completed TUV certification for our 

initial panel product, and also passed the 

requirements for a UL Class A fire rating. In 

particular, Nanosolar successfully completed all 

of the mechanical and electrical tests, including 

IEC61646 Section 10.1 (visual inspection), 

IEC61646 Section 10.2 (Max Power 

Determination), IEC61646 Section 10.3 

(Insulation Test), IEC61646 Section 10.16 (wet 

leakage current test), IEC61646 Section 10.8 

(outdoor exposure test, 60 kWh/m2

, IEC61646 

Section 10.4 (Measurement of Temperature 

Coefficients), IEC61646 Section 10.5 (NOCT), 

IEC61646 Section 10.6 (Performance at STC 

and NOCT), IEC61646 Section 10.7 

(Performance at Low irradiance), IEC61646 

Section 10.9 Hot-Spot Endurance test, and 

IEC61646 Section 10.15 (wet leakage current 

test). Further, Nanosolar has successfully 

passed IEC61646 Section 10.10 (UV Protection 

test at 15 KWh/m2

), IEC61646 Section 10.11 

(Thermal Cycling Test, 200 cycles, -40C to 

+85C), IEC61646 Section 10.12 (Humidity 

Freeze Test, 10 cycles, -40C to +85C, 85% RH), 

IEC61646 Section 10.13 (Damp Heat Test, 1000 

hours, 85C, 85% RH), IEC61646 Section 10.14 

(Robustness of Termination Test), IEC61646 

Section 10.15 (Wet Leakage Current Test), 

IEC61646 Section 10.16 (Mechanical Load 

Test), IEC61646 Section 10.17 (Hail Test), and 

IEC61646 Section 10.19 (Light Soaking). Based 

on the TUV data, Nanosolar also received a UL 

equivalency listing. 

3.2 Demonstration of Nanosolar Panel 

Performance under Thermal Cycling 

Nanosolar panels were tested under the 

IEC61646 testing protocols for thermal cycling, 

and retained more than 95% of initial power 

output after 200 thermal cycles, and more than 

90% of power output after 450 thermal cycles 

(Fig. 3), twice the number of required thermal 

tests per IEC. 

Fig. 2. Nanosolar panels mounted on Sunlink 

system on a flat roofing structure. 

26
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Fig. 3. Power output (%) for Nanosolar panels 

vs. number of thermal cycles as per IEC61646 

testing. Red line depicts testing limit for standard 

IEC testing. 

3.3 Demonstration of Installation of Nanosolar 

Panel with Sunlink Mounting System 

Figure 2 shows a Nanosolar panel array 

deployed using a Sunlink mounting system. The 

installation process was measured in time and 

motion studies and is highly streamlined by 

using a small number of mounting components, 

standard tool usage, and a plug-in installation 

strategy. 

4. Significance 

In addition to lower panel cost, the Nanosolar 

panel design drives balance-of-system and 

deployment cost efficiency in several other ways 

relative to other thin-film products, including cost 

savings on mounting materials, mounting labor, 

cabling materials length, cabling labor, and 

shipping cost. For example, using dual panes of 

tempered glass, substantially increased panel 

strength, allowing a 2-m mounting span (relative 

to a 1.2-m span for typical thin film), a 41% 

decrease in mounting material. Using highcurrent carrying conductive metal foils in the cell 

design allows assembly of longer panel arrays, 

and Nanosolar uses only 1.6 km of cabling per 

megawatt compared to 20 km per megawatt for 

typical thin-film panels, a 92% savings in cabling 

cost per panel. Using dual “edge box” 

connectors optimally positioned for landscapemode inter-connection means that cabling 

interconnection is 85% faster than that of thinfilm panels with standard junction box designs. 

Balance of system cost has been further 

reduced through the Sunlink mounting system 

for commercial rooftops, where, in addition to 

low materials cost, the mounting system 

provides high component efficiency (with little 

hardware required for installation) and versatile 

build “as you go” installation (using 2 by 1 m 

subarrays). This subarray modularity gives a 

solar system layout designer the flexibility to 

maneuver around rooftop obstructions. 

5. Patents 

Patent 359,246, “Methods for Thermal 

Processing Flexible Substrates,” 1/23/09 

Patent 369,524, “Improved Solution Deposition 

System,” 2/11/09 

Patent 176,902, “Roll-to-Roll Manufacturing of 

Back-Contacted Solar Cells,” 5/9/09 

Patent 180,814, “Solar Cell Interconnection” 

5/22/09 

Patent 180,815, “Material Additive” 

5/22/09Patent 180,817, “Structure and 

Process for Solar Cell Electrodes” 5/22/09 

Patent 559,451, “Methods for Thermal 

Processing Flexible Substrates,” 9/1/09. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2008. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research 

Activity 

FY 2008 

DOE 

Funding 

($K) 

Cost Share 

($K) 

SunLink, LLC San Rafaal, CA 

info@sunlink.com 

Development low-cost mounting 

solution thin-film module 

0 104 

27
 
 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

TPP Recipient: Soliant Inc.

“Concentrating Solar Panels: Bringing the Highest 

Power and Lowest Cost to the Rooftop”
 

Total Award Amount: $13,660K; DOE/Recipient Share $4,887K/$8,7723k 

D R A F T

Program Objectives 

•	 Develop a tracking/concentrating solar module that has the same geometric form factor as a 

conventional, flat roof-mounted PV panel, producing more power and cost less than conventional 

panels of the same size 

•	 Reach target LCOE: $0.079/kWh in 2010 

•	 Reach target efficiency: 26% in 2010 (22% for 2008 prototype, 24% for 2009 pilot) 

•	 Reach target performance: equivalent to 650 Wp in 2010 (490W for 2008 prototype, 540W for 

2009 pilot). 

2009 Accomplishments 

•	 Designed and built pilot plant capable of producing more than 1 MWp1 per year of manufactured 

tracking/concentrating solar panels that mount to standard racking systems on commercial 

rooftops, with standard output electrical connections 

•	 Expanded earlier system on Soliant HQ rooftop to full 4.4 kWp; system operated within 

specifications for most of 2009 until decommissioned for research purposes
 

•	 Installed two 2.0 kWp beta systems on customer rooftops 

•	 Internally tested units with energy output equivalent to 449Wp flat plate. 

Future Directions 

•	 Improve efficiency and power output 

•	 Reduce manufacturing cost 

•	 Ensure that delivery volume manufactured units are establishing path to goal LCOE. 

1 Beginning in Phase 2 of the project, Soliant discontinued use of the descriptive but nonstandard “watts 

equivalent” in favor of the emerging CPV Wp STC standard that is emerging from IEC TC82 WG7. In this 

report the phrase “equivalent to Wp” is used where necessary to maintain a link to the original proposal; 

in all other places Wp means CPV Wp STC. 

28
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Introduction 

Soliant Energy is a venture-capital-backed 

startup focused on bringing advanced 

concentrating solar panels to market. The 

fundamental innovation of this approach a 

racking solar concentrator developed specifically 

for commercial rooftop applications, resulting in 

the lowest LCOE for rooftop electricity 

generation. 

D R A F T

Today, the commercial rooftop segment is the 

largest and fastest-growing market in the solar 

industry. Soliant Energy concentrating panels 

can make a major contribution to the TPP 

program objectives of reducing the cost of solar 

electricity and rapidly deploying capacity. 

Soliant’s commercialization focus was reshaped 

in 2009, shifting from an emphasis solely on 

panel efficiency to LCOE. Since the inception of 

the TPP program, LCOE has become the de 

facto standard for comparing commercial 

photovoltaic systems. Although estimation and 

prediction models still differ, the emergence of 

performance-based incentive and feed-in tariff 

systems, as well as power purchase agreement 

financing structures, makes LCOE the natural 

metric for photovoltaic systems. 

During 2009, Soliant made progress on several 

fronts, including manufacturing capacity, 

technology development, market awareness, 

and sales. 

2. Technical Approach 

Because the Soliant effort is intended to produce 

capital equipment with high reliability under 

harsh conditions, the technical approach is 

borrowed from the automotive industry. The first 

phase of the effort, from 9/07 through 3/08, was 

engineering validation, with a goal of 

demonstrating a working product design. This 

phase was completed with delivery of a 

prototype unit validated by Sandia to meet all 

key objectives. 

The second phase is design validation (DV), 

which further refines the design and readies it 

for manufacturing. Substantial progress has 

been made toward completing this phase by 

establishing a pilot manufacturing line in an 

existing facility in Monrovia, CA. This phase was 

to be completed in December 2008. Product 

improvements identified during the initial part of 

the DV, however, prompted Soliant to undertake 

a second DV iteration. 

The third phase is production validation and will 

culminate in the first large-scale deliveries of our 

product to customers in 2011. 

The technical approach of the original proposal 

included a strong but largely separate task of 

receiver packaging development. 

3. Results and Accomplishments 

•	 Worked with UL to define draft 8703 for 

photovoltaic concentrators 

•	 Designed product revisions to ensure UL 

certification; passed critical UL tests 

•	 Expanded earlier system on Soliant HQ 

rooftop to full 4.4 kWp; system operated 

within specifications until decommissioned in 

late 2009 for research purposes 

•	 Outfitted second Soliant facility for 1 MWp 

per year production capacity 

•	 Installed two 2.0 kWp beta systems on 

customer rooftops 

•	 Continued long-term reliability testing 

•	 Received important customer commitments 

toward purchase of product. 

The major focus of effort in 2009 was to ramp up 

manufacturing capacity of a panel that passes 

UL and meets customer needs. With a few 

modifications, this goal was accomplished. A 

pilot-scale manufacturing plant was specified, 

designed, equipped, and validated that, running 

at full capacity, could produce in excess of 600 

kWp of Soliant SE-500X concentrating solar 

panels. The Soliant SE-500X produces an 

annual power equivalent to 449 Wp flat plate, or 

416 kWh/m2

/year in Phoenix. The energy output 

of the beta SE-500X was verified by Sandia in 

early 2009. Figure 1 shows the Soliant rooftop 

array at full power from the early morning sun. 

29
 
 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

been developed. Mechanisms for threedimensional articulation of the optical element is 

also being investigated as part of this effort. 

Fig. 1. The 4.4 kWp array at Soliant HQ. 

In April 2009 an additional building adjacent to 

the Monrovia headquarters was leased and 

outfitted as a module- and panel-assembly line. 

The ribbon-cutting for this facility took place in 

August and first panels were delivered from it in 

September. Congressman David Dreier is third 

from right in Figure 2. 

Fig. 2. Ribbon-cutting for pilot plant. 

Important progress was made in 2009 toward 

UL listing of the SE-500X product. Soliant 

worked closely with UL to define the UL8703 

draft safety standard for photovoltaic 

concentrators. Soliant passed the fire testing 

elements of this standard in 2009 and at year 

end was accumulating hours toward the longterm tests such as outdoor exposure. 

The subcontract with MIT has seen further 

progress. A model for impacts of various 

alternatives in a multi-echelon supply chain has 

Fig. 3. Beta system installed. 

In December 2009, beta systems of 

approximately 2 kWp each to third party 

evaluators were delivered. One of these ( Fig. 3) 

is grid-connected, and the other is awaiting 

municipal approvals for grid connection that is 

expected in 1Q10. 

4. Planned Calendar 2010 Activities 

Three to five beta-sized systems of 

approximately 2kWp each are expected to be 

installed. We also plan to sell ten 10 kWp 

systems. UL listing is expected in 2Q10. 

5. 2009 Special Recognitions, Awards, and 

Patents 

Two U.S. patents applications were filed in this 

period. One U.S. patent was issued. 

6. 2009 Publications 

N.	 Fromer, R. Johnson, S. Missirian, and J. 

Bobruk, “Soliant Energy Concentrator Module 

Performance and Comparison To Silicon Flat 

Panel Performance,” poster session, 34th 

Annual IEEE Photovoltaic Specialists’ 

Conference (PVSC34), 2009. A similar paper 

was presented in a poster session at the SPIE 

Solar Energy + Technology 2009 San Diego, 

August 2009. 

30
 

Organization Location Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 
 Spectrolab, Inc. Sylmar, CA Development and supply of III-V 

concentrator PV cells 18 0 

Massachusetts Institute 

of Technology Cambridge, MA Advanced research in manufacturing engineering 56 0 

SunEdison, Inc. Beltsville, MD Customer-perspective review of 

proposed panel specification 0 0 

D R A F T

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

31
 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TPP Awardee: SunPower Inc.
 Grid-Competitive Residential and Commercial Fully Automated PV Systems Technology
 

Total Award Amount: $52,647K; DOE/Recipient Share: $24,700K/$27,947K 

D R A F T

Objectives 

•	 Develop turn-key, high-efficiency residential and commercial systems that are cost-effective in 

delivering electricity at grid parity 

•	 Decrease LCOE values to 9–12¢ cents/kWh and 13–18¢ cents/kWh, respectively, for the 

commercial and residential markets
 

•	 Achieve target LCOE values through development of 20% efficient modules and reduced system 

development and installation time. 

Accomplishments 

•	 Achieved world-record panel efficiency at 20.4%, as verified by NREL 

•	 Demonstrated pilot manufacturing capability to produce 23%+ cells 

•	 Released large-format modules into production for commercial markets 

•	 Demonstrated production ramp and deployment through installation of 2 MWp of innovative 

commercial rooftop product 

•	 Completed design for 75-MW automated module line 

•	 Integrated automated design and simulation software for commercial applications. 

Future Directions 

•	 Implement domestic manufacturing capacity for modules 

•	 Demonstrate pilot manufacturing and field deployment of next-generation tracker technology 

•	 Demonstrate development of a fully equipped systems kit that is delivered as a unit to the site of 

residential installations. 

1. Introduction 

As a participant in the DOE TPP Program, 

SunPower Corporation is developing turn-key PV 

systems that are designed to be cost-effective in 

delivering electricity at grid parity. Taking 

advantage of its vertical integration strategy, 

SunPower is addressing cost reduction throughout 

the value chain, from wafer technology through 

installation deployment. In addition to internal 

resources, SunPower, as the prime TPP 

contractor, is partnering with Dow Corning, Tigo 

Energy, Solar Bridge, and NREL to investigate 

new materials, develop innovative inverter 

designs, and validate efficiency and performance 

characteristics, respectively. 

2. Technical Approach 

The SunPower project examines multiple levels of 

the value chain. Internal efforts focused on 

developing integrated system-level products and 

leveraging improvements in the wafer and cell 

technologies. 

3. Results and Accomplishments 

The SunPower project includes tasks focused on 

(1) wafering; (2) back-contact cells; (3) module 

design; (4) system product design; (5) 

manufacturing implementation; (6) enabling 

software; (7) residential-installation tools; (8) 

performance modeling and monitoring; and (9) 

inverter design and reliability. Summary results 

from a subset of these tasks follow. 

3.1 Wafering Technology Development 

SunPower focused efforts on reducing final wafer 

thickness and increasing wafer diameter. Work 

included changes to the manufacturing processes 

and equipment set to enable use of the thinner 

and larger wafers. SunPower successfully 

processed wafers, cells, and modules using 145­

μmthickness. The production of cells at this 

thickness has been fully implemented in the 

SunPower large-scale manufacturing operations. 

3.2 High Performance Back-Contact Solar Cells 

Solar cell conversion efficiency leverages cost 

savings throughout the value chain. Today 

SunPower manufactures cells with nominal 

efficiency of 21.2% in full production. 

32
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

Under this program, SunPower pursued a variety 

of options for improving on this cell efficiency and 

lowering manufacturing cost. This work has 

included evaluating the geometry effects, 

optimizing the collecting junction, using long 

lifetime silicon, and studying the effects of surface 

passivation. 

SunPower demonstrated pilot production 

capability to produce 23%+ cells, which enabled 

the world-record panel efficiency of 20.4%. 

Fig. 1. IV curve of next-generation solar cell from 

the prototype line indicating an efficiency of 

23.4%. 

3.3 Low Cost, High Performance Modules for Easy 

System Integration 

SunPower developed and released two new 

commercial laminates and modules for integration 

with rooftop and ground-mounted system 

solutions. These new formats incorporate lower 

cost materials, improved shipping features, and 

innovative materials that improve overall 

performance. Both formats have been UL certified 

on the TPP program. 

Fig. 2. Delivery of SunPower 96-cell modules to 

commercial rooftop site. 

SunPower also worked on developing bifacial and 

Class A fire-rated modules. In parallel, Dow 

Corning evaluated polymer materials to replace 

the front glass on conventional modules. 

3.4 Unitary Product Design 

Building on its vertical integration, SunPower is 

designing system-level solutions that integrate 

module and system design elements to optimize 

material use, performance, and overall product 

design to deliver a turnkey system for either 

rooftop or ground applications. The development 

of a complete set of system components will 

radically reduce installation time, eliminate 

redundant materials and labor, and improve 

system aesthetics. 

In this phase of the program, SunPower has 

released the T5 commercial rooftile. This product 

builds on the 96-cell module platform with a 

polymeric frame that integrates mounting 

hardware, stacking features, wiring guides, and 

interconnection points. This integrated frame 

design reduces the BOS costs and parts count. 

Fig. 3. T5 commercial rooftile units installed at 1.1­

MW site in Santa Clara, CA. 

For ground-mount applications, SunPower 

designed and released the next-generation tracker 

built around the 96-cell and 128-cell module 

formats. In addition to the improved PV capacity, 

this design achieves LCOE cost reduction through 

optimized steel and concrete materials, as well as 

improved packing densities and installation 

methods to reduce deployment costs. 

3.5 Cells-to-Systems Factory 

The work under the TPP program is geared 

toward enabling implementation of a domestic 

33
 
 

 

 

 

 

 

 

 

 

 

cells-to-systems factory. This activity has been 

divided into production lines for cells-to-laminates 

and laminates-to-systems conversion. In the 

future, SunPower plans to integrate the assembly 

lines. 

In this phase of the program, SunPower installed 

and ramped a 24-MWp manufacturing line of the 

T5 commercial rooftop product in Richmond, CA. 

Laminates are assembled into T5 units on this 

new line. During FY 2009, SunPower 

manufactured and installed 1.3 MW of this 

product. 

D R A F T

Fig. 4. Manufacturing line of T5 commercial 

rooftile units in Richmond, CA. 

For the cells-to-laminates line, SunPower 

completed the design of an automated, 75-MWp 

laminate/module line. Equipment orders were 

placed with vendors, and negotiations concerning 

site selection were initiated. 

3.6 Engineer to Order Software 

To reduce deployment-related expenses, 

SunPower worked to significantly reduce the time 

and effort to design a PV system. SunPower 

successfully developed and implemented an 

engineer-to-order system that takes system design 

inputs and semi-automatically generates optimized 

and engineering correct designs, drawing sets, 

bills-of-materials, and cost and energy simulation 

that accounts for site-specific obstructions. Typical 

commercial solar projects take several weeks to 

design, analyze, simulate, and contract. Through a 

comprehensive set of design automation 

improvements, the design time is being reduced to 

about one hour. 

During FY 2009, SunPower expanded the internal 

software to cover all rooftop solutions, including 

the newly released T5 product. SunPower issued 

the first release of a web-based energy simulation 

engine that is linked to the design software. In 

addition, SunPower also issued the release of a 

comprehensive, parametric-based cost engine that 

will eventually link to the design tools. 

3.7 15-Year Warranty Inverter 

During this phase, SunPower initiated partnerships 

with Tigo Energy and Solar Bridge to develop a 

15-year warranty inverter. 

4. Planned FY 2010 Activities 

•	 Implement domestic manufacturing capacity 

for modules 

•	 Demonstrate pilot manufacturing and field 

deployment of next-generation tracker 

technology 

•	 Develop fully equipped systems kit that is 

delivered as a unit to residential installations 

•	 Expand engineer-to-order tools for use with 

ground-mount systems applications. 

34
 
 

 

D R A F T

5. FY 2009 Special Recognitions, Awards, and 

Patents 6. Major FY 2009 Publications 

During FY 2009, SunPower filed 20 U.S. patent J. Botkin and M. Culligan, “The Unitary Ideal in 

applications and 12 international applications. No Commercial PV System Product Design,” 34th 

patents were issued during this period. IEEE PVSC, Philadelphia, PA, June 7–12, 2009. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization Location/E-mail Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

SunPower Corporation San Jose, CA 

Prime contractor: addressing 

wafer, cell, module, and system 

design and deployment 

$15,774 $8,241 

Dow Corning Corporation Midland, MI Subrecipient: new material 

investigations $166 $83 

Tigo Energy, Inc. Los Gatos, CA Subrecipient: 15-year warranty 

inverter $55 $28 

Solar Bridge Champaign, IL Subrecipient: 15-year warranty 

inverter $162 $81 

NREL Golden, CO FFRDC: device measurement and 

characterization - -

Ribbon Technology* Cupertino, CA Subrecipient: wafering technology $64 $32 

Xantrex* Livermore, CA Subrecipient: 15-year warranty 

inverter $102 $102 

SiGen* San Jose, CA Subrecipient: wafering technology $254 $204 

Solaicx* Santa Clara, CA Subrecipient: ingot growth 

technology $227 $163 

* Subcontract ended during FY 2009. 

35
 
 

 

 

 

 

 

 

 

 

 

D R A F T

TPP Awardee: United Solar Ovonic LLC
 “Low Cost Thin Film Building-Integrated PV Systems”
 

Total Award Amount, $39,849K; DOE/Recipient Share, $19,339K/$20,510K 

Objectives 

•	 Address the commercial BIPV market and reduce the LCOE to 12.8¢/kWh in 2010 to meet DOE’s 

short-term goal 

•	 Reduce the LCOE for commercial BIPV further to 7.6¢/kWh in 2015 to meet DOE’s 2015 goal. 

Accomplishments 

•	 Obtained NREL-confirmed 11.7% stable total-area (0.268 cm2

) efficiency on an a-Si:H/ncSi:H/nc-Si:H triple-junction device, using a small-area MVHF batch reactor on a Ag/ZnO back 

reflector with production time constraints; achieved world-record stable total-area efficiency of 

12.5% at same deposition rate but longer deposition time than the current production deposition 

time 

•	 Obtained NREL-confirmed 9.5%–9.8% stable total-area (0.268 cm2

) efficiency on a-Si:H/aSiGe:H/a-SiGe:H triple-junction solar cells on Al/ZnO back reflectors with production time 

constraints and with a-Si:H and a-SiGe:H cells deposited at ≥ 0.6 nm/s 

•	 Obtained NREL-confirmed 10.1% stable aperture-area (~400 cm2

) efficiency on an a-Si:H/ncSi:H/nc-Si:H triple-junction device on a Ag/ZnO back reflector, using large-area MVHF batch 

reactor with production time constraints 

•	 Obtained NREL-confirmed 8.7% stable aperture-area (~400 cm2

) efficiency on an a-Si:H/aSiGe:H/a-SiGe:H triple-junction device, using a large-area MVHF batch reactor on a Al/ZnO back 

reflector with production time constraints 

•	 Demonstrated cost saving of 7¢/W using grid wire produced in-house 

•	 Developed and installed in-line monitors in roll-to-roll deposition machines to measure efficiency 

of solar cells and thicknesses of individual layers and demonstrated excellent agreement with 

corresponding off-line post-deposition measurements 

•	 Developed standard PV system installation design and interface with utility grid 

•	 Achieved power rating of 144 W on > 80% of 22L laminates 

•	 Attained power rating of 158 W on prototype 22L laminate product using a Ag/ZnO back reflector 

•	 Conducted qualification tests on new sources of stainless steel substrate, EVA, ETFE, and back 

lamination materials that will lead to substantial cost reduction of our commercial product. 

•	 Developed low-cost solution for a removable solar module for EPDM and TPO roofs that will 

reduce the overall installation cost. 

•	 Designed and installed two 75-kW PV systems with wireless data acquisition capability: (i) direct 

bond application of our field-applied PV laminates to a metal roof and (ii) removable solution 

deployed on a membrane roof (TPO). 

Future Directions 

•	 Advance the state-of-the-art technology for nc-Si:H, and a-Si:H and a-SiGe:H materials and solar 

cells for both small-area and large-area deposition and attain higher conversion efficiency with 

production-compatible parameters 

•	 Investigate new light trapping schemes in solar cells 

•	 Insert new deposition technology and increase the power rating of prototype 22L laminate on 

Ag/ZnO back reflector with increased power rating 

•	 Investigate new module designs, assembly processes, and materials to reduce module,
 

installation, and systems level costs.
 

36
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Introduction 

United Solar Ovonic (United Solar) is working to 

develop a low-cost solution for the commercial 

BIPV and BAPV markets. The goal of this 

program is to reduce the cost of various cost 

centers, including modules, inverters and other 

balance of systems (BOS), and installation, such 

that the LCOE will be reduced by 15%–20% by 

2010, consistent with DOE’s goal of 2010. In 

addition, they plan to develop new materials and 

new manufacturing processes for even higher 

module efficiency and lower cost production 

processes to address DOE’s 2015 LCOE goal. 

The United Solar team includes experts from 

universities, NREL, and industry. 

D R A F 

Based on the analysis of all the cost centers 

associated with providing a complete 

2. Technical Approach 

T

BIPV/BAPV solution, the company divided the 

project into five tasks: solar module 

improvement, inverter and balance system, 

system engineering and integration, deployment, 

and project management and TPP collaborative 

activity. 

Work on the module represents the largest 

portion of the program and underscores a 

multipronged thrust to reduce module cost. One 

subtask focuses on materials and process 

optimization of the current manufacturing lines to 

improve the current manufacturing process to 

increase the efficiency of the current product 

and throughput. A second subtask addresses 

the need to improve the solar cell device 

efficiency. Higher cell efficiency directly 

translates to higher product rating for the same 

footprint and thereby lower cost. One way to 

attain higher efficiency cells is to use nc-Si:H 

material as a potential replacement for a-SiGe:H 

alloys in the multijunction cell. In conjunction, the 

high-rate MVHF technology is being developed 

for deposition of a-Si:H, a-SiGe:H, and nc-Si:H 

materials and cells to obtain higher efficiency 

and reduce capex. The MVHF deposition 

technology has shown promise for possible 

deployment in future roll to roll production 

machines. There is also an effort to improve the 

back reflector and associated deposition 

technologies. 

Another effort is directed toward bringing down 

the cost of stainless steel substrate, grid wires, 

packaging materials, and miscellaneous 

materials that go into the module. Innovative 

detachable module solutions are being 

developed that are more appealing and will 

reduce installation cost. 

Within the inverter and BOS area, the work 

focuses on new designs and better integration of 

inverters for building integrated applications. In 

the area of system engineering and integration 

tier, the work focuses on inexpensive installation 

designs for different types of roofs. For 

deployment facilitation, the work focuses on 

demonstrating cost reductions by installing, 

monitoring, and using lessons learnt from test 

arrays in different locations on different types of 

roofs. 

This project coordinates the efforts of several 

partners including equipment manufacturers, 

academia, national laboratories, inverter 

companies, and engineering design companies. 

The entities were selected on the basis of their 

competence and relevance to our flexible BIPV 

product. 

3. Results and Accomplishments 

United Solar achieved target performance with 

both potential device designs and processes as 

listed under Accomplishments. 

Another goal was the performance against 

target LCOE (for 2010). United Solar’s average 

module price and total system cost decreased 

significantly in 2009. Using projected costs of 

inverter and balance of systems, United Solar is 

on track to achieve their LCOE targets for 2010 

and 2015. 

Several other goals were achieved in 

miscellaneous areas ranging from the smallarea high-rate VHF a-Si:H, a-SiGe:H 

multijunction solar cells, to backend process 

improvement and material reduction. A key 

achievement was the improvement of the power 

rating of the current product. Before Phase I, the 

current product was rated at 136 W and 128 W. 

Under Phase II, the product rating increased to 

144 W. 

4. Planned FY 2010 Activities 

•	 Attain ≥12% stable total -area (0.268 cm 2

) 

efficiency on multijunction device 

37
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

incorporating nc-Si:H on Ag/ZnO back 

reflector 

•	 Attain ≥10.5% stable aperture-area (~400 

cm2

) efficiency on multijunction device 

incorporating at least one nc-Si:H layer at 

rate ≥ 1nm/s on Ag/ZnO back reflector 

•	 Attain ≥10.2% stable total -area (0.268 cm2

) 

efficiency on multijunction cells on Ag/ZnO 

back reflector incorporating a-Si:H and aSiGe:H deposited at ≥ 0.6 nm/s 

•	 Attain 9.5% stable aperture-area (~400 cm2

) 

efficiency on multijunction cells, using largearea MVHF batch reactor on Ag/ZnO back 

reflector incorporating a-Si:H and a-SiGe:H 

deposited at ≥ 0.6 nm/s 

•	 Using RTR machines, attain 22L laminates 

having power ratings of 155 W on Ag/ZnO, 

using new, inexpensive, back reflector 

deposition techniques 

•	 Continue to work with academia and NREL 

for better understanding of a-Si:H, a-SiGe:H, 

and nc-Si:H layers made by MVHF and 

explore new back reflectors 

•	 Continue to work on cost reduction of grid 

wire for current collection and alternative 

packaging materials 

•	 Conduct systems engineering and 

integration to develop novel and advanced 

application processes that will reduce the 

overall installation cost of United Solar 

roofing laminate modules 

•	 Continue to advance in-line diagnostic 

technology for in situ monitoring of device 

parameters 

•	 Continue to work with inverter companies to 

bring down the cost further 

•	 Obtain certification for new installation 

schemes. 

5. FY 2009 Special Recognitions, Awards, 

and Patents 

Subhendu Guha, principal investigator of this 

program, received the PVSEC 2009 award for 

his contribution to science and technology of 

photovoltaic. 

Eight patent applications were filed. 

6. Major FY 2009 Publications 

A. Banerjee, G. DeMaggio, K. Lord, B. Yan, F. 

Liu, X. Xu, K. Beernink, G. Pietka, C. Worrel, 

B. Dotter, J. Yang, and S. Guha, “Advances in 

Cell and Module Efficiency of a-Si:H Based 

Triple-Junction Solar Cells Made Using Roll-toRoll Deposition,” 34th IEEE PVSC, 2009. 

D.C. Bobela, H.M. Branz, G. Yue, B. Yan, P.C. 

Taylor, and P. Stradins, “Defect Creation in aSi:H and Its Relation to Hydrogen Bonding and 

Microstructure,” Mater. Res. Soc. Symp. Proc. 

1153, 2009. 

P. Hugger, J.D. Cohen, B. Yan, J. Yang, and S. 

Guha, “Insights and Challenges toward 

Understanding the Electronic Properties of 

Hydrogenated Nanocrystalline Silicon,” Phil. 

Mag. 89, 2541 (2009). 

P.G. Hugger, J.D. Cohen, B. Yan, G. Yue, J. 

Yang, and S. Guha, “Structural and Electronic 

Properties of Hydrogenated Nanocrystalline 

Silicon,” Mater. Res. Soc. Symp. Proc. 1153, 

2009. 

P. G. Hugger, J. Lee, J. D. Cohen, G. Yue, X. 

Xu, B. Yan, J. Yang, and S. Guha, “Junction 

Capacitance Study of a-SiGe:H Solar Cells 

Grown at Different Rates with RF and VHF 

Glow Discharge,” Mater. Res. Soc. Symp. 

Proc. 1153, 2009. 

K. Wang and D. Han, G. Yue, B. Yan, J. Yang, 

and S. Guha, “Light-Induced Increase of Nonradiative Recombination Centers in 

Hydrogenated Nanocrystalline Silicon Solar 

Cells under Reverse Electric Bias,” Appl. Phys. 

Lett. 95, 023506 (2009). 

X. Xu, D. Beglau, S. Ehlert, Y. Li, K. Lord, G. 

Yue, B. Yan, A. Banerjee, J. Yang, and S. 

Guha, “High Efficiency Large Area a-SiGe:H 

Based Multi-junction Solar Cells Using MVHF,” 

Proc. 23rd ICANS, Netherlands, 2009. 

X. Xu, D. Beglau, S. Ehlert, Y. Li, T. Su, G. Yue, 

B. Yan, K. Lord, A. Banerjee, J. Yang, S. 

Guha, P.G. Hugger, and J.D. Cohen, “High 

Efficiency Large Area a-Si:H and a-SiGe:H 

Multi-junction Solar Cells Using MVHF at High 

Deposition Rate,” Mater. Res. Soc. Symp. 

Proc. 1153, 2009. 

X. Xu, Y. Li, S. Ehlert, G. Yue, B. Yan, T. Su, J. 

Zhang, A. Banerjee, J. Yang, and S. Guha, 

“Comparative Study of MVHF and RF 

Deposited Large Area Multi-junction Solar 

Cells Incorporating Hydrogenated NanoCrystalline Silicon,” Mater. Res. Soc. Symp. 

Proc. 1153, 2009. 

X. Xu, T. Su, D. Beglau, S. Ehlert, G. Pietka, D. 

Bobela, Y. Li, K. Lord, G. Yue, J. Zhang, B. 

Yan, C. Worrel, K. Beernink, G. DeMaggio, A. 

Banerjee, J. Yang, and S. Guha, “High 

Efficiency Large Area Multi-Junction Solar 

Cells Incorporating a-SiGe:H and nc-Si:H 

Using MVHF Technology,” 34th IEEE PVSC, 

2009. 

38
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

B. Yan, G. Yue, X. Xu, J. Yang, and S. Guha, 

“High Efficiency Amorphous and 

Nanocrystalline Silicon Solar Cells,” Proc. 23rd 

ICANS, Netherlands, 2009; Phys. Status Solidi 

A (2010). 

B. Yan, G. Yue, L. Sivec, J. Yang, and S. Guha, 

“Extraction of Carrier Transport Parameters 

from Hydrogenated Amorphous and 

Nanocrystalline Silicon Solar Cells,” SPIE, 

2009. 

J.	 Yang and S. Guha, “Status and Future 

Perspective of a-Si:H, a-SiGe:H, and nc-Si:H 

Thin Film Photovoltaic Technology,” SPIE, 

2009 (invited). 

J. Yang, B. Yan, G. Yue, and S. Guha, “Light 

Trapping in Hydrogenated Amorphous and 

Nano-Crystalline Silicon Thin Film Solar Cells,” 

Mater. Res. Soc. Symp. Proc. 1153, 2009. 

J. Yang, B. Yan, G. Yue, X. Xu, A. Banerjee, 

and S. Guha, “Light-Induced Effect on the 

Performance of Thin-Film Silicon Solar Cells,” 

presented at 1st Staebler-Wronski Effect 

workshop, Germany, April 2009. 

G. Yue, L. Sivec, B. Yan, J. Yang, and S. Guha, 

“High Efficiency Amorphous and 

Nanocrystalline Silicon Based Multi-junction 

Solar Cells Deposited at High Rates on 

Textured Ag/ZnO Back Reflectors,” Mater. 

Res. Soc. Symp. Proc. 1153, 2009. 

G. Yue, L. Sivec, J.M. Owens, B. Yan, J. Yang, 

and S. Guha, “Optimization of Back Reflector 

for High Efficiency Hydrogenated 

Nanocrystalline Silicon Solar Cells,” Appl. 

Phys. Lett. 95, 263501 (2009). 

G. Yue, B. Yan, L. Sivec, J. M. Owens, S. Hu, X. 

Xu, J. Yang, and S. Guha, “Improvement of aSi:H and nc-Si:H Multi-junction Solar Cells by 

optimization of Textured Back Reflectors,” 34th 

IEEE PVSC, 2009. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research 

Activity 

FY 2009* 

($K) 

Cost 

Share* 

($K) 

University of Oregon/ 

J. David Cohen Eugene, OR 

Electronic and optical 

characterization of materials for 

a-Si:H, a-SiGe:H, and nc-Si:H 

materials and solar cells 

150 0 

Syracuse University/ 

Eric Schiff Syracuse, NY 

Diagnostic development of 

mobility characterization tool for 

a-Si:H, a-SiGe:H, and nc-Si:H 

solar cells and optical modeling 

studies for light trapping in aSi:H, a-SiGe:H, and nc-Si:H solar 

cells 

148 37 

Colorado School of 

Mines/ 

P. Craig Taylor 

Golden, CO 

Defect characterization of 

materials and devices using 

NMR, ESR, and PL 

150 31 

NREL/ 

Pauls Stradins Golden, CO 

Full material characterization and 

modeling of high rate materials 

using various characterization 

methods 

150 0 

* Phase II awarded amounts. 

39
 
 

 

____________________________________________________________________________________ 

 

____________________________________________________________________________________ 

 

 

 

 

 D 

 

R A F T

University Process & Product Development Partnerships 

Performing Organizations:	 Arizona State University (ASU); California Institute of Technology 

(Caltech); Georgia Tech Research Corporation (GIT); Massachusetts 

Institute of Technology (MIT); North Carolina State University (NCSU); 

Pennsylvania State University (Penn State); University of Delaware (UD) 

(2); University of Florida (UF); University of Toledo (UT) (2) 

Key Technical Contacts:	 Carolyn Elam (DOE/GO, Primary Contact), 303-275-4953, 

carolyn.elam@go.doe.gov 

Joe Lucas (DOE/GO), 303-275-4849, joe.lucas@go.doe.gov 

Jim Payne (DOE/GO), 303-275-4756, jim.payne@go.doe.gov 

Holly Thomas (DOE/GO), 303-275-4818, holly.thomas@go.doe.gov 

DOE HQ Technology Manager:	 Marie Mapes, 202-586-3765, marie.mapes@hq.doe.gov 

FY 2009 Budget:	 $2,892K (DOE/GO) 

Objectives 

•	 Leverage university understanding and experience to improve photovoltaic (PV) products and 

process development 

•	 Develop projects offering direct, near-term improvements in PV products and development 

processes. 

Accomplishments 

•	 Demonstrated >20% efficiency using local back-contact structure formed by dielectric etching and 

laser ablation (ASU) 

•	 Demonstrated back-surface recombination velocity of 125 cm/s and back-surface reflectance of 

93% using local back contact structure (GIT) 

•	 Achieved a small-area device efficiency of 15.5% (AR coated, measured at NREL) on Na doped 

Cu(InGa)Se2 films deposited in the roll-to-roll system (UD). 

Future Directions 

•	 Fabricate and characterize InxGaAs1-x/InP /Si and InxGaAs1-xP/InP /Si solar cells (CalTech) 

•	 Fabricate 19%–20% efficient cells with dielectric passivated rear contact with screen-printed local 

BSF (GIT) 

•	 High-temperature XRD studies of base-CIGS thin films multi-layer precursors (UF). 

1. Introduction	 commercialization efforts and supplies industry 

with a stream of qualified scientists. 

The University PV Process and Product 

Development Support research area is part of the 2. Technical Approach 

system development and manufacturing phase of 

the Solar Energy Technologies Program, restricted University PV Process and Product Development 

to U.S. universities. Universities hold a Support awarded 11 projects in six topic areas in 

fundamental understanding of materials and FY 2008. The topic areas and awards were CdTe 

device physics as well as experience with lab- (1), CIGS (2), CPV (3), Thin Silicon (1), Organic 

scale processes and prototype production. This PV (1), and Wafer-Silicon (3). Agreements are 

experience uniquely positions universities to listed in the table that follows. Progress for each 

leverage their knowledge in assisting the transition award is described in Section 3. 

of PV technology from laboratory to marketplace. 

Additionally, market-oriented research offers 

students exposure to the growing PV-related 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

Agreement Title 

FY 2009 

Budget 

($K) 

ASU—G. Tamizhmani 

Reliability Evaluation of Concentrator 

Photovoltaic Modules per IEC 

Qualification Specifications 33 

Caltech—H.A. Atwater 

100-mm Engineered InP-on-Si 

Laminate Substrates for InP-based 

Multijunction Solar Cells 273 

GIT—A. Rohatgi 

Development of Rear-Contact 

Technologies for Next-Generation 

High-Efficiency Commercial Silicon 

Solar Cells 344 

MIT—A. Buonassisi 

Defect Engineering, Cell Processing, 

and Modeling for High-Performance, 

Low-Cost Crystalline Silicon PV 499 

NCSU—S. M. Bedair 

Tunable Narrow Bandgap Absorbers 

for Ultra High Efficiency Multijunction 

Solar Cells 256 

Penn State—C. A. Grimes 

TiO2 Nanotube Array-Organic 

Semiconductor Heterojunction Solar 

Cells for Efficient, Low-Cost, Large 

Area Scalable Solar Energy 

Conversion 297 

UD—E. Eser 

Development of a Low-Cost Insulated 

Foil Substrate for Cu(InGa)Se2 PV 299 

UD—U. Das 

High-Efficiency Back-Contact Silicon 

Heterojunction Solar Cells 292 

UF—T. Anderson 

Routes for Rapid Synthesis of 

CuGaxIn1-xSe2 Absorbers 83 

UT—X. Deng 

High-Rate Fabrication of a-Si-Based 

Thin-Film Solar Cells Using LargeArea VHF PECVD Processes 260 

UT—R. Collins 

Improved CdTe PV Modules by 

Atmospheric Pressure Vapor 

Deposition 256 

3. Results and Accomplishments 

3.1 Reliability Evaluation of Concentrator 

Photovoltaic Modules per IEC Qualification 

Specifications (ASU) 

Testing cost and time for the CPV partners will be 

reduced by as much as 65%. ASU accomplished 

the following: 

•	 Performed thermal cycling tests with pulsating 

current on the CPV receivers 

•	 Initiated long-term outdoor testing of CPV 

modules on two-axis trackers 

•	 Ordered an environmental chamber 

•	 Modified the building to install the chamber. 

3.2 100-mm Engineered InP-on-Si Laminate 

Substrates for InP-based Multijunction Solar Cells 

(Caltech) 

This work is to advance III-V/Si laminate substrate 

development for multijunction solar cell 

technology, and to achieve low-cost, highefficiency multijunction solar cells fabricated on 

100-mm InP/Si laminate substrates. Caltech 

fabricated InP laminate substrates for III-V 

multijunction cell fabrication on 100-mm-diameter 

Si substrates, and together with partner 

Spectrolab developed high-quality InAlAs epitaxial 

alloys for application as a top cell in InP-based 

multijunction cells. Caltech also developed a 

“virtual template substrate” process for fabricating 

laminate substrates at different lattice constants, 

using the InxGaAs1-x/InP system. Caltech is also 

focusing on developing a robust process for 

fabricating 100-mm InP/Si substrates. Work to 

establish and validate a wafer specification for an 

InP/Si substrate that is commercially 

manufacturable at high volumes continues, using 

prototype InGaAsP/InGaAs and 

InAlAs/InGaAsP/InGaAs multijunction solar cells. 

3.3 Development of Rear-Contact Technologies 

for Next-Generation High-Efficiency Commercial 

Silicon Solar Cells (GIT) 

The objective is to develop low-cost, high-quality 

rear contacts and fabricate production-ready highefficiency monocrystalline (~20%) and 

multicrystalline (17%–18%) silicon solar cells. GIT 

accomplished the following: 

•	 Modeled effect of amorphous silicon 

heterojunction on solar cell efficiency 

•	 Developed dielectric with low fixed-charge 

density and optimized local back-contact 

geometry 

•	 Deposited silane-free SiCX and evaluated 

passivation quality 

•	 Demonstrated back-surface recombination 

velocity of 125 cm/s and back-surface 

reflectance of 93% using local back-contact 

structure 

•	 Demonstrated > 20% efficiency using local 

back-contact structure formed by dielectric 

etching and laser ablation. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3.4 Defect Engineering, Cell Processing, and 

Modeling for High-Performance, Low-Cost 

Crystalline Silicon PV (MIT) 

The objective is to close the efficiency gap 

between industrial multicrystalline silicon (mc-Si) 

and monocrystalline silicon solar cells and 

conserve the economic advantage of low-cost, 

high-volume substrates inherent to mc-Si. MIT 

accomplished the following: 

D R A F T

•	 Identified and decoupled the lifetime limiting 

defects types in “good” and “bad” regions of 

ingot multicrystalline silicon solar cell material 

•	 Used equivalent lifetime modeling to estimate 

the impact of each characteristic region on 

device performance 

•	 Determined the distribution and states of 

impurities in raw feedstock material (quartz 

and woodchips/charcoal) 

•	 Reduced dislocation densities in mc-Si via 

high-temperature annealing. 

3.5 Tunable Narrow Band Gap Absorbers for Ultra 

High Efficiency Multijunction Solar Cells (NCSU) 

The objective is to reduce LCOE by improving the 

efficiency of III-V multijunction solar cell and lead 

to a practical and achievable efficiency > 45% 

through a four-junction cell. Using organometallic 

chemical vapor deposition at 600°C and 625°C, 

epitaxial structures for the fabrication of simple 

GaAs test cells and similar structures with 

superlattices were fabricated into test cells. The 

structures have high doping back-surface fields 

(BSFs) and are unpassivated on the front 

surfaces, but no high bandgap window layer. 

Researchers compiled the spectral response 

results to find the effect of barrier width on the 

barrier transmission probability (internal quantum 

efficiency of the single wells). Results indicate that 

structures with barrier widths less than 30 Å 

demonstrated an Isc equal to or better than that of 

our GaAs standard cell, illustrated in Figure 1. 

Because the superlattices have more than 20 

periods, a blue response of greater than 80% of 

the GaAs response shows that we have exceeded 

99% transmission through the barriers. Major 

accomplishments are as follows: 

•	 Grew InGaAs-GaAsP strain balanced 

superlattices 

•	 Incorporated strain-balanced superlattice in 

GaAs p-i-n device 

•	 Observed spectral response from superlattices 

<1,3 eV 

•	 Exceeded 99% transmission through the thin 

GaAsP barriers. 

Fig. 1. Effect of barrier thickness on spectral 

response 

3.6 TiO2 Nanotube Array-Organic Semiconductor 

Heterojunction Solar Cells for Efficient, Low-Cost, 

Large-Area Scalable Solar Energy Conversion 

(Penn State) 

The grant’s purpose is to reliably produce scalable 

and highly efficient solid-state solar cells using a 

heterojunction of TiO2 nanotube arrays and an 

organic semiconductor with a goal to manufacture 

low-cost, large-area, air-stable solar cells with 

photoconversion efficiencies of 6% to 8%. Penn 

State accomplished the following: 

•		 Developed new acene molecules that serve as 

both dye and hole-transporter 

•		 Developed optimal routes for intercalation of 

hole transporting p-type polymers within the 

pores of one-dimensional electron transporting 

transparent TiO2 nanotube array films 

• Achieved photostable dye-sensitized 

heterojunction solid-state solar cells of 6% 

photoconversion efficiency 

• Achieved Förster resonance energy transfer in 

solid-state dye-sensitized solar cells, enabling 

enhanced solar spectrum capture and 

utilization. 

3.7 Development of a Low-Cost Insulated Foil 

Substrate for Cu(InGa)Se2 PV (UD—Eser) 

The goal is to develop low cost stainless-steel 

flexible-substrate coated with high-temperature 

silicone-based resin (SBR) dielectric for use in 

processing Cu(InGa)Se2-based PV. UD 

accomplished the following: 

•	 Reduced defects in the SBR coatings shorting 

Mo layer to the stainless-steel foil 

substantially; the remaining defects were 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

burned away with an applied voltage of less 

than 3 V 

•	 Showed, using SIMS depth-profiling data, that 

SBR coatings were robust diffusion barriers for 

elements in the stainless steel base. 

•	 Characterized the NaF evaporation source, 

which is being used routinely in the R2R 

process system to dope Cu(InGa)Se2 films 

D R A F T

•	 Achieved a small-area device efficiency of 

15.5% (AR coated, measured at NREL) on 

Na-doped Cu(InGa)Se2 films deposited in the 

R2R system 

•	 Showed small-area device average efficiency 

over 9 feet of a Cu(InGa)Se2 web of 10.8%, 

with a maximum of 13.2%. 

•	 Showed small-area end-point efficiencies of 

11.9% (at 2 feet from the leading edge) and 

11.5% (at 29 feet from the leading edge) on 30 

feet of Cu(InGa)Se2 web 

•	 Achieved small-area device efficiency of 8.5% 

on Cu(InGa)Se2 films prepared by precursor 

selenization 

•	 Demonstrated Cu(InGa)Se2 laser scribing on 

small area samples. 

3.8 High-Efficiency Back Contact Silicon 

Heterojunction Solar Cells (UD—Das) 

The objective is to implement an interdigitated 

back-contact (IBC) silicon solar cell using lowtemperature heterojunction (HJ) depositions. The 

use of silicon HJs allows a simpler design of rearcontact solar cells and higher performance at 

lower deposition temperatures. Results and 

accomplishments in FY 2009 include the following: 

•	 Demonstrated lowtemperature stack layer (2 

nm a-Si:H/60 nm SiNX/20 nm SiCX) for c-Si 

front surface passivation and antireflection 

(AR) structure with surface recombination 

velocity (SRV) < 7 cm/s. 

•	 Achieved highly transparent evaporated ZnS 

films for c-Si front surface passivation with 

SRV ~ 30 cm/s. 

•	 Implemented a-Si:H-based stack layer as a 

robust, process-compatible front surface 

passivation, and AR structure leads to VOC > 

700 mV in IBC-SHJ solar cells on thin (<150 

μm) n-type Fz wafer 

•	 Modified and prepared various interfaces 

between c-Si and thin a-Si:H layers essential 

to improve solar cell FF and were 

demonstrated by two-dimensional numerical 

simulation and in experimental front SHJ solar 

cells. 

•	 Front SHJ solar cells with improved interfaces 

exhibited FF > 79% on thin (< 150 μm) 

polished Fz and FF > 75% on 150 μm 

SunPower textured wafers. 

3.9 Routes for Rapid Synthesis of CuGaxIn1-xSe2 

Absorbers (UF) 

The objective is to develop predictive models that 

quantitatively describe reaction pathways to 

synthesize CIGS for increased throughput as a 

result of shortened reaction time for absorber 

synthesis. Additional cost reductions owing to 

process scale-up will be realized with quantitative 

rate data. The target is a synthesis time of 2 

minutes or under. Progress to date includes the 

following: 

•	 Performed high-temperature X-ray diffraction 

(HT-XRD) studies of the Ga-Se and In-Se 

binary systems using both codeposited and 

bilayer precursors: the Ga-based reactions 

were much faster than In-based ones, and 

pathways for stacking sequence of 

Cu/Ga/In/Se and Ga/In/Cu/Se layered 

structure were compared 

•	 Using a sublattice model, assessed the metalSe binary phase diagrams and evaluated the 

pseudo-binary CIS-CGS phase diagram; also 

assessed the Cu-Ga binary system using the 

sublattice model framework 

•	 Performed detailed high-temperature XRD 

studies on samples provided by two of our 

industrial collaborators; these studies provided 

valuable insight into their processes 

•	 Validated a low-temperature route to grain 

growth of CIS nanoparticles using peritectic 

decomposition of CuSe2 or CuSe in 

temperature ramp experiments; initiated a 

study of the effect of Na addition on the 

nanoparticle growth pathway and rate. 

•	 Reviewed available data and performed a 

preliminary analysis of CALPHAD-based 

diffusion mobility descriptions for phases in the 

3 metal-Se, 3 metal-metal, and CIS systems. 

3.10 High-Rate Fabrication of a-Si-Based ThinFilm Solar Cells Using Large-Area VHF PECVD 

Processes (UT—Collins) 

Two clear objectives of this effort are (1) to 

develop and improve a large area (3 × 3 ft)

PECVD system for high rate fabrication of 8 Å/s aSi and 20 Å/s nc-Si or 8 Å/s a-SiGe absorber 

layers with high uniformity in film thicknesses and 

in material structures, and (2) develop and 

optimize large-area PECVD processes to achieve 

high-performance a-Si/nc-Si or a-Si/a-SiGe 

tandem-junction solar cells with >10% stable 

efficiency. Accomplishments include the following: 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• Systematically studied a-Si and a-SiGe solar • Install and commission the second 

cells deposited in lab-scale (4 × 4 in.) and environmental chamber 

large-area (3 × 3 ft) PECVD systems at 

elevated pressures of 1 ~ 4 Torr and power 

density 

•	 Achieved high deposition rate of >8 Å/s for aSi and a-SiGe absorber layers without 

compromising the cell performance 

D R A F T

•	 Modified the large-area PECVD cathode to 

improve the discharge stability and uniformity 

•	 Developed a-SiGe cells with graded Ge 

profile; the efficiency of a-Si/a-SiGe tandem 

cells deposited at a high rate reached >10% 

•	 Fabricated full-laminated a-Si/a-SiGe modules 

of 1.5 × 1.5 in. window area; the module 

efficiency reached 10.28% from NREL 

measurement results 

•	 Optimized the front transparent conductive 

oxide films to improve light absorption and 

current collection 

•	 Conducted numerical simulation of gas 

distribution in a large-area PECVD system 

•	 Installed multichannel RTSE on small-area (4 

× 4 in.) PECVD system; demonstrated the 

phase diagrams of PECVD a-SiGe cells 

deposited at high rate. 

3.11 Improved CdTe PV Modules by Atmospheric 

Pressure Vapor Deposition (UT—Deng) 

This project will advance an atmospheric pressure 

vapor deposition (APVD) process for CdTe 

modules and to achieve module performance 

comparable to competing CdTe technologies while 

retaining the manufacturing cost advantages of 

APVD. Accomplishments include the following: 

•	 Achieved an average efficiency of greater than 

12% for CdTe cells as thin as 1 micron with 

the appropriate post-deposition treatment and 

optimized back contact scheme 

•	 Obtained a map of the CdS bulk layer 

thickness from spectroscopic ellipsometry 

measurements over a 120 x 60 cm area of a 

glass plate coated with TEC-15 and HRT 

layers 

•	 Optimized a dual 

electrochemical/photochemical treatment 

process for CdTe cells. 

4. Planned FY 2010 Activities 

ASU 

•	 Install and commission the first environmental 

chamber, order second chamber 

•	 Collect and report test data on the outdoor 

exposure tests 

•	 Perform two qualification tests for each of the 

two partners. 

CalTech 

•	 Fabricate and characterize InxGaAs1-x/InP /Si 

and InxGaAs1-xP/InP /Si solar cells 

•	 Fabricate and characterize InxAlAs1-x/InP /Si 

solar cells 

•	 Develop comprehensive laminate substrate 

wafer specification and defect characterization 

protocol. 

GIT 

•	 Develop and optimize technology to open local 

contact windows using screen printable 

dielectric etching paste and laser patterning 

technique 

•	 Develop Al paste and firing technique to form 

high-quality Al BSF through the contact 

windows without warping thin wafers 

•	 Fabricate 19%–20% efficient cells with 

dielectric passivated rear contact with screen 

printed local BSF 

•	 Develop the technology for the local plated 

contacts and inkjet printing to form local rear 

contacts 

•	 Fabricate cells with the plated and inkjet rear 

contacts with efficiency of 18%–20% 

NCSU 

•	 Achieve reflectivity of > 80% with Bragg 

reflector 

•	 Optimize full cell structure (passivation, 

windows) for incorporation into multijunction 

cell 

•	 Optimize strained-layer superlattice 

composition for current and voltage 

•	 Begin technology transfer to Spectrolab. 

UD—Eser 

•	 Demonstrate 12% or higher efficiency devices 

on Cu(InGa)Se2 films prepared by precursor 

selenization 

•	 Optimize laser scribing of the Cu(InGa)Se2 

films and of the top contact ITO 

•	 Fabricate prototype 3 x 3 in. minimodule. 

MIT 

•	 Evaluate which defects are and are not 

passivated during hydrogenation in cell 

processing, and explore low-temperature 

annealing to improve solar cell device 

performance 

•	 Develop and release an impurity simulation 

tool to predict the effect of impurities on silicon 

material performance 

•	 Transfer to industrial partners by 2011. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Penn State 

•	 Optimize the performance of solid-state solar 

cells comprising dye-sensitized TiO2 nanotube 

films intercalated with p-type polymeric blends 

•	 Synthesize functionalized pentacene 

derivatives and incorporate them into TiO2 

nanotube array hybrid solar cells to decrease 

bandgap, increase stability, and improve 

compatibility with oxide surfaces 

D R A F T

•	 Explore high-throughput fabrication techniques 

to form the active layer organic semiconductor 

films on TiO2 

•	 Quantify and overcome the limiting 

parameters affecting solar cell performance. 

UD —Das 

•	 Investigate effect of different front-surface 

passivation and AR layer on optical and 

electrical performances of IBC-SHJ solar cells 

•	 Characterize and modify different interfaces to 

achieve high VOC (>700 mV) and FF (>80%) of 

SHJ solar cells 

•	 Fabricate IBC-SHJ solar cells on thin wafers 

(~ 150 μm) with improved interface quality. 

UF 

•	 Perform high-temperature XRD studies of 

base-CIGS thin-film multilayer precursors 

•	 Perform high-temperature XRD studies of 

grain growth using nanoparticles 

•	 Complete assessment of the ternary Cu-In-Ga 

system 

•	 Perform DICTRA modeling of binary Se 

couples to extract diffusion mobilities: Cu-Se, 

In-Se, and Ga-Se. 

UT—Deng 

•	 Improve gas distribution and discharge 

uniformity in a large-area 3 × 3 ft PECVD 

system in combination with theoretical 

simulation 

•	 Further improve the deposition rates and 

stability of a-Si, a-SiGe, nc-Si, and nc-SiGe 

solar cells grown at high pressure 

•	 Fabricate a-Si/a-SiGe or a-Si/a-SiGe/nc-SiGe 

multi-junction solar cells at a high deposition 

rate. 

UT—Collins 

•	 Select the best advanced solar tuned glass for 

further study of CdTe solar cells 

•	 Evaluate the performance of spatial scanning 

SE for CdTe solar cells 

•	 Continue studies of rapid thermal on-line 

activation 

•	 Select optimum atmospheric pressure 

metallization procedure 

•	 Perform scribing on cell structures with the 

optimized thicknesses chosen after Year 1 

•	 Perform testing on minimodules 

(interconnected and encapsulated) to identify 

possible issues. 

5. FY 2009 Special Awards and Patents 

U.S. provisional patent application, R.W. Birkmire 

et al., “Methods for Fabricating All-Back-Contact 

Heterojunction Solar Cells,” serial number 

61/187,812 filed on June 17, 2009. 

Penn State 

U.S. patent application, X. Feng, K. Shankar, and 

C.A. Grimes, “Single-Crystal Nanowires and 

Liquid Junction Solar Cells.” 

6. Major FY 2009 Publications 

UD—Das 

U.K. Das, D. Xu, O. Jani, M. Lu, S. Bowden, and 

R.W. Birkmire, “Designing Rear Surface for 

Carrier Transport in all Back Contact Silicon 

Heterojunction Solar Cells,” Tech. Digest, 18th 

International Photovoltaic Science and 

Engineering Conference & Exhibition, Jan. 19– 

23, 2009, Kolkata, India. 

UT—Collins 

J. Li, J. Chen, M. Sestak, C. Thornberry, and R.W. 

Collins, "Spectroscopic Ellipsometry Studies of 

Thin Film CdTe and CdS: From Dielectric 

Functions to Solar Cell Structures," 34th IEEE 

PV Specialists Conference, June 7-12, 2009, 

Philadelphia, PA, Invited Paper 505. 

MIT 

D.P. Fenning, M.I. Bertoni, and T. Buonassisi, 

“Insights Into the Optimal Phosphorus Diffusion 

Profile for Silicon Solar Cells,” Proc. 24th 

European Photovoltaic Solar Energy 

Conference, Hamburg, Germany, 2009. 
 

 

 

 

 

 

 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

D R A F T

Organization/ 

Principal Investigator Location Description/Title of Research Activity 

ASU/ G. Tamizhmani 

Solfocus, Inc. 

Warren Nishikawa 

Soliant Energy, Inc. 

Brad Hines 

Mountain View, CA 

Pasadena, CA 

Perform thermal cycling test of receivers 

with current injection; outdoor exposure 

testing of the modules / assemblies 

Caltech/ H.A. Atwater 

Spectrolab 

Dr. Daniel C. Law 

Sylmar, CA Assist with cell processing, InxGa1-xAs cell 

fabrication 

GIT/ A. Rohatgi 

SiXtron Advanced 

Materials, Inc. Varennes, Quebec, Canada 

Furnish silane-free solid source for SiN-/SiCbased AR-coatings and passivation layers 

for Si cells 

NCSU/ S.M. Bedair 

Spectrolab 

Ken Edmondson 

Sylmar, CA Support integration of NCSU subcell into 

multijunction cell 

Penn State/ C.A. Grimes 

University of Kentucky Lexington, KY Assist in the design and synthesis of organic semiconductors 

UD/ E. Eser 

Dow Corning Corp. 

Elizabeth McQuiston 

Midland, MI Develop silicone-based dielectric coated 

stainless-steel foils 

UD/ U. Das 

SunPower 

Richard Swanson 

Sunnyvale, CA Produce textured thin wafers and participate 

in technical discussions 

UT/ X. Deng 

Xunlight Corporation 

X. Deng 

Toledo, OH Furnish materials, labor, and equipment for 

Xunlight’s roll-to-roll production line 

UT/ R. Collins 

Solar Fields 

Dr. Norm Johnston 

University of Nevada, Las 

Vegas 

Dr. Clemens Heske 

University of Michigan 

Kai Sun 

NSG Pilkington 

David Stricklert 

Perrysburg, OH 

Las Vegas, NV 

Ann Arbor, MI 

Northwood, OH 

Supply large-area thin-film deposition 

processing 

Provide electron and photon spectroscopies 

Provide high resolution electron microscopy 

Supply ASTG plates 
 

 

D R A F T

PV Component Development Summary 

The PV Systems and Component Development agreement for subcontracted R&D activities 

includes the PV Incubator Solicitation, the Pre-Incubator (device and development evolution) 

solicitation and the Industry Thin Film Partnerships. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

PV Component Development 137226 50 0 13776 

PV Incubator Solicitation 11664 50 0 11714 

Industry Thin Film 

Partnerships 2062 0 0 2062 
 

 

 

___________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

Photovoltaic Technology Incubator 

D R A F T

Performing Organization:	 National Renewable Energy Laboratory (NREL) 

Key Technical Contact:	 Martha Symko-Davies (NREL), 303-384-6528, 

Martha_symko_davies@nrel.gov 

DOE HQ Technology Manager:	 Scott Stephens, 202-586-0565, scott.stephens@ee.doe.gov 

FY 2009 Budget:	 $11,664K (NREL) 

Objectives 

•	 Shorten the timeline for companies to transition prototype and precommercial photovoltaic (PV) 

technologies into pilot- and full-scale manufacture 

•	 Move companies into commercial production quickly and successfully 

•	 Position companies to be competitive for market entry by 2012. 

Accomplishments 

•	 Completed merit review and analysis to select negotiations for third round of Incubator
 

subcontracts in August 2009
 

•	 Began stage-gate reviews for the second round of Incubators; six companies are in this round, 

one to date was down-selected 

•	 Completed the first round of Incubator subcontracts, October 2009; seven of 10 companies 

completed the Incubator successfully within 18 months. 

Future Directions 

•	 Issue a fourth letter of interest (LOI) for the PV Technology Incubator in fiscal year FY 2010. This 

will combine the Pre-Incubator and the Incubator with merit criteria updated to better represent 

the maturity levels for small businesses that will be competitive for this upcoming procurement 

•	 Complete merit review for responses to the fourth Incubator/Pre-Incubator LOI by September 

2010 

•	 Complete stage-gate reviews of round 2 Incubators of progress, deliverables, and ability for 

commercialization by January 2010 

•	 Begin negotiations with the companies selected under the third Incubator solicitation. Complete 

awards by March 2010. 

1. Introduction 

The primary objective of the PV Technology 

Incubator project is to shorten the timeline for 

companies to transition PV technologies into pilot 

and full-scale manufacture. Companies selected 

are diverse and are able to meet the objectives set 

out by the SETP program. Incubator companies 

should be able to achieve market entry by 2011. 

This PV Technology Incubator project targets 

research and development on PV cell and module 

prototypes with demonstrated functionality in 

either large-area cell/module form or, preferably, 

prototypes produced in pilot-scale operations. The 

emphasis on proposed activities should focus on 

the barriers to manufacturing scale-up and 2010 

commercialization. 

Advances are needed to achieve prototype 

modules and pilot production, which will be 

facilitated through projects funded under this LOI. 

It is expected that subcontract duration will be 18 

months, and each award will be $3 million under 

this solicitation. Entrance opportunities for the 

Incubator project are anticipated every 9–12 

months as funding opportunities become 

available. The entrance criterion is demonstrated 

PV cells or process lab devices or modules. A 

successful demonstration for the entrance criterion 

is a quantifiable and verifiable baseline 

measurement. The successful exit criterion would 

be for prototype modules and pilot production 
 

 

 

 

 

 

 

 

 

 

 

D R A F T

demonstration greater than 3 MW/year. These 

entry and exit criteria are provided to applicants as 

general guidelines for maturity of technology that 

the U.S. Department of Energy (DOE) intends to 

fund through this LOI, but the guidelines are 

flexible. The guidelines will be revisited in FY 

2010. 

The success of the PV Technology Incubator 

project is attributable to the financial resource 

supported fully by the DOE and the capabilities 

and the experience the researchers bring to each 

project. Kick-Off meetings begin the dialogue with 

the Companies and NREL researchers. 

Involvement begins immediately and is very 

effective in this program. 

2. Technical Approach 

2.1. PV Incubator Management 

The Project Management and Support subtask 

manages the Incubator project, manages 

subcontracts awarded, and coordinates NREL inhouse activities in support of the small businesses. 

Table 1. PV Incubator Project Tasks and Budget 

Task Title FY 2009 

Budget ($K) 

PV Technology Incubator 

Management 1,170 

PV Technology Incubator 

Subcontracts 10,434 

2.2. PV Incubator Scope 

NREL solicited LOIs from individual U.S. small 

businesses and small business led teams that 

were working on research and development of 

demonstrated PV cell and module prototypes. The 

LOI emphasized overcoming the barriers to manufacturing scale-up and 2011 commercialization. 

Topic areas include: 

•	 Novel wafer-based silicon (Si) modules 

•	 Polycrystalline thin films 

•	 Film silicon on a foreign substrate 

•	 High-efficiency cells, including multijunction, 

and concentrating PV (CPV) module concepts 

•	 Organic PV, dye-sensitized solar cells, or 

other polymer-based solar cells 

•	 Low-X concentration CPV systems with limited 

or 1-axis tracking module designs. 

Table 2. FY 2007 PV Incubator Subcontractors 

Round 1. Successful companies completed early FY 

2009. 

Subcontractor Title of Subcontract 

Abound Sola r Advanced CdTe PV Technology 

Ca liSola r New Metallization Technique 

Suitable for 6-mW Pilot Production 

of Efficient Multicrystalline Solar 

Cells Using Upgraded 

Metallurgical Si 

Mic roLink Epitaxial Liftoff Fabrication of LowCost, High-Efficiency, GaAsBased, Dual-Junction Solar Cells 

for Concentrator Applications 

Ple xtronics Economic On-Grid Solar Energy 

via Organic Thin Film Technology 

P rim eS tar S o lar Production Scale-up of World 

Record CdTe/CdS Cell 

SolFocus Reflective Optics CPV Panels 

Enabling Large-scale, Reliable 

Generation of Solar Energy Costcompetitive with Fossil Fuels 

SoloPower CIGS Technology based on 

Electroplating 

Table 3. Subcontractors Selected in Response to 

the FY 2008 PV Incubator Solicitation. Subcontracts 

will be completed during FY 2010 

Subcontractor Project Title 

1366 

Technologies, Inc. 

Self Aligned Cell – Scaling Up 

Manufacture of a Cost Effective 

Cell Architecture for MultiCrystalline Silicon Photovoltaics 

Innovalight, Inc. High-Efficiency, Low-Cost Solar 

Cells Manufactured Using 

“Silicon Ink” On Thin Crystalline 

Silicon Wafers 

Skyline Solar, Inc. Accelerating the Transition of 

Skyline Solar’s Module to 

Manufacturing: Medium 

Concentration onto Silicon = Low 

Cost × Explosive Scalability 

Solexel, Inc. Productization and Manufacturing 

Scaling of High-Efficiency Solar 

Cell and Module Products Based 

on a Disruptive Low-Cost, MonoCrystalline Technology 

Spire 

Semiconductor 

Corporation, LLC 

Manufacturing of High-Efficiency 

Bi-Facial Tandem Concentrator 

Solar Cells 

3. Results and Accomplishments 

1366 Technologies is focusing efforts on a self 

aligned cell, scaling pp manufacturing of a costeffective cell architecture for multicrystalline 

silicon photovoltaics. During the Incubator project, 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

1366 invented a patterning machine that makes a 

structured texture on multicrystalline cells that 

improves the cell efficiency. 1366 also developed 

a dispensing machine that created front 

metallization with three times the conductivity and 

one-third the width of screen-printed fingers. The 

dispensing machine makes it possible for cell 

manufacturers to switch from silver conductors to 

copper conductors. Copper is two orders of 

magnitude cheaper than silver. 

Innovalight is focusing on increasing the efficiency 

of crystalline silicon solar cells and modules by 

developing low-cost manufacturing processes 

using ink-jet printing of "silicon ink" onto thin 

crystalline silicon wafers. During 2009, they 

exceeded their efficient target for 25 x 25 mm 

crystalline silicon cells incorporating optimized 

antireflection coating, metallic contact grid, and 

optimized front surface texturing by achieving 

more than the required 17% on all 125 x 125 mm 

cells. They also demonstrated a less than 10% 

degradation in the efficiency, Jsc, Isc, Voc, Pmax, 

and FF on (nonpackaged) 125 x 125 mm cells 

after exposure to 85°C/85% relative humidity for 

250 hours. 

Skyline Solar is focusing on manufacturing linear 

CPV concentrators designed for medium 

concentration (10–50X) on silicon solar cells. Their 

project emphasizes a low-cost CPV product using 

aluminum reflectors, optics with flexible 

tolerances, lightweight structures to minimize 

installation costs, and standard industrial 

manufacturing processes to maximize scalability. 

Skyline Solar achieved an array efficiency of 

12.5% + 0.4% with their 12-m2 prototype module. 

Solasta’s project emphasizes optimizing and 

scaling up solar cells that incorporate a unique 

nanocoax architecture with an a-Si absorber layer. 

Nanocoax solar cells consist of arrays of vertical 

nanopillars coated by a layer of a-Si, followed by a 

conformal layer of a transparent conductive oxide 

(TCO). They achieved 8% initial efficiency on 1­

cm2 nanocoax cells and plan to submit 1-cm2 

nanocoax cells with 10% initial efficiency to NREL 

by February 2010. Solasta intends to achieve 100­

cm2 nanocoax solar cells with > 15% efficiency 

and prepare for pilot production by the end of the 

18-month subcontract. 

Solexel is focusing on fabricating epitaxially grown 

monocrystalline silicon thin-film solar cells and 

incorporates these cells into a module designed to 

reduce efficiency loss. The epitaxial silicon is 

grown on and lifted off of a crystalline silicon 

template that can be reused numerous times to 

yield many thin film silicon substrates (TFSS), 

which are then processed into solar cells. By the 

end of their 18-month subcontract, Solexel intends 

to achieve a 3-MW pilot manufacturing line that 

produces 156 x 156 mm TFSS cells with > 19%. 

The focus of the Spire Semiconductor Corporation 

research activities is to develop a manufacturable, 

42.5% efficient, bifacial, tandem CPV solar cell 

suitable for 500X concentration. This multijunction 

approach is highly innovative and can achieve 

greater than 43% efficiency during the project. The 

results to date include developing the InGaP top 

cell with a bandgap of ~1.9 eV, the InGaAs bottom 

cell with bandgap of ~ 1.0 eV, and low-absorption 

TJs suitable for > 500X device fabrication. Cell 

results to date are a 39.3% tandem cell at 218X 

and 35.6% tandem cell at 500X, independently 

verified by NREL. 

The round 3 Incubators solicitation was released 

in May 2009 with selections during FY 2009 and 

announced into FY 2010. These companies are 

Alta Devices, Semprius, Solar Junction, and 

TetraSun. The subcontracts are anticipated to be 

completed by March 2010. The subcontracts will 

mostly use ARRA funding. 

The Pre-Incubator solicitation was released in 

January 2009, and 11 selections were made. 

These awards were completed by late November 

2009. The selections are Crystal Solar, TiSol, 

Banyan, Microlink, EPIR, Vanguard, Ascent, 1366 

Technologies, Lightwave, Spectrawatt, and Luna 

Innovations. These 1-year subcontracts will 

complete with a finished prototype ready to apply 

for the Incubator solicitation. 

4. Planned FY 2010 Activities 

The Round 3 Incubators selected during FY 2009 

and announced in January 2010 will be awarded 

by March 2010. These companies are Alta 

Devices, Semprius, Solar Junction, and TetraSun. 

These will mostly use ARRA funding. 

A fourth solicitation incorporating the Incubator 

and Pre-Incubator will be released in Spring 2010. 

Updates to the solicitation will include such items 

as the merit criteria. This type of change is to 

better represent the maturity levels for small 

businesses that will be competitive for this 

upcoming procurement. Typically we expect 8–10 

Incubators and 12–16 Pre-Incubators to be funded 

under this solicitation. These subcontracts will 
 

 

 

 

 

 

D R A F T

then undergo a stage-gate review in late 2010. At Additionally, we will track the potential in terms of 

that time their progress will be evaluated we will megawatts, job creation, and other quantitative 

decide whether to continue with the second 9- metrics to better evaluate the success of the 

month phase of the subcontract. program. 

5. Industry Partners 

The following organizations partnered in the Incubator project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title 

Research Activity 

FY 

2009 

($K) 

Cost 

Share 

($K) 

1366 Technologies, 

Inc. 

Frank Van Mierlo 

16 Outlook Dr. 

Lexington, MA 02421 

Phone: 617-818-6996 

Email: mierlo@1366tech.com 

Self Aligned Cell – Scaling Up 

Manufacture of a Cost Effective Cell 

Architecture for Multi-Crystalline Silicon 

Photovoltaics 

1,500 330 

Innovalight Inc. 

Nick Cravalho 

Innovalight, Inc. 

965 East Arques Avenue 

Sunnyvale, CA 94085 

Email: ncravalho@innovalight.com 

New Metallization Technique Suitable for 

6-MW Pilot Production of Efficient 

Multicrystalline Solar Cells Using 

Upgraded Metallurgical Si 

1,509 972 

Skyline Solar, Inc. 

Scott McHugo Skyline Solar, Inc. 

185 East Dana St. 

Mountain View, CA 94041 

Phone: 650-864-9770 x2122 

Email: smchugo@skylinesolar.com 

Accelerating the Transition of Skyline 

Solar’s Module to Manufacturing: Medium 

Concentration onto Silicon = Low Cost × 

Explosive Scalability 

1,300 820 

Solasta, Inc. 

Mike Naughton 

Pittsburgh, PA 

swilliams@plextronics.com Nanocoax Solar Cells 1,431 315 

Solexel, Inc. 

Mehrdad Moslehi 

1530 McCarthy Blvd. 

Milpitas, CA 95035-7405 

Phone: 408-715-9554 x222 

Email: moslehi@solexel.com 

Productization and Manufacturing Scaling 

of High-Efficiency Solar Cell and Module 

Products Based on a Disruptive Low-Cost, 

Mono-Crystalline Technology 

1,400 397 

Spire Semiconductor 

Corporation, LLC 

Steven Wojtczuk 

25 Sagamore Park Rd. 

Hudson, NH 03051 

Email: swojtczuk@spiresemi.com 

Manufacturing of High-Efficiency Bi-Facial 

Tandem Concentrator Solar Cells 1,382 278 
 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

Industry Thin Film Partnerships 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

DOE Golden Field Office (DOE/GO) 

Key Technical Contact: Harin S. Ullal (NREL), 303-384-6486, harin_ullal@nrel.gov 

DOE HQ Technology Manager: Scott Stephens, 202-586-1201, scott.stephens@ee.doe.gov 

FY 2009 Budget: $985K (NREL) 

Objectives 

•	 Support the Technology Partnership Pathway project to achieve levelized cost of electricity 

(LCOE) by 2015 

•	 Support the near-term transition to first-time manufacturing and commercial introduction of 

reliable copper indium diselenide (CIS) and cadmium telluride (CdTe) 

•	 Build a technology base on which these advanced photovoltaic (PV) technologies can continue to 

be successful in improving manufacturing and to progress in performance, reliability, and cost 

reductions, resulting in products that can compete in the PV marketplace 

•	 Sustain innovation to support progress toward ambitious, long-term PV cost and performance 

goals (e.g., 15% efficient modules costing less than $50/m2 and capable of lasting 30 years), 

which are appropriate for cost-competitive LCOE and grid parity electricity. 

Accomplishments 

•	 Achieved a production cost of $0.92/Wto $1.14.W for thin film PV technology and then further 

reduced it to $0.85/W in FY 2009 (First Solar) 

•	 Provided support to assist two technology partners, U.S. manufacturing facilities, to expand: First 

Solar, 159 MWp (1,200 MW worldwide) and Global Solar, 40 MWp (75 MWp worldwide) 

•	 Supported industry growth, when possible, as the production of thin films in the United States 

grew from about 10 MWp in 2003 to an estimated 300 MWp in 2009. 

Future Direction 

• The three subcontracts, two industries and one university, are being or have been phased out. 

1. Introduction 

Thin-film PV technologies have good potential to 

meet ambitious cost and performance goals, 

such as achieving long-term goals for a levelized 

cost of electricity by 2015. The Thin Film PV 

Partnership Program is designed to accelerate 

progress toward meeting those goals. The 

partnership includes subcontracted R&D in CIS 

and CdTe. The partnership members work 

closely with NREL’s internal researchers, 

facilitating collaborative activities with academia 

and U.S. thin-film industry groups. 

2. Major FY 2009 Presentations and 

Publications 

We published several subcontract reports and 

presentations. Other important publications and 

presentations include the following: 

H.S. Ullal, “Polycrystalline Thin Film Solar 

Electric Technologies,” presented at the 18th 

International Photovoltaic Science and 

Engineering Conference, Kolkata, West 

Bengal, India, January 19–23, 2009. 

H.S. Ullal, “The Great Thin Film Debate,” 

panelist and speaker at Solar Power 

International 2008, Oct 13-16, 2008, San 

Diego, CA. 

H.S. Ullal, “Thin Film Debate,” panelist and 

speaker at Solar Power International 2009, 

October 27-29, 2009, Anaheim, CA. 

3. University and Industry Partners 
 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator 

Location/E-mail Description/Title of Research Activity FY 

2009 

($K) 

Cost 

Share 

($K) 

First Solar, LLC 

Scotty Gilmore 

Perrysburg, OH 

sgilmore@firstsolar.com 

Development of robust high efficiency thin film 

CdTe PV modules 

270 270 

Global Solar Energy 

Scott Wiedeman 

Tucson, AZ 

swiedman@globalsolar.com 

Cost and reliability improvements for CIGS based 

on flexible substrates 

660 660 

University of South Florida 

Chris Ferekides 

Tampa, FL 

ferekide@eng.usf.edu 

High efficiency CdTe cells by CSS 55 4 

D R A F T
 

 

 

 

D R A F T

Evaluation, Validation & Analysis Summary 

As the market for solar energy systems grows, the energy produced by solar systems (kWh) and 

the value of the energy (¢/kWh) are replacing capacity (watts) and cost ($/W) as primary metrics. 

Modeling and analysis tools and accompanying data are needed that accurately estimate both 

the energy output and the cost of energy from solar systems. This information is critical not only 

to system design and project management, but also to setting research priorities based on the 

potential impact of various technology development options. 

The solar community was surveyed in 2006 to identify specific modeling priorities. The data show 

broad support, especially among industry (manufacturers and integrators) for reliability/lifetime 

modeling for components and integrated systems, better solar resource data, and performance 

algorithms for PV components and systems. Manufacturers supported development of design 

optimization tools, but the likely users of such tools, the integrators, did not support this area. 

Customers were especially interested in financing algorithms. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Evaluation, Validation & Analysis 6720 4495 2045 13260 

System Modeling 678 615 0 1293 

Systems Analysis 1740 0 650 2390 

Reliability R&D 2970 1555 1000 5525 

Test & Evaluation 1332 2275 0 3607 

Regional Experiment Stations 0 50 395 445 
 

 

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Systems Performance Modeling 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Sandia National Laboratories (SNL) 

Key Technical Contacts: Nate Blair (NREL, Primary Contact), 303-384-7426, nate.blair@nrel.gov 

Chris Cameron (SNL, Primary Contact), 505-844-816, 

cpcamer@sandia.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budgets: $678K (NREL), $615K (SNL) 

Objectives 

•	 The system modeling efforts of this project seek to enhance the U.S. Department of Energy 

(DOE) Solar Energy Technologies Program (SETP) Solar Advisor Model (SAM) to develop 

capabilities to calculate energy output, energy costs, and cash flows using up-to-date component 

and system data while enabling parametric analysis. 

•	 These efforts also will validate SAM and, potentially, other solar models for a variety of
 

technologies, applications, and locations.
 

•	 These tools can be used by industry and government to guide research and development (R&D) 

prioritization and to provide credible energy production and cost data using a common platform 

for project development, evaluation, and due diligence. 

•	 These efforts also will provide additional tools to industry to meet their planning, R&D, siting, and 

other modeling needs to help accelerate market penetration. 

•	 These efforts will support progress evaluation at Stage-Gate assessments for the Technology 

Pathway Partnerships (TPPs). 

•	 This project also will maintain and advance the online PV tool called PV-Watts. 

Accomplishments 

• Reconstruction of the entire Solar Advisor Model (SAM) core code in C++ for these reasons: 

o	 It is significantly faster 

o	 Allows greater interaction with risk-assessment tools such as @Risk and CrystalBall 

o	 Incorporates Monte Carlo analysis (in conjunction with SNL) 

o	 Enables SAM as a WebApp and a Apple Mac version 

o	 Allows easier interaction with Excel, Matlab and other Web tools 

o	 Improved maintainability 

•	 Release new SAM versions with: 

o	 PV-Watts Model as perfoption 

o	 Simple shading 

o	 Enhanced graphical capabilities 

o	 Simple PV electric storage 

o	 Physically different PV subsystems can be combined in a single financial analysis 

o	 Enhanced graphic user interface (GUI) and greater graphical output capability including 

Tornado-chart analysis 

o	 Added time-of-use utility rates and automated independent power producer (IPP) financing 

optimization 

o	 Updated databases of component performance parameters 

•	 Conducted multiple in-person and Web-based trainings for SAM. 

•	 Provided analysis and review of levelized cost of energy calculations for TPP Stage Gates. 

•	 Install system to collect data in diffuse climate for use in performance model validation. 

•	 Began development of an analytical tool to assess performance model accuracy and uncertainty. 
____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

Future Directions 

•	 Continue DOE and user support, including analysis for TPP Stage Gate reviews, and hold a fullday user forum. 

•	 Acquire additional data sets, including thin-film and concentrating photovoltaic (CPV) system 

data, for use in model validation. 

•	 Complete an assessment of performance model accuracy and uncertainty. 

•	 Convene an industry workshop on performance modeling tool development and validation. 

•	 Support grid-integration work including the incorporation of complex utility-rates and electric loads 

for residential and commercial systems. 

•	 Continue support to SETP analysis activities at NREL and SNL. 

1. Introduction 

The objective of this project is to combine PV, 

CSP, and thermal solar technologies into a single 

model making use of high-quality performance 

models developed by NREL, SNL, and other 

partners. This will facilitate comparison by 

handling performance, costs, and financing 

consistently across technologies. There will be a 

high emphasis on a quality user interface to 

promote greater usage of quality tools by industry 

and DOE. This project also captures several 

smaller activities such as PV-Watts and (starting in 

FY 2010) In My Back Yard (IMBY). 

2. Technical Approach 

The system modeling task consists of systems 

performance and cost modeling and validation 

projects. The primary function of the SAM is to 

allow users to investigate the impact of variations 

in physical and financial parameters to better 

understand their impact on key figures of merit for 

solar power systems. Figures of merit related to 

the cost and performance of these solar power 

systems include, but are not limited to, system 

output, peak and annual system efficiency, 

levelized cost of energy, and system capital and 

operation and maintenance (O&M) costs. SAM is 

used not only by DOE, laboratory management, 

and research staff, but also is widely-used 

throughout the solar community. Its combination of 

robust performance models for multiple solar 

technologies with detailed financial models in a 

publicly available package is unique. The task also 

supports maintenance and continued development 

of PV-Watts, which is a popular model for simple 

performance estimates for PV systems. For FY 

2010, this activity also covers the IMBY model. 

3. Results and Accomplishments 

There was a great deal accomplished for SAM 

development in FY 2009. The primary activity was 

the development and release of a rebuilt code 

base for SAM. This was done for a variety of 

reasons including ongoing issues with the original 

platform chosen and its ongoing speed issues. 

While not a planned deliverable, this activity was 

accomplished while still accomplishing the other 

planned deliverables (and some originally slated to 

be enhanced activities). 

Planned FY 2009 activities for the SAM can be 

broken into two general groupings – core activities 

(jointly funded by PV and CSP funds) and PVspecific activities. 

With more than 11,000 individuals having 

downloaded SAM, user-support continues to be a 

growing issue especially as some long-time users 

delve ever deeper into the capabilities. 

Documentation has been greatly improved across 

all aspects of SAM with multiple avenues to 

access help both within the tool and online. 

Specific PV SAM Accomplishments: 

•	 A specific annual one-day workshop was held 

at Solar Power International (SPI). 

•	 Added PV-Watts as a PV Option in SAM 

•	 Shading: simple module shading as an option 

was added to the model. 

•	 Electric Storage: The ability to model electric 

storage (either on-grid or off) likely in the form 

of batteries was added. 

•	 Support the needs of the PV program by 

sponsoring university-level development of 

enhanced PV modeling capabilities relevant to 

the current systems. This should result in an 

enhanced CEC model. 

•	 Added capability to sum different system 

outputs and do financial analysis at an 

aggregate level. 

•	 Continued to add components to the module 

and inverter databases. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

•	 In collaboration with Navigant Consulting, 

perform cost and levelized cost of energy 

(LCOE) reviews at all TPP Stage Gates. 

Performance Model Validation:
 

It is essential that PV performance models have 

validated accuracy.
 

•	 An approach to model validation has been 

developed in collaboration with industry that 

involves collection of data sets for diverse 

technologies and in diverse climates; input of 

system design data as well as measured 

weather and irradiance data into a range of 

widely-used performance models; and 

comparison of model predictions with 

measured results to assess model accuracy. 

•	 To supplement data sets from NREL and SNL, 

both located in sunny climates, an automated 

weather and irradiance data system was 

installed on the roof of DOE Headquarters to 

gather data on five systems, including three 

thin-film systems, located in a diffuse climate. 

•	 Development of an automated tool to permit 

rapid assessment of model accuracy and 

uncertainty was begun. This tool also will 

provide insight into the steps needed to 

improve model accuracy. 

4. Planned FY 2010 Activities 

Task #1: DOE and Industry User Support-SAM. 

This activity involves providing user support for 

SAM via an e-mail address supported by a 

subcontractor. With more than 11,000 individual 

users (obviously some more active than others) 

this is a significant effort. This activity also involves 

reworking the SAM Web site to incorporate the 

capabilities of our current Google Group site. 

TPPs are supported in the use of SAM at stage 

gates and in parametric analysis to highlight 

development opportunities. In FY 2010, we will 

begin to apply stochastic techniques to permit 

multivariate parametric analysis. 

Task #2: SAM Model Enhancement (Core). 

•	 Incorporate direct access to DSIRE incentive 

Web feed. 

•	 Complete SAM code restructuring: 

o	 Documentation 

o	 Sample files for working with Excel/other 

tools 

o	 Examples of sub-system aggregation 

Task #3: SAM Model Enhancement (PV-Specific). 

The specific goals for FY 2010 are: 

•	 Enable detailed modeling to support grid 

integration work 

o	 Work with grid integration team to 

implement detailed algorithms for building 

load management, storage management 

and dispatch and inverter control. 

o	 Use new software structure to call SAM 

from distribution model (Dew) to enable 

more complex PV production profiles 

within their distribution grid models. 

o	 This should allow accurate modeling of 

local high-penetration of PV systems. 

•	 Incorporate improvements from 5-parameter 

model improvements currently under 

development by subcontractor. 

•	 Incorporate algorithmic improvements for new 

technologies (CIGS, Organics). These could 

come fromSNL’s efforts or from industry input. 

The chosen modeling options have yet to be 

determined. 

Task #4: Model Validation.
 

Additional data sets to enable model validation will
 

be collected, including data on CPV systems.
 

Development of the model validation and
 

assessment tool will be completed and will be
 

used to evaluate modeling of crystalline-silicon,
 

thin-film, and CPV systems.
 

Task #5: PV-Watts (Support and Model 

development). Under this task, NREL will continue 

to maintain and provide user support to the PVWatts community as well as the various tools that 

incorporate the PV-Watts algorithms. This also will 

include setting up version control for the code and 

rebuilding the online interface for PV-Watts to be 

more user-friendly. 

Task #6: IMBY Support. This activity was 

supported in FY 2009 by Solar America Cities 

(SAC). The primary activities for this year would 

be to incorporate more appropriate building load 

data, database driven utility rates, and incentives, 

as well as potentially incorporating the new SAM 

as the calculation engine for both performance 

and financial analysis. 

Task #7: Convene Industry Workshop. An industry 

workshop will be held on modeling and analysis 

tools development and integration needs. We will 

present key results from model validation, 

progress in model enhancements, and uncertainty 

analysis. The workshop will set the stage for 

transfer of important model enhancements and will 

collect industry input to guide further model 

development and technology transfer. 
5. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

D R A F T

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of Research 

Activity 

FY 2009 

($K) 

Janzou Consulting 

Steve Janzou 

Evergreen, CO 

Steve.janzou@nrel.gov 

Steve’s efforts were to program 

the front-end and basic engine of 

the Solar Advisor Model 

140 

University of 

Wisconsin-Madison 

Prof. Sanford Klein 

Madison, WI 

Klein@engr.wisc.edu 

Development of an advanced 

PV module model 105 

Paul Gilman Chicago, IL 

PaulGilman@earthlink.net 

Paul provides user support and 

technical writing support 40 

Clean Power 

Research 

Tom Hoff 

Napa, CA 

tomhoff@cleanpower.com 

Satellite-based Irradiance Data 

and Analysis 50 

Precision Solar 

Technologies 

Tim Leonard 

Tijeras, NM 

TMLeonard@TapTheSun.com 

Automated Portable Weather 

and Irradiance Data System 39 
 

 

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Systems Analysis 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Lawrence Berkeley National Laboratory (LBNL) 

Key Technical Contacts:	 Robert Margolis (NREL), 202-488-2222, robert.margolis@nrel.gov 

Ryan Wiser (LBNL), 510-486-5474, RHWiser@lbl.gov 

DOE HQ Technology Manager:	 Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budgets:	 $1,740K (NREL), $300K (LBNL) 

Objectives 

•	 Give a broad range of analytical support to the U.S. Department of Energy’s (DOE) Solar Energy 

Technologies Program (SETP) 

•	 Conduct analysis to provide key research contributions in market, value, policy, financial, and 

market transformation analysis 

•	 Develop resources such as publications, data sources, and models to support the ongoing 

informational, decisional, and strategic planning needs of the SETP. 

Accomplishments 

•	 Launched the solar vision study, a major research and modeling activity involving industry-wide 

collaboration, to assess the feasibility of high solar energy deployment scenarios 

•	 Launched the manufacturing cost model project to fill a critical R&D gap 

•	 Began market transformation analysis, including workforce development analysis 

•	 Conducted research for and drafting of the 2008 annual solar market trends report 

•	 Completed numerous solar financing reports and briefs on feed-in tariff policy design and 

implementation, solar photovoltaics (PV) financing for the residential, nonresidential, and federal 

government sectors, and the impacts of policies on solar PV financing and deployment 

•	 Completed core development of the SolarDS (Solar Deployment System) PV market penetration 

model, presented the model to SETP, and published documentation and sample results 

•	 Released the Open PV Mapping database and web site, a collaborative repository and analysis 

tool for all available U.S. PV installation data: http://openpv.nrel.gov/ 

•	 Completed collecting data and analyzing the installed cost of solar PV installations, including 

publishing reports detailing findings for data through 2007 and 2008 (LBNL) 

•	 Continued to analyze and publish research in PV system integration (LBNL) 

•	 Provided short-term analysis support to SETP to respond to information requests from Congress, 

the Office of Energy Efficiency and Renewable Energy (EERE) corporate office, NREL, and other 

stakeholders. 

Future Directions 

•	 Continue and expand analysis in the market, value, policy, financial, and market transformation 

areas 

•	 Conduct research and modeling to follow the analysis and findings of the solar vision study 

•	 Continue PV manufacturing cost modeling 

•	 Give analysis support for DOE SETP’s strategic planning efforts 

•	 Publish the 2009 annual solar market trends report 

•	 Continue to analyze and publish on topics pertaining to solar financing, and support the WebView 

as an online resource for solar (and renewable energy) financing information and tools 

•	 Continue to develop and enhance modeling tools and online resources such as the SolarDS 

model, the Open PV Mapping database, and the PV value clearinghouse 

•	 Develop a strong foundation for market transformation analysis, including workforce development 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• Produce topical reports and give general analytic support to meet the needs of DOE SETP and to 

fill analysis gaps for the solar industry. 

1. Introduction 

The primary objectives of the systems analysis 

activity are to 1) give a broad range of analytical 

support to SETP; 2) develop resources such as 

publications, data sources, and models to support 

the ongoing informational, decisional, and 

planning needs of the SETP; and 3) conduct 

analysis to contribute key research in market, 

value, policy, financial, and market transformation 

analysis. Analysis in these areas consists of: 

D R A F 

•	 

annual solar market trends report, give solar 

technology roadmap support, and continue to 

d

Market ana

emergi

evelop 

ng 

and implement models such as the 

solar energy markets, prepare 

lysis: Analyze existing and 

an 

T

SolarDS PV market penetration model. 

•	 Value analysis: Give inputs, support, and 

review for SETP’s annual benefits analysis 

(GPRA) process, develop methods and tools 

for improving quantification of the benefits and 

costs of distributed PV, and maintain the PV 

Value Clearinghouse. 

•	 Policy analysis: Conduct research that 

examines the impacts of existing and potential 

policies on solar technology development and 

deployment. 

•	 Financial analysis: Conduct research and 

analysis pertaining to solar financing in all 

sectors. Support the WebView as an online 

resource for solar (and renewable energy) 

financing information and tools. 

•	 Market transformation analysis: Serve as a 

foundation for analysis on market 

transformation issues, including workforce 

development and other critical topics. 

2. Technical Approach 

Market, value, policy, financial, and market 

transformation analysis relies on two main 

technical approaches. 

The first is to use and improve existing models 

and to build new models and tools that can be 

employed to develop long-term market-penetration 

projections for solar technologies. Current 

emphasis is on developing and enhancing new 

and existing models, as well as integrating models 

and model results, such as for the solar vision 

study. Model development involves examining 

both the system and policy drivers of solar 

technologies in various markets in the short and 

long term. A general emphasis has been and 

continues to be improving the representation of 

solar technologies in all models. Modeling efforts 

are a foundation for other solar analysis activities 

and inform the SETP and the broader solar 

industry by serving as an analytical basis for 

projecting the economic and environmental 

benefits and costs of solar technology deployment. 

Examples of models are NREL’s Regional Energy 

Deployment System (ReEDs), SolarDS, the DOE 

Energy Information Administration’s NEMS, 

MARKAL, and others. 

The second approach is to use a range of policy 

analysis tools and techniques to evaluate policies 

and other factors that affect the value of PV 

technologies in various markets. These include 

existing models, spreadsheets, and other tools 

(such as implementing surveys and gathering and 

synthesizing information from a wide range of 

sources). Here, the emphasis is on using 

analytical tools to quantify how changing policies, 

rate structures, system designs, and other factors 

have affected or will affect the value of solar 

technologies to consumers, utilities, governments, 

and other players. 

3. Results and Accomplishments 

Accomplishments resulting from market, value, 

policy, financial, and market transformation 

analysis in FY 2009 include: 

•	 Launched the solar vision study, including 

establishing a schedule, industry-wide working 

groups, concepts and scenarios, a report 

outline, meetings, an overall study workshop, 

and making progress on chapter outlines and 

resource gathering 

•	 Launched the manufacturing cost model 

project to fill a critical R&D gap, starting with 

modeling for wafer silicon PV 

•	 Conducted research and drafting of the 2008 

version of the annual Solar Market Trends 

report 

•	 Conducted and published an analysis of solar 

market forecasts and the impact of the 

financial crisis on these forecasts 

•	 Supported EERE program benefits analysis 

(GPRA) for SETP 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

•	 Completed core development of the SolarDS 

PV market penetration model, presented the 

model to SETP, and published documentation 

and sample results 

•	 Released the Open PV Mapping database and 

web site, a collaborative repository and 

analysis tool for all available U.S. PV 

installation data: http://openpv.nrel.gov/ 

•	 Completed data collection and analysis of the 

installed cost of solar PV installations, 

including publication of reports for data 

through 2007 and 2008 (LBNL) 

•	 Completed preliminary analysis of the value of 

net metering for residential PV customers in 

California, with forthcoming publication (LBNL) 

•	 Updated the PV value clearinghouse: 

http://www.nrel.gov/analysis/pvclearinghouse/ 

•	 Published work on the PV Carbon Wedge— 

Pathways for U.S. Growth and Sensitivity to 

Manufacturing Emissions 

•	 Completed analysis on key drivers and 

sensitivities for grid parity analysis for 

residential PV, publication forthcoming 

•	 Conducted research and analysis on solar 

financing, resulting in completion of numerous 

solar financing reports on the following topics: 

1) feed-in tariff policy design and 

implementation, 2) solar PV financing for the 

residential sector, 3) solar PV financing for 

deployment by Federal government agencies, 

4) financing non-residential PV projects 

(LBNL), 5) implications of ITC changes on the 

residential PV market (LBNL), 6) solar leasing 

for residential PV (fact sheet), 7) potential 

regulatory and legal challenges to the third 

party PPA model (11/09), 8) insurance for PV 

systems (12/09) 

•	 Continued to develop the WebView project, a 

forthcoming on-line resource for solar and 

other renewable energy financing, in 

preparation for FY 2010 release 

•	 Launched market transformation analysis 

efforts, especially in workforce development 

and state technical support 

•	 Updated analysis on state-level renewable 

portfolio standard developments for input into 

the solar vision study, market report, and other 

analysis products (LBNL) 

•	 Hosted PV variability workshop with Utility 

Wind Integration Group, SEPA, and DOE; 

published summary of lessons learned; and 

continued to collaborate with labs, DOE, 

utilities, and solar industry to obtain access to 

short-time-scale PV output data 

(NREL/SNL/LBNL) 

•	 Continued to analyze spatial and temporal 

scales of PV variability and the benefit of 

geographic diversity in reducing short-timescale ramps, with forthcoming report (LBNL) 

•	 Published response to an article in 

Environmental Science & Technology that 

concluded that operational integration 

constraints would reduce CO2 offset benefits 

and lead to net increase in NOx emissions 

from wind and solar generation (LBNL) 

•	 Gave short-term analysis support to SETP to 

respond to information requests from 

Congress, the EERE corporate office, the 

public, and other stakeholders. 

4. Planned FY 2010 Activities 

As solar markets grow at a record pace and solar 

technologies continue to evolve rapidly, the need 

for targeted analysis will be critical to inform 

decisions affecting the solar industry. Ongoing 

activities and expansions of current activities 

under this task include 1) conducting research and 

modeling in followup to the solar vision study, 2) 

continuing PV manufacturing cost modeling, 3) 

giving analysis support for DOE SETP’s strategic 

planning, 4) publishing the 2009 annual solar 

market trends report, 5) continuing analysis and 

publication on solar financing topics and release of 

the WebView as an online resource for financing 

information and tools, 6) continuing to develop and 

enhance modeling tools and online resources 

such as the SolarDS model, the Open PV 

Mapping database, and the PV value 

clearinghouse, 7) developing a strong foundation 

for market transformation analysis, including 

analysis on workforce development, and 8) 

producing topical reports and giving general 

analytic support to meet the needs of DOE SETP 

and to fill analysis gaps for the solar industry. 

5. Major FY 2009 Publications 

J.E. Bartlett, R.M. Margolis, and C.E. Jennings, 

Effects of the Financial Crisis on Photovoltaics: 

An Analysis of Changes in Market Forecasts 

from 2008 to 2009, NREL TP-6A2-46713, 

Golden, CO: NREL (2009). 

M. Bolinger, Financing Non-Residential 

Photovoltaic Projects: Options and Implications, 

LBNL-1410E, Berkeley, CA: LNBL (2009). 

M. Bolinger, “Third-Party Finance for Commercial 

Photovoltaic Systems: The Rise of the PPA,” 

Clean Tech Law & Business 1, Spring, 35 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

(2009); LBNL-1999E, Berkeley, CA: LNBL
 

(2009).
 

M. Bolinger, G. Barbose, and R. Wiser, Shaking 

Up the Residential PV Market: Implications of 

Recent Changes to the ITC. LBNL and the Clean 

Energy States Alliance; Berkeley, CA: LNBL 

(2008). 

M. Bolinger, G. Barbose, and R. Wiser, (2009). 

“Full Steam Ahead for PV in U.S. Homes?” 

Renewable Energy Focus, Vol. 9, Issue 7, 

Jan./Feb. 2009, pp. 58-60. LBNL-1998E. 

Berkeley, CA: LNBL (2009). 

M.Bolinger, R. Wiser, and E. Ing, "Exploring the 

Economic Value of EPAct 2005's PV Tax 

Credits," in Solar Power: Energy of the Future, 

N.R. Khadpekar, ed. Hyderabad, India: The Icfai 

University Press, 30-44 (2009). LBNL-2918E, 

Berkeley, CA: LNBL (2009). 

K. Cory, B. Canavan, and R. Koenig, “Power 

Purchase Agreement Checklist for State and 

Local Governments.” Energy Analysis Fact 

Sheet Series on Financing Renewable Energy 

Projects, NREL FS-6A2-46668, Golden, CO: 

NREL (2009). 

K. Cory, C. Coggeshall, J. Coughlin, and C. 

Kreycik, Solar Photovoltaic Financing: 

Deployment by Federal Government Agencies, 

118 pp.; NREL TP-6A2-46397. Golden, CO: 

NREL (2009). 

Cory, K.; Couture, T.; Kreycik, C. (2009). Feed-in 

Tariff Policy: Design, Implementation, and RPS 

Policy Interactions. 23 pp.; NREL TP-6A2-45549. 

Golden, CO: NREL (2009). 

J. Coughlin and K. Cory, Solar Leasing for 

Residential Photovoltaic Systems (Fact Sheet), 

NREL TP-670-43572, Golden, CO: NREL 

(2009). 

J. Coughlin, and K. Cory, Solar Photovoltaic 

Financing: Residential Sector Deployment, 

NREL TP-6A2-44853, Golden, CO: NREL 

(2009). 

P. Denholm, E. Drury, and R. Margolis, Solar 

Deployment System (SolarDS) Model: 

Documentation and Sample Results, NREL TP6A2-45832, Golden, CO: NREL (2009). 

P. Denholm, R.M. Margolis, and J.M. Milford, 

“Quantifying Avoided Fuel Use and Emissions 

from Solar Photovoltaic Generation in the 

Western United States,” Environ. Sci. Technol. 

43(1), 226 (2009); NREL JA-670-43179, Golden, 

CO: NREL (2008). 

E. Doris, S. Ong, and O. Van Geet, Rate Analysis 

of Two Photovoltaic Systems in San Diego, 

NREL TP-6A2-43537, Golden, CO: NREL 

(2009). 

E. Drury, P. Denholm, P. and R.M. Margolis, “PV 

Carbon 'Wedge': Pathways for U.S. Growth and 

Sensitivity to Manufacturing Emissions,” in R. 

Campbell-Howe, ed., Proc. Solar 2009 

Conference, 11-16 May 2009, Buffalo, NY; 

including Proc. 38th ASES National Solar 

Conference, Boulder, CO: American Solar 

Energy Society. 6 pp.; NREL CP-6A2-46797, 

Golden, CO: NREL (2009). 

E. Drury, P. Denholm, and R.M. Margolis, “Solar 

Photovoltaics Wedge: Pathways for Growth and 

Potential Carbon Mitigation in the U.S.” Environ. 

Res. Lett. 4(3), 034010 (2009); NREL JA-6A2-

45512, Golden, CO: NREL (2009). 

B. Kropolis, R. Margolis, and D. Ton, “Harnessing 

the Sun,” Power Energy Mag. 7, Issue 3, 22 

(May-June 2009). 

A. Mills, R. Wiser, M. Milligan, and M. O’Malley, 

Comment on “Air Emissions Due to Wind and 

Solar Power,” Environ. Sci. Technol. 43(15), 

6106 (2009). 

R. Wiser, G. Barbose, and C. Peterman, Tracking 

the Sun: The Installed Cost of Photovoltaics in 

the U.S. from 1998-2007, LBNL-1516E, 

Berkeley, CA: LNBL (2009). 

R. Wiser, G. Barbose, C. Peterman, and N. 

Darghouth, Tracking the Sun II: The Installed 

Cost of Photovoltaics in the U.S. from 1998-

2008, LBNL-2674E, Berkeley, CA: LNBL (2009). 
 

 

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Reliability Research & Development 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Sandia National Laboratories (SNL) 

Key Technical Contacts: Sarah Kurtz (NREL, Primary Contact), 303-384-6475, 

sarah.kurtz@nrel.gov 

Jennifer Granata (SNL, Primary Contact), 505-844-8813, 

jegrana@sandia.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budgets: $4,200K (NREL), $2,198K (SNL) 

Objectives 

•	 Help industry develop more reliable photovoltaic (PV) systems and make increasingly confident 

predictions of performance, degradation, lifetime, and associated costs for system operation and 

maintenance 

•	 Develop a suite of tools, which enable reduced LCOE through improved product reliability and 

improved predictions of LCOE 

•	 Develop best practices specific to the PV industry that enhance reliability. 

Accomplishments 

•	 Completed the first two rounds of the test-to-failure protocol for module reliability at NREL; this 

protocol moving toward more quantitative predictions for PV modules 

•	 Gave multiple presentations describing studies of CPV reliability related to understanding the 

stress related to concentrated light, testing of the die-attach, and application of concentrated UV 

light 

•	 Documented the thermal exposure of modules within the context of how to design for thermal 

endurance adequate to avoid safety issues 

•	 Completed baseline failure modes and effects analyses (FMEAs) for crystalline silicon modules, 

CdTe modules, CIGS modules, and residential inverters; in addition, Sandia facilitated companyspecific FMEAs for two companies focusing on systems-level effects 

•	 Demonstrated the PV Reliability and Availability Predictive Model (PVRAM) initial capability 

based on 5 years of operations, maintenance, and field failure data from Tucson Electric Power’s 

Springerville 4.6 MW PV plant 

•	 Established the database and web-based interface to collect PV systems field O&M data for 

reliability assessments and predictions (SNL) 

•	 Produced 20 publications, presentations, and webinars on results. 

Future Directions 

•	 Combine the PVRAM with weather, performance, and cost-predictive models in a user-friendly 

environment 

•	 Develop accelerated test methods and correlate with field data 

•	 Standardize fully developed accelerated test methods to gain acceptance for industry use 

•	 Collect accurate field data in a cost-effective manner to empower the community to use the 

exponentially growing supplies of data 

•	 Quantify effects of weather to estimate acceleration factors relevant to various weather patterns. 

1. Introduction	 It complements other parts of the program by 

studying the long-term performance, degradation, 

Reliability is an essential element of reaching the and failure of PV modules and systems, and how 

Solar Energy Technologies Program’s cost goals. to design short-term tests to predict these. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Technical Approach 

Real-time Reliability Studies (NREL & SNL)— 

Deployment, monitoring, and analysis of data for 

PV modules/systems outdoors at the labs and 

elsewhere, using experiments designed to quantify 

degradation rates and identify failure 

modes/mechanisms for deployment in different 

locations. 

D R A F T

Accelerated & Diagnostic Reliability (SNL)— 

Studies of accelerated stress testing, diagnostic 

studies of failure mechanisms, and development 

of new diagnostic tests. This work includes 

environmental chamber testing, IR imaging, 

adhesion measurements, I-V testing, other 

electrical testing, and transmission/reflectance 

measurements. 

Module Accelerated Testing (NREL)—Studies of 

accelerated stress testing on modules. This work 

includes environmental chamber testing, I-V 

testing, and other testing that is associated with 

module qualification tests. Notably, this effort 

supports DOE contract deliverables, as needed. 

Component/Material Accelerated Testing 

(NREL)—Studies of accelerated stress testing, 

diagnostic studies of failure mechanisms, and 

development of new diagnostic tests. This work 

includes IR imaging, adhesion measurements, I-V 

testing, other electrical testing, and 

transmission/reflectance measurements. Testing 

components, materials, and subassemblies can 

give more direct information while still being 

directly relevant to module testing. Although 

collaborations are fruitful, cell-level reliability work 

is primarily funded by the technology areas. 

Predictive Model Development (SNL & NREL)— 

Discussions with industry to develop FMEAs, 

develop/validate PVRAM, and collect relevant 

operations, maintenance, and field failure data into 

a database. 

Industry Workshop and Standards Support (SNL & 

NREL)—Plan and host an industry workshop and 

participate in writing/discussion of standards. 

Note: Technical support of standards work is 

supported in other tasks as well. 

3. Results and Accomplishments 

Level 3 and 4 milestones: 

•	 Completed testing/assessments scheduled for 

reliability stage-gates for the TPPs (09/09) 

•	 Expanded predictive model development to 

include operating data from APS and TEP 

(09/09) 

•	 Developed accelerated UV testing method to 

more quickly diagnose CPV problems (06/09) 

•	 Completed baseline FMEAs for c-Si, CdTe, 

CIGS, CPV systems, and residential inverters; 

documented highest level reliability concerns 

(available on NREL website) (08/09) 

•	 Started developing techniques, designs, and 

processes to apply and assess reliability of 

conductive adhesives for interconnecting PV 

(09/09) 

•	 Initiated long-term system exposure of three 

technologies in three locations in collaboration 

with SunPower (09/09) 

•	 Completed first iteration of test-to-failure 

protocol (06/09). 

Real-time Reliability Studies (NREL & SNL)—A 

study was initiated in partnership with SunPower 

to deploy nine small systems in three locations to 

study system degradation rates. Baseline testing 

for two locations was completed in FY 2009. 

Further baselines and deployment will occur in FY 

2010. At NREL, the array field was repaved, 

communications lines updated, and plans made 

for installing several new products for monitoring. 

Accelerated & Diagnostic Reliability (SNL)— 

Sandia developed and exercised an accelerated 

life test for conductive tapes used in place of 

soldering in PV modules. The initial results led an 

industry partner to change its design. Two 

publications documented the results. 

Sandia implemented CT scanning and advanced 

X-ray techniques for advanced failure analysis 

diagnostic work. These techniques helped three 

companies improve their designs for CPV cell 

assemblies, modules, and microinverters. Results 

were published. 

Systems-level reliability assessments were 

completed for TPP and incubator partners, 

including Soliant, Dow, and Abound Solar. 

Sandia completed an accelerated testing chamber 

and performed initial testing on conductive oxides 

for thin-film module use. The accelerated test 

capability allows varying humidity, temperature, 

light, and oxygen levels while testing the 

conductivity of the sample in situ. 

Module Accelerated Testing (NREL)—The first two 

rounds of the test-to-failure protocol were 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

completed. Results were discussed with members 

of Solar ABCs and “Application of the NREL Testto-Failure Protocol for PV Modules” was presented 

by Peter Hacke at the Si Workshop in August 

2009. This protocol is moving toward more 

quantitative predictions for PV modules. 

D R A F T

Accelerated module stress testing was completed 

in support of stage-gate reviews and other support 

of TPP and incubator projects, including Dow, 

PrimeStar, CaliSolar, BP Solar, 1366, Skyline, and 

Spectrolab. 

Component/Material Accelerated Testing 

(NREL)—Testing of CPV components and 

materials included assessing transmission of 

concentrated sunlight through various CPV optical 

designs to assess the use environment of the 

various component materials; developing the 

capability to apply concentrated UV and 

application of this stress to various encapsulant 

materials; and performing quantitative studies of 

the effects of thermal cycling on the CPV die 

attach. Results from these studies were presented 

to the community. 

Predictive Model Development (SNL & NREL)— 

Sandia facilitated the development of system-level 

FMEAs for two companies with new technologies. 

The PVRAM initial capability was demonstrated 

based on 5 years of operations, maintenance, and 

field failure data from Tucson Electric Power’s 

Springerville 4.6-MW PV plant. Results were 

published in two conference proceedings. 

XFRACAS was chosen as the O&M and field 

failure data collection tool to be used in 

conjunction with PVRAM. Two utility partners, 

Tucson Electric Power and Arizona Public Service, 

began beta-testing the XFRACAS tool for three 

large PV systems. 

Industry Workshop and Standards Support (SNL & 

NREL)—Support of standards development 

included completing a first draft for an IEC Power 

Rating for CPV, and participating in a SEMI-DOE 

workshop on c-Si Terrestrial Photovoltaic Cells 

and ASTM and IEC standards meetings. 

To better define how to test for safety issues 

related to thermal aging, a study documented the 

expected thermal exposure to modules deployed 

in hot locations. 

The importance of reliability to the long-term 

success is becoming evident to the community. 

When given the opportunity, this project strived to 

educate the PV community about reliability issues; 

for example, Sarah Kurtz presented an invited talk 

on “Reliability Challenges for Solar Energy” at the 

IEEE IRPS conference, introducing many reliability 

engineers to PV reliability issues; and Jennifer 

Granata and Michael Quintana gave a webinar 

hosted by SEPA entitled, “Reliability of PV 

Systems – How Long Can We Expect Them to 

Last?” This webinar had more than 100 virtual 

attendees. 

4. Planned FY 2010 Activities 

•	 Complete stage-gate reliability assessments and 

testing for TPPs, incubators, and other DOE 

SETP participants 

•	 Assess performance of modules/systems fielded 

at NREL and SNL to identify those that have 

degraded 

•	 Perform at least three sensitivity studies using 

PVRAM and publish results 

•	 Hold industry workshop to facilitate industry 

dialogue 

•	 Publish aggregated degradation data/high level 

predictive model results from SLTE and PVRAM 

•	 Propose details of new accelerated test for a 

specific technology to correlate with real-time 

field degradation. 

5. FY 2009 Special Awards and Patents 

NREL Patent: M.O. Reese, A. Dameron, T. 

Moricone, and M.D. Kempe, "Electrical Calcium 

Test," Patent application filed 08/09. 

6. Major FY 2009 Publications 

N. Bosco, C. Sweet, and S. Kurtz, “Reliability 

Testing the Die-Attach of CPV Cell Assemblies,” 

34th IEEE Photovoltaic Specialists Conference, 

Philadelphia, 2009. 

E. Collins, M. Dvorack, J. Mahn, M. Mundt, and M. 

Quintana, “Reliability and Availability Analysis of 

a Fielded Photovoltaic System,” 34th IEEE 

Photovoltaic Specialists Conference, 

Philadelphia, 2009. 

A.A. Dameron, M.O. Reese, T.J. Moricone, and 

M.D. Kempe, "Understanding Moisture Ingress 

and Packaging Requirements for Photovoltaic 

Modules," Photovoltaics Intl. 13, 121 (2009). 

J.A. delCueto, C.A. Deline, D.S. Albin, S.R. 

Rummel, and A. Anderberg, "Striving for a 

Standard Protocol for Preconditioning or 

Stabilization of Polycrystalline Thin-Film 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Photovoltaic Modules," SPIE, San Diego, CA, 

2009. 

J.E. Granata and M.A. Quintana, “Reliability of PV 

Systems – How Long Can We Expect Them to 

Last?” SEPA Webinar, June 2009. 

J.E. Granata and M.A. Quintana, “System Level 

Reliability Methodologies,” International AsiaPacific Partnership Reliability Workshop, July 

2009. 

P. Hacke, D. Trudell, K. Terwilliger, N. Bosco, E. 

Gelak, and S. Kurtz, “Application of the NREL 

Test-to-Failure Protocol for PV Modules,” 19th 

Crystalline Silicon Workshop, Vail, CO, 2009. 

M.D. Kempe, "Design Criteria for Photovoltaic 

Back-Sheet and Front-Sheet Materials," 

Photovoltaics Intl. 10, 100 (2008). 

M.D. Kempe, M. Kilkenny, T.J. Moricone, and J.Z. 

Zhang, "Accelerated Stress Testing of 

Hydrocarbon Encapsulants for MediumConcentration CPV," 34th Photovoltaic 

Specialists' Conference, Philadelphia, PA, 2009. 

M.D.	 Kempe, T. Moricone, and M. Kilkenny, 

"Effects of Cerium Removal from Glass on 

Photovoltaic Module Performance and Stability," 

SPIE, San Diego, CA, 2009. 

S.	 Kurtz, J. Granata, and M. Quintana, 

“Photovoltaic-Reliability R&D Toward a SolarPowered World,” Proc. SPIE Optics and 

Photonics, San Diego, CA, 2009. 

S. Kurtz, K. Whitfield, D. Miller, J. Joyce, J. 

Wohlgemuth, M. Kempe, N. Dhere, N. Bosco, 

and T. Zgonena, “Evaluation of HighTemperature Exposure of Rack-Mounted 

Photovoltaic Modules,” 34th IEEE Photovoltaic 

Specialists Conference, Philadelphia, 2009. 

D.M. Miller, M.D. Kempe, C.E. Kennedy, and S.R. 

Kurtz, “Analysis of Transmitted Optical Spectrum 

Enabling Accelerated Testing of CPV Designs,” 

Proc. SPIE Optics and Photonics, San Diego, 

CA, 2009. 

M. Mundt, E. Collins, M. Dvorack, J. Mahn, and M. 

Quintana, “Reliability and Availability Analysis of 

a Fielded Photovoltaic System,” presented at 

June 2009 International Applied Reliability 

Symposium. 

C.R.	 Osterwald and T.J. McMahon, “History of 

Accelerated and Qualification Testing of 

Terrestrial Photovoltaic Modules: A Literature 

Review,” Progress PV 17(1), 11 (2009). 

F.J. Pern, S.H. Glick, X. Li, C. DeHart, T. Gennett, 

M. Contreras, and T. Gessert, “Stability of TCO 

Window Layers for Thin-Film CIGS Solar Cells 

upon Damp Heat Exposures: Part III,” SPIE, San 

Diego, CA, 2009. 

E.C. Quintana, M.A. Quintana, K.D. Rolfe, K.R. 

Thompson, and P. Hacke, “Exploring Diagnostic 

Capabilities for Application to New Photovoltaic 

Technologies,” 34th IEEE Photovoltaic 

Specialists Conference, Philadelphia, 2009. 

M.A. Quintana, “Photovoltaic Module Reliability 

and Photovoltaic System Reliability,” 

International Photovoltaic Reliability Workshop, 

Shanghai, China, December 2008 (Invited 

Presentation). 

N.R. Sorensen, M.A. Quintana, J.D. Puskar and 

S.J. Lucero, “The Effect of Metal Foil Tape 

Degradation on the Long-Term Reliability of PV 

Modules,” 34th IEEE Photovoltaic Specialists 

Conference, Philadelphia, 2009. 

N.R. Sorensen, M.A. Quintana, J.D. Puskar and 

S.J. Lucero, “The Effect of Metal Foil Tape 

Degradation on the Long-Term Reliability of PV 

Modules,” SPIE, San Diego, CA, 2009. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of 

Research Activity 

FY 2009 

($K) 

Cost 

Share ($K) 

Arizona State Univ. 

A. Cronin 

Tucson, AZ 

cronin@physics.arizona.edu 

Evaluation of data from 

Tucson Electric Power field 20 5 

Arizona State Univ. 

G. Tamizhmani 

Gilbert, AZ 

manit@asu.edu 

O&M Database Data Entry for 

APS 15 0 

BEW Engineering Richmond, CA 

Ray.hudson@bewengineering.com 

Inverter Reliability 

Assessment Support 20 0 

ReliaSoft Phoenix, AZ 

Doug.Ogden@ReliaSoft.com 

Development of Reliability 

Software tools specific to PV 35* 0 

South Dakota State 

Univ. 

Brookings, SD 

Michael.Ropp@SDSTATE.EDU 

Outdoor Module Exposure 

Testing 40 0 

* Multiyear contract; $35K in FY 2009 funds. 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

Test & Evaluation 

Performing Organizations: Sandia National Laboratories (SNL) 

D R A F T

National Renewable Energy Laboratory (NREL) 

Key Technical Contacts: Jennifer Granata (SNL, Primary Contact), 505-844-8813, 

jegrana@sandia.gov 

Bill Marion (NREL, Primary Contact), 303-384-6793, 

bill.marion@nrel.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budgets: $2,775K (SNL), $1,750K (NREL) 

Objectives 

•	 Develop, employ, validate, and furnish industry with test and evaluation (T&E) methodologies to 

measure, understand, predict, and certify the performance of PV components and systems. 

•	 Provides test and evaluation of PV modules, arrays, inverters/balance of systems (BOS), and 

systems to TPP participants, other PV industry, labs, and universities in support of work sponsored by 

DOE’s Solar Energy Technologies Program (SETP). 

•	 Supports testing and evaluation of the integration of PV systems into the electric power grid by 

working with system integrators and utilities. 

Accomplishments 

•	 Completed all stage-gate evaluations for TPPs, Incubators, SEGIS, and other DOE contract 

participants (NREL—Boeing, Skyline, Plextronics; SNL—Amonix, Greenray, United Solar, Soliant) 

•	 Awarded the subcontract for transfer of SNL’s PV Module Database maintenance and routine outdoor 

PV module testing to populate the database to TUV-PTL (05/09) 

•	 Completed CPV testbed and summary report on CPV modules tested (NREL) 

•	 Wrote SPIE paper on precondition and stabilizing methods of thin-film PV modules, and the use of 

capacitance-voltage (C-V) measurements as an indication of stability (NREL) 

•	 Designed a multi-irradiance sensor array at SNL and began to procure the equipment needed to 

develop a network of irradiance sensors to study modeling and performance issues 

•	 Enhanced SNL’s laboratory capabilities to evaluate SEGIS stage-gate deliverables that include 

energy management capabilities, load shedding capacities, and voltage support capabilities 

•	 Developed several contractual partnerships with industry and utilities to develop system performance 

enhancements that include advanced battery technologies and utilization capabilities, advanced 

automated controls, and reliability prediction algorithms 

•	 Produced 11 publications and presentations on FY 2009 results. 

Future Directions 

•	 Develop protocols and capabilities for test and evaluation of new components and systems, including 

systems-level technologies such as CPV ; develop more efficient and more accurate methods to 

characterize large-scale fielded systems 

•	 Enhance capabilities to define and conduct tests to provide information/data for validation and 

improvement of systems-level models, including reliability and other performance models as well as 

developing data/information for input to performance and economic models 

•	 Transfer improved test procedures and methods to standards committees 

•	 Evaluate PV systems with enhanced energy management capabilities 

•	 Conduct pre-production and production evaluations on inverters with an emphasis on interoperability, 

controls, and arc fault detection/mitigation 

•	 Develop solutions related to integration of high levels of PV systems into electric power grids 

•	 Implement high-resolution irradiance data for high penetration of PV distributed generation systems 

•	 Investigate the possibilities of power smoothing capabilities using storage systems. 
____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1. Introduction 

T&E is a cross-cutting activity that supports the 

SETP areas of Reliability, Modeling and Analysis, 

Concentrating PV, PV Grid Integration, Codes and 

Standards, and Solicitations. T&E support is 

critically important to DOE and industry 

participants to determine if cost and performance 

stage-gate criteria are met for DOE contracts with 

an emphasis on bringing new products to the U.S. 

market. T&E spans the product development 

cycle, from early proof-of-concept devices to 

prototypes and commercial products. 

D R A F 

2. 

The FY 2009 funding agreement consisted of eight 

activities: (1) Lab

Technical Approach 

-Based Industry Support, (2) Lab 

T

T&E Data Collection, (3) Standards Development 

and Industry Transfer, (4) Field T&E, (5) Grid 

Integration T&E, (6) Inverter/BOS R&D, (7) PV 

Module Database, and (8) Energy Ratings Method 

Validations. Depending on the activity, SNL and 

NREL had either shared or sole responsibility. 

They had shared responsibility for activities 1–5, 

SNL had sole responsibility for activities 6 and 7, 

and NREL had sole responsibility for activity 8. 

T&E work includes characterizing the performance 

and reliability of TPP and other DOE-funded 

projects; developing protocols and capabilities for 

test and evaluation of new components and 

systems; and developing and maintaining 

capabilities to define and conduct tests to provide 

information/data for validation and improvement of 

reliability and performance models. All test data 

are acquired using calibrated instruments (e.g., 

radiometers, meteorological sensors, data 

acquisition systems). 

3. Results and Accomplishments 

•	 All stage-gate evaluations completed for 

TPPs, incubators, and other DOE contract 

participants (09/09) 

•	 Summary report on CPV modules tested 

(09/09) 

•	 Test technology transfer to TUV-PTL test lab 

(initiated 05/09) 

•	 SEGIS evaluation procedure completed and 

implemented (on-going into FY 2010) 

•	 Completed report on systems level testing for 

Grid Integration (09/09) 

•	 Completed NREL technical report and IEEE 

PVSC paper on results from the Anatolia 

Subdivision with SMUD (09/09) 

•	 Began collecting high-resolution data at Nellis 

AFB and Lanai PV systems (09/09). 

3.1 Lab-Based SAI and Industry Support 

We completed testing for several stage-gate 

evaluations for TPPs, incubators, and other DOE 

contract participants. Testing was performed both 

onsite and at the participant’s facility. Many of 

these evaluations were used to verify LCOE 

targets during stage gate assessments. 

Performance and energy production testing of 

CPV modules representing various concentrating 

technologies began in January 2009 at NREL. The 

data are used for stage-gate evaluations and for 

characterization of CPV performance. A technical 

report was completed outlining initial performance 

results, lessons learned, and recommendations for 

establishing this type of test facility, including 

testing protocols. 

Fig. 1. Two-axis tracker at NREL with CPV 

modules from 5 manufacturers. 

3.2 Lab T&E Data Collection 

Quality-assessed hourly and 15-minute interval 

data sets of measured meteorological and PV 

system performance data for a 1-year period were 

developed using data from existing PV systems at 

NREL and SNL. These data sets are available to 

interested parties for model validation of system 

performance models. 

At NREL, this activity also supports the operation 

and maintenance of the Performance and Energy 

Rating Testbed (PERT). This test bed measures 

performance for up to 45 PV modules, with test 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

durations of weeks to years, depending on the 

stage-gate, energy rating, or reliability activity it 

supports. 

SNL developed a new cell test capability for 

multijunction solar cells using laser beam induced 

current techniques and presented a paper at the 

2009 PVSC. 

D R A F T

3.3 Standards Development and Industry Transfer 

Current standards lack specifics on how to 

precondition CdTe and CIGS modules so that 

when tested for reporting conditions the results are 

well coordinated with subsequent field 

performance. This work examined existing and 

proposed methods. Using capacitance-voltage 

measurements was discovered to be a useful 

indicator of stability. A record of invention of this 

measurement method was submitted by NREL. 

This work continues in FY 2010. 

SNL trained eight companies on site for Module 

and Cell Test Technology Transfer and 

participated in Codes and Standards development: 

IEC 62108, UL 8703 for CPV. 

3.4 Field T&E 

For a PV system, both snow and shadowing 

losses may be difficult to predict. To address these 

issues, a heated pyranometer for accurate 

irradiance measurements and digital images to 

detect snow coverage on the PV array were 

demonstrated to be useful for assessing 

performance losses from snow. The results of a 

literature survey, in conjunction with experiments, 

were used to present methods for determining 

performance losses from shading. 

The Field Test Protocol draft was completed in FY 

2009. It was exercised for feedback during 

simultaneous field testing of two generations of 

Amonix MegaModules (~5 kW) in Las Vegas, NV. 

3.5 Grid Integration T&E 

Grid Integration T&E focused on systems level 

testing to determine the effect of PV systems on 

the electrical grid. NREL and SNL coordinated 

activities to evaluate different types of PV 

systems. NREL T&E activities included monitoring 

the Anatolia with Sacramento Municipal Utility 

District and Alamosa with Xcel Energy/SunEdison. 

SNL Grid activities included monitoring the Nellis 

AFB and Las Vegas Valley Water District with 

SunPower and NV Energy, and the Lanai PV 

system with SunPower. Confidentiality concerns 

on the part of system owners have made it difficult 

to widely disseminate the data and analysis 

results, particularly for large PV systems. Some of 

these issues are being addressed through the PV 

Variability Working Group that SNL and NREL 

lead. 

3.6 Inverter/BOS R&D 

Power controls and microgrid control schemes 

were of particular importance in FY 2009. SNL 

collaborated with industry to implement real and 

reactive power control in inverters, and 

implemented a three-phase microgrid control 

scheme. In support of DOE contracts, SNL 

implemented laboratory enhancements necessary 

to validate SAI/SEGIS developments. 

3.7 PV Module Database 

The subcontract for transfer of SNL’s PV Module 

Database maintenance and routine outdoor PV 

module testing to populate the database was 

awarded to TUV-PTL in May 2009. Work began on 

the transfer process, with expected completion of 

test capability transfer in June 2010. In addition, 

SNL doubled the number of modules in SNL’s PV 

Module database to 422 and updated the 

database used in the Solar Advisor Model. 

3.8 Energy Ratings Method Validation 

Two types of methods were evaluated for 

correcting the short-circuit current of PV modules 

for variations in the solar spectrum under clear 

skies: (1) empirical relationships based on air 

mass, and (2) use of spectral irradiance models 

and PV module spectral response data. Methods 

of the first type were the SNL absolute air-mass 

function, or f(AMa), and the CREST air-mass 

function, or f(AM). The second type used SEDES2 

and SMARTS spectral irradiance models. 

For predicting the short-circuit current under clear 

skies for a multicrystalline silicon PV module and 

an amorphous silicon PV module, the methods 

using spectral irradiance models and PV module 

spectral response data performed better than the 

empirical air mass methods. This work continues 

in FY 2010 to assess performance under both 

clear and cloudy skies. 

4. Planned FY 2010 Activities 

•	 Complete all stage-gate evaluations for TPPs, 

incubators, SEGIS, and other DOE SETP 

participants (09/10) 

•	 Report on effect of aerosol and water vapor 

variations on CPV performance at NREL 

(09/10) 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

•	 Document procedure for AC module 

performance testing (09/10) 

•	 Provide Executive Summary to DOE of thinfilm system tests (09/10) 

•	 Draft stabilization procedure for testing thinfilm PV modules (09/10) 

•	 Complete two Round Robin module tests with 

TUV-PTL to prepare for hand-off of outdoor 

baseline module testing (07/10) 

•	 Document standard SNL test protocols to 

support test technology transfer (09/10) 

•	 Report on shade mitigation performance of 

“Solar Magic” devices (03/10) 

•	 Provide Field Test Protocol to industry (09/10) 

•	 Report on effect of long-term inverter 

operation and exposure of SWTDI and SNL 

located inverters (09/10) 

•	 Document results of PV AFCI testing of PV 

systems and develop arc fault generator and 

test bed for PV AFCI (09/10) 

•	 Document cloud cover evaluation data sets for 

use by dynamic models and PV power 

ramping control capabilities development 

(09/10) 

•	 Report on procedures for correcting for 

spectrum for energy rating standards (09/10) 

•	 Evaluate procedures for determining PV 

module nominal operating cell temperatures 

(NOCTs) and participate in round robin 

validation efforts (09/10). 

5. Major FY 2009 Publications 

J.A.	 del Cueto, Deline, Albin, Rummel, and 

Anderberg, “Striving for a Standard Protocol for 

Preconditioning or Stabilization of Polycrystalline 

Thin Film Photovoltaic Modules,” 2009 SPIE 

Conference. 

C. Deline, “Partially Shaded Operation Of A GridTied PV System,” 2009 PVSC. 

J.E. Granata, “Cell and Indoor PV Module 

Measurements,” and “Outdoor PV Module and 

System Measurements,” International 

Photovoltaic Reliability Workshop, Shanghai, 

China, Dec. 2008. 

J.R. Finn, Hansen, and Granata, “Multiple Junction 

Cell Characterization Using the LBIC Method: 

Early Results, Issues, and Pathways to 

Improvement,” 34th IEEE PVSC, 2009. 

J.E. Granata, Boyson, Kratochvil, and Quintana, 

“Long-Term Performance and Reliability 

Assessment of 8 PV Arrays at Sandia National 

Laboratories,” 34th IEEE PVSC, 2009. 

S.	 Gonzalez, Kuszmaul, and Ellis, “Long-Term 

Inverter Operation Demonstration at Sandia 

National Laboratories,” 34th IEEE PVSC, 2009. 

A. Kimber, Dierauf, Mitchell, Whitaker, Townsend, 

NewMiller, King, Granata, Emery, Osterwald, 

Myers, Marion, Pligavko, Panchula, Levitsky, 

Forbess, and Talmud, “Improved Test Method to 

Verify the Power Rating of a Photovoltaic (PV) 

Project,” 2009 PVSC. 

S.S.	 Kuszmaul, Gonzalez, Ellis, and Serban, 

“Commanding Inverters to Establish Coordinated 

μ-grid Functionality at Sandia National 

Laboratories,” 34th IEEE PVSC, 2009. 

B. Marion, “Instrumentation for Evaluating PV 

System Performance Losses from Snow,” 2009 

ASES Conference. 

M. Muller, Development of an Outdoor 

Concentrating Photovoltaic Module Testbed, 

Module Handling and Test Procedures, and 

Initial Energy Production Results, NREL/TP-520-

46569, Golden, CO: NREL (2009). 

M. Muller, Rodriguez, and Marion,	 ”Performance 

Comparison Of A BIPV Roofing Tile System In 

Two Mounting Configurations,” 2009 PVSC. 

P. McNutt, Hambrick, Keesee, and Brown. “Effects 

of Photovoltaics on Distribution system Voltage 

Regulation”, 34th IEEE PVSC, 2009. 

P. McNutt, Hambrick, Keesee, and Brown. Impact 

of SolarSmart Subdivisions on SMUD’s 

Distribution System.” NREL/TP-550-46093, 

Golden, CO: NREL (July 2009). 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Ametek Power Systems San Diego, CA 

tony.ng@ametek.com PV Simulator Development 60 13 

TUV-PTL Phoenix, AZ 

gtamizhmani@tuvptl.com 

Transfer of SNL’s Outdoor Module 

Test Technology and PV Module 

Database maintenance 

173 40.4 
 

 

 

 

 

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Regional Experiment Stations 

Performing Organizations: Southwest Regional Experiment Station (SWRES) 

D R A F T

Southeast Regional Experiment Station (SERES) 

Key Technical Contacts:	 Steve Palmeri (DOE/GO), 303-275-4832, steve.palmeri@go.doe.gov 

Holly Thomas (DOE/GO), 303-275-4818, holly.thomas@go.doe.gov 

DOE HQ Technology Manager:	 Charlie Hemmeline, 202-586-6646, Charlie.hemmeline@hq.doe.gov 

FY 2009 Budgets:	 $1,136K (SWRES), $855K (SERES) 

Objectives 

•	 Ensure that education, training, outreach, and technical support required to accelerate the rate of 

nation’s photovoltaic (PV) deployment are available and effectively implemented to support 

growth of the PV market 

•	 Lead and support industry and national laboratories in (1) testing systems, modules, and 

inverters; (2) creating and implementing procedures, codes, and standards for quality, safe, and 

cost-effective installed systems; (3) certifying hardware; and (4) resolving system engineering 

issues observed in fielded systems 

•	 Furnish technical support to the Department of Energy (DOE), national laboratories, Solar 

America Cites, Showcase Projects, and industry in executing and validating stage gates for 

Technology Pathway Partnerships (TPP). 

Accomplishments 

•	 Completed second-period requirements of 3-year award and began the final period work 

•	 Conducted product testing, system evaluations, and R&D activities that related to cutting 

levelized cost of energy (LCOE), increasing system efficiency, and cutting initial costs of PV 

systems, particularly as required by Solar America Initiative participants 

•	 Furnish technical outreach as member of Tiger Teams to Solar America Cities and Showcases. 

Future Directions 

•	 Continue to lead or serve as a member of Tiger Teams to Solar America Cities and Showcases 

•	 Continue testing and evaluation of fielded PV systems for TPP stage-gate testing, general system 

benchmarking, and characterization of PV systems and components for performance, cost, and 

reliability 

•	 Continue training and participate in developing and disseminating codes and standards. 

1. Introduction 

The regional experiment stations (RES) consist 

of two organizations: SERES and SWRES. 

These stations are affiliated with local 

universities, the University of Central Florida for 

SERES, and New Mexico State University for 

SWRES. 

The ongoing work by these organizations entails 

a wide range of technical work in such 

areas as: 

•	 Module reliability R&D 

•	 Inverter and balance of system (BOS) 

development 

•	 PV systems engineering, analysis, 

evaluation, and optimization, especially for 

fielded systems 

•	 Education, advance codes, and standards. 

2. Technical Approach 

2.1 PV Systems Assistance Center 

The Photovoltaic Systems Assistance Center 

(PVSAC) is a virtual laboratory comprising 

engineers and staff from both SWRES and 

SERES. PVSAC is an independent third-party 

evaluator to evaluate TPP interim results during 

their stage-gate reviews. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Organization/ 

Principal Investigator 

Description/ 

Title of Research 

Activity 

University of Central 

Florida/Florida Solar 

Energy Center/ Bob 

Reedy/Stephen Barkaszi 

PV System Research 

and Technical 

Assistance 

Southwest Technology 

Development Institute/ 

Andrew Rosenthal 

PV System Research 

2.2 Infrastructure Development 

Both organizations conduct training, design 

review and approval, and codes and standards 

development. 

2.3 Long-Term Component Testing 

RES supply unique and severe environments for 

long-term exposure (hot/dry and hot/humid) for 

stressing PV modules and inverters in outdoor 

system-like configurations. 

3. Results and Accomplishments 

3.1 SERES 

•	 Participated as a Tiger Team lead in the 

Solar America Program; in this capacity, 

furnished extensive technical support 

through bid specification development, 

design review, engineering design, policy 

support and development, and training 

•	 Continued the partnership with ETL-Intertek 

to conduct performance testing of PV 

modules in accordance with UL-1703 and 

IEC standards; assisted ETL-Intertek in 

entering the commercial testing arena as a 

Nationally Recognized Testing Laboratories 

(NRTL) 

•	 Conducted comprehensive design reviews 

for numerous small-scale PV systems 

installed in Florida, evaluating for code 

compliance and basic functional 

performance criteria 

•	 Conducted the week-long course Installing 

PV Systems at the Florida Solar Energy 

Center (FSEC) monthly; the course was also 

held for Solar America City participants 

•	 Evaluated module performance versus 

module nameplate numerous PV module 

makes and models; this information is the 

basis for determining stabilized module 

performance information and long-term 

performance 

•	 Installed several additional PV systems in 

Florida for disaster relief applications, 

primarily at schools that serve as emergency 

shelters to ensure power availability during 

grid outages at these critical locations; 

SERES performed design review, 

acceptance testing, and performance 

monitoring 

•	 Continued data collection for side-by-side 

comparison of utility interactive inverters, 

using identical arrays and monitoring 

performance continuously under real-world 

conditions in a hot-humid climate 

•	 Transferred system certification/design 

review to Miami-Dade and Broward counties 

as part of the expedited solar permitting 

process; several major utilities require 

certification for interconnection. 

3.2 SWRES 

•	 Served as Tiger Team lead or participant 

Solar America Cities: Tucson, AZ; Santa 

Rosa, CA; San Jose, CA; Austin, TX; and 

Pittsburgh, PA; performed modeling and site 

assessment for Solar America Showcase 

Forest City (Oahu, HI) 

•	 Participated in merit reviews when 

requested to support DOE 

•	 Designed special inverter power quality data 

acquisition systems (DASs) and operated 

six for 5-year tests for inverter long-term 

reliability with Sandia National Laboratories 

and FSEC with 100% data availability 

•	 Inspected and approved all 2009 Solar 

Decathlon PV systems; supplied immediate 

support to NREL with modeling system 

performance of several systems affected by 

grid outages during judging, enabling the 

competition to be judged accurately and on 

time 

•	 Participated in developing and planning the 

system long-term exposure tests that will 

take place at three different regions around 

the country over the next several years; took 

responsibility for all DAS development, 

construction, and installation for the project 

•	 Continued to perform on-site exposure 

testing and monitoring for innovative 

concentrating PV technologies, emerging 

CIGS modules, and innovative PV-assisted 

heat pump development for one of the 

nation’s largest heating and cooling 

manufacturers (Lennox) 

•	 Consulted with electrical inspectors 

nationwide on major code concerns 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Conducted Internet-based training and 

Webinar for more than 60 electricians, 

inspectors, and installers 

•	 Trained more than 1,440 designers, 

inspectors, and installers in National 

Electrical Code® (NEC) workshops during 

12-month reporting period. 

D R A F T

4. Planned FY 2010 Activities 

•	 Continue to lead or participate as a member 

of technical outreach Tiger Teams for Solar 

America Cities and Showcases, crosscutting activities, and training courses 

•	 Continue testing and evaluating fielded PV 

systems for general system benchmarking 

PV systems and component performance, 

cost, and reliability characterization 

•	 Continue training and participate in the 

developing and disseminating codes and 

standards 

•	 Continue to support market transformation 

activities with needs that capitalize on the 

SERES research and technology transfer 

work 

•	 Continue to increase capabilities in field-test 

and outdoor validation activities for hothumid climates, including high voltage 

testing 

•	 Increase PV module testing capabilities for 

certification programs to help minimize test 

time and to reduce backlogs for industry for 

an expanding U.S. industry 

•	 Continue and expand small residential 

inverter testing facilities 

•	 Continue workforce development efforts 

through course offerings in PV system 

design and installation. 

5. Major FY 2009 Publications 

SERES 

W. Young, Florida's Emergency Shelter 

Program, FSEC-CR-1812-09, Cocoa, FL: 

Florida Solar Energy Center, Aug. 11, 2009. 

W. Young, Solar 2009: Deploying Mobile PV 

Emergency Power Systems in a Disaster, 

FSEC-PF-446-09, Cocoa, FL: Florida Solar 

Energy Center, Sept. 18, 2009. 

SWRES 

A. Rosenthal, “Esthetically Designed Municipal 

PV System Maximizes Energy Production and 

Revenue Return,” 38th ASES National Solar 

Conference, May 11-16, 2009, Buffalo, NY. 

J. Wiles, “Array to Inverter and Things in 

Between,” Home Power 131, Mar/Apr (2009). 

J. Wiles, “Combiner to DC Disconnects,” Home 

Power 129, Jan/Feb (2009). 

J. Wiles “Connecting Inverters to the Grid—Part 

I,” Home Power 134, Sep/Oct (2009). 

J. Wiles, “New Grounding Methods,” Home 

Power 127, Oct/Nov (2008). 

J. Wiles, "Inverter Grounding," Home Power 

133, Jul/Aug (2009). 
 

 

 

D R A F T

Grid Integration Summary 

The PV Grid Integration efforts address both the technical and analytical challenges that need to 

be overcome to enable the incorporation of high amounts of PV into the electrical power system. 

By combining PV with storage, controls, and other appropriate technologies, the PV grid 

integration projects build the foundation for realizing high-penetration scenarios while enhancing 

the operation of the electricity grid. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Grid Integration 475 5415 200 6090 

PV Grid Integration 475 725 200 1400 

Solar Energy Grid Integration 

Systems (SEGIS) 

Solicitation 0 4690 0 4690 
 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

Photovoltaic Grid Integration Support 

Performing Organizations: Sandia National Laboratories (SNL) 

D R A F T

National Renewable Energy Laboratory (NREL) 

Key Technical Contacts: Abraham Ellis (SNL, Primary Contact), 505-844-7717, 

aellis@sandia.gov 

Ben Kroposki (NREL, Primary Contact), 303-275-2979, 

benjamin.kroposki@nrel.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budgets: $725K (SNL), $475K (NREL), $200K (Other) 

Objectives 

•	 Resolve the technical and analytical challenges that need to be overcome to enable the 

penetration of high amounts of photovoltaics (PV) into the electrical power system
 

•	 Develop grid integration tests and field demonstrations that implement high-penetration PV 

•	 Develop technical analysis, modeling, and simulation tools and economic modeling and policy 

analysis to evaluate high-penetration PV scenarios 

•	 Develop briefing materials for stakeholders, with a focus on utility operations and planning entities 

that help them quantify the benefits and impacts of large-scale PV grid integration. 

Accomplishments 

•	 Completed IEEE Power and Energy Special Issue on Solar Integration 

•	 Completed report on IEA Task 11: PV Hybrid Power Systems and Task 14: High Penetration PV 

Systems 

•	 Started PV Variability working group 

•	 Completed analysis of PV variability using data from PV systems of several sizes 

•	 Organized several industry workshops to disseminate information and collect industry input: High 

Penetration PV workshop, Ontario, CA; SEGIS-ES and Inverter Communications Workshop, 

Albuquerque, NM; PV Variability Workshop, Cedar Rapids, IA 

•	 Started planning 4th International Conference on Integration of RE and DER 

•	 Organized Renewable Energy Modeling Task Force under WECC to analyze industry
 

requirements for PV system planning models.
 

Future Directions 

•	 Continue support of IEA PVPS Task 11 and Task 14 

•	 Continue to support PV Variability working group 

•	 Continue to support industry activities aimed at overcoming barriers to high-penetration PV. This 

includes collaborating with WECC, NERC, IEEE, and similar organizations 

•	 Continue to leverage federal investment through industry partnerships 

•	 Improve modeling of short circuit, power flow, and dynamic models for PV systems 

•	 Quantify and model PV output variability from large PV systems. 

1. Introduction	 potential forecasted. As this market share grows, 

however, concern about potential impacts on the 

Improved PV efficiencies and lower costs have stability and operation of the electricity grid may 

rapidly expanded the PV market to include utility, create barriers to future expansion. PV Grid 

distributed generation, and building-integrated Integration investigates the technical and 

applications. The commercial and residential analytical challenges that need to be overcome to 

market continues to be the fastest-growing market enable high amounts of PV to penetrate the 

segment for solar energy, with significant growth electrical power system. By combining PV with 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

storage, controls, and other appropriate 

technologies, our research builds the foundation 

for realizing high-penetration scenarios while 

enhancing electricity grid operation. 

2. Technical Approach 

D R A F T

The technical approach in the PV grid integration 

area emphasizes three main tasks: 

The Grid Integration Support task supports the 

overall PV Grid Integration agreement. This 

includes developing the FY 2010 planning 

documents, annual reports, program reviews, and 

multiyear research plan input. This task also 

supports work on the International Energy Agency 

(IEA) PVPS tasks that relate to grid integration 

and support of the PV Variability working group. 

The System Level Testing task supports work 

conducted at field test sites examining the issues 

with integrating high penetrations of PV into the 

electric power system. NREL currently works with 

SMUD on testing and evaluating a residential 

distribution circuit with a large amount of installed 

PV and with Xcel Energy/SunEdison on deploying 

a large 8 MW plant. SNL is working with a large 1 

MW plant integrated into the electric power system 

of the island of Lanai and the large 14 MW PV 

plant at Nellis Air Force Base (AFB). 

The Distributed Renewable Energy System 

Analysis task includes developing analysis, 

modeling, and simulation tools; conducting 

technical analysis on high-penetration scenarios 

for PV systems; and understanding their effect on 

the electric power system. This task will develop 

enhanced component and system models for 

distributed renewable energy systems (e.g., 

sources, energy storage units). 

3. Results and Accomplishments 

For Grid Integration Support, in FY 2009 we 

compiled and published a special issue of IEEE 

Power and Energy magazine. The issue contained 

six articles on various aspects of integrating solar 

into the electric power system. 

NREL hosted the Task 11: PV Hybrid and Minigrid 

working group to discuss progress on the IEAsponsored program. NREL staff presented the 

state of research in PV hybrid and microgrid 

research and projects in the United States. NREL 

is working on a report to describe the current state 

of more than 40 PV hybrid power systems that 

have been installed in the nation over the last 30 

years. The Task 11 group reviewed the status of 

its various topics, including design issues, control 

issues, penetration of PV into minigrids, and 

sustainability. 

SNL organized or hosted several industry 

workshops to disseminate information and obtain 

industry input: 

•	 Renewable Energy Grid Integration Systems, 

Lanai, HI, with participation from APEC. 

•	 High-Penetration PV workshop, Ontario, CA. 

•	 PV Inverter Communication workshop, 

Albuquerque, NM, in partnership with EPRI. 

•	 SEGIS-ES, Albuquerque, NM, focusing on 

energy storage for PV applications. 

SNL and NREL organized the PV Variability 

workshop, held in Cedar Rapids, IA, in 

collaboration with UWIG and SEPA. Analysis of 

high-resolution PV data, including large PV plants, 

was presented, some for the first time. A public 

report summarizing the key findings was compiled. 

As part of the Industry Support task, SNL and 

NREL lead or play a technical support role in 

several key activities. Some examples are: 

•	 SNL and NREL lead and facilitate the PV 

Variability working group, where many key 

stakeholders are collecting and analyzing data 

related to PV variability and grid integration 

challenges. 

•	 SNL is participating in NERC’s Integration of 

Variable Generation Task Force (IVGTF), to 

recommend standards specifically addressing 

variable generation. 

For Distributed Renewable Energy System 

Analysis, we worked on developing higher 

temporal resolution PV output sets as part of the 

Western Wind and Solar Integration Study 

(WWSIS). We developed an algorithm based on 

measured PV system performance that produces 

10-min PV output values at sites with hourly 

irradiance data. 

An analysis of 1-min power output histories from 

six PV plants in Las Vegas and 1-s output from a 

SNL PV array and an anonymous multi-megawatt 

plant allowed SNL to characterize the effect of 

geographic dispersion on output variability at a 

variety of temporal and spatial scales. Preliminary 

results were presented at UWIG meeting in Cedar 

Rapids on 10/7/09, and included in a paper 

submitted to Electricity Journal. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Better simulation models for PV systems (both 

distributed and large scale) continue to be a 

critical industry need. In FY 2009, SNL partnered 

with Northern Plains Power Technologies to 

improve PV inverter dynamic models for the 

Matlab platform. The models allow for adjustment 

of voltage and frequency trip thresholds, and 

SEGIS functionality (ramp rate limits and 

dynamically adjustable power factor). These 

models enable more detailed analysis of highpenetration PV deployment scenarios. 

D R A F T

In FY 2009, SNL organized the WECC Renewable 

Energy Modeling Task Force, an industry group 

whose specific mission is to develop models for 

interconnection and planning of distributed and 

utility-scale PV systems. 

4. Planned FY 2010 Activities 

The Grid Integration Support task supports U.S. 

representation on the IEA PVPS Task 11 and the 

new IEA PVPS Task 14: High Penetration of PV 

Systems in Electricity Grids. The intention of the 

new task is to discuss and report on highpenetration grid-connected scenarios in a number 

of PVPS countries and solve the problems and 

issues associated with this development with incountry experts. 

SNL and NREL will work with industry 

stakeholders to write the Grid Integration chapter 

of the Solar Vision study. SNL will continue to 

support several tasks of the NERC IVGTF efforts, 

emphasizing PV grid integration aspects. 

This task also supports the PV Variability working 

group. NREL and SNL co-lead this ad hoc group 

of industry and laboratories that was formed in FY 

2009 as a forum to discuss the variability of PV 

caused by clouds. In FY 2010, the first face-toface workshop will be held. 

We will continue to collaborate with EPRI and 

other partners in Europe and Asia to organize and 

execute the 4th International Conference on 

Integration of Renewable and Distributed Energy 

Resources. SNL leads the scientific committee for 

the conference, and DOE is a sponsor. 

For the System Level Testing task, in FY 2010, 

NREL will continue working with SMUD on their 

Anatolia III Solar Subdivision and with Xcel 

Energy/SunEdison on the Alamosa system. Data 

from these systems will help identify potential 

issues with large penetrations of PV on distribution 

feeders as well as quantify the effect these 

systems are having on actual operating electrical 

distribution systems. 

SNL will continue to work on data collection and 

analysis of the Lanai and the Nellis AFB PV 

systems, and will produce a report documenting 

the operating experience of large PV systems, 

focusing on grid impacts. High-resolution data 

collection is already under way at both locations. 

In FY 2010, SNL will begin to collect and analyze 

data at the DeSoto PV plant in Florida, and will 

install irradiance sensor networks at Lanai and 

DeSoto to support modeling and analysis. 

The Distributed Renewable Energy System 

Analysis task includes developing analysis, 

modeling, and simulation tools and conducting 

technical analysis on high-penetration scenarios 

for PV systems and understanding their impact on 

the electric power system. This task will develop 

enhanced component and system models for 

distributed renewable energy systems (e.g., 

sources, energy storage units). In FY 2010 we will 

develop inverter fault current models to help 

understand the effect of PV systems under short 

circuit conditions. 

SNL will focus on developing and validating 

generic, nonproprietary, positive-sequence 

dynamic models for central-station and distributed 

PV systems. This work will be done through the 

WECC Renewable Energy Modeling Task Force 

that SNL leads. This effort will also produce 

guidelines for power flow and dynamic 

representation of PV systems in planning and 

interconnection studies. Laboratory testing of PV 

inverters conducted at SNL and NREL will support 

the modeling. 

In FY 2010, SNL will quantify PV output variability 

of large PV systems and develop models that can 

predict statistical characteristics of PV output 

variability as a function of, e.g., PV system size, 

tracking system. Data from existing and planned 

irradiance sensor networks will be used to develop 

and validate the models. This work will lay the 

foundation to significantly increase the time and 

spatial resolution of existing solar resource data, 

For technology development, SNL plans to 

demonstrate how imaging can be used to forecast 

short-term PV output. Several technical challenges 

such as cloud segmentation will need to be 

solved. SNL will also demonstrate using advanced 

batteries to mitigate PV output variability. The 
 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

demonstration will also quantify the effect of 

regulation duty on advanced battery degradation. 

The experiment will compare the effectiveness of 

several smoothing algorithms. 

For codes and standards, NREL and SNL will 

organize a workshop on standards for highpenetration PV, in close collaboration with SEPA. 

SNL will develop test protocols for standards being 

developed through the EPRI/SNL Inverter 

Communications activity. This work will directly 

benefit the DOE and EPRI Smart Grid 

Demonstration projects. 

5. Major FY 2009 Publications 

J. Bebic, R. Walling, K. O’Brien, and B. Kroposki, 

“The Sun Also Rises—Planning for Large-Scale 

Solar Power,” IEEE Power and Energy 

Magazine, May/June 2009. 

S. Gonzalez, S. Kuszmaul, and A. Ellis, “LongTerm Inverter Operation Demonstration at 

Sandia National Laboratories,” 34th IEEE 

Photovoltaic Specialists Conference, 

Philadelphia, 2009. 

T. Key, “Finding a Bright Spot—Utility Experience, 

Challenges, and Opportunities in Photovoltaic 

Power,” IEEE Power and Energy Magazine, 

May/June 2009. 

B. Kroposki, R. Margolis, and D. Ton, “Harnessing 

the Sun—An Overview of Solar Technologies,” 

IEEE Power and Energy Magazine, May/June 

2009. 

E. Liu, J. Bebic, B. Kroposki, J. de Bedout, and W. 

Ren, “Distribution System Voltage Performance 

Analysis for High-Penetration PV,” IEEE 2030 

Conference, Atlanta, GA, November 2008. 

A.	 Mills, M. Ahlstrom, M. Brower, A. Ellis, R. 

George, T. Hoff, B. Kroposki, C. Lenox, N. Miller, 

J. Stein, and Y. Wan, Understanding Variability 

and Uncertainty of Photovoltaics for Integration 

with the Electric Power System, LBNL-2855E. 

Berkeley, CA: Lawrence Berkeley National 

Laboratory, December 2009. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Sacramento Municipal 

Utility District (SMUD) Sacramento, CA Evaluation of SolarSmart Subdivisions 50K 50K 

Xcel Energy and 

SunEdison Alamosa, CO Evaluation of the Alamosa 8 MW PV system 50K 50K 

BEW San Ramon, CA PV inverter interconnection and 

planning models $15K Contract 

Northern Plains Power 

Technologies Brookings, SD Development of detailed models of PV inverters with SEGIS capability $25K Contract 

SunPower Richmond, CA 

Evaluation of Lanai PV system 

data, installation of wireless 

irradiance sensor network 

$25K $25K 

NV Energy Las Vegas, NV Analysis of PV system data from 

Las Vegas Valley Water District $10K $10K 

EPRI Knoxville, TN Inverter communications 

standards and test protocols $10K $10K 
 

____________________________________________________________________________________ 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

Solar Energy Grid Integration Systems Industry Projects 

D R A F T

Performing Organization:	 Sandia National Laboratories (SNL) 

Key Technical Contacts:	 Ward Bower (SNL), Primary, 505-844-5206, wibower@sandia.gov 

Scott Kuszmaul (SNL), 505-844-5401, sskuszm@sandia.gov 

DOE HQ Technology Manager:	 Kevin Lynn, 202-586-1044, Kevin.Lynn@ee.doe.gov 

FY 2009 Budgets:	 $7,092K (SNL Program), $4,800K (SNL ARRA) 

Objectives 

•	 Lay the groundwork for high levels of photovoltaic (PV) electrical grid penetration 

•	 Advance the power electronics, controls, energy management, and communications for grid 

integration and microgrid applications for PV technologies 

•	 Enable PV systems to meet the goal of making solar power cost-competitive with today’s 

conventional sources of electricity while improving other values such as time-of-day metering 

•	 Integrate PV systems to use energy management, energy storage, and communications for total 

system optimization that also meets the Solar Energy Technologies Program (SETP) levelized 

cost of energy (LCOE) goals 

•	 Commercialize and deploy advanced, integrated, PV-system technologies that will enhance our 

nation’s energy security and confront the serious challenges of environmental responsibility and 

global climate change. 

Accomplishments 

•	 Completed an extremely aggressive schedule to move the Solar Energy Grid Integration Systems 

(SEGIS) solicitation from Stage 1 (conceptual designs and market analysis) into Stage 2 

(prototype development) with a project downsize to five promising industry contractor teams 

•	 Completed quarterly, final, and critical reviews to track progress and select high likelihood of 

successful commercialization 

•	 Gave progress technical feedback to contractors to help ensure successful prototype 

development with DOE program-compatible cost goals related to LCOE and system integration. 

Future Directions 

•	 Complete Stage 2 prototype development involving five SEGIS contractors 

•	 Complete witness testing of prototypes with evaluation of performance, functionality, and 

compliance with required and upcoming interconnect rules
 

•	 Evaluate Stage 2 progress and determine “Best Value” contractor proposals to move into Stage 3 

(toward commercialization) 

•	 Guide SEGIS Stage 3 to bring commercialized developments to a focused demonstration site and 

to evaluate interconnection functionality with multiple disciplines. 

1. Introduction	 applications are the critical components being 

developed. Fully integrated inverters, controllers, 

The SEGIS project promotes the development of and communications components will incorporate 

advanced PV smart-grid-ready technologies energy storage and management functions and 

allowing increased penetration of PV into the utility communicate with other energy management 

grid while maintaining or improving the power systems that are increasingly used for building 

quality and reliability of the utility grid. Highly energy conservation. Complete and fully 

integrated, innovative, advanced inverters, integrated systems will include utility energy and 

controllers, balance-of-system (BOS), and communication portals to pioneer PV system 

associated BOS elements for residential, interfaces with emerging products such as 

commercial, and utility-scale solar energy Advanced Metering Infrastructure (AMI). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Products and interconnection methodologies are 

being developed to support the move from the 

electrical grid of today, which was designed for 

one-way power flow, to the grid of tomorrow, 

which will seamlessly accommodate two-way 

power flows as required by wide-scale deployment 

of solar and other distributed resources. The 

interconnect methods being developed are to work 

with what is allowed today for interconnections 

and what may likely be adopted as future options. 

The work is often the first of its kind but likely will 

be used to help guide the needs of evolving 

standards and the new Smart Grid. 

Figure 1 shows a pictorial representation of a fully 

interactive system with the SEGIS developments 

located in the central box with communications 

between all elements of the intertied system. 

Fig. 1. Representation of SEGIS in the electrical 

load, resource information, and utility 

infrastructure. 

2. Technical Approach 

The SEGIS project is based on a very aggressive 

competitive solicitation with three stages of work: 

(1) Market Analysis and Concept; (2) Prototype 

Development and Evaluations, and (3) Toward 

Commercialization. Each stage must be 

completed and show significant progress toward 

the goals of the project and SETP. To advance to 

the next stage, contractors must compete with 

progress and final reports for the stage, 

presentations at critical review meetings, and a 

next-stage proposal update. 

The SEGIS solicitation serves both evolutionary 

and revolutionary advances in PV BOS and 

intelligent connections to the utility grid and 

microgrids. The project covers PV systems from 

100 W through 1 MW where 1 MW size systems 

will use a modular approach to build the system. 

The SEGIS solicitation strongly encourages and 

has resulted in strong teaming with the primary 

contractor, electric utilities, communications firms, 

energy storage, energy management, and energy 

conservation experts to ensure bottom-up 

integration of developed systems. Stage 3 is a 

commercialization effort requiring either in-house 

manufacturing capabilities or partnerships with 

firms ensuring high quality manufacturing with 

quality control plans. All SEGIS contractors must 

have designs for long lifetime and high reliability 

and are required to participate in programs that 

improve likelihood for longevity and reliability such 

as the Highly Accelerated Lifetime Testing 

(HALT®) or equivalent. SEGIS contractors are 

also required to participate in pertinent codes and 

standards making processes. 

3. Results and Accomplishments 

Placing Stage 2 contracts with project downsizing 

was a level 3 milestone and was completed on 

schedule on June 26, 2009. Level 3 milestones for 

FY 2009 include completion of project reviews, 

project critical reviews at SNL and final Stage 1 

reports by 12 contractors. Milestones for SEGIS 

contracts are set to specific program dates and 

must be completed on time and linked to the 

competitive schedule to the next stage. 

Table 1. FY 2009 SEGIS Milestones and 

Accomplishments 

Milestones Accomplishments 

1st Stage 1 Quarterly 

Reports (12 contractors) 

Updated market analysis and 

concept designs (9/09) 

2nd Stage 1 Quarterly 

Reports (12 contractors) 

Completed with technical 

feedback (12/09) 

DOE Solar Program 

Review Presentations. 

Open overview presentations 

completed at DOE (2/09) 

Final Stage 1 Reports 

(12 contractors) 

Completed and used in selection 

criteria for downsize (3/09) 

Project Critical Reviews 

(12 contractors) 

Completed contractor full-day 

review presentations (4/09) 

Complete Stage 1 

Contractor Reviews 

Completed by evaluation team for 

down-select process (4/09) 

Stage 2 downsize (5 

Contracts) 

Contracts completed (6/26/09) for 

Best Value advances 

1st Stage 2 “Quarterly 

Reports” (5 contractors) 

Completed with webinars to 

review progress since kickoff 

meetings (8/09) 

Figure 2 shows the setup and measurement of 

advanced maximum power point tracking being 

developed through SEGIS. It has been determined 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

that the communications aspects of connecting PV 

to an intelligent grid will require communications to 

monitor the grid, communications to the electrical 

utility command and control, communications to 

the owner of the system, and communications to 

provide the required safety. The communications 

studied through SEGIS included power line carrier 

(PLC), internet and Ethernet, fiber optics, wireless, 

available SCADA (Supervisory Control And Data 

Acquisition), and connections to the many AMI 

units being deployed by utilities. 

Fig. 2. Demo of PV Powered advanced max 

power point tracking for all PV technologies. 

4. Planned FY 2010 Activities 

FY 2010 work will complete Stage 2 of the SEGIS 

solicitation with five contractors. The progress of 

each contractor will be evaluated through witness 

testing of the prototype deliverables, a one-day 

critical review at SNL, delivery and evaluation of 

final Stage 2 reports, and evaluations of the 

proposed Stage 3 work. Evaluations will be based 

on “Best Value” for the SEGIS program and SETP 

goals. Figure 3 shows the project schedule. 

Stage 3 will be completed in FY 2011. SNL is 

developing plans to deploy the commercialized 

products, where real-time grid-tied or microgrid 

installations will be installed and evaluated for 

performance working with intelligent grids. 

An added activity in FY 2010 will be to address the 

need for arc-fault detection by PV systems 

installed on roofs of buildings. Current activities 

include collaborating with Underwriters 

Laboratories to develop a standard for arc-fault 

detection devices. This work is preliminary and will 

eventually cover detection and mitigation methods 

for arcs within PV modules, intermodule wiring, 

junction boxes, and inverter input circuits. 

Table 2. FY 2010 Activities 

Activity Date Results/Impact 

Bill of Material 

Memo 

9/09 Helps ensure steady 

progress by each contractor 

Workforce 

Buildup Memo 

9/09 Logs anticipated job creation 

through developing and 

manufacturing systems 

Mid Year 

Report 

1/10 Reports progress analysis 

and feedback to contractors 

Testing and 

Prototype 

Readiness 

Review 

2/10 Reviews preparation and 

readiness for testing, 

equipment needed, and 

priorities 

Stage 2 

Progress 

Report 

2/10 Evaluates progress in Web 

meeting (contractor and 

SNL) 

DOE Program 

Review 

5/10 Serves as a 

communications pathway to 

DOE and PV community 

Witness 

Evaluation Test 

on Prototypes 

4­

5/10 

Measures performance and 

functionality of SEGIS 

advances and prototypes: a 

stage-gate input 

Stage 2: Final 

Report – Stage 

3 Update 

6/10 Is a proprietary report on 

progress, findings, lessons 

learned, and stage-gate 

input 

Evaluate and 

Select Stage 3 

Contractors 

6/10 Uses selection criteria for 

the SEGIS project and 

combines critical reviews, 

witness testing, and Stage 3 

likelihood of success 

Kickoff 

Meetings for 

Stage 3 

Contractors 

8/10 Serve as sanity check on 

anticipated work for the 

commercialization stage for 

SEGIS 

5. FY 2009 Special Recognitions 

The SEGIS solicitation moved from the conceptual 

design and market analysis stage to the prototype 

development stage. Various publications are 

recognizing the SEGIS solicitation and contractors 

and their work. The article “Year of Energy 2009” 

from Sigma Xi, the Scientific Research Society, 

stated, “Such SEGIS research is also critically 

important to improving utilities’ management of 

traditional energy generation and demand-side 

resources for improving the utilization of their 

existing infrastructure.” 

6. Major FY 2009 Publications 

W. Bower, “Grid-tied Inverter Technology and 

Functionality Options for Intelligent Grid 

Applications,” Intersolar North America 

Conference, San Francisco, CA, July 14–16, 

2009. 
 

 

 

 

 

 

 

 

 

 

 

 

A. Ellis and W. Bower, “The US DOE Solar Energy REGIS Workshop, Lanai, HI, February 14, 2009. 

Grid Integration Systems Program ‘SEGIS’,” 

D R A F T

20% Cost Share 

Stage 2 

Prototype Development 

Prototype Design and Testing 

Ø Control Strategy Development 

Ø Electrical and Mechanical 

Ø Energy Balance Calculations 

Ø Reliability Calculations 

Ø Operational Characterizations 

Ø Performance Measurements 

Ø External Interaction Validations Quarterly & Mid-year Reports Reports and Review T&E/Hardware Deliverables/Reports END OF STAGE 

REPORTS 

ü Stage 2 Technical & 

Market/Cost Report 

ü Critical Program 

Review 

20% Cost Share 

Stage 1 

Concept and Feasibility 

Proof of Concept/Feasibility 

Ø Research and Development 

Ø Advantages and Disadvantages 

Ø Barriers and Needs 

Ø Likelihood of Success 

Ø Market and Cost Analysis 

Ø Value-Added Analysis 

Ø Market and Tech Impacts Proposal to SNL Quarterly Reports Reports and Stage 3

Proposal to SNL 

SEGIS INITIAL 

PROPOSAL 

ü Stage 1 Complete 

Technical & Cost 

ü Stage 2 Complete 

Technical & Cost 

ü Stage 3 T&C (Brief 

Overview) 

END OF STAGE 

REPORTS and

 STAGE 3 PROPOSAL 

ü Stage 1 Technical 

Report 

ü Stage 1 Market 

Analysis Report 

ü Critical Program 

Review 

ü STAGE 3 DETAILED 

TECHNICAL & 

COST PROPOSAL) 

50% Cost Share 

Stage 3 

Pilot Production 

(Toward Commercialization) 

Pilot Production Design 

Ø Hardware Delivery 

Ø Test & Evaluations 

Ø Validations and verifications 

Ø Production Analysis 

Ø Bill of Materials 

Ø Final Cost Analysis 

Ø Hardware Commercialization Quarterly & Mid-year Reports Reports and Review T&E/Hardware Deliverables/Reports 

END OF STAGE 

REPORTS 

ü Stage 3 Final 

Technical & Market/ 

Cost Report 

ü Peer Reviewed 

Conference Paper 

ü Final Program 

Review 

Fig. 3. Timetable for SEGIS solicitation. 

7. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of Research Activity 

FY 

2009 

($K)* 

Apollo Solar/ 

John Pfeifer 

Bethel, CT 

John.Pfeifer@ApolloSolar. 

com 

“An Advanced Grid-tied Inverter, Charge Controller, Energy 

Monitor and Internet Gateway.” Advanced modular components for 

power conversion, energy storage or management, and a portal 

for communication. The gateway provides communication with 

utility portals to control two-way power flows. 

$864 

Petra Solar/ 

Adje Mensah 

Somerset, NJ 

Adje.Mensah@petrasolar.c 

om 

“Development of Economically Viable, Highly Integrated, Highly 

Modular SEGIS Architecture.” Multilayer control/communication 

with PV systems to interconnectivity, cost reduction, system 

reliability, and safety resulting in a cost-competitive, easy to install, 

modular and scalable system. 

$1,657 

Princeton Power/ 

Paul Heavener 

Princeton, NJ 

“Demand Response Inverter.” A complete design for a 100-kW 

“Demand Response Inverter System with proprietary technology. 

The design will be optimized for low-cost, high-quality manufacture 

and integrates control capabilities including dynamic energy 

storage and demand-side load response. 

$1,553 

PV Powered/ 

Mesa Scharf 

Bend, OR 

“MPPT and EMS Advancements.” Develop a suite of maximum 

power point tracking (MPPT) algorithms for all available and 

emerging PV module technologies. State-of-the-art two-way 

communications and integration with building energy management 

and utility management networks. 

$1,612 

University of 

Central Florida/ 

Robert Reedy 

(FSEC) 

Orlando, FL 

reedy@fsec.ucf.edu 

“Grid-Smart Inverters.” Grid integration concepts for PV that 

incorporate battery storage, utility control, communication, 

monitoring functions, and building energy management. Validate 

“anti-islanding” strategy for PV inverters to maintain PV during grid 

disturbances, while meeting safe operation rules. 

$770 

Total Program 

Funds 

$6,456 

.* 

ARRA Funds amounting to $4.8M total was expended with delivery of the Readiness Review deliverable in 3/10. 
 

 

D R A F T

Resource & Safety R&D Summary 

Accurate knowledge of quantity and quality of solar/optical radiation is essential to determine 

solar renewable energy system performance, substantiate progress in manufacturing and device 

development, and validate measurements and models of available solar resources. The task 

provides technical foundation for high quality optical/solar radiation sensor calibrations, 

measurements, data, and solar radiation resource models for solar energy system engineering 

applications and performance testing. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Resource & Safety R&D 1630 0 470 2100 

Solar Radiometry and 

Modeling 880 0 0 880 

Resource Assess & Character 750 0 0 750 

ES&H/Lifecycle Research 0 0 470 470 
 

____________________________________________________________________________________ 

____________________________________________________________________________________ 

 

 

Solar Radiometry & Metrology 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Daryl Myers (NREL), 303-384-6768, daryl.myers@nrel.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budget: $880K (NREL) 

Objectives 

•	 Support Measurements and Characterization ISO 17025 accreditation scope 

•	 Provide ISO 17025 compliant broadband and spectral radiometric calibrations traceable to 

international and national reference standards 

•	 Participate in consensus standards by American Society for Testing and Materials (ASTM) and 

International Lighting Commission and CIE standards development on solar system testing 

•	 Reduce uncertainties in solar radiometric data and solar radiation models 

•	 Transfer technology to the solar industry related to optical and solar measurements and data. 

Accomplishments 

•	 Verified NREL reference standard stability relative to World Radiometric Reference (WRR) at 

10/08 NREL Pyrheliometer Comparison (NPC): NREL, Sandia, and 21 other participants 

•	 Performed 32 spectral and 280 broadband solar broadband radiometer calibrations for NREL and 

solar industry partners 

•	 Classified 3 industrial partner and 3 NREL flash solar simulators with respect to ASTM E927 

•	 Transferred NREL Pulse Analysis Spectroradiometer System (PASS) technology to Newport 

Corp. through Technical Partnership Agreement TSA-08-202 

•	 Published NREL technical report, ASES paper on relative performance of radiometric
 

instrumentation for 15 models of solar radiometer (see publications)
 

•	 Published spectral model to convert hourly (TMY2) broadband solar data to hourly spectral 

distributions for all sky conditions. Need for further modifications identified. (see publications) 

•	 Responded to 301 requests for technical information from industry, university, and DOE inquiries. 

•	 Author or co-author on 1 journal article, 1 report, and 5 conference papers (see publications). 

Future Directions 

•	 Prepare for International Pyrheliometer Comparison, 10/10, Davos Switzerland 

•	 Improve broadband to spectral conversion model (extend wavelength range; improve accuracy) 

•	 Deploy and analyze instrument systems for high spatial, (~0.5 km) temporal ( less than 5 s) 

resolution data collection for PV grid integration applications 

•	 Expand scope of ISO 17025 accreditation to include broadband/spectral radiometer calibrations. 

1. Introduction	 irradiance scale for Photovoltaic (PV) 

Measurements and Characterization task ISO 

Accurate solar radiometric measurements and 17025 accreditation. We conduct measurement 

models reduce uncertainties associated with solar and modeling research that provides expertise and 

energy conversion systems, ultimately influencing quantifies bankable data for project proposals 

the levelized cost of energy (LCOE). Accurate results for industry. 

solar data are needed for solar research and 

bankable industry resource data. We provide 2. Technical Approach 

traceable transfer chain from the World 

Meteorological Organization World Radiometric We conduct measurement research and publish 

Reference (WMO/WRR) and the National Institute results and respond to technical assistance 

of Standards and Technology (NIST) spectral requests. We maintain NREL optical radiation 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

reference standards and conduct research to 

identify and quantify bankable data for solar 

projects. We serve with consensus standards 

groups to develop useful industry standards. See 

www.nrel.gov/solar_radiation.

3. Results and Accomplishments 

D R A F T

Established uncertainty limits for PVUSA test 

condition (PTC) rating methodology for several PV 

technologies. See Table 1 and publications. 

Table 1. Limits of uncertainty NREL 1.6-kWp dual 

junction system using PTC approach. 

Modified SEDES2 spectral model to convert hourly 

broadband data into spectral distributions. Figure 

1 is example of cloudy day measured and 

modeled spectra. 

Fig 1. Measured and modeled cloudy sky spectra 

4. Planned FY 2010 Activities 

•	 Deploy and analyze high time resolution (<5 s 

samples) and high spatial (~0.5 km) resolution 

radiometric sensors for PV grid integration 

support 

•	 Extend wavelength range, improve accuracy 

spectral conversion model 

•	 Extend ISO 17025 accreditation to spectral 

calibrations. 

5. Major FY 2009 Publications 

C.A. Gueymard and D.R. Myers, “Evaluation of 

Conventional and High-Performance Routine 

Solar Radiation Measurements for Improved 

Solar Resource, Climatological Trends, and 

Radiative Modeling,” Solar Energy 83(2), 171-

185 (2009). 

D. Myers, “Comparison of Historical Satellite 

Based Estimates of Solar Radiation Resources 

with Recent Rotating Shadowland Radiometer 

Measurements,” R. Campbell-Howe, ed., Proc. 

Solar 2009 Conf., 11-16 May 2009, Buffalo, NY. 

NREL CP-550-46806 (2009). 

D. Myers, “Evaluation of the Performance of the 

PVUSA Rating Methodology Applied to Triple 

Junction PV Technology,” R. Campbell-Howe, 

ed., Proc. Solar 2009 Conf., 11-16 May 2009, 

Buffalo, NY. NREL CP-550-46799 (2009). 

D.R. Myers, “Terrestrial Solar Spectral 

Distributions Derived from Broadband Hourly 

Solar Radiation Data.” Paper No. 74100A. Tsai, 

B.K. ed., Optical Modeling and Measurements 

for Solar Energy Systems III: Proceedings of 

SPIE Conference, 2-4 August 2009, San Diego, 

CA. NREL CP-550-46254 (2009). 

Myers, D.; Wilcox, S. M. “Relative Accuracy of 1-

Minute and Daily Total Solar Radiation Data for 

12 Global and 4 Direct Beam Solar 

Radiometers.” R. Campbell-Howe, ed., Proc. 

Solar 2009 Conf., 11-16 May 2009, Buffalo, NY. 

NREL CP-550-46803 (2009). 

S.	 Wilcox and D. Myers, “Joint Solar Power 

Industry and Department of Energy Solar 

Resource and Meteorological Assessment 

Project (SOLRMAP).” Paper No. 741006, Tsai, 

B.K., ed., Optical Modeling and Measurements 

for Solar Energy Systems III: Proceedings of 

SPIE Conference, 2-4 August 2009, San Diego, 

CA. NREL CP-550-46537 (2009). 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal 

Investigator 

Location/E-mail Description/Title of Research 

Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Z. Li Stratford, CT 

yun.li@newport.com 

PASS for flash solar simulator 

tests TSA-08-202 

$15.8 

NREL Labor 

$35 Newport 

Equipment 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

Solar Resource Characterization 

D R A F T

Performing Organization: National Renewable Energy Laboratory (NREL) 

Key Technical Contact: Dave Renné (NREL), 303-384-7408, david.renne@nrel.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@hq.doe.gov 

FY 2009 Budget: $750K (NREL) 

Objectives 

•	 Develop reliable and accurate methods for estimating solar resources over large areas with high 

temporal and spatial resolution 

•	 Continue providing updates to the National Solar Radiation Database (NSRDB) and typical 

meteorological year version 3 (TMY3) data sets 

•	 Evaluate the impacts of cloud characteristics on resource and grid-integrated system variability 

•	 Evaluate short-term solar resource forecasting methods 

•	 Provide technical and Operating Agent (OA) support to IEA/SHC Task 36 Solar Resource 

Knowledge Management.
 

Accomplishments 

•	 Developed further in-house capability of modeling solar resources using satellite imagery 

•	 Undertook a roadmapping exercise to identify research priorities over the next 5 years in 

modeling, forecasting, measurement capabilities, and photovoltaic (PV) variability analysis 

•	 Analyzed data sets to evaluate ramp rates and other characteristics of grid-tied PV outputs 

•	 Developed field campaign designs to further evaluate resource variability under various climatic 

and cloud cover conditions 

•	 Through IEA/SHC Task 36 continued work in evaluating various methods for determining 1–3-day 

ahead solar resource forecasting 

•	 Gave presentations on PV variability analysis and IEA/SHC Task 36 outcomes at various
 

conferences and workshops
 

•	 Made a strategic new hire (Manajit Sengupta) to lead our in-house capabilities in resource 

modeling, forecasting, and benchmarking. 

Future Directions 

•	 Develop various empirical and physically based satellite modeling and solar resource forecasting 

capabilities (in combination with CSP) 

•	 Undertake 2-3 field measurement campaigns to gather critical data on resource variability at time 

scales of 15 minutes or less, for PV grid integration studies 

•	 Provide effective information dissemination and public outreach mechanisms 

•	 Continue to provide technical and OA support to IEA/SHC Task 36 and future tasks 

•	 Produce periodic updates to the NSRDB (in combination with CSP). 

1. Introduction	 validating short-term solar forecasts in formats 

suitable for large-scale utility operations of solar 

This project focuses on developing and systems, and updating and disseminating the 

disseminating more reliable and accurate National Solar Radiation Data Base. 

measurements and estimates of the solar 

resource, including high temporal and spatial 2. Technical Approach 

resolution data sets for evaluating the 

performance of a significant amount of PV To accomplish these goals, we undertook four 

systems interconnected to a grid distribution or technical tasks (some of this work was costtransmission system. The scope includes the 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

shared through funds from the CSP Market 

Transformation efforts): 

Solar Resource Model Development and 

Application: Using geostationary satellite imagery, 

we are developing an empirical model to produce 

high spatial (5–10 km) and temporal (15–30 min) 

data sets for the North American region. 

D R A F T

Test and Evaluate Solar Resource Forecasting 

Methodologies: Adopting procedures deployed by 

European researchers in IEA/SHC Task 36, we 

examine the suitability of various 1–3 day ahead 

and 0–6 hour ahead solar forecasting capabilities 

based on National Weather Service (NWS) 

forecast products, numerical mesoscale weather 

models, and satellite-derived cloud vector motion 

analysis. 

Conduct PV Variability Assessments: Using 

existing high-resolution solar resource data as well 

as PV output data from developers from actual 

projects, we examine PV ramp rates and other 

resource characteristics that result from cloud 

passages and other short-term weather 

phenomena. 

Stakeholder Support: There are increasing 

demands for public dissemination of high quality 

resource data and data products. This task 

provides web-based and personalized technical 

assistance to our stakeholders to ensure that the 

most appropriate data products are used for 

specific applications. 

3. Results and Accomplishments 

In the solar resource modeling task, through our 

consultant Bernard Walter Consulting, we 

established procedures to access geostationary 

satellite data (both visible and IR channels), and 

are finalizing a procedure for converting this 

imagery into high resolution solar resource 

estimates, both GHI and DNI. The empirical 

modeling approach is nearing completion and will 

be tested in FY 2010. We are also developing a 

more physically based satellite model, to be used 

for research and benchmarking, collaborating with 

NOAA, University of Wisconsin, and Colorado 

State University (CSU). In FY 2009 we focused on 

developing a scope of effort and establishing 

partnerships with the key researchers involved in 

NOAA’s Geostationary Satellite Installation Project 

(GSIP). A prototype of the GSIP algorithm is 

currently being run at CSU, and we expect to team 

with our university partners to produce high 

temporal and spatial resolution GHI datasets in 

2010. 

We obtained a number of data sets from project 

developers operating grid-tied PV systems, and 

are analyzing these data to develop statistical 

relationships on PV ramp rates and other resource 

variability characteristics. These results are used 

to devise models to create PV data on subhourly 

time steps, for use in high-penetration PV grid 

integration evaluations. These studies are also 

being used to design field campaigns, to be 

undertaken in FY 2010, on gathering key data sets 

to evaluate and model the impacts of partly cloudy 

conditions and cloud passages across large scale 

and distributed grid-tied PV arrays. 

Through IEA/SHC Task 36 we are gaining critical 

information and data on solar resource forecasting 

techniques being examined in several regions 

around Europe. NASA/LaRC in this country 

previously evaluated some of these techniques, 

and this work will continue under support from the 

SETP later in FY 2009 and in FY2010. Although 

mesoscale model input improves the result of 

solar resource forecasts using NWS forecast 

products, considerable work needs to be done to 

obtain sufficient reliability of these forecasts for 

utility-scale operations. 

4. Planned FY 2010 Activities 

Work in all four task areas will continue in FY 

2010, in some cases with continued support from 

the CSP subprogram. The PV and CSP tasks will 

be consolidated into a single agreement under the 

Systems Integration subprogram in 2010. Specific 

work will include: 

•	 Finalize and benchmark an empirically-based 

satellite-derived solar modeling capability 

•	 Begin work on a physically based satellitederived modeling capability, in cooperation 

with NOAA and universities 

•	 Carry out two or three field campaigns to 

gather high temporal resolution solar and PV 

output data for determining PV variability 

characteristics based on various weather and 

climatic conditions 

•	 Update the NSRDB (through 2007 for hourly 

data and through 2009 for monthly data) 

•	 Further benchmark and identify research 

priorities of solar resource forecasting 

schemes 

•	 Give ongoing technical assistance to data 

users through web-based data dissemination, 
 

 

 

D R A F T

publications, and participation in workshops 5. Major FY 2009 Publications 

and lab visits. 

D. Renné, IEA/SHC Task 36: Solar Resource 

Knowledge Management: Annual Report to the 

IEA Solar Heating and Cooling Program, 

IEA/SHC. 

6. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

FY 2009 

($K) 

Cost Share 

($K) 

Bernard Walter 

Consulting 

Seattle, WA 

bwalter@cablespeed.com 

Develop empirical satellitederived high spatial and 

temporal resolution satellitederived solar resource model 

100 50* 

State University of 

New York/Albany: R. 

Perez 

Albany, NY 

perez@asrc.cestm.albany.edu 

Analyze cloud motion vectors 

for 0-6 hour ahead solar 

forecasting 

60 0 

State University of 

New York/Albany: R. 

Perez 

Albany, NY 

perez@asrc.cestm.albany.edu 

Test and evaluate various 1–3 

day ahead solar forecasting 

methodologies 

50*** 25** 

University of Oregon: 

F. Vignola 

Eugene, OR 

Ned.Money@idea.com 

Provide data collection and 

analysis of legacy Pacific 

Northwest solar network 

50**** 0 

* Partial funding from Western Wind and Solar Integration Study.
 

** Partial funding from CSP Market Transformation Program.
 

*** To be awarded in FY 2010.
 

**** Carryover from FY 2008.
 
 

 

 

____________________________________________________________________________________ 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

Environmental Health & Safety/Lifecycle Research 

D R A F T

Performing Organization: Brookhaven National Laboratory (BNL) 

Key Technical Contact: Vasilis Fthenakis, 631-344-2830, vmf@bnl.gov 

DOE HQ Technology Manager: Kevin Lynn, 202-586-1044, kevin.lynn@ee.doe.gov 

FY 2009 Budget: $470K 

Objectives 

•	 Assist in preserving the safe and environmentally friendly nature of photovoltaics and in 

minimizing environmental health and safety (EH&S) risks and associated costs, to ensure the 

public support and economic viability of photovoltaic (PV) systems 

•	 Identify potential EH&S barriers of PV materials, processes, or applications and define strategies 

to overcome such barriers 

•	 Maintain the EH&S Research Center as the world’s best source on PV EH&S, providing accurate 

information related to EH&S issues and perceptions. 

Accomplishments 

•	 Published leading articles and gave keynote addresses on PV sustainability 

•	 Promoted international collaborations on life-cyle assessment (LCA) of PV energy technologies 

•	 Hosted a PV Industry Recycling Scoping workshop and led an International Energy Agency (IEA) 

PVPS task 

•	 Assisted several companies on site-specific EH&S issues 

•	 Answered several requests for EH&S information from the public and the industry. 

Future Directions 

•	 Perform comparative LCA of additional solar technologies to guide toward safe and 

environmentally friendly alternatives
 

•	 Research recycling separations and cost optimization. 

1. Introduction 

The activities of the Environmental, Health and 

Safety Research Center focus on minimizing 

potential EH&S impacts associated with current 

and future PV energy systems and applications. 

This objective is accomplished by proactive 

research, rigorous industry outreach, and technical 

communications. 

The overall goal is to preserve the safe and 

environmentally friendly nature of PV and 

minimize EH&S risks and associated costs, to 

ensure the public support and economic viability of 

PV systems. Also, the Center serves as the 

world’s best source on PV EH&S, providing 

accurate information related to EH&S issues and 

perceptions. This activity supports the overall 

communications and outreach objectives of the 

Solar Energy Technologies Program. 

2. Technical Approach 

The major areas of BNL's activities are hazard 

identification and characterization, hazard 

management, industry outreach, and information 

dissemination. Ongoing efforts are required 

because the PV industry is undergoing changes in 

type and quantities of materials, in manufacturing 

processes, and in scale, and because continuous 

vigilance is required in safety and loss prevention. 

Task Title FY 2009 

Budget ($K) 

1. Hazard 

Identification/Characterization 220 

2. Hazard Management/Recycling 60 

3. Industry Outreach/DOE/NCPV 

Information Dissemination 120 

4. IEA Task 12 70 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3. Results and Accomplishments 

Task 1: Conducted leading research on PV 

sustainability metrics, resources of minor metals, 

land use, and economic-environmental feasibility 

of large-scale PV penetration. 

D R A F T

Task 2: Organized and conducted a Recycling 

Industry Scoping workshop, IEEE PVSC, June 

2009. 

Started recycling cost optimization studies. 

Conducted studies on the environmental impacts 

of large-scale PV deployment. 

Task 3: Provided facility-specific assistance to PV 

manufacturing companies, and advised PV 

companies, universities, public utilities, and 

concerned citizens on EH&S issues. 

Task 4: -Answered several requests for EH&S 

information from different agencies, business 

partners, citizen organizations, and the media. Led 

the IEA Task 12, a collaborative effort by 

specialists from 10 countries, creating a unified 

expert front on PV EH&S, LCA, and recycling. 

Published and presented extensively (8 journal 

papers, 11 presentations [4 keynote]). 

4. Planned FY 2010 Activities 

Task 1: This task is part of BNL’s proactive 

research to overcome EH&S barriers to support 

for large-scale implementation of PV. Activities 

planned for FY 2010 include: 

•	 LCA of additional PV technologies (e.g., CIGS, 

HCPV) 

•	 end-of life in LCA 

•	 harmonization of LCA results 

•	 Solar vision siting and environmental tasks. 

Task 2: These activities are pivotal in preserving 

the safe and environmentally friendly nature of the 

PV industry as it moves toward large-scale 

manufacturing. In FY 2010, research at BNL will 

focus on: 

•	 Improving technical and economic feasibility 

•	 Collaborating with PVCycle. 

Task 3: In FY 2010, BNL will: 

•	 Serve as the lead organizer and US 

representative to IEA PV EH&S Task 12 

•	 Guide the industry and R&D labs on accident 

prevention and pollution prevention 

•	 Support DOE and NCPV as needed. 

Task 4: The results of BNL’s research will be 

disseminated with new publications, e-mail and 

the web. The PV EH&S Research Center serves 

as a clearinghouse for EH&S information 

requested by potential customers, business 

partners, citizen organizations, and the media. 

5. Major FY 2009 Publications 

J.K.	 Choi and V.M. Fthenakis, “Economic 

Feasibility of Photovoltaic Module Recycling: 

Survey and Model,” Journal of Industrial 

Ecology, in press. 

V.M.	 Fthenakis, “Sustainability of Photovoltaics: 

The Case for Thin-Film Solar Cells,” Renewable 

and Sustainable Energy Reviews 13, 2746 

(2009). 

V.M.	 Fthenakis, and H.C. Kim, “Land Use and 

Electricity Generation: A Life Cycle Analysis,” 

Renewable and Sustainable Energy Reviews 13, 

1465 (2009). 

V.M.	 Fthenakis and H.C. Kim, “Prospective Life 

Cycle Assessment of Nanotechnology: Multijunction a-Si Photovoltaics,” Progress in 

Photovoltaics Research and Applications, in 

press. 

V. Fthenakis,	 J. Mason, and K. Zweibel, “The 

Technical, Geographical and Economic 

Feasibility for Solar Energy to Supply the Energy 

Needs of the United States,” Energy Policy 37, 

387 (2009). 

V.M.	 Fthenakis, W. Wang, and H.C. Kim, “Life 

Cycle Inventory Analysis in the Production of 

Metals used in Photovoltaics,” Renewable and 

Sustainable Energy Reviews 13, 493 (2009). 

V.	 Fthenakis, H. Kim, S. Gualtero, and A. 

Bourtsalas, “Nanomaterials in PV Manufacture: 

Some Life Cycle Environmental and Health 

Considerations,” Proc. 34th IEEE PV Specialists 

Conf., Philadelphia, June 2009. 

V. Fthenakis, M. Raugei, M. Held, H.C. Kim, and 

J. Krones, “An Update of Energy Payback Times 

and Greenhouse Gas emissions in the Life Cycle 

of Photovoltaics,” Proc. 24th European 

Photovoltaic Solar Energy Conf., Hamburg, 

Germany, September 21–25, 2009. 

6. University and Industry Partners 

Several, through EPIA and IEA Task 12, at no cost 

to our project. 
 

 

 

 

 

D R A F T

Market Transformation Highlights 

Fiscal year 2009 saw a continued development of the Market Transformation portfolio, now in its 

third year of expanded effort. 

Market Transformation activities seek to reduce the barriers to solar implementation and 

complement the program’s R&D portfolio by focusing on the non-hardware costs associated with 

installation. Combined with technology improvements, Market Transformation aims to support the 

delivery of cost-competitive solar electricity by 2015. 

Market Transformation activities target a wide range of decision-makers who affect the 

deployment of solar energy technologies. These include states, local governments, utilities, the 

educational community, codes and standards bodies, and the solar industry. 

Key activities in FY 2009 included supporting 25 Solar America City partnerships, the Solar 

America Board for Codes and Standards (Solar ABCs), the Solar Electric Power Association 

(SEPA), and multiple state outreach organizations. Technical assistance efforts across the 

portfolio were led by the National Renewable Energy Laboratory (NREL) and Sandia National 

Laboratories (SNL). 

In FY 2009, Market Transformation comprised the following areas: 

• Codes & Standards 

• Workforce Development 

• Technical Assistance 

• Technical Outreach 

• Operations and Planning 

NREL SNL Other Solar 

FY09 Budget Total $K Total $K Total $K Total $K 

Market Transformation 3627 1506 7616 12716 

Codes & Standards 200 100 905 1205 

Workforce Development 0 0 565 565 

Technical Assistance 2050 1140 2126 5316 

Technical Outreach 175 0 1250 1425 

Operations & Planning 1202 266 2098 3533 
 

 

 

 

 

D R A F T

Codes & Standards Summary 

The purpose of the Codes & Standards project is to improve the responsiveness, 

effectiveness, and accessibility of solar codes and standards to U.S. stakeholders at all 

levels. Current codes and standards that affect the domestic deployment of solar 

photovoltaic (PV) technologies include the National Electrical Code, Underwriters 

Laboratories (UL) product safety standards, the Institute of Electrical and Electronics 

Engineers (IEEE) standards for grid interconnection, and many others. The U.S. 

Department of Energy (DOE) supports solar codes and standards efforts to ensure the 

continued safe and rapid growth of the domestic solar market. 

NREL SNL Other Solar 

FY09 Budget Total $K Total $K Total $K Total $K 

Codes & Standards 200 100 905 1205 

Solar America Board for Codes 

& Standards 0 0 905 905 

Codes Laboratory Support 200 100 0 300 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Solar America Board for Codes & Standards 

Performing Organizations: New Mexico State University (NMSU) 

D R A F T

Research Foundation of the State University of New York at Albany
 

(SUNY)
 

Tucson Electric Power (TEP)
 

Key Technical Contact: Holly Thomas (DOE/GO), 303-275-4818, holly.thomas@go.doe.gov 

DOE HQ Technology Manager: Charlie Hemmeline, 202-586-6646, charlie.hemmeline@hq.doe.gov 

FY 2009 Budget: $780K (NMSU) 

Objectives 

•	 Establish consistent support for codes and standards development to enable solar technology 

deployment on a large scale (NMSU) 

•	 Improve the responsiveness, effectiveness, and accessibility of codes and standards in all 

markets, including federal, state, local, and utility (NMSU) 

•	 Establish utility photovoltaic (PV)-capacity credits models to reduce market barriers and promote 

solar energy technology acceptance (NMSU) 

•	 Develop a central repository for collecting and disseminating documents, regulations, and 

technical materials related to solar codes and standards (NMSU) 

•	 Describe and experimentally compare methods quantifying the effective capacity credit of 

nondispatchable resources such as PV and build consensus for proposed methods (SUNY) 

•	 Develop, test, and verify methods to accurately evaluate the capacity credit of time-variant PV 

generation and develop utility-based methods to evaluate the value of solar generation to electric 

utilities (TEP). 

Accomplishments 

•	 Published two codes and standards study reports; conducted outreach to targeted audiences on 

these and previous study reports (NMSU) 

•	 Convened three stakeholder meetings to provide input on codes and standard issues; distributed 

four newsletters on Solar America Board for Codes & Standards (ABCs) activities and other 

related codes and standards activities (NMSU) 

•	 Began work on new tasks identified during previous year’s gap analysis (NMSU) 

•	 Adopted Solar ABCs policy on module nameplate tolerances (NMSU) 

•	 Conducted fire safety research on rating of PV modules mounted on different roofing materials 

(NMSU) 

•	 Participated in developing international and national standards through International
 

Electrotechnical Commission (IEC) Technical Committee 82 and other standard-making 

organizations (NMSU)
 

•	 Modeled two methods to quantify the capacity credit of dispersed PV: (1) the effective load 

carrying capability (ELCC), based on the concept of loss of load probability, and (2) the solar load 

control capacity (SLC), based on load control with a small amount of demand response or 

storage to firm PV capacity (SUNY) 

•	 Published a report, Utility Solar Generation Valuation Methods (TEP). 

Future Directions 

•	 Publish six additional codes and standards study reports and two white papers. Continue 

outreach to targeted audiences on report recommendations (NMSU) 

•	 Facilitate stakeholder involvement and communication on codes and standards issues through 

stakeholder meetings, electronic newsletters, and the Solar ABCs Web site (NMSU) 
 

 

 

•	 Participate in developing international and national standards through IEC Technical Committee 

82 and other standard-making organizations (NMSU) 

•	 Adopt Solar ABCs policy on recommended standards for PV modules and systems (NMSU) 

•	 Identify major gaps in the current work on codes and standards and prioritize them for a strategic 

plan for future work (NMSU). 

D R A F T
 

 

 

 

 

D R A F T

Workforce Development Summary 

The purpose of the Workforce Development project is to ensure the rapid scale-up of a 

well-trained domestic solar workforce that can deliver safe, high-quality solar 

installations nationwide. The downstream workforce includes solar installers and sales 

professionals, local code officials, and inspectors who oversee installations. Increasing 

the availability of well-qualified installers and local training opportunities will support 

continued installation cost reduction as well as prevent worker shortages from inhibiting 

the growth of the domestic solar market. Funding in Fiscal Year 2009 supported the 

North American Board of Certified Energy Practitioners (NABCEP) for the certification of 

solar personnel and the Interstate Renewable Energy Council (IREC) for solar training 

and accreditation of instructors. 

NREL SNL Other Solar 

FY09 Budget Total $K Total $K Total $K Total $K 

Workforce Development 0 0 565 565 

PV Certification 0 0 265 265 

Training and Accreditation 0 0 300 300 
 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

___________________________________________________________________________________ 

 

 

Photovoltaic Installer Certification 

D R A F T

Performing Organization: North American Board of Certified Energy Practitioners (NABCEP) 

Key Technical Contacts: Yana Rasulova (DOE/GO, Primary Contact), 303-275-4890, 

yana.rasulova@go.doe.gov 

Carolyn Elam (DOE/GO), 303-275-4953, carolyn.elam@go.doe.gov 

Kathleen Bolcar (DOE HQ), 202-586-6646, kathleen.bolcar@ee.doe.gov 

DOE HQ Technology Manager: Charlie Hemmeline, 202-586-6646, Charlie.hemmeline@hq.doe.gov 

FY 2009 Budget: $875K (NABCEP) 

Accomplishments 

•	 Increased the number of individuals who achieve the NABCEP Certifications and pass the 

photovoltaics (PV) entry level exam: 

o	 325 individuals received NABCEP’s Solar PV Installer Certification in 2009, a 98% increase 

from 2008; 14 administrators of the exam and 912 candidates have received the NABCEP 

Solar PV Installer certification 

o	 3,510 individuals obtained NABCEP’s PV Entry Level Certificate of Knowledge of Solar PV 

Systems in 2009. NABCEP has issued 4,812 Entry Level Certificates of Knowledge since 

the certificate’s inception in 2005 

o	 26 individuals received the Solar Thermal Installer Certification in 2009; 111 individuals have 

obtained NABCEP’s Solar Thermal Installer Certification. 

•	 NABCEP submitted its second Annual Surveillance Report to the American National Standards 

Institute (ANSI) to demonstrate NABCEP’s ongoing compliance with its ISO/IEC 17024 

accreditation. 

Future Directions 

•	 Conduct an aggressive marketing and outreach campaign to ensure significant increases in the 

number of individuals pursuing NABCEP certification 

•	 Increase awareness within the business community, state and federal agencies, and consumer 

base about the benefits of NABCEP certification 

•	 Develop and announce a new family of certification programs that address the rapidly changing 

needs and roles in the renewable energy market. 

1. Introduction 

Since 2003, NABCEP has been awarding 

professional credentials and certificates to 

renewable energy practitioners. NABCEP’s 

rigorous competency standards send a clear 

message to consumers, business leaders, and 

public officials that the industry stresses highquality, safe, and ethical business practices and 

workmanship standards. NABCEP has the 

following Certification and Certificate Programs: 

•	 Solar PV Installers 

•	 Solar Thermal Installers 

•	 Recertification programs for its certified Solar 

PV and Solar Thermal Installers 

•	 Entry Level Certificate of Knowledge for Solar 

PV Systems 

2. Technical Approach 

NABCEP’s primary objectives are to develop and 

implement quality credentialing and certification 

programs for renewable energy practitioners. 

Competency standards, such as those established 

by NABCEP, play a critical role in developing the 

renewable energy workforce and will help prevent 

disruptions in the rapid growth trajectory of the 

renewable energy market. NABCEP recognizes 

that renewable energy professionals receive their 

training and work experiences in a variety of ways 
 

 

 

 

 

 

 

 

 

 

and has developed a series of eligibility categories 

to reflect these varied backgrounds. Both the PV 

and solar thermal credentialing programs are 

based on strict credentialing guidelines. 

3. Results and Accomplishments 

D R A F T

•	 325 individuals received NABCEP’s Solar PV 

Certification in 2009 

•	 3,510 individuals obtained NABCEP’s PV 

Entry Level Certificate of Knowledge of Solar 

PV Systems in 2009 

•	 26 candidates were awarded the Solar 

Thermal Installer Certification in 2009 

•	 111 individuals have obtained NABCEP’s 

Solar Thermal Installer Certification 

•	 NABCEP submitted its second Annual 

Surveillance Report to ANSI to demonstrate 

NABCEP’s ongoing compliance with its 

ISO/IEC 17024 accreditation 

•	 NABCEP’s new Web site was launched 

(03/09) 

•	 During fiscal year (FY) 2009, NABCEP 

exhibited or presented, or both, at numerous 

conferences, including the following: 

o	 NESEA 2009 

o	 ASES 2009 

o	 PV America 2009 

o	 Solar Power International 2009 

o	 The Renewable Energy and Energy 

Efficiency Workforce Education 

Conference 

o	 The Midwest Renewable Energy Fair 

o	 The IEC National Convention & Electric 

Expo 

o	 The MREA Solar Thermal Conference. 

4. Planned FY 2010 Activities 

The first exam of NABCEP’s Small Wind Installer 

Certification is scheduled for September 11, 2010 

and a new PV Technical Sales Certification will 

also be available in the fall of 2010. NABCEP will 

continue to conduct marketing and outreach to 

ensure significant increases in the number of 

individuals pursuing NABCEP certification; work to 

increase awareness within the business 

community, state and federal agencies, and 

consumers about the benefits of NABCEP 

certification; and develop a new family of 

certification programs for the rapidly changing 

needs and roles in the renewable energy market. 

5. FY 2009 Special Recognitions 

•	 ANSI/ISO/IEC 17024 Accreditation 

6. Major FY 2009 Publications 

•	 Bi-monthly NABCEP Newsletters 

7. University and Industry Partners 

NABCEP works closely with representatives from 

numerous companies and organizations, including 

but not limited to the following: 

•	 The National Renewable Energy Laboratory 

•	 The National Electrical Contractors 

Association 

•	 The International Brotherhood of Electrical 

Workers 

•	 The Independent Electrical Contractors 

•	 BP Solar 

•	 Sandia National Laboratories 

•	 The National Joint Apprenticeship & Training 

Committee 

•	 The Small Wind Certification Council 

•	 SunPower Corporation 

•	 The North Carolina Solar Center 

•	 The Florida Solar Energy Center 

•	 The Solar Energy Industries Association 

•	 The Solar Electric Power Association 

•	 The American Wind Energy Association 

•	 The Midwest Renewable Energy Association 

•	 Lane Community College 

•	 Austin Community College 

•	 Hudson Valley Community College 

•	 SUNY Ulster 

•	 Solar Energy International 

•	 Home Power magazine 

•	 The New York State Energy Research and 

Development Authority. 
 

 

 

 

 

 

________________________________________________________________________________ 

 

 

 

 

 

 

 

 

________________________________________________________________________________ 

 

 

 

Solar Outreach & Communications 

D R A F T

Performing Organization: Interstate Renewable Energy Council (IREC) 

Key Technical Contacts: Yana Rasulova, (DOE/GO, Primary Contact), 303-275-4890, 

yana.rasulova@go.doe.gov 

Kathleen Bolcar (DOE HQ), 202-586-2820, kathleen.bolcar@ee.doe.gov 

DOE HQ Technology Manager: Charles Hemmeline, 202-586-6646, charlie.hemmeline@hq.doe.gov 

Total FY 2009 Funding: $975K 

Objectives 

•	 Offer models and assistance on net metering/interconnection to lower both barriers and cost for 

installing solar electricity through the Connecting to the Grid Project 

•	 Monitor and participate as appropriate in public hearings/meetings and supply input that could 

affect solar barriers or commercialization through public hearings on solar codes and standards 

•	 Encourage and coordinate quality training workshops and other learning opportunities, as well as 

assist educational providers through the Workforce Training and Quality Assessment Project 

•	 Connect experts with market transformation stakeholders on key issues in a cost-effective and 

convenient format 

•	 Manage and maintain Web site that offers easily accessible news, information, tools, best
 

practices, and materials
 

•	 Prepare annual reports on solar market trends and impacts regarding interconnection and net 

metering, training and certification programs, state incentives, and other relevant issues. 

Accomplishments 

•	 Continued educating and supporting information about net metering - in 16 states 

•	 Continued educating and supporting information about interconnection in 13 states 

•	 Launched University On-Line Directory of 4-year universities that are offering undergraduate and 

graduate courses in renewable energy and energy efficiency 

•	 Held 10 workshops for code officials (both photovoltaic [PV] and solar thermal) 

•	 Held five phone/webinar seminars on key topics such as the NEC, tax credits, and market trends 

•	 Published and posted on the IREC website 26 issues of the IREC/SETP e-newsletter for more 

than 4,100 subscribers and 12 issues of the Interconnection/Net Metering e-newsletter for more 

than 4,200 subscribers 

•	 Published Annual Solar Market Trends Report and 6th edition of Connecting to the Grid Guide. 

Future Directions 

•	 Coordinate workforce training and quality assessment workshops with states, cities, and 

stakeholders
 

•	 Continue to publish newsletters and hold telephone seminars 

•	 Develop Solar Codes and Standards Hearing Project to address infrastructure barriers with states 

•	 Maintain the IREC website. 

1. Introduction	 coordinates with industry, DOE, national 

laboratories, states, cities, and counties. 

IREC promotes increased stakeholder 

communications and education under the Solar 2. Technical Approach 

Market Transformation activities; addresses 

infrastructure barriers to solar energy; and IREC continues to promote better 

communications among stakeholders, address 
 

 

 

 

 

 

 

 

 

 

 

infrastructure barriers by promoting easy and fair 

hook-up rules to the utility grid, promote quality 

training based on industry competency 

standards, and coordinate with multiple federal, 

state, and local stakeholders. 

Workforce development and quality training are 

critical components, and IREC works with 

community colleges, the North American Board 

of Certified Energy Practitioners, the Institute for 

Sustainable Power, and subject matter experts. 

D R A F T

3. Results and Accomplishments 

•	 Participated in net metering and 

interconnection regulatory proceedings, 

rulemakings, and workshops in 20 states 

•	 Organized five informative, interactive phone 

seminars 

•	 Convened 10 workshops for code officials 

•	 Convened four Introductory Workshops on 

Training and four Faculty Development 

Workshops 

•	 Continued educating and supporting 

information about net metering in 16 states 

•	 Continued educating and supporting 

information about interconnection in 13 

states 

•	 Launched University On-Line Directory of 4-

year universities offering undergraduate and 

graduate courses in renewable energy and 

energy efficiency 

•	 Expanded On-Line Directory of Renewable 

Energy Training Providers 

•	 Held four 2-day faculty development 

workshops 

•	 Held four introductory workshops on 

developing quality training programs set to 

industry standards 

•	 Held 10 workshops for code officials (both 

PV and solar thermal) 

•	 Held five phone/webinar seminars on key 

topics such as the NEC, tax credits, market 

trends 

•	 Published 26 issues of the IREC/SAI enewsletter for more than 4,100 subscribers 

and posted on the IREC website 

•	 Published 12 issues of the 

Interconnection/Net Metering e-newsletter 

for more than 4,200 subscribers 

•	 Updated Job Trends Report 

•	 Published Annual Solar Market Trends 

Report 

•	 Published the 6th edition of the Connecting 

to the Grid Guide 

•	 Published updated Net Metering and 

Interconnection Model Rules and 

Procedures 

•	 Published 2009 Update & Trends Report. 

4. Planned FY 2010 Activities 

•	 Promote quality standards for training 

•	 Conduct six phone seminars on current and 

“hot” topics 

•	 Hold six PV Workshops for Code Officials 

•	 Hold four Solar Thermal Workshops for 

Code Officials 

•	 Hold one or two Faculty Development 

Workshops 

•	 Publish 12 Interconnection/Net Metering 

newsletters and 26 State/Stakeholder 

newsletters 

•	 Monitor and engage in emerging trends in 

net metering, interconnection, and related 

issues such as SSAs, Community Solar, and 

Smart Grid 

•	 Update Best Practices in Training. 

5.	 Major FY 2009 Publications 

•	 Annual Updates & Trends Report 

•	 6th edition of Connecting to the Grid 

•	 Updated Net Metering and Interconnection 

Model Rules and Procedures. 

•	 Annual Solar Market Trends Report 

6. University and Industry Partners 

IREC works closely with many groups, industry, and community colleges, which include the following: 

•	 North Carolina Solar Center at North Carolina State University 

•	 The Southwest Technology Development Institute at New Mexico State University 

•	 New York State Energy Research and Development Authority 

•	 North American Board of Certified Energy Practitioners 

•	 Institute for Sustainable Power 

•	 Hudson Valley Community College, Lane Community College, and other community colleges 

•	 Industry and stakeholder groups. 
 

 

 

 

 

 

D R A F T

Technical Assistance Summary 

The purpose of the Technical Assistance project is to provide high quality technical 

support to key stakeholders in their efforts to procure and install solar technologies, and 

design programs to promote accelerated market development. The U.S. Department of 

Energy’s (DOE’s)funded technical assistance can often be a critical driver of action and 

is an important tool to meet Market Transformation objectives. In Fiscal Year 2009, DOE 

provided technical support to our 25 Solar America City partnerships, several Solar 

America Showcase installation projects, and federal sector stakeholders through the 

Government Solar Installation Program. Organizations funded to deliver this technical 

assistance included the National Renewable Energy Laboratory (NREL), Sandia 

National Laboratories (SNL), the Florida Solar Energy Center (FSEC), New Mexico State 

University, and CH2MHill. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Technical Assistance 2050 1140 2126 5316 

Integrator 0 0 1250 1250 

Regional Experiment 

Station Support 0 0 400 400 

Laboratory Support 1500 1140 276 2916 

Solar America Cities 0 0 0 0 

Solar America Showcases 0 0 0 0 

Government Solar Installer 

Program 0 0 0 0 
 

 

____________________________________________________________________________________ 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

Technical Assistance Provider & Tiger Team Integrator 

D R A F T

Performing Organization: CH2M HILL, Inc. 

Key Technical Contact: Joe Lucas (DOE/GO), 303-275-4849, joe.lucas@go.doe.gov 

DOE HQ Technology Manager: Hannah Muller, 202-586-4883, hannah.muller@ee.doe.gov 

FY 2009 Budget: $1,550K 

Objectives 

•	 Supply supplemental technical assistance to the U.S. Department of Energy (DOE) Solar Energy 

Technologies Program’s Market Transformation projects 

•	 Coordinate and communicate to ensure collaboration of Tiger Team members across geographic 

areas, to maximize limited resources, to avoid duplication of efforts, and to achieve the highest 

quality product and delivery of services to the recipients. 

. 

Accomplishments 

•	 Collected metrics data from all 25 Solar America Cities (SAC) to measure program success and 

effect 

•	 Completed solar mapping portals for Berkeley, Portland, San Francisco, and San Diego 

•	 Completed solar for emergency management studies for New York City and Boston 

•	 Completed solar site assessments for San Jose, Forest City, HI, and Minneapolis/St. Paul 

•	 Completed solar economic development analysis for Milwaukee. 

Future Directions 

•	 Support all 25 SAC as they move from technical assistance to special projects 

•	 Prepare a guidebook for best practices in solar permitting for the City of Philadelphia 

•	 Develop a marketing and outreach plan for the City of New Orleans 

•	 Develop solar mapping portals for Orlando, Madison, and New Orleans 

•	 Develop a solar hot water strategy for the City of Knoxville 

•	 Prepare a report outlining strategies for employing solar technologies for emergency
 

management infrastructure
 

•	 Prepare a report outlining strategies for economic development that can be used by all 25 SAC, 

including a cost convergence model. 

1. Introduction 

CH2M HILL was competitively awarded a 5-year 

contract to provide technical assistance to the 

DOE Solar Program’s Market Transformation 

projects, including, but not limited to, Solar 

America Cities, Solar America Showcases, and 

Government Solar Installation Program projects. 

Technical assistance includes solar technology 

assistance, city/municipal planning, 

market/financial analysis support, 

architectural/structural analysis support, technical 

project implementation, regional facilitation, solar 

metrics data collection, communication, outreach 

and education, and project management. 

2. Technical Approach 

CH2M HILL is a member of the Tiger Teams 

offering technical expertise to the various 

participants in DOE programs. In addition, the 

company serves ensures collaboration of Tiger 

Team members, maximizes limited resources, and 

avoids duplication of effort through coordination 

and communication. 

3. Results and Accomplishments 

Solar for Emergency Management: Completed two 

studies investigating the use of solar technology to 

support emergency management infrastructure. 

New York City and Boston were evaluated to 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

establish best solar technology alternatives for 

maintaining reliable power supplies during crisis 

events for public safety and business and 

economic continuity. 

Solar Mapping Portal: Completed solar mapping 

portals for Berkeley, Portland, San Francisco, and 

San Diego. The portal tool allows residents and 

businesses to locate and obtain information on 

solar installations in their city and, in some cases, 

calculate the solar potential of their property. The 

application uses the Clean Power Estimator to 

estimate the resident’s energy savings and 

payback time over the life of the project. Links to 

local solar installers are given if the resident wants 

to take the next step. 

D R A F 

Solar Metrics Data Collection

31 

These 

watt to the average permitting time required for 

metrics 

measure everything from installed cost per 

of solar development in all 25 

: Continued to study 

SAC. 

T

solar implementations. When this study is 

complete, the SAC will have an accurate picture of 

their solar maturity and the DOE will have a 

baseline from which to measure success of the 

program. 

Solar Site Assessments: Assisted SAC and 

Showcase Projects by conducting initial solar site 

assessments to determine the suitability of local 

buildings for solar projects. Assessments include 

roof inspections for suitable solar systems, 

modeling the energy output of proposed systems 

as well as cost, and other information a city would 

need to issue a Request for Proposal. 

Solar Economic Development: Assisted the City of 

Milwaukee in developing a report investigating 

solar products manufacturing and the critical 

elements of the supply chain; made suggestions 

on how the city could position itself to be 

successful in attracting or growing solar products 

manufacturing industries. 

Media Relations and Outreach: Worked with 

partner GroundFloor Media to develop a 

comprehensive media relations and outreach plan 

for the SAC program. This included media training, 

support of multiple events from a media 

perspective, and messaging and branding 

campaigns to maintain a clear and consistent 

message for the SAC program. 

CREBs Application Assistance: Assisted the City 

of Santa Rosa and five other Sonoma County 

cities in completing the engineering sections of 

their Clean Renewable Energy Bonds (CREBs) 

applications to the Internal Revenue Service, with 

8 of 10 applications approved; the projects are 

now eligible for funding through tax-free bonds. 

System Commissioning: Assisted in 

commissioning a 1-MW PV system on the Orange 

County Convention Center in Orlando, FL. Efforts 

included planning the commissioning, performing 

the tests required to ensure operation of the 

system is consistent with design, and publishing a 

report on findings. 

4. Planned FY 2010 Activities 

Regional Facilitation: Provide regional facilitation 

for the SAC. Seven regional facilitators will work 

with specific cities and assist Tiger Team leads in 

coordinating efforts related to the SAC program. 

Responsibilities will include recording city 

accomplishments, offering limited technical 

assistance and connecting cities with technical 

resources, communicating DOE information, and 

maintaining a consistent and steady channel of 

communications. 

Marketing Plans: Work with partner Imagine Solar 

to develop a comprehensive solar outreach and 

marketing plan for the City of New Orleans. 

Solar Mapping Portals: Continue developing solar 

mapping portals for several cities, including 

Orlando, New Orleans, and Madison. 

Solar Hot Water Strategy: Perform a qualitative 

analysis of solar hot water markets in 

Knoxville/Knox County. 

Cross-Cutting Projects: Assist with two crosscutting projects intended to be applicable to all 25 

SAC. The first continues the work performed for 

New York City and Boston to focus on using solar 

technology to support and bolster emergency 

management infrastructure. 

The second project will focus on economic 

development and will include a background and 

overview of the physical and business 

requirements of the major job-generating 

segments of the solar photovoltaics industry. 

Guidebook for Solar Permitting: Assist the City of 

Philadelphia in developing a guidebook for 

permitting for solar. 
 

 

 

 

5. University and Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

D R A F T

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research 

Activity 

FY 2009 

($K) 

Clean Energy Associates 

Steve Wiese 

Austin, TX 

steve.wiese@cleanenergyassoci 

ates.com 

Assisted in the development of 

parameters and a weighting system 

to determine solar install targets for 

all 25 Solar America Cities 

20 

Imagine Solar 

Michael Kuhn 

Austin, TX 

michael.kuhn@imaginesolar.com 

Assisted CH2M HILL in performing 

training and site assessments for 

Minneapolis/St. Paul 

20 

GroundFloor Media 

Ramonna Tooley 

Denver, CO 

rtooley@groundfloormedia.com 

Assisted CH2M HILL in providing 

media outreach, solar event media 

support, media training, messaging, 

and branding in support of the Solar 

America Cities program 

300 
 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

Laboratory Support 

Performing Organizations: Florida Solar Energy Center (FSEC) 

D R A F T

Key Technical Contacts: 

DOE HQ Activity Managers: 

FY 2009 Budgets: 

National Renewable Energy Laboratory (NREL)
 

New Mexico State University (NMSU)
 

Oak Ridge National Laboratory (ORNL)
 

Sandia National Laboratories (SNL)
 

Jason Coughlin (NREL), 303-384-7434, Jason.Coughlin@nrel.gov
 

Norm Durfee (ORNL), 865-574-1830, durfeenw1@ornl.gov
 

Vipin Gupta (SNL), 915-491-1158, vpgupta@sandia.gov
 

Beth Richards (SNL), 505-844-6951, ehricha@sandia.gov
 

Charlie Hemmeline, 202-586-6646, charles.hemmeline@ee.doe.gov 

Hannah Muller, 202-586-4883, hannah.muller@ee.doe.gov 

$2,996K (DOE), $2,996K (technical assistance from national 

laboratories) 

Objectives 

•	 Provide financial assistance awards, also called cooperative agreements, of up to $200,000 to each 

of the 12 newly awarded cities under the Solar America Cities 2008 solicitation, in addition to 13 Solar 

America Cities awarded in 2007. These awards will be used to propose activities that support DOE 

objectives and Solar Energy Technologies Program Market Transformation (MT) activities. The 25 

cities all have populations of 100,000 or more 

•	 Provide up to $250,000 in tailored technical assistance from DOE national laboratories and 

contractors to each of the Solar America Cities to accomplish project goals. 

Accomplishments 

•	 Held the Solar America Cities 2nd Annual Meeting in San Antonio, which brought together the 2007 

and 2008 awardees to share best practices, share lessons learned, present new ideas, and engage 

in networking 

•	 Launched Solar America Cities Information Network (SAmCIN) 

•	 Provided technical assistance for each of the 2007 and 2008 cities. The following entities provided 

this assistance: the National Renewable Energy Laboratory (NREL), Sandia National Laboratories 

(SNL), Oak Ridge National Laboratory (ORNL), the Southwest Regional Experiment Station 

(SWRES) at New Mexico State University (NMSU), and the Southeast Regional Experiment Station 

(SERES) at the Florida Solar Energy Center (FSEC). 

Future Directions 

•	 Integrate solar energy technologies into city energy planning and remove market barriers to solar 

energy development that exist in urban planning charters, zoning regulations, building codes, and 

permitting and inspections procedures 

•	 Promote solar energy technologies through outreach, curriculum development, incentive programs, 

and other innovative approaches targeted at residents and local businesses Develop a 

comprehensive city government approach to solar implementation involving key stakeholders, 

utilities, and private partners 

•	 Target specific barriers through the special projects 

•	 Institutionalize the Solar America Cities approach, experiences, lessons learned, and types of 

activities with long lives in other cities 

•	 Establish target barriers to solar employment through the use of cross-cutting projects (e.g., solar hot 

water). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 D 

 

R A F T

1. Introduction 

Through the U.S. Department of Energy's Solar 

America Cities partnership, 25 major U.S. cities 

are working to accelerate the adoption of solar 

energy technologies for a cleaner, more secure 

energy future. Each of the 25 cities has a team of 

technical and communications experts who are 

dedicated to helping them develop a sustainable 

solar infrastructure that removes market barriers 

and encourages the adoption of solar energy by 

residents and businesses. 

The teams are led by experts from FSEC, NREL, 

NMSU, ORNL, and SNL. 

2. Technical Approach 

The objectives of the Solar America Cities 2009 

Special Projects funding opportunity 

announcement (FOA) were to facilitate 

mainstream adoptions of solar technologies and 

to create models for other cities that include 

experience and expertise in financing, permitting, 

and technical integration. DOE selected 25 cities 

to help set the foundation for a solar energy 

market that can serve as a model for cities 

around the nation. 

Each Solar America City was eligible for the 

Special Projects FOA. The cities submitted 

proposals outlining their plans to scale up their 

most promising projects and concepts. The goal 

was to overcome key barriers to urban solar 

energy use in their communities, allowing 

innovative programs and policies to be replicated 

across the nation. 

On-Site Technical Assistance 

In their proposals, the cities identified the 

technical assistance their projects might require 

in areas such as city planning, technology 

selection, project financing, building codes, 

architecture, and community outreach. DOE 

appointed a technical assistance leader, called a 

Tiger Team Lead, to each city. Members of the 

Tiger Team were drawn from NREL, SNL, 

ORNL, the SWRES at NMSU, and SERES at 

FSEC. 

3. Results and Accomplishments 

In April 2009, DOE held the Solar America Cities 

2nd Annual Meeting to share experiences, 

lessons learned and give the 2007 and 2008 

cities opportunities to network. 

DOE launched a Solar America Cities SAmCIN 

to promote the goals and accomplishments. 

Details of accomplishments in each city follow. 

Ann Arbor took its real-time monitoring system 

for the photovoltaic (PV) systems at the Leslie 

Science Center on Earth Day (April 22, 2009). 

The city is having CH2M HILL perform system 

commissioning of three PV systems and two 

solar thermal systems located at three separate 

sites within the city. 

Austin issued a final report on benchmarking of 

solar energy programs.

1 Austin also assessed 

potential for distributed renewable power within the 

city and the potential for energy generation from 

renewable energy sources in west Texas that would 

serve Austin electricity customers. 

Berkeley partnered with Community Energy Services 

Corporation (CESC) to create the SmartSolar Program 

to promote cost-effective investment in solar water 

heating (SWH) and solar electric technologies in the 

residential and small-to-medium commercial/public 

building sectors. 

Boston explored innovative financing strategies 

to facilitate the bulk purchase, financing, and 

installation of solar energy technologies. 

Madison developed a Madison Solar Map to 

integrate with NREL's IMBY tool. The integrated 

map and tool will give citizens interested in 

rooftop solar information on various PV systems 

that would fit their roofs. 

New Orleans conducted Solar Thermal Training. 

The city also completed the installation of an 

advanced hurricane-resistant 28-kilowatt (kW) 

solar roof on Warren Eaton Senior High School 

through a partnership among Energy 

Corporation, Nike Corp, Winrock International, 

USGB LA chapter, and the City of New Orleans. 

New York reduced or even eliminated many of 

the barriers to PV deployment that were 

identified in the New York City Million Solar 

1

City of Austin. U.S. Department of Energy 2007 Solar 

America City, City of Austin, Texas Benchmarking of 

Solar Energy Programs. December 2008. Available for 

download at 

http://www.solaramericacities.energy.gov/cities/austin/ 

City-of-Austin-Texas-Benchmarking-of-Solar-EnergyPrograms.pdf 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Roofs Initiative. The New York Solar America 

Cities team proposed the Smart Solar City 

Project and made significant progress toward 

understanding the technical barriers to 

interconnecting distributed PV to a network grid. 

A citywide data acquisition system (Smart Solar 

City DAS) that can communicate with a smart 

grid is being developed. 

D R A F T

Pittsburgh hired a consultant to perform a site 

assessment of the General Services Repair Shop in 

Pittsburgh. The city also launched a fellowship 

program to carry the solar torch once the Tiger 

Team and City Team have been disbanded. 

Portland initiated a complementary suite of 

neighborhood-focused activities and programs 

designed to lower the barriers to solar 

installations for residents. The city also installed 

a solar roof membrane at the Scott K-8 School. 

Salt Lake City helped develop and improve 

solar-panel installation courses and instruction 

modules through a grant awarded to Salt Lake 

Community College. These courses and 

modules will be used by several community 

colleges and schools in 11 surrounding states. 

San Diego kicked off plans to initiate large-scale 

solar financing options through property taxes 

starting in 2010. The city submitted a proposal to 

equip city-owned recreation centers with 

renewable generation and storage for full-service 

wildfire emergency response islands. 

San Francisco provided PV safety training for local 

firefighters in December 2009. 

Tucson continued to explore the installation of 

solar-powered streetlights in portions of the city 

and to investigate widening the application of 

commercial SWH to, for example, launderettes 

and car washes. Tucson Electric Power received 

regulatory approval for a 25-megawatt (MW) 

solar farm on city land. The city also held its 4th 

Annual Solar Rock Event. 

Denver brought a 1.6-MW Sharp solar array 

online to power Denver International Airport’s 

fuel-storage and distribution facility. The city also 

created a Web site to support local governments 

in the metro area interested in launching 

municipal solar programs. 

Houston continued to develop an idea for 

deploying solar at the Port of Houston to supply 

backup power for crane operations in the event 

of a grid power outage. The city also developed 

a survey to be used for consumer marketing in 

Houston, held a class on innovative solar 

financing for Houston stakeholders, installed a 

large PV demonstration on the George Brown 

Convention Center, and discussed financing 

options with a variety of stakeholders. 

Knoxville designed and issued a bid package 

for solar installation on the new Knoxville Transit 

Center and on Knox Heritage House. The city 

also installed solar on Ijams Nature Center and 

on Knoxville Convention Center with block grant 

funds. Finally, the city brought in experts for 

SWH and inspector training. 

Milwaukee displayed a Solar in the City exhibit 

at the Betty Brinn Children's Museum. In 

addition, the city held five PV introductory 

classes for installers, two site assessment 

classes, four intermediate PV installation 

classes, SWH classes, and ten homeowner 

classes. Finally, the city completed 25 site 

assessments to examine the feasibility of PV and 

solar thermal technologies. 

Orlando continued the rebate program it 

launched in 2008, which offers $200 per 

customer for installing a solar thermal system 

and receiving an energy audit. 

Philadelphia conducted an initial round of 

meetings to solicit feedback from critical 

stakeholders for Philadelphia’s solar future. 

Sacramento identified 16 potential sites for solar 

PV. Ten of these sites exist and six would be 

new construction sites. 

San Antonio conducted a press conference on 

the groundbreaking of a “Peak Performance 

House,” an experimental solar laboratory. 

San Jose conducted site evaluations of nine city 

facilities for installation of both novel and mature 

solar technologies. The city’s finance department 

used detailed solar financial analysis to develop 

a finance model to help the city decide among 

options, which include direct purchase, PPA, or 

doing nothing. 

Santa Rosa completed a site assessment and 

preliminary design for a 65-kW solar PV support 

structure for the parking lot at the city’s 

wastewater treatment plant. 
 

 

Seattle developed “Solar Works in Seattle!” 

workshops to educate Seattle City Light (the 

local utility) customers. 

Minneapolis–Saint Paul launched a new solar 

PV rebate program, which the State Energy 

Office will put in place throughout the state. A 

consultant provided PV code training to building 

officials from the Twin Cities, and CH2M HILL 

conducted site assessments and site 

assessment training courses. 

D R A F T
 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

Solar America Cities 

Performing Cities Awarded in 2007: 

D R A F T

Ann Arbor, MI; Austin, TX; Berkeley, CA; Boston, MA; Madison, WI; New 

Orleans, LA; New York, NY; Pittsburgh, PA; Portland, OR; Salt Lake 

City, UT; San Diego, CA; San Francisco, CA; Tucson, AZ 

Performing Cities Awarded in 2008: 

Denver, CO; Houston, TX; Knoxville, TN; Milwaukee, WI; Orlando, FL; 

Philadelphia, PA; Sacramento, CA; San Antonio, TX; San Jose, CA; 

Santa Rosa, CA; Seattle, WA; Minneapolis–Saint Paul, MN 

Key Technical Contacts:	 Stephanie Sung, (DOE/GO), 303-275-4899, 

Stephanie.sung@go.doe.gov 

Joe Lucas (DOE/GO), 303-275-4849, joe.lucas@go.doe.gov 

Steve Palmeri (DOE/GO), 303-275-4832, steve.palmeri@go.doe.gov 

DOE HQ Activity Manager:	 Charles Hemmeline, 202-586-6646, Charlie.hemmeline@ee.doe.gov 

FY 2009 Budgets:	 $2.4 million (DOE), $2.4 million (technical assistance from national 

laboratories)* 

*These funds were awarded in fiscal year (FY) 2008; however, the awardees 

actively pursued project goals through FY 2009. 

Objectives 

•	 Manage and support the financial assistance awards (cooperative agreements) for the 25 Solar 

America Cities that support the objectives of DOE and activities under the Solar Market 

Transformation Program 

•	 Provide up to $200,000 in tailored technical assistance from DOE national laboratories and 

contractors to each of the 2008 recipient cities to accomplish the project goals. 

Accomplishments 

•	 Issued a Funding Opportunity Announcement (FOA) for Solar America Cities Special Projects that 

resulted in the award of 40 projects to 16 current Solar America Cities with a total value of more than 

$9 million in federal funds 

•	 Held the Solar America Cities 2nd Annual Meeting in San Antonio, bringing together the 2007 and 

2008 awardees to share best practices and lessons learned, present new ideas, and engage in 

networking 

•	 Provided technical assistance for each of the 2007 and 2008 cities. The following entities provided 

this assistance: the National Renewable Energy Laboratory (NREL), Sandia National Laboratories 

(SNL), Oak Ridge National Laboratory (ORNL), the Florida Solar Energy Center (FSEC), and the 

Southwest and Southeast Regional Experiment Stations (RESs) at New Mexico State University 

(NMSU). 

Future Directions 

•	 Integrate solar energy technologies into city energy planning and remove market barriers to solar 

energy development that exist in urban planning charters, zoning regulations, building codes, and 

permitting and inspections procedures 

•	 Promote solar energy technologies through outreach, curriculum development, incentive programs, 

and other innovative approaches targeted at residents and local businesses 

•	 Develop a comprehensive city government approach to solar implementation involving key 

stakeholders, utilities, and private partners 
 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

• Bring about a widespread increase in the adoption of solar energy technologies across the cities in 

the residential, commercial, and public building sectors, as well as at utilities. 

D R A F T

1. Introduction 

Launched in 2006, Solar America Cities is a key 

component of DOE’s Solar Energy Technology 

Program (SETP) Market Transformation efforts to 

accelerate the development of advanced solar 

technologies with the goal of making them costcompetitive with conventional forms of electricity from 

the utility grid by 2015. 

2. Technical Approach 

The Solar America Cities objective is to support cities 

ready to take a comprehensive, systemic, citywide 

approach to solar technology. The program is 

designed to facilitate mainstream adoption and 

provide a model for other cities to replicate. DOE 

selected 13 Solar America Cities in June 2007 and 12 

more cities in March 2008 to help lay the foundation 

for a solar energy market that can serve as a model 

for cities around the nation. 

Each of the 25 cities submitted a proposal outlining its 

plans to build a sustainable solar infrastructure, 

streamline city-level regulations, and promote the 

adoption of mainstream solar technology among 

residents and businesses. 

The winning cities for 2008 and 2007 follow: 

Solar America Cities 2008 FY 2008 

Budget ($K) 

Denver, CO 200 

Houston, TX 200 

Knoxville, TN 200 

Milwaukee, WI 200 

Orlando, FL 199 

Philadelphia, PA 200 

Sacramento, CA 200 

San Antonio, TX 200 

San Jose, CA 200 

Santa Rosa, CA 200 

Seattle, WA 200 

Minneapolis–Saint Paul, MN 200 

Solar America Cities FY 2007 

2007 Budget ($K) 

Ann Arbor, MI 200 

Austin, TX 187 

Berkeley, CA 200 

Boston, MA 150 

Madison, WI 200 

New Orleans, LA 200 

New York , NY 190 

Pittsburgh, PA 200 

Portland, OR 200 

Salt Lake City, UT 197 

San Diego, CA 200 

San Francisco, CA 200 

Tucson, AZ 200 

On-Site Technical Assistance 

In their proposals, each of the 25 Solar America Cities 

identified the technical assistance their projects might 

require in areas such as city planning, technology 

selection, project financing, building codes, 

architecture and community outreach. DOE 

appointed a technical assistance lead, called a Tiger 

Team leader, to each city. Members of the Tiger 

Teams were drawn from NREL, SNL, ORNL, the 

Southwest and Southeast RESs at NMSU, and 

FSEC. 

3. Results and Accomplishments 

DOE held the Solar America Cities 2nd Annual 

Meeting in San Antonio (March 30–April 2, 2009) to 

share experiences and lessons learned and give the 

cities an opportunity to network. 

DOE continued to refine and add enhancements to 

the Solar America Cities Web site at 

http://solaramericacities.energy.gov/Home.aspx. 

These improvements have allowed the Solar America 

Cities to add content and access the best practice 

documents and other valuable materials created 

during the first two years of the Solar America Cities 

combined effort. 

Details of accomplishments in each city follow. 

Ann Arbor trained code officials on solar technology, 

trained local teachers on solar energy curriculum, and 

drafted the Ann Arbor Solar Plan. 

Austin installed two solar installations at two 

community college campuses. Solar Curriculum for K12 has been completed and is being used by the 

school district this year. 

Berkeley developed and launched a program to offer 

clients independent advice and guidance integrating 

solar and energy efficiency. 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

Boston initiated 500 kilowatts (kW) of municipally 

owned photovoltaic (PV) projects including a 240-kW 

system at the headquarters of the Boston Water and 

Sewer Commission and more than 100 kW at five 

public schools. Solar Boston also coordinated the 

installation of the first city-owned solar water heating 

(SWH) system at the Boston Public Health 

Commission’s treatment facility on Long Island in 

Boston Harbor. 

Madison installed 12 SWH and 8 PV systems on city 

buildings to demonstrate the technology to the public. 

A solar agent evaluated 500 private properties of 

solar-interested owners and advised owners about 

solar options. 

New Orleans commissioned a 28-kW PV system on 

Warren Easton High School. Full-day symposiums on 

both solar thermal and PV inspections were 

presented to Orleans Parish Code Officials. The city 

also established a NABCEP solar installer training 

program in the New Orleans Community College 

System. 

New York worked with NREL on a study of barriers 

and solutions to interconnecting PV on the local 

utility’s network grid system. The city also completed 

studies on solar in emergency management and on 

the impacts of real-time pricing on solar economics. 

Pittsburgh hosted the Northeast Region Solar 

Conference to share best practices and regulatory 

models with cities in the Northeast. The city also 

conducted training for municipal officials to promote 

solar across the different city departments. 

Portland launched the Oregon Clean Energy map 

(available at http://oregon.cleanenergymap.com/) 

encouraging residents and businesses in the Portland 

metro area to choose renewable energy. In addition, 

the Solar Now Partners developed and launched a 

new commercial solar workshop series titled Basics of 

Commercial Solar. 

Salt Lake City worked to resolve the existing 

financial and regulatory barriers in an effort to 

dramatically propel Salt Lake City and County toward 

the shared long-term solar goal of increasing solar 

installations to 10 megawatts (MW) by 2015. With 

these barriers removed, Phase II of the Solar Salt 

Lake Project expects to create roughly $60 million in 

new solar investment opportunities and more than 

220 new solar manufacturing, installation, and 

maintenance jobs in Utah. 

San Diego focused on developing a Barriers and 

Solutions report, based on survey data and focus 

group meetings, which documents the perspectives 

from resident, realtor, and permit reviewers. The city 

also expanded its Solar Map, found at 

http://sd.solarmap.org/solar/index.php, and populated 

it with all of the solar installations in the city, 

Associated with the map are a searchable database, 

an electric rate analyzer, and an informative solar 

blog. 

San Francisco worked through the Mayor's Solar 

Founders' Circle to allow the San Francisco 

Department of the Environment to conduct 92 rooftop 

solar assessments for commercial and nonprofit 

buildings in the city. In addition, the city held three 

Solar Champions courses in cooperation with PG&E's 

Pacific Energy Center training facility. San Francisco 

also convened a new SWH working group to identify 

and address ways to facilitate and increase SWH 

adoption in the city. 

Tucson completed the Greater Tucson Solar 

Development Plan (available at 

http://www.pagnet.org/documents/solar/SolarDevPlan 

2009-01.pdf), issued $7.6 million in CREBs, and 

began constructing 1 MW of PV on various city sites. 

In addition, the city implemented a Solar Ready 

Homes ordinance; conducted a two-day SWH training 

session for 60 installers, inspectors, and others; and 

assisted in developing a Green Map of Tucson 

showing PV and SWH installations. 

Denver, working with partner county Boulder, 

launched the ClimateSmart Loan Program, developed 

a Web site to promote solar development within local 

government, installed 1.6 MW of new PV at Denver 

International Airport, and issued a joint RFP with 

Denver Public Schools that will result in almost 3 MW 

of new solar in 2010. 

Houston installed 50-kW polycrystalline solar and 50-

kW thin film solar arrays at the George R. Brown 

Convention Center, along with an educational kiosk.. 

Houston Mayor Bill White gave the keynote address 

at the press event marking the completion of the 

project. The city also expanded and improved on its 

Solar Houston Initiative Web site at 

www.solarhoustontx.org. 

Knoxville facilitated the creation of a 96-hour solar 

PV installation curriculum program at Pellissippi State 

Community College. In conjunction with IREC, the 

Solar Knoxville Program hosted a full-day training 

seminar on PV systems and the National Electrical 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

Code (NEC) for regional code officials and building 

inspectors. 

Milwaukee launched a marketing campaign (e.g., 

radio ads, a Web site, a large graphic display, and a 

revolving children’s exhibit). The city also contracted 

a solar coach to conduct outreach and lead local solar 

classes and workshops, and contracted for a 

feasibility study for solar manufacturing. Finally, the 

city presented solar financing options to its Common 

Council. 

Orlando developed and advanced the GIS Solar 

Mapping Project as well as planning for Stakeholder 

Charette and Solar Training Workshops. The city also 

worked on the SOQ applications for a 10-MW PV 

project. 

Philadelphia conducted over 10 site investigations to 

determine feasibility for solar PV on both public and 

private facilities. The city began installing a solar PV 

project at the Philadelphia Water Department’s 

Wastewater Treatment facility. In addition, for smaller 

scale projects, the city’s Licenses and Inspections 

team is working with the local utility and DOE to 

develop a guidebook for the permitting process and to 

expedite projects under 10 kW. 

Sacramento identified 11 potential sites for solar PV 

with completed preliminary sizing of systems. The city 

edited Solar License Agreement and Solar Power 

Purchase Agreements provided by DOE, which are 

now ready for the city’s use. The city also developed 

a revised standardized application and established a 

flat fee for residential permits. Both supersede the 

existing fee waiver that expired on December 31, 

2009. 

San Antonio released the City of San Antonio: 

Mission Verde Sustainability Plan. (available at 

http://www.sanantonio.gov/oep/sustainabilityplan.asp 

?res=1024&ver=true). Working with the Metropolitan 

Partnership for Energy, Solar San Antonio, and CPS 

Energy, the city also developed a San Antonio Green 

Awards event that includes a Solar Technology 

award. CPS Energy unveiled two 10-MW solar 

installations located in San Antonio and West Texas. 

San Jose installed 6 PV arrays on municipal facilities 

and negotiated PPAs with a vendor for a 1.3-MW PV 

array at the city’s Central Service Yard. The city also 

began coordinating and developing a Property 

Assessment for Clean Energy (PACE) program, 

sponsored the 2nd Annual Regional Renewable 

Energy Summit, and developed a city employee solar 

financing pilot program. 

Santa Rosa held training classes on safety and 

installation procedures for solar PV and solar thermal 

installers, provided support and facilitated stakeholder 

input during the development of a PACE financing 

program known as, the Sonoma County Energy 

Independence Program (SCEIP). This program was 

the first countywide PACE program in the United 

State. In addition, the city implemented a 

standardized residential solar permit form and 

process for Sonoma County. 

Seattle engaged more than 700 residents through 

Solar Works! workshops and provided NEC 690 code 

training to more than 100 utility staffers and electrical 

inspectors. In addition, the city drafted an 

interconnection standard for systems up to 20 MW, 

tapped into NREL's technical assistance for help on 

production metering and secondary network issues, 

and conducted thorough research on community solar 

models. 

Minneapolis–Saint Paul began a revitalization of the 

state’s solar rebate program; initiated a $3-million 

distributed solar, energy efficiency, and energy 

storage pilot program in the Minneapolis–Saint Paul 

Energy Innovation Corridor; and launched several 

new solar energy programs directed to cities, 

counties, and school districts. The cities also created 

several training opportunities for local government 

staff, covering best practices in solar system 

permitting, solar site assessments on public buildings, 

and regulatory barriers to solar energy systems 

development. 

4. Planned FY 2010 Activities 

•	 Replicating the PACE Program model for local 

governments to give residential and commercial 

sectors financial incentives to integrate solar into 

homes and businesses 

•	 Targeting outreach to local governments across 

the United States, which will present best 

practices and models developed from the 25 

current Solar America Cities 

•	 Developing outreach and education programs 

designed to inform the public about the steps 

necessary to implement solar, as well as the 

resources and incentives available 

•	 Facilitating demonstration installations with 

accompanying educational components 

•	 Developing solar training programs and 

roadmaps for integrating solar energy into each 

city’s emergency planning 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 Expanding solar installer training programs that 

steps city planners through all phases of solar 

implementation on city properties 

•	 Creating Web sites featuring comprehensive onestop-shopping for solar information with solar 

mapping capabilities 

•	 Continuing to implement energy audits and solar 

assessments across the Solar America Cities 

•	 Publishing information on solar financing options 

and developing city-specific fact sheets and 

project case studies 

•	 Identifying and implementing cost-effective tools 

to overcome market barriers to the adoption of 

commercial and residential-scale solar 

technologies. 

D R A F T

5. Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/Principal Investigator Location/E-mail Description/Title of Research 

Activity 

FSEC 

Dave Click 

Cocoa, FL 

DaveClick@fsec.ucf.edu Tiger Team Lead 

NMSU 

Andy Rosenthal 

Las Cruces, NM 

arosenth@nmsu.edu Tiger Team Lead 

NREL 

Alicen Kandt 

Andy Walker 

Jason Coughlin 

Jesse Dean 

Liz Brown 

Nancy Carlisle 

Otto VanGeet 

Sheila Hayter 

Golden, CO 

alicen.kandt@nrel.gov 

andy.walker@nrel.gov 

jason.coughlin@nrel.gov 

jesse.dean@nrel.gov 

elizabeth.brown@nrel.gov 

nancy.carlisle@nrel.gov 

otto.vangeet@nrel.gov 

sheila.hayter@nrel.gov 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

ORNL 

Curt Maxey 

Oak Ridge, TN 

maxeylc@ornl.gov Tiger Team Lead 

SNL 

Dick Fate 

Elizabeth Richards 

Greg Kolb 

Vipin Gupta 

Warren Cox 

Howard Passell 

Albuquerque, NM 

refate@sandia.gov 

ehricha@sandia.gov 

gjkolb@sandia.gov 

vpgupta@sandia.gov 

wbcox@sandia.gov 

hdpasse@sandia.gov 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 

Tiger Team Lead 
 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

Solar America Showcases 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Key Technical Contacts: 

Sandia National Laboratories (SNL) 

New Mexico State University (NMSU) 

Florida Solar Energy Center (FSEC) 

Steven Palmeri (DOE/GO, Primary Contact), 303-275-4832, 

steve.palmeri@go.doe.gov 

Cecile Warner (NREL), 303-384-6516, cecile_warner@nrel.gov 

Vipin Gupta (SNL), 915-491-1158, vpgupta@sandia.gov 

Andy Rosenthal (NMSU), 505-646-1323, arosenthal@nmsu.edu 

Robert Reedy (FSEC), 321-638-1470 reedy@fsec.ucf.edu 

DOE HQ Technology Manager: Charlie Hemmeline, 202-586-6646, charles.hemmeline@ee.doe.gov 

FY 2009 Budgets: $650K 

Objectives 

•	 Accelerate demand for solar technologies among key end-use sectors. 

•	 Assist in creating high visibility solar projects that increase public awareness of solar power. 

•	 Create replicable, large-scale projects that can become models for other U.S. entities. 

Accomplishments 

Forest City #2 Military Communities 

•	 Conducted a site assessment that defined the design features of a photovoltaics (PV) Smart Grid 

at the Kaneohe Bay Marine Corp Base, Hawaii. 

•	 Defined the technical options for siting a PV array and solar water heating (SHW) collector on a 

historic Marine Corps officer housing unit slated to become a net zero energy home. 

•	 Conducted a site survey to define options to explore in greater depth on the technology selection, 

operation with energy storage, and grid integration of a 2-3 MW solar farm on the Big Island. 

City of San Jose 

•	 Provided follow-up technical assistance, based on the site evaluations the team did the year 

before at eight city facilities. 

Future Directions 

•	 Continue to seek solar projects to support in fiscal year (FY) 2010 that accelerate demand for 

solar technologies. 

1. Introduction 

The purpose of Solar America Showcases (SAS) 

is to accelerate demand for solar technologies 

among key end-use market sectors. Under this 

activity, DOE provides technical assistance to 

large-scale, high-visibility solar installation projects 

that have the ability to impact the market for solar 

technologies through large project size, use of a 

novel solar technology, and/or use of a novel 

application for a solar technology. In addition, it is 

desired that the project be replicable or have 

replicable components. Although it is not expected 

that projects meet all of these parameters, ideally 

projects reflect some or most of these qualities. 

Large-scale installations may include PV, 

concentrating solar power (CSP), and SWH 

applications. 

The types of installations DOE SAS supports are 

described in the following paragraphs: 

Regarding the scale of the project, SAS awards 

until April of 2009 were required to include projects 

with solar systems greater than 100 kilowatts. This 

requirement was increased to a minimum of 250 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

kilowatts for the most recent winners. Projects 

may include multiple sites and do not have to be 

co-located. In addition to the initial installation, the 

kW total also may include planned follow-on 

activities (direct replication efforts). Examples 

include installations in residential subdivisions, 

shopping centers, office buildings or parks, big box 

retail locations, factories, and utility solar 

production. 

Regarding the visibility of the project, DOE seeks 

projects that are centrally located in towns, are 

sited near highly trafficked vehicle or pedestrian 

areas, house hundreds of residents or workers, 

are a part of an area frequented by tourists, are 

part of a popular public destination (e.g. shopping 

centers, courthouses, etc.), or have some other 

high visibility component. The project also would 

have an outreach component that provides 

information about the installation. 

Regarding the novel solar technology, DOE tries 

to support projects that introduce new solar 

technologies that hold the promise of reducing 

initial costs, simplifying installation, and boosting 

consumer confidence, but which have little testing 

to date that demonstrates such improvements. 

Examples include new cell or module technology, 

new materials, or innovative installation and 

mounting techniques. By offering technical 

assistance, DOE can help these new solar 

technologies develop a performance record in the 

marketplace, identify technical problems early in 

mass product releases, and devise solutions and 

alternatives that move specific solar technologies 

to cost-competitiveness by 2015. 

Regarding the novel solar application, DOE tries to 

support projects that utilize solar technology in 

new ways. One example would be to include new 

methods of building integration beyond traditional 

roof-mounted modules. DOE also supports 

innovative designs and methods that open up 

previously untapped markets or end uses to solar 

technology adoption. Acceptable solar 

applications also could include those that are used 

in other geographic areas but not in the vicinity 

(state or region) of the proposed site. 

Regarding replicability, DOE looks to support 

projects that can either be replicated by the entity 

requesting the technical assistance or by others. 

The entire project should be replicable, or have 

replicable components, unless installations are of 

an extremely large size that justifies DOE support 

without replicability. Replication of projects is a 

critical component to advance solar 

commercialization. 

2. Technical Approach 

SAS awarded technical assistance to 

organizations that represented a broad spectrum 

of applications with cross-cutting issues that 

allowed the SETP Market Transformation activity 

to work on several barriers. These barriers 

included: 

•	 Addressing financing barriers for solar 

applications in a municipality. 

•	 Creating a Request for Proposals (RFP) that 

municipalities can use for soliciting bids on 

solar installations. 

•	 Developing an economically sound model for 

doing site surveys across a large housing 

complex. 

•	 Researching inverter location and 

interconnection issues. 

•	 Developing protocols for acceptance testing 

and commissioning processes on new solar 

installations. 

3. Results and Accomplishments 

Forest City #2 Military Communities SAS Project 

•	 Conducted a site assessment that defined the 

design features of a PV Smart Grid at the 

Kaneohe Bay Marine Corp Base. 

•	 Defined the technical options for siting a PV 

array and SHW collector on a historic Marine 

Corps officer housing unit slated to become a 

net zero energy home. 

•	 Conducted a site survey to define options to 

explore in greater depth on the technology 

selection, operation with energy storage, and 

grid integration of a 2-3 MW solar farm on the 

Big Island. 

The Big Island project is a window to the future for 

the U.S. mainland. The Big Island grid already has 

approx. 30% of intermittent renewable energy 

sources linked to it. What the utility (HELCO) 

needs now is a predictable and dispatchable 

supply of electricity from renewable sources such 

as solar. This requires the integration of storage 

which is what the Technical Assistance Team will 

explore in greater depth and detail. 

City of San Jose SAS Project 

The Technical Assistance Team answered followon technical questions from the City of San Jose, 

based on the site evaluations the team did the 

year before at eight city facilities. These technical 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

questions covered a range of issues from the • Work on compressed air storage and solar 

location of solar near burrowing owl habitats to the engineering support will start later in FY2010. 

effect of solar PV on the warranty lifetime of the 

roof to the aesthetically blending the PV array into 4. Planned FY 2010 Activities 

D R A F T

the barrel roof of the convention center. The 

follow-on assistance also included a survey of 

power purchase agreement terms and conditions 

to address city requirements to abide by nonappropriation clause provisions stipulated by the 

state and non-substitution clause provisions to 

reassure PPA provider interests. 

SW Solar SAS Project 

The technical support team for SW Solar Tech will 

provide technical support as SW Solar Tech 

develops and fields an innovative energy system 

that includes solar energy dishes (up to 5 MW), 

compressed air energy storage and natural gas 

backup. To date, the following have been 

completed: 

•	 Traveled to Phoenix to coordinate work. 

•	 Work on cyber analysis and power systems 

analysis has begun. 

•	 Complete San Jose SAS 

•	 Complete main part of technical assistance for 

Forest City #2 SAS 

•	 Complete Mystic Seaport Showcase (FSEC) 

•	 Initiate and lead new State of New Mexico 

Zero Energy Home Showcase (NMSU) 

•	 Initiate and lead University of Central Florida 

Showcase (FSEC) 

•	 Bring SW Solar Showcase to a technically and 

organizationally sensible conclusion 

•	 Plan people and budget to initiate one new 

SAS project (e.g., Kennecott Land or new 

showcase from Mar 2010 FOA). 
 

 

 

 

 

 

 

 

 

 

 

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____________________________________________________________________________________ 

Government Solar Installation Program 

Performing Organizations: National Renewable Energy Laboratory (NREL) 

D R A F T

Sandia National Laboratories (SNL) 

CH2M Hill 

Key Technical Contacts: Steven Palmeri (DOE/GO, Primary Contact), 303-275-4832, 

steve.palmeri@go.doe.gov 

Carolyn Elam (DOE/GO), 303-275-4953, carolyn.elam@go.doe.gov 

Cecile Warner (NREL), 303-384-6516, cecile_warner@nrel.gov 

Vipin Gupta (SNL), 915-491-1158, vpgupta@sandia.gov 

Steven Peck (CH2M Hill), 720-286-2552, steve.peck@CH2M.com 

DOE HQ Technology Manager: Charles Hemmeline, 202-586-6646, charles.hemmeline@ee.doe.gov 

FY 2009 Budgets: $630K 

Objectives 

•	 Support federal agencies to achieve commitment to purchasing 2 gigawatts (GW) of solar power 

at federal facilities and 1 GW at state and local facilities, with all transactions and installations to 

be completed by 2012 ahead of the final renewable energy purchase phase of the Energy Policy 

Act of 2005 (EPAct 2005). 

•	 Lower production costs for solar components through a market-based approach of using 

governmental energy needs to build demand for solar products and increase production.
 

•	 Maximize installation of secure, on-site renewable energy projects at all DOE sites, optimize 

affordable purchases of renewable electricity by DOE facilities, or both. 

Accomplishments 

•	 Developed a model for a Federal Photovoltaic (PV) Request for Proposals vetted through 

financial and solar communities and the General Services Administration (GSA).
 

•	 Initiated development of a dynamic Government Solar Installation Program Web-enabled tool. 

•	 Prepared a report technically defining the solar energy opportunities for federally-owned 

Congressional office buildings in Washington, D.C.
 

•	 Prepared a report providing technical assessment of the potential for using solar energy and 

other key energy efficiency features as part of the Elephant House renovation in progress at the 

National Zoological Park in Washington, D.C. 

•	 Reviewed four PV feasibility studies for the GSA. 

•	 Assessment of Alcatraz site in California. 

•	 Initiated work on the Federal Solar Guidebook. 

Future Directions 

•	 Continue assessments of governmental buildings and implementation of solar rooftop 

installations.
 

•	 Work with the DOE Federal Energy Management Program (FEMP) to identify the best federal 

buildings where solar makes the most sense. 

•	 Identify and partner with other federal agencies to help identify locations where solar can be 

installed in a cost-effective manner on their buildings. 

•	 Accelerate Federal adoption of solar with strategic technical assistance. 

•	 Assist GSA with American Recovery and Reinvestment Act of 2009 (ARRA) installations. 

1. Introduction The Government Solar Installation Program 

(GSIP) is a market-based challenge to public 

entities—federal agencies, states, cities, 
 

 

 

 

 

 

 

 

 

 

 

 

counties, and other local governments—to 

increase their use of solar energy power. GISP 

is carried out in partnership with DOE’s 

Transformational Energy Action Management 

(TEAM) Initiative, a department-wide effort 

aimed at reducing energy intensity across the 

nationwide DOE complex by 30%. GSIP is a 

single program with a three-phased structure. In 

Phase 1, DOE will evaluate DOE facilities for 

pilot sites for solar installations. In Phase 2, 

DOE will complete installations on the 

appropriate sites identified in Phase 1. In Phase 

3, DOE will work with other federal agencies to 

apply the lessons learned and assist with solar 

installations on their individual facilities. 

D R A F 

The major partners in the GSIP are the DOE 

Solar Energy Technologies Program (SETP), 

DOE 

(FEMP)

(GSA). The organization’s roles include: 

Federal Energy Management Program 

, and General Services Administration 

T

SETP 

•	 Phase 1: Primary responsibility for the pilot 

installations. 

•	 Phase 2: Participate in decision-making on 

solar TEAM projects. 

•	 Phase 3: Provide technical assistance. 

FEMP 

•	 Phase 1: Provide government energy 

procurement assistance to SETP. 

•	 Phase 2: Take primary responsibility for 

installations to complete the TEAM effort. 

•	 Phase 3: Assist with energy purchases. 

GSA 

•	 Phase 1: Provide procurement vehicles for 

power purchase agreements (PPAs) as well 

as direct system and service purchases. 

•	 Phase 2: Develop a Web portal. 

•	 Phase 3: Take primary responsibility for 

procurements with DOE support. 

Technical assistance teams, also known as 

Tiger Teams, provide any needed assistance 

and are comprised of representatives from the 

national laboratories (NREL, ORNL, and SNL) 

as well as CH2M Hill, New Mexico State 

University and the University of Central Florida. 

2. Technical Approach 

The GSIP initiative meets or exceeds energy 

efficiency goals mandated by EPAct 2005, as 

well as Executive Order 13423, directing federal 

agencies to: 

•	 Reduce energy intensity and greenhouse 

gas emissions. 

•	 Increase energy efficiency and use of 

renewable energy technologies. 

•	 Adopt sustainable design practices. 

•	 Reduce petroleum use in federal fleets. 

This initiative adopts a more ambitious timeline 

and targets changes that will have an impact on 

DOE’s energy use as early as next year. 

GSIP is a single program with a three-phased 

structure: Phase 1 includes DOE facilities and 

will collaborate with DOE’s TEAM Initiative. The 

TEAM Initiative is a nationwide effort to reduce 

energy intensity by 30% in DOE buildings. This 

energy reduction will save approximately $90 

million in taxpayer dollars per year, after projects 

are paid for. The TEAM Initiative aims to meet or 

exceed the aggressive goals for increasing 

energy efficiency throughout the federal 

government as stated in the executive order. 

Phase 2 will focus on the most appropriate sites 

for solar applications identified during Phase 1. 

The GSIP program approach is to use power 

purchase agreements, except where straight 

purchases are more cost effective. The program 

will initially emphasize solar installations in 

regions of the country with regulations or 

incentives in place, conducive to solar energy 

projects, such as in California and New Jersey. 

The program then will transition to other regions 

as the cost of PV falls and other state or local 

incentives for renewable energy develop. 

Phase 3 of the GSIP broadens the effort to 

include other federal agencies beyond DOE, as 

well as state and local governments. Lessons 

learned during the first two phases of the 

program will be useful for helping other agencies 

to overcome barriers to solar installations. 

The strategic approach of the GSIP is to: 

•	 Leverage federal purchase power to create 

significant demand pull. 

•	 Promote U.S.-manufactured products. 

•	 Promote an installation development model 

using a power purchase agreement model. 

•	 Increase demand for installers and thereby 

boost U.S. jobs. 
 

 

 

 

 

 

 

 

 

 

D R A F T

•	 Facilitate achievement of EPAct 2005 and 

other federal goals by using a market-based 

approach rather than regulation. 

•	 Use growing capital markets to finance 

installations. 

•	 Support domestic power purchase 

agreement providers. 

•	 Facilitate the process by minimizing 

government involvement. 

3. Results and Accomplishments 

The following projects were either installed or 

assessed as part of this program: 

Fallon 3MW PV Analysis: 

Provided technical information to the Navy to 

support their “Right of Way” application for a 3 

MW solar plant at Fallon AFB. Conducted an 

analysis to determine the mounting options for 

single axis PV collectors. 

San Juan, Puerto Rico – GSA Courthouse: 

Conducted a feasibility assessment to optimize 

the placement of solar energy systems for both 

photovoltaic (PV) and solar thermal on the 

Federico Degetau Federal Building (Federal 

Building) and the Clemente Ruiz Nazario U.S. 

Courthouse (Courthouse). This was a follow-on 

report to one submitted on March 25, 2009 titled 

“Feasibility of Solar Energy Systems on Two 

Government Buildings in San Juan, Puerto 

Rico," which was a scoping study; this is a 90% 

feasibility study for the PV and solar thermal 

systems. 

Alcatraz Island, and Calexico, California 

Assist in the preparation of the request for 

proposals (RFP) and bid evaluations including 

technical and financial consideration (cost, 

incentives, operation and maintenance (O&M 

cost), and determined life cycle cost, which the 

selection is based on). 

4.	 Planned FY 2010 Activities 

•	 Finalize the Federal Solar Guidebook and 

conduct outreach activities to distribute. 

•	 Provide technical assistance in awarding 

contract for an off-grid PV hybrid system on 

Alcatraz Island in California. 

•	 Continue to review PV feasibility studies and 

project proposal for the GSA on an as 

needed basis. 

5. University Partners 

The following organizations partnered in GSIP research activities during FY 2009. 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

New Mexico State University 

Andy Rosenthal 

Las Cruces, NM 

arosenthal@nmsu.edu Technical assistance teams, also known as Tiger 

Teams, are comprised of representatives from the 

national laboratories (NREL and SNL) as well as 

Florida Solar Energy Center universities. 

Robert Reedy 

University of Central Florida 

reedy@fsec.ucf.edu 
 

 

 

D R A F T

Technical Outreach Summary 

The purpose of the Technical Outreach project is to provide high-quality solar technology 

and policy information to key stakeholders to accelerate solar adoption and domestic 

market growth. Technical outreach efforts aim to support policy and program innovation, 

as well as speed the dissemination of current best practices. Specifically, the U.S. 

Department of Energy (DOE) has identified state decision-makers (including State 

Energy Offices, Public Utility Commissions, and state Legislatures) and utilities as being 

critical to the establishment of robust domestic solar markets. State governments have 

led the way on solar market development through renewable portfolio standards and 

other policies. Additionally, utilities play a key role in the growth of solar through their 

interconnection and net-metering practices, and by increasing the share of solar in their 

own generation mix. To reach these important audiences, DOE Fiscal Year 2009 funding 

supported the Solar Electric Power Association (SEPA), the Interstate Renewable 

Energy Council (IREC), the National Conference of State Legislatures (NCSL), the 

National Association of Regulatory Utility Commissioners (NARUC), and the Clean 

Energy Group (CEG). 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Technical Outreach 175 0 1250 1425 

Utility Outreach 0 0 175 175 

State Outreach 175 0 975 1150 

Market Transformation 

Analysis – PV Cost Trends 0 0 100 100 
 

 

 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

____________________________________________________________________________________ 

 

State & Utility Outreach 

Performing Organizations: National Conference of State Legislatures (NCSL) 

D R A F T

Clean Energy Group (CEG)
 

National Association of Regulatory Utility Commissioners (NARUC)
 

Solar Electric Power Association (SEPA)
 

Key Technical Contact:	 Steve Palmeri, 303-275-4832, steve.palmeri@go.doe.gov 

DOE HQ Technology Manager:	 Charlie Hemmeline, 202-586-6646, charlie.hemmeline@hq.doe.gov 

FY 2009 Budgets:	 NCLS (*$247.5K) 

CEG (*$247.5K) 

NARUC (*$203.4K) 

SEPA ($175K) 

*(These awards were fully funded in FY 2007; however, the awards actively 

pursued project goals through FY 2009.) 

Objectives 

•	 Foster dialogue among, and educate, state officials (state public utility commissioners and state 

energy office officials) and furnish them with the resources and technical basis needed to effect 

changes to state policy and regulation 

•	 Increase the implementation of policies that foster solar technology deployment 

•	 Enlist the assistance of a utility membership organization to deliver key technical and 

informational assistance to utilities to promote their acceptance and use of solar.
 

Accomplishments 

•	 Released the legisbrief “Financing Renewable Energy and Energy Efficiency,” which introduces 

legislators to property tax financing approaches for solar and energy efficiency and improved its 

database for a comprehensive legislation list (NCSL) 

•	 Updated website and listserve resources tools for state policy makers and decision makers 

interested in developing solar programs and policies and released a new Renewable Energy 

Finance Toolkit for states and municipalities (CEG) 

•	 Released the Solar Energy Technology and Policy Reference Guide with information on solar 

regulatory policies, technologies, and state and industry perspectives (NARUC) 

•	 Launched a utility solar toolkit, an innovative new online tool with “smart filters” for accessing 

research reports, webinar recording, RFPs, online tools, upcoming events, and news, and held 

first annual Utility Solar Conference. 

Future Directions 

•	 Hold a Solar Policy Institute for southeastern legislators October 8–9, 2009, and a web audio 

conference on property-assessed clean energy financing options in February 2010 (NCSL) 

•	 Hold two webinars on solar program best practices, publish a state solar program database 

results through 2008 (CEGI) 

•	 Hold a regional dialogue for the Northeast and Mid-Atlantic to examine the regional solar initiative 

(NARUC). 

•	 Create a Solar Program Options Tool (SPOT) and an Online Resource Library (SEPA). 

1. Introduction	 R&D to meet aggressive cost and installed 

capacity goals. To complement the R&D and 

The DOE Solar Energy Technologies Program is testing/evaluation DOE is conducting market 

partnering with key stakeholders to accelerate transformation (MT) efforts to reduce market 

commercialization of photovoltaic (PV) systems barriers and promote market expansion of solar 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D R A F T

energy technologies. This falls into two areas: (1) 

provide technical, regulatory, institutional, 

financial, and educational solutions to market 

transformation barriers; and (2) accelerate 

demand for new solar technologies, primarily 

through technical assistance in reaching levelized 

cost of energy and cost-competitiveness goals by 

2015. 

2. Technical Approach 

Cooperative agreements are ongoing with several 

organizations. Their work and plans are as follows. 

CEG: $345,000 (FY 2007–FY 2009): 

CEG uses education, research, and information 

services to (1) supply information and technical 

assistance to state leaders and state renewable 

energy programs in developing effective solar 

programs; (2) identify and foster solar program 

best practices; and (3) identify and promote 

strategic opportunities for states and DOE to 

advance solar technology deployment through 

partnerships, collaboration, and targeted activities. 

NCSL: $263,672 (FY 2007–FY 2009) 

NCSL’s Solar Energy Project offers outreach to 

state policymakers on solar technology and policy 

options that can assist in integrating solar energy 

into the fuel mix while breaking down market 

barriers to the adoption of solar energy 

technology. 

NARUC: $303,004 (FY 2007–FY 2009) 

NARUC continues to (1) furnish key state 

agencies with resources to help solar technologies 

overcome regulatory and market barriers; and (2) 

take advantage of emerging opportunities to 

encourage greater deployment and penetration of 

solar technologies into society. Their work 

continues to include outreach and education, 

regulatory and technical best practices, and 

renewable portfolio standards (RPS) and market 

structures. 

SEPA: $1,597,092 (FY 2007–FY 2009) 

( 

SEPA works with utilities through utility-owned 

systems and utility programs to facilitate 

customers’ use and ownership of solar electric 

power. 

3. Results and Accomplishments 

The DOE and NARUC State Solar Energy 

Analysis Partnerships created work plans and are 

working closely together to reach the outlined 

goals. Twelve state commissions are involved in 

direct NREL assistance for solar-related technical 

and policy issues. Through these partnerships, 

best practices and policy standards are being 

created for state use in future decision-making. 

NARUC released the Solar Energy Technology 

and Policy Reference Guide, available from; 

www.naruc.org/programs.cfm?c=Domestic. 

Solar Energy Institute for Southeastern 

Legislators: NCSL Held the Solar Energy Institute 

in Washington, DC for on October 8-9, 2009. , The 

meeting was tailored to the Southeast and 

included a tour of the solar decathlon NCSL). 

Solar Legisbriefs: NCSL published a legisbrief on 

financing renewable energy through property tax 

assessments and utility on-bill programs. 

Solar Legislation Database: NCSL expanded the 

reach of its solar legislation database 

(www.ncsl.org/?tabid=13011), which now contains 

nearly 800 solar-related bills. 

Solar Information and Analysis for Legislators: 

NCSL responded to more than 50 solar-specific 

information requests in 2009 by state legislators 

and their staff. NCSL testified before legislators in 

Nebraska on renewable energy and solar policy. 

Solar Regional Utility Outreach Coordinators: 

SEPA’s three regional directors continued and 

expanded their direct utility outreach efforts. 

Utility Solar Toolkit & Tools: SEPA launched the 

Utility Solar Toolkit on their website, with 

numerous solar resources. 

Utility Focus at Events: SEPA held two solar 

industry conferences: the Utility Solar Conference 

was geared toward utilities exclusively with 

approximately 300 attendees, and the Solar Power 

International Conference had utility-only events 

such as networking and conference sessions 

geared toward utility interests. 

Utility Focused Research Reports: SEPA released 

six research reports pertaining to topics that relate 

to utilities’ interest in solar. 

PV Peer Network: CEG added new members to 

the PV Peer Network, a listserve comprising more 

than 100 state clean energy fund managers, policy 

leaders, and stakeholders from 30 states, Puerto 

Rico, and Guam. Four Network webinars were 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D 

 

R A F T

held on PV cost trends, state solar program 

initiatives, and solar marketing strategies. 

State-Federal RPS Implementation Collaborative: 

CEG managed the collaborative, released 

Recommended Principles and Best Practices for 

State RPS Programs, and organized the second 

annual National RPS Summit. 

Smart Solar Marketing Strategies Report: CEG 

and SmartPower published Smart Solar Marketing 

Strategies: A Clean Energy State Program Guide. 

Solar Workshops: CEG held a “State Best 

Practices for Solar Marketing workshop at the 

Clean Energy States Alliance (CESA) national 

meeting; conducted session on state solar 

program innovations at the ASES Solar 

Conference; held a session for CESA on the 

implications for state solar programs of increasing 

utility interest in supporting/owning solar PV; 

presented at a Midwest State Recovery 

Roundtable; and presented at the Council of State 

Governments annual meeting on approaches to 

clean energy and solar project financing. 

Primer on RE Finance Tools for States: CEG and 

CESA published Distributed Renewable Energy 

Finance and Policy Toolkit, a guidebook to assist 

states in using effective financing tools to support 

clean energy project development. 

Direct State Support: CEG furnished direct 

technical assistance to more than 15 state solar 

programs and more than 50 state officials on solar 

policy and program development. 

Renewable Energy Database: CEG and CESA 

developed a national database to summarize the 

project results and trends of state efforts 

(www.statesadvancingsolar.org) and listserve 

(pvpeernetwork@cleanenergystates.org). 

4. Planned FY 2010 Activities 

CEG 

•	 Hold a webinar on a new CESA report, 

Distributed Renewable Energy Finance and 

Policy Toolkit (03/10), and on RPS support 

policies for PV technology (06/10) 

•	 Hold solar workshops, including PACE 

financing for CESA national meeting (02/10) 

•	 Present State Solar Marketing 

Recommendations Report at the 2010 ASES 

Meeting (05/10) 

•	 Release annual revision to state clean energy 

funding results database (05/10). 

NARUC 

Activities for FY 2010 will consist of a mixture of 

written reports and trainings for NARUC and 

NASEO members, including: 

•	 Complete FAQ on feed-in tariffs for state 

government officials 

•	 Go on solar fact-finding mission to Europe with 

Solar States Working Group (08/10) 

•	 Write paper on solar policy design and its 

effect on the advancement of solar energy 

(08/10). 

NCSL 

•	 Another Solar Policy Institute for southeastern 

state legislators 

•	 Expand current technical outreach with 

several states that are developing solar and 

renewable energy incentives 

•	 Contact newly elected legislators to supply 

information and technical assistance on solar 

energy other renewable energy issues 

•	 Hold a web-audio conference for state 

policymakers on property-assessed clean 

energy financing, case studies, and options 

•	 Continue to refine and expand solar bill 

tracking abilities, adding summaries of solar 

policy activity to NCSL’s web site. 

SEPA 

•	 Contact target utilities and facilitate regional 

working group meetings and regional 

workshops 

•	 Conduct 2nd Utility Solar Conference, May 

2010, in Colorado 

•	 Hold utility networking receptions at various 

industry functions, continue adding to peer 

networking tool and publicizing it 

•	 Develop research tools, including research 

reports, solar toolkit, newsletters, and 

webinars. 

5. Major FY 2009 Publications 

G. Andersen, “Financing Renewable Energy and 

Energy Efficiency,” Legisbrief 17(31) (AugustSeptember 2009). 

SEPA, Special Report: Electric Utilities and Solar: 

A Market Review, Washington, DC: Solar 

Electric Power Association, October 2008. 

W. Shirley and M. Taylor, Decoupling Utility Profits 

for Sales,” Washington, DC: Solar Electric Power 

Association, February 2009. 

C. Kubert and M. Sinclair, Distributed Renewable 

Energy Finance and Policy Toolkit, Montpelier, 

VT: Clean Energy States Alliance, December 
 

D R A F T

2009. Available from: 

http://www.cleanenergystates.org/Publications/c 

esa-financial_Toolkit_Dec2009.pdf. 

6. Industry Partners 

The following organizations partnered in the project’s research activities during FY 2009. 

(These awards were fully funded in FY 2007; however, the awards actively pursued project goals through FY 2009.) 

Organization/ 

Principal Investigator Location/E-mail Description/Title of Research Activity 

John Nimmons & 

Associates, Morse and 

Associates 

1220 19th St., NW, Suite 401, 

Washington, DC Facilitating Utility Use and Integration of Solar 

Electric Power 
 

 

 

 

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___________________________________________________________________________________ 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Photovoltaic Cost Trends 

D R A F T

Performing Organization: Lawrence Berkeley National Laboratory (LBNL) 

Key Technical Contact: Ryan Wiser (LBNL), 510-486-5474, rhwiser@lbl.gov 

DOE HQ Technology Manager: Charlie Hemmeline, 202-586-6646, charles.hemmeline@ee.doe.gov 

FY 2009 Budget: $50K 

Objectives 

•	 Summarize and analyze trends in the installed cost of grid-connected photovoltaic (PV) systems 

in the United States based on project-level cost data. 

Accomplishments 

•	 Completed inaugural edition in Tracking the Sun report series (February 2009) 

•	 Completed all analysis and a review draft of the second report in the series, Tracking the Sun II 

(final report published in early FY 2010) 

•	 Presented the work in numerous forums, including CPUC workshop, PG&E briefing, SPI 2008, 

webinars sponsored by SEPA, and the PV Peer Review Network 

•	 Contributed to DOE’s Solar Market Data Report and NREL’s Open PV Project. 

Future Directions 

•	 Compete third edition of the Tracking the Sun report series (publication expected July 2010)which 

will summarize cost trends for projects installed through 2009 

•	 Compete statistical analysis of cost data and associated journal article 

•	 Continue contributions to DOE’s annual Solar Market Data Report. 

1. Introduction 

The project analyzes trends related to the installed 

cost of grid-connected PV systems in the United 

States. 

2. Technical Approach 

The analysis uses project-level data collected from 

PV incentive programs throughout the country. 

The most recent edition, Tracking the Sun II, was 

based on data from approximately 71% of all gridconnected PV systems installed nationwide from 

1998 to 2008. 

3. Results and Accomplishments 

LBNL completed its second annual Tracking the 

Sun report (October 2009). The report series has 

proven to be highly valuable to the solar industry 

and policy makers: it represents the only detailed 

summary of U.S. installed cost trends, based on a 

reasonably comprehensive dataset. These data 

and the associated analyses also formed a key 

input into DOE’s annual Solar Market Data Report. 

4. Planned FY 2010 Activities 

LBNL will again produce an updated report on 

installed cost trends for PV systems installed 

through 2009. The data will be collected from the 

same PV incentive programs as before, potentially 

adding several more programs. Publication is 

expected in July 2010. The data and updated 

analysis will again be a key input into the third 

annual DOE solar data report. FY 2010 funding 

will also allow LBNL to contribute to database 

coordination among parties (including SEIA, 

NREL, and IREC) developing datasets of 

installation-level PV data. Funding will also be 

used to conduct more-detailed statistical analysis. 

5. Major FY 2009 Publication 

R. Wiser, G. Barbose, and C. Peterman, Tracking 

the Sun, LBNL-1516E, Berkeley, CA: Lawrence 

Berkeley National Laboratory (2009). 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Concentrating Solar Power Highlights
 

D R A F T

The revitalization of Concentrating Solar Power (CSP) that began in fiscal year 2007, continued in 

FY 2009 but at an accelerated pace. Although the normal appropriation maintained the budget at 

$30 million, the American Recovery and Reinvestment Act of 2009 (ARRA) doubled that amount. 

The combination enabled the addition of 15 new storage contracts with the industry and 

universities as well as the addition of new and upgraded facilities at both Sandia National 

Laboratories (SNL) and the National Renewable Energy Laboratory (NREL). These new activities 

complemented research and development (R&D) carried out by the labs and the dozen existing 

R&D contracts with industry that addressed many aspects of trough, tower, dish, and Fresnel 

systems. Optimism for continued growth led to the development of a baseload funding 

opportunity announcement to address the long-term potential of CSP. Awards for this solicitation 

will be made in FY 2010. In addition to R&D, the CSP subprogram worked closely with the 

Bureau of Land Management (BLM) on the Solar Programmatic Impact Statement (PEIS). 

The addition of storage contracts in FY 2009 is indicative of the high value the U.S. Department 

of Energy (DOE) places on CSP systems capable of storing energy. These new contracts are 

exploring salt mixtures with lower melting points and higher heat capacities, a number of phase 

change materials, storage in solids, and storage through chemical reactions. Another set of 

storage activities resulted from a solicitation specifically for national laboratories that was enabled 

by the ARRA funding. This solicitation led to awards from six laboratories: three for storage and 

three for advanced heat transfer fluids. 

Most of the ARRA funding, however, went toward facilities, with both SNL and NREL establishing 

laboratories to do materials research and to help industry test component concepts. Both labs 

also improved those facilities which help the industry to determine the performance of solar 

collectors. ARRA funds enabled SNL to replace the 35-year-old glass reflectors on the heliostats 

at the National Solar Thermal Test Facility. In cooperation with Southern California Edison, ARRA 

funds were also used to decommission Solar II, which had fallen into disrepair. 

Work on the PEIS accelerated during FY 2009. BLM, which was not able to provide funding for 

the PEIS during FY 2008, added nearly $10 million to the effort in FY 2009, significantly 

increasing the work being done by Argonne National Laboratory (ANL) to gather environmental 

data and identify areas of the southwest best suited for large utility-scale solar projects. BLM 

announced 24 solar study areas comprising 676,000 acres (over 1,000 square miles) which may 

be appropriate for solar. ANL looked at each area in more detail than previously planned, pushing 

back the completion of the draft to December 2010 and the final PEIS to December 2011. 

NREL SNL Other Solar 

Total $K Total $K Total $K Total $K 

Concentrating Solar Power 6726 6035 17239 30000 

Parabolic Trough R&D 1949 580 4669 7198 

Dish/Stirling R&D 0 1500 1765 3265 

Thermal Storage R&D 965 1250 3743 5958 

Advanced CSP Concepts 725 900 2910 4535 

CSP Market Transformation 2435 250 2240 4925 

Operations & Planning 652 1555 1912 4120 

ARRA funds 4400 18400 8100 30900 

SNL facilities 0 18400 0 18400 

Solar 2 decommission 0 0 2500 2500 

NREL facilities 4400 0 0 4400 

Laboratory solicitation 1000 0 4600 5600 
Parabolic Trough R&D

Performing Organizations: National Renewable Energy Laboratory (NREL)

 Sandia National Laboratories (SNL)

 

Key Technical Contacts: Chuck Kutscher (NREL), 303-384-7521, chuck.kutscher@nrel.gov 

Tim Moss (SNL), tamoss@sandia.gov 

 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budgets: $2,277K (NREL), $780K (SNL)

____________________________________________________________________________________

Objectives

NREL

• Support development of near-term parabolic trough technology for central station power 

generation

• Support development of advanced technologies for next-generation parabolic trough solar fields, 

thermal energy storage, and power plant technologies to meet long-term goals of the DOE Solar 

Program Multi-Year Technical Plan (MYTP)

• Support the expansion of U.S. industry to supply parabolic trough technology

• Support continued SunLab collaboration on parabolic trough technology development and testing.

SNL

• Improve TOP mirror alignment of existing trough plants that increases the intercept factor, which 

increases the efficiency of the plant, which decreases the LCOE:

o Improve algorithm calculating amount of mirror misalignment

o Improve data acquisition program to obtain photographs with optimum contrast and hue to 

optimize edge finding in the data analysis program

o Improve analysis program for less human interaction finding mirror and receiver edges

o Align a second loop at Kramer Junction and Sunray– yet to be determined

• Use salt in troughs to allow higher operating temperatures and increase the efficiency of the 

turbine generator as well as thermal storage, which will lower the LCOE; salt, however, has a 

higher freezing temperature than the current fluid being used (approximately 100°C vs. 15°C); 

explore ways to recover from a freeze and its effects on the receiver

• Test trough module and receiver on the AZTRAK rotating platform

• Test Sky Fuel trough module in early 2010.

Accomplishments

NREL

Trough Solar Field

Reflector Optical Measurement

• Used the Video Scanning Hartmann Optical Test (VSHOT) instrument to evaluate the new 

SkyTrough parabolic trough collector; made significant improvements; tested individual mirrors 

from Rioglass and a SolarCat dish

• Developed a larger target for VSHOT to allow testing of larger mirrors.

Receiver Heat Loss

• Tested the newest model Schott and Solel receiver tubes and performed preliminary experiments 

on the impact of xenon/hydrogen mixtures in the receiver vacuum space

• Performed preliminary tests on a system to inject inert gas into contaminated receivers in the field.

Hydrogen Mitigation

• Expanded computer model of hydrogen generation and transport to include an estimate of the time 

required to remove hydrogen from an operating trough field; also signed a nondisclosure 

agreement with FPL Energy and began discussions of collaborative work in FY 2010.

Optical Efficiency Test Loop

D R A F T
• Completed normal incidence and incident angle modifier testing of the SkyFuel parabolic trough 

collector and helped SkyFuel make design improvements. 

Advanced Trough Materials

• Signed a license agreement with a U.S. industry partner who will license the improved solar 

selective coating.

Distant Observer Technique

• Significantly improved analysis software needed to determine receiver position and mirror slope 

errors from photographic images taken from an aerial platform; performed numerous tests of a 

small test collector using a camera mounted in both a balloon and a radio-controlled plane; took 

images of the SkyTrough from elevated land-based positions. 

Power Cycle and Balance of Plant

Heat Rejection

• Produced a report giving the water savings and cost penalties associated with air and hybrid 

cooling (WorleyParsons). 

O&M Cost Analysis

• Prepared a report summarizing O&M data.

Plant Optimization and Costing

• Compared various modeling programs and chose IPSEpro because it provides the most flexibility 

for user-generated subroutines

Industry Support

• Served as technical advisors for four trough FOA contracts: Abengoa, Solar Millennium, Alcoa, 

and SkyFuel 

• Provided technical support to a wide range of CSP companies, including SkyFuel, Abengoa, 

Schott, Solel, and Rioglass.

SNL

TOP Alignment

• Modified TOPCAT software to account for module-to-module alignment issues within a solar 

collector array (SCA), perspective, and mirror focal length deviations from the ideal 

• Enabled TOPCAT software to manually control camera brightness and hue to account for the 

variability of daylight from morning to afternoon and from clear sky to cloudy skies

• Modified TOPCAT hardware and software to accommodate LS-3 modules

• Acquired TOP Alignment data for multiple loops at SEGS II, VI, VII, VIII, and IX

• Aligned one LS-3 loop at SEGSVIII that resulted in more than 5°F, or more than 3.5%, increase in 

the temperature of that loop.

Salt Freeze/Thaw

• Researched impedance heating as a means to recover from a freeze.

• Researched receivers filled with salt will plastically deform during a freeze/thaw if it is completely 

filled with salt but does not bend at all if it is only partially filled.

Testing

• Consolidated control room instrumentation racks to increase overall space to facilitate the SkyFuel 

testing; the software is being upgraded to allow all operations to run on one computer instead of 

two.

Future Directions

NREL

Trough Solar Field

Reflector Optical Measurement

• Continue to improve the VSHOT capability, with an emphasis on developing a platform for 

performing outdoor tests

• Continue to test collectors from manufacturers such as SkyFuel, Alcoa, Abengoa, and FPL 

Energy. 

Receiver Heat Loss

D R A F T
• Test various mixtures of hydrogen and inert gas in receiver tubes; continue to test the latest 

receiver designs.

Hydrogen Mitigation

• Perform tests of hydrogen purging in the receiver test laboratory. 

Optical Efficiency Test Loop

• Conduct optical efficiency measurements of the new Alcoa and Abengoa collectors; this will 

include both normal incidence and incidence angle modifier tests. 

Advanced Trough Materials

• Continue outdoor and weatherometer tests to determine long-term durability of reflector 

materials

• Develop an accelerated test for anti-soiling coatings.

Distant Observer Technique

• Perform distant observer testing at one or more operating parabolic trough plants.

Power Cycle and Balance-of-Plant

Plant Optimization and Costing

• Develop a detailed parabolic trough model.

Heat Rejection

• Use IPSEpro to conduct analyze parallel hybrid cooling systems for parabolic trough plants and 

publish a paper on this subject.

Industry Support

• Continue to provide support for industry FOA contracts as well as provide other industry support 

on an as-needed basis. 

SNL

TOP Alignment

• Align another loop at SEGS II and SEGS VI (or VII depending on the plant operators), or more, 

and document its improvement.

________________________________________________________________________________

1. Introduction

Parabolic trough technology is now actively being 

reintroduced into the marketplace. The Acciona 

Solar 64 MW Nevada Solar One power plant 

outside of Las Vegas was dedicated in October 

2008 (Fig. 1). The focus of the DOE parabolic 

trough R&D efforts has been to:

• Advance technologies that have an 

opportunity to be deployed in early projects

• Encourage the development of advanced 

technologies that will improve the 

competitiveness of future parabolic trough 

plants

• Encourage expanded U.S. supply in these 

early plants

• Develop improved tools, testing capabilities, 

and the knowledge base necessary to support 

the needs of a growing U.S. parabolic trough 

industry. 

2. Technical Approach

At NREL, the parabolic trough R&D effort is 

divided into three areas: (1) trough solar field, (2) 

power cycle and balance of plant, and (3) industry 

support.

Fig. 1. New 64-MW Solar One power plant using 

Acciona parabolic trough concentrator and Schott 

receivers.

2.1 Trough Solar Field 

The solar field technology agreement focuses on 

SunLab development of new parabolic trough 

solar technology and tools for evaluating trough 

technology. In FY 2009, NREL activities focused 

on the following:

D R A F T
Reflector Optical Measurement: The Video 

Scanning Hartmann Optical Test (VSHOT) 

instrument (see Fig. 2) allows NREL to quickly 

assess the accuracy of the reflector shape. NREL 

is constantly improving this technology and using it 

to help industry maximize the accuracy of new 

mirrors and collectors. 

Fig. 2. Optical testing of new SkyTrough collector.

Receiver Heat Loss: NREL measures the heat 

loss of the latest commercial receiver tubes in its 

receiver test laboratory. This laboratory is also 

used to study means for mitigating hydrogen gas 

infiltration into receiver tubes. The apparatus is 

shown in Figure 3. 

Hydrogen Mitigation: NREL uses a computer 

model of hydrogen generation and transport to 

examine ways to mitigate this problem, which 

increases receiver heat loss. NREL also invented 

a concept for removing hydrogen centrally in a 

plant and is working with an industry partner to 

test this concept in an actual plant.

Fig. 3. Parabolic trough receiver thermal loss test 

bed.

Optical Efficiency Test Loop: NREL's loop consists 

of a two-axis tracker and fluid flow system that 

allows the direct outdoor measurement of the 

overall optical efficiency of parabolic trough 

collectors at normal and off-normal incidence 

angles.

Advanced Trough Materials: NREL uses extensive 

materials testing capability to measure the 

performance of reflector and absorber materials. 

State-of-the art deposition chambers are used to 

create new thin-film coatings. Outdoor test racks 

and weatherometers are used to determine the 

long-term durability of materials, and the results 

are compiled into an extensive materials data 

base. 

Distant Observer Technique: NREL is developing 

an aerial-mounted photographic technique for 

rapidly assessing the performance of an individual 

collector or an entire field of collectors. By 

analyzing photographs of the images of receiver 

tubes in the collector mirrors taken at a distance 

and from different angles, errors associated with 

mirror slope errors and receiver positioning can be 

determined.

2.2 Power Cycle and Balance of Plant

The power cycle and balance of plant agreement 

focuses on improving overall parabolic plant 

performance.

Plant Optimization and Costing: NREL has used 

subcontractors and consultants to perform overall 

plant modeling, but determined it is more costeffective and provides greater flexibility in analysis 

to bring this capability in-house. NREL compared 

different commercial modeling packages and 

chose one that was best suited to our needs. This 

model is being used to optimize CSP plants and 

subsystems, and it can generate results for 

inclusion in the Solar Advisor Model.

Heat Rejection: Water consumption is a key 

concern with CSP plants in desert regions of the 

Southwest. This activity uses computer models to 

study alternative means for reducing water 

consumption.

2.3 Industry Support

This activity focuses on technical support to the 

CSP industry. NREL provides technical support to 

a wide range of CSP industry members, including 

FOA awardees. 

2.4 TOP Alignment 

D R A F T
The development of the TOP Alignment system 

has been a stepped approach. The average time 

to acquire data started at 70 s/module and has 

been reduced to less than 20 s/module thanks to 

hardware and software improvements. TOPCAT 

has been used to acquire data from at least one 

loop at every LS-2 and LS-3 trough plant in 

California. The first loops aligned were LS-2 loops 

at SEGSVI, which saw less than 10°F 

improvement, and SEGSII, which saw no 

improvement. The null improvement at SEGS II 

led to improving the mirror alignment algorithm to 

include module-to-module misalignments within an 

SCA, perspective, and different mirror focal 

lengths. After these improvements, a LS-3 loop at 

SEGS VIII was aligned with a documented 

improvement of 5°F, or 3.5%. Improvements in the 

analysis software will be aimed to increase its 

ability to find the mirror and receiver edges to 

decrease the analysis time from the current 5 

min/module.

2.5 Rotating Platform

The system has not operated since early 2004. To 

facilitate startup, all legacy systems were removed 

and the remaining systems consolidated. The 

software was also upgraded. The data acquisition 

system will be upgraded later in FY 2010.

2.6 Salt Freeze/Thaw

This was designed to be a quick test to 

understand the effects of salt freezing and thawing 

in trough receivers. The receivers are mounted 

above ground horizontally and filled with HiTec HT 

salt with a freezing point around 120°C.

3. Results and Accomplishments

3.1 Trough Solar Field 

Reflector Optical Measurement: In FY 2009 NREL 

made additional improvements to this technology, 

such as constructing an outdoor test platform. 

NREL used the capability to measure the 

performance of several industry collectors and 

mirrors. Extensive testing resulted in significant 

improvements to the SkyFuel parabolic trough 

collector, and this won a 2009 R&D 100 Award. 

Receiver Heat Loss: NREL continued to obtain 

performance data on the latest receiver designs 

and also conducted tests on receiver tubes 

containing xenon gas. The latest test results on 

the effect of xenon on the Schott PTR 70 receiver 

tube are shown in Figure 4.

Advanced Absorber Materials: NREL finalized a 

licensing agreement with a major receiver 

manufacturer to develop NREL’s low-emittance 

absorber coating (Fig. 5).

Hydrogen Mitigation: NREL expanded its 

computer model of hydrogen generation and 

transport to include an estimate of the time 

required to remove hydrogen from an operating 

trough field. NREL also signed a nondisclosure 

agreement with FPL Energy and began 

discussions of collaborative work in FY 2010.

Optical Efficiency Test Loop: NREL completed 

normal incidence and incident angle modifier 

testing of the SkyFuel parabolic trough collector 

and helped SkyFuel make design improvements. 

Control modifications were made to the two-axis 

tracker to allow for incident angle modifier tests.

Distant Observer Technique: NREL obtained 

several large balloons, including a radio-controlled 

gimbal for carrying a camera. NREL also obtained 

a telescope for taking distant images from ground 

locations. Extensive imaging was taken of the 

SkyTrough collector and a smaller test collector. 

Significant improvements were made in the 

software used to analyze the images. 

Photogrammetry methods were also used to 

accurately determine the position of the camera. 

In FY 2009, NREL reached an agreement with 

Schott to license our low-emissivity absorber 

coating. 

Fig. 4. Parabolic trough receiver thermal loss test 

bed results for mixed gases.

0.01 0.1 1 10 100 1000 10000 100000

0

100

200

300

400

500

600

700

800

900

Gas pressure in HCE annulus (Pa)

Heat loss from HCE (W/m length)

100% Hydrogen

75% Xenon/25% Hydrogen

100% Xenon
Fig. 5. In foreground of photo, NREL#6A solar 

selective coating deposited by directly and 

reactively evaporating the layers by elemental codeposition. Shown in the background is the 

deposition system.

FY 2009 milestones:

- Completed VSHOT measurements of slope 

error of new SkyTrough solar collector

- Completed optical efficiency measurements of 

SkyTrough Collector and issued a report

- Deployed a prototype distant observer tool 

(09/09)

- Completed heat loss testing of latest Schott 

PTR70 and PTR80 receivers.

3.2 Power Cycle and Balance of Plant

Plant Optimization and Costing: In FY 2009 NREL 

compared various computer models that can be 

applied to CSP power plants: Aspen, GateCycle, 

TRNSYS, and IPSEpro. IPSEpro was deemed the 

most powerful and adaptable. It is also used by 

EPRI and by European CSP researchers, making 

it possible to compare and share modules. We

began to develop a detailed parabolic trough 

model.

Heat Rejection: NREL made final improvements to 

a report to Congress, NREL also began to develop 

cooling system models in IPSEpro.

FY 2009 milestones:

- Completed report to DOE, “Concentrating 

Solar Power Commercial Application Study:

Reducing Water Consumption of 

Concentrating Solar Power Electricity 

Generation”

- Identified and obtained IPSEpro, process 

simulation software (06/09)

- Completed a detailed power plant model 

(09/09).

3.3 Industry Support

NREL provided technical support to a wide range 

of CSP industry members, including FOA 

awardees. 

FY 2009 milestones:

• Participated in regular review meetings and for 

SkyFuel, Abengoa, Alcoa, and Solar 

Millennium FOA line focus collector projects

• Provided VSHOT measurement support to 

Alcoa and SkyFuel.

3.4 TOP Alignment

SNL’s data acquisition improvements in the 

hardware included using GigE cameras with an 

auto-brightness ability greatly increased the 

download times and the time to obtain a 

photograph within a certain manually determined 

exposure, mounting a new and improved TOPCAT 

system on the back of a truck instead of a trailer 

greatly improved mobility in the field, added ability 

to use system on LS-3 modules, and a ultrasonic 

meter to measure the actual distance from the 

camera to the trough module. With the 

improvements in the acquisition hardware and 

software the time to acquire data was reduced 

from 70 seconds/module to less than 20 

seconds/module. With close to 5,000 modules for 

each 30 MW trough plant reducing this time is very 

important. The data analysis software was 

improved to account for module-to-module 

alignments within an SCA, the perspective from 

the cameras not being perfectly aligned to the 

trough module, and changes in the mirror focal 

lengths being different from the ideal focal length. 

With these improvements a LS-3 loop at SEGS 

VIII was aligned. Very good temperature data was 

obtained before and after the alignment that 

showed a 5°F, or 3.5%, improvement in 

temperature.

FY 2009 task/milestones:

o Align an LS-3 loop (05/09).

3.5 Rotating Platform Testing

In general, SNL prepared the rotating platform 

system for testing the SkyFuel trough module. The 

software was updated to the latest version. The oil 

loop interlock box made up of relays, which many 

were sticky and not operating properly, was 

replaced with a FPGA-based system.

FY 2009 task/milestones:

o Complete testing of SkyFuel trough module 

(not completed). 

This was not completed because SkyFuel did not 

deliver a trough module to test. It was installed on 
the rotating platform the last week of September. 

The testing is scheduled to be completed 07/10.

3.6 Salt Freeze/Thaw

SNL completely set up a new system with data 

acquisition, controller, impedance heating system, 

and set up two trough modules for the freeze/thaw 

test. Because of equipment problems, the 

computer and controller both died on the same 

day, and testing is still ongoing.

4. Planned FY 2010 Activities

The NREL task/milestones are as follows:

• Extend VSHOT capability to examine the 

impact of structural loads on reflector shape

• Test the Distant Observer system at an 

operating parabolic trough installation

• Test the Alcoa and Abengoa parabolic trough 

collectors at the Optical Efficiency Test Loop

• Improve the speed of the SolTrace optical 

computer model

• Conduct receiver heat loss measurements on 

the latest commercial receiver tubes, including 

a tube that uses NREL’s low-emissivity 

coating

• Test a hydrogen mitigation method at an 

operating parabolic trough plant

• Utilize in-house modeling capability to 

evaluate the performance of hybrid cooling 

systems

• Provide continued technical assistance to the 

CSP industry, especially for those companies 

that won contracts under the parabolic trough 

Federal Opportunity Announcement (FOA).

The SNL task/milestones are as follows: 

• Continue upgrades on the TOPCAT system 

(09/08)

• Modify TOPCAT for the Solar Millennium 

trough (03/10)

• Complete testing of the SkyFuel trough 

module on the rotating platform (7/10)

• Begin work on a trough sensor for closed loop 

tracking (9/10).

5. Major FY 2009 Publications

K. Stynes, C. Gawlik, C. Kennedy, and C. 

Kutscher, “Optical Efficiency Measurements of 

the SkyTrough Solar Collector,” April 10, 2009.

F. Burkholder and C. Kutscher, “Heat Loss Testing 

of Schott’s 2008 PTR70 Parabolic Trough 

Receiver.” 

J. Crawford and F. Burkholder, “Heat Loss Testing 

of Schott’s Prototype PTR 80-4.7 (2008) 

Parabolic Trough Receiver,” August 2009.

K. Stynes, F. Burkholder, G. Jorgensen, A. Gray, 

T. Wendelin, K. Gawlik, and J. Crawford, 

“Feasibility Study of the Distant Observer 

Method for Rapid Optical Characterization of 

Parabolic Trough Solar Fields,” September 2009.

6. University and Industry Partners

The following organizations received subcontract funds to support activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity FY 2009($K)

WorleyParsons Dry and hybrid cooling systems analysis $100

Kearney and Associates Seattle, WA

dwk@jkearney.com

Development of a solar field acceptance test 

standard $25
Parabolic Trough Industry Projects

Performing Organizations: Alcoa, Inc. 

Abengoa Solar, Inc. 

Key Technical Contacts: Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953,

carolyn.elam@go.doe.gov 

Jim Payne, DOE/GO, 303-275-4756, jim.payne@go.doe.gov 

Brad Ring, DOE/GO, 303-275-4930, brad.ring@go.doe.gov 

DOE HQ Technology Managers: Frank (Tex) Wilkins, (202) 586-1684, frank.wilkins@ee.doe.gov 

Tommy Rueckert, (202) 586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budgets: $1,222K

____________________________________________________________________________________

Objectives

• Develop energy supply technologies that are reliable, affordable, and environmentally sound; 

expand national electricity generation portfolio to increase energy security by diversifying 

domestic energy supply options. Concentrating solar power (CSP) is one of the most attractive 

renewable energy options in the southwestern United States, with a nominal levelized cost of 

energy (LCOE) target of 7–¢10¢/kWh by 2015 and 5–¢7¢/kWh by 2020

• Advance U.S.-based trough technology by encouraging development and eventual U.S. 

manufacturing of key parabolic trough components or subsystems

• Emphasize design for manufacturability and/or near-term (commercial applications within the next 

5 years) U.S. supply of key parabolic trough components or subsystems. 

Accomplishments

• Announced competitive selections in late 2007 and made awards before mid-2008

• Defined roles and responsibilities of program management team, including technical advisors at 

the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories

• Finished Phase 1 (two projects; now in Phase 2); the third project is near the end of Phase 1. 

Future Directions

• Evaluate progress toward critical milestones and make decisions at the end of the each project’s 

first phase, starting in FY 2009 and extending into FY 2010. 

____________________________________________________________________________________

1. Introduction

These CSP trough development activities are 

expected to produce commercial parabolic 

trough components or subsystems within the 

next 5 years, enabling CSP to meet a nominal 

LCOE target of 7¢–10¢/kWh by 2015 and 5¢–

7¢/kWh by 2020.

One objective of this area of interest is to 

advance U.S.-based trough technology by 

encouraging the development and eventual U.S. 

manufacturing of key parabolic trough 

components or subsystems that currently can be 

obtained only from a few foreign companies. 

The selected projects are:

Organization, Principal Investigator,

and Agreement Title

FY 2009 

Budget 

($K) 

Alcoa, Inc.—Adam Schaut

“Reflector Technology Development 

and System Design for CSP 

Technologies”

402

Abengoa Solar, Inc.—Keith Boyle

“Development of Advanced Polymeric 

Reflector for Concentrating Solar 

Power”

609

Abengoa Solar, Inc.—Patrick 

Marcotte

“Development of Next-Generation 

Parabolic Trough Collectors and 

Components for CSP Applications"

D 

211

R A F T
Alcoa, Inc.

Reflector Technology Development and System Design for CSP Technologies

Total Award: $3,658K DOE/Recipient: $2,128K/$1,530K

Objectives

• Develop aluminum-intensive collector with superior total life-cycle cost

• Achieve 25%–50% cost savings for the solar field, lowering LCOE at least 20%

• Achieve high optical performance and superior outdoor durability (10 years)

• Positively affect U.S. manufacturing base. 

Accomplishments

• Showed two independent approaches to reflective surface development had performance or cost 

parity with commercially available technology, so this portion of the program was discontinued

• Performed detailed design, performance analysis, and cost modeling on an advanced, aluminumintensive trough concept

• Found through cost modeling that 20%–25% solar field cost saving is achievable

• Fabricated and tested full-scale trough prototype at Alcoa Technology Center to validate 

performance of advanced trough concept.

Future Directions

• Continue validation testing of trough prototype at NREL

• Complete Phase 2 report, including revising Phase 3 plans based on Phase 2 results

• Initiate Phase 3. 

____________________________________________________________________________________

1. Introduction

Current baseline solar trough collectors differ in 

supporting structure (aluminum space frame vs. 

steel torque-box), but both predominantly use 

parabolic, silver-metalized glass mirrors, which

have disadvantages such as fragility, weight, and 

cost. Alcoa is using an optimized system design 

approach to develop an advanced, aluminumintensive collector. 

2. Technical Approach

Alcoa’s efforts on this program during FY 2009 

focused on Phase 2 of a three-phase project. The 

technical approach followed the tasks outlined in 

Alcoa’s Statement of Project Objectives. These 

high level tasks are as follows:

2.1 Reflective Surface Optimization

2.2 Detail System Design

2.3 Internal Critical Design Review

2.4 Prototype Build 

2.5 System Validation

2.6 Update Phase 3 Plan

2.7 Phase 2 Review with DOE. 

3. Results and Accomplishments

Alcoa researchers investigated two aluminumbased reflective surface development approaches 

throughout Phases 1 and 2 of the program: thin 

film and silver film. For thin film, they used 

deposition testing on coated and leveled aluminum 

sheets via accelerated procedures, finding that the 

required reflectivity could not be obtained at a 

lower cost compared to commercially available 

thin film products. For silver film, they produced 

and evaluated various silver-metalized films. 

Although reflective performance targets could be 

obtained, the estimated cost would be at parity to 

commercially available silver film products. Based 

on these results, Alcoa discontinued developing 

an aluminum reflective product for CSP 

applications.

Alcoa completed the detailed design, analysis, and 

cost modeling for the down-selected trough 

concept from Phase 1. Because the design still 

achieved desired production cost targets, they 

built a full-scale trough prototype to validate the 

performance of the design. In 2009, the trough 

prototype was structurally and optically (V-Shot) 

tested at Alcoa. Final validation of the prototype 

trough will be done at NREL in 2010, which will 

conclude Phase 2 of the program.

4. Planned FY 2010 Activities

In 2010, the full-scale trough prototype will be 

shipped to Golden for further performance 

D R A F T
validation testing on NREL’s large payload tracker. 

Prototype validation testing will include VSHOT, 

wind loading, and thermal efficiency.

Initial results will be available by mid-2010, and 

although additional thermal efficiency work will 

continue throughout 2010, Phase 2 completion will 

be based on the initial results. Phase 2 reporting, 

a rescoping of Phase 3, and the decision about 

proceeding to Phase 3 will be completed.

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

Alcoa, Inc./Adam 

Schaut Alcoa Technical Center, PA

Adam.schaut@alcoa.com

Recipient/Awardee, Reflector Technology Development 

and System Design for Concentrating Solar Power 

(CSP) Technologies

CSP Services (DLR)/

Eckhard Luepfert

Cologne, Germany

e.luepfert@cspservices.de

Subcontractor to Alcoa, Inc., CSP technology and 

performance expertise

D R A F T
Abengoa Solar, Inc.

Development of Advanced Polymeric Reflector for Concentrating Solar Power

Total Award: $2,076K DOE/Recipient: $1,512K/$565K 

Objectives

• Reduce cost of parabolic trough collector systems by reducing cost of reflector

• Develop reflector technology that will be used in Abengoa Solar’s U.S. projects planned for initial 

operation in 2010–2013 timeframe

• Source as much collector technology (e.g., reflector components) from U.S. sources as possible.

Accomplishments

• Successfully transferred and validated deposition process from lab to commercial environment

• Produced high-quality, hard coat protected samples with reflectance, well beyond glass mirrors

• Completed Phase 1 objectives with cost model results showing a clear path to reduced LCOE. 

Future Directions

• Transfer, refine, and validate process for pilot-scale production

• Create full-scale solar reflector using ASRM

• Complete Phase 2 objectives; use Phase 2 results to show a reasonable path to reduced LCOE. 

____________________________________________________________________________________

1. Introduction

The Abengoa team is evaluating the possibility of 

commercial production of a lab-scale advanced 

solar reflector material (ASRM) for CSP, which 

could lead to entirely new approaches to low-cost 

concentrator design. 

2. Technical Approach

The team will scale up the ASRM (produced in 

2003 under sponsorship by NREL) from laboratory

scale to limited production runs on a commercialscale 48-inch wide roll coater. Phase 1 work will 

test validate the scale-up to commercial roll-to-roll 

coating, and production costs will be modeled. 

During Phase 2, the process will be scaled up to a 

1⁄2-width pilot production system. Results will be 

used to create a full-scale solar reflector to 

demonstrate the technical and cost specifications 

of the system and to refine the cost model. This 

phase will demonstrate limited scale-up and cost 

effects of that scaling effort. During Phase 3, the 

team will scale the ASRM up to full width to 

demonstrate pilot production. Products from this

test run will be used in a full-scale solar reflector to 

field test the product. 

3. Results and Accomplishments

Phase 1 task highlights:

• Initial ASRM samples produced in commercial 

environment

• Prototype samples produced and sent to 

NREL

• NREL data show 96%–97% solar weighted 

value reflectance across samples

• ASRM passes initial scrub-washing abrasion 

tests with negligible degradation.

The ASRM process was transferred to a 

commercial roll-to-roll environment at Marian 

facilities. The resulting ASRM samples were

produced at 12-inch widths, and showed good 

consistency and specularity across the width (Fig. 

1). 

Fig. 1. Sample produced in 09/09, showing both 

high reflectance and specularity.

NREL measured samples with reflectance in the 

range of 96%–97% and negligible degradation in 

initial tests for durability and scrub-resistance.

Using ASRM deposition data, Swisher’s cost 

modeling shows a reasonable path to reduced 

LCOE, based on existing commercially available 

D R A F T
reflective film products and on large-scale CSP 

systems.

3. Planned FY 2010 Activities

Phase 1 will be evaluated in early 2010 for 

progression to Phase 2, and go/no-go and budget 

decisions will affect what is feasible. The focus of 

Phase 2 would be:

• Transfer process to pilot production chamber

• Produce and test pilot production samples, 

demonstrating multiple E-beam sources, 

expanded sample width, and higher overall 

throughput rates

• Collector test samples, designing and building 

a test module and solar reflector to begin 

small scale, initial tests of pilot production 

samples in the field.

4. University and Industry Partners

Organization/

Principal Investigator Location Description/Title of Research Activity

SAIC/ 

Dr. Russell Smilgys McLean, VA Transition of ASRM work into commercial environment

CSI/Marian/

Tom Judish San Diego, CA Integration of ASRM into commercial equipment and scale-up of production

Swisher & Assoc./

Dr. Richard Swisher Northfield, MN Transition, adaption, and cost model revision for ASRM

D R A F T
Abengoa Solar, Inc.

Development of Next-Generation Parabolic Trough 

Collectors and Components for CSP Applications

Total Award: $606K (Phase I) DOE/Recipient: $485K/$121K 

Objectives

• Reduce cost of collector technologies that could be deployed in first U.S. CSP plants in 2010–

2013 time frame

• Develop alternative collector structures, components, and field deployment techniques

• Employ innovative approaches to developing next generation of lower-cost parabolic trough 

technologies that can compete on equal footing with conventional power generation

• Build on results of initial phases, complete initial deployment of new generation of trough

technology aimed at achieving major cost reductions for medium-term deployments. 

Accomplishments

• Compared in depth three state-of-the-art CSP trough collector candidates and identified best 

design elements, construction techniques, and final LCOE performance of each

• Performed advanced design and evaluation of a near-term advanced collector, culminating in 

prototype testing

• Identified and commenced analysis of promising pathways for midterm trough development.

Future Directions

• Test and iterate near-term collector to advance the state of the art in cost and performance

• Continue to build analysis, evaluation, and testing capabilities, complete module-scale (ASI 

Lakewood) and loop-scale (SolarTAC) collector test sites 

• Complete specification for midterm collector system and evaluate multiple design concepts

• Prototype one or more midterm trough candidates, test and evaluate LCOE impacts.

____________________________________________________________________________________

1. Introduction

The goal is to develop the technology needed to 

build a competitive parabolic trough industry for 

the U.S. utility market. To achieve this objective, 

the project plans to reduce the cost of collector 

technologies and use innovative approaches to 

develop the next generation of lower cost 

parabolic trough technology.

2. Technical Approach

In Phase 1 the team evaluated and compared 

three state-of-the-art collector systems aimed at 

LCOE reduction beyond established designs (LS-2 

/EuroTrough/Astro). This system-level evaluation 

established uniform metrics and test protocols to 

enable accurate LCOE-based design comparison. 

This process involved growth in knowledge and 

capability within Abengoa that is informing current 

efforts to develop and validate next- generation 

collectors and subcomponents.

Going forward, the most promising designs from 

Phase I will be further improved and tested 

extensively to maximize near-term project 

performance. In parallel, several more radical 

design approaches that move away from current 

subframe and reflector configurations are being 

developed and will ultimately result in testing of a 

true “next-generation” collector system.

3. Results and Accomplishments

The Phase 1 contracted work was completed in 

06/09 and continuation to Phase 2 was approved 

11/2009. Results of the Phase 1 effort were:

• Identified a 5¢/kWh LCOE spread among 

near-term trough collector candidates

• Identified near-term SCA cost reduction 

opportunities of at least 10% additional

• Explored midterm collector designs to realize

SCA savings 25%–35%

• Tested first and second generation prototypes 

of a near-term improved collector system 

(Abengoa design team)

• Erected Lakewood, CO test site for structural, 

optical, and small-scale operating tests; 

preparing for loop-scale deployment and 

operational testing at SolarTAC (Aurora, CO)

D R A F T
• Internalized several new capabilities, including 

VSHOT, laser radar metrology, NASTRAN 

FEA, and ray-tracing, in Phase 1; these are 

being leveraged to support the development 

process. 

4. Planned FY 2010 Activities

• Complete small-scale (Lakewood) and loopscale (SolarTAC) test sites, and perform 

extensive testing to validate Phase 1 

assumptions

• Test second generation (ongoing) and third

generation Phoenix (Q3 2010) 

• Analyze costs and performance to inform 

development of advanced Phoenix troughs 

(Gen 3+)

• Complete structural, optical, and solar field 

modeling tools from Phase 1

• Perform parametric optimization to refine

midterm trough specification (aperture width 

and concentration, collector length)

• Perform first-order analysis of midterm

structure concepts, down-select

• Design and fabricate advanced trough 

prototype. 

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Arizona State 

University School of 

Construction 

Management / Dr. 

Kenn Sullivan

Phoenix, AZ / 

Kenneth.Sullivan@asu.edu

Construction Labor Review and 

Survey of Related Industry 

Experience

Martin / Martin 

Consulting Engineers /

Stan Welton,

Denver, CO / 

Welton@martinmartin.com Analysis & Design of Solar 

Collector Foundations

D R A F T
Dish/Stirling R&D Summary 

The Dish-Engine R&D program is focused on support leading to commercial deployment of dish 

engine systems. Sandia National Laboratories (SNL) has worked closely with Stirling Energy 

Systems (SES) on their pre-production SunCatcherTM dish Stirling system in support of several 

announced projects totaling well over 1 gigawatt installed over the next few years. SNL’s primary 

area of support this year included optical design and characterization, including tools that were 

deployed to the factory and development floors. Four new prototype systems were installed at 

SNL for developmental testing, and a 60-unit installation near Phoenix was started. SNL optical 

tools and analysis played a key role in these new systems. In addition, SNL supported controls 

development systems engineering tasks, and reliability improvement.

SNL supported Infinia Corp. in the installation and testing of (4) 3-kilowatt units at SNL, which are 

being used for product development and certification testing. SNL also supported the U.S. 

Department of Energy (DOE) funding opportunity announcement (FOA) with several dish engine 

companies. SNL assisted Infinia in filling capsules for thermal storage testing, and monitored 

design work on a 30-kW free piston Stirling engine. Finally, SNL supported Brayton Energy in 

their FOA, particularly with optical analysis and characterization tool support.

The future appears bright for dish engine companies. The technology is maturing to commercial 

readiness through large infusions of private capital in rigorous design for manufacture and 

deployment processes. This approach to deployment is leading the way to highly producible 

designs ready to supply utility scale power.

NREL SNL Other Solar

Total $K Total $K Total $K Total $K

Dish/Stirling R&D 0 1500 1765 3265

Dish Solar Field 0 1400 0 1400

CSP Funding Opportunity 

Announcement – Dish 0 100 1765 1865

D R A F T
Dish Engine R&D

Performing Organizations: Sandia National Laboratories (SNL) 

National Renewable Energy Laboratory (NREL)

DOE Golden Field Office

Key Technical Contact: Charles Andraka (SNL), 505-844-8573, ceandra@sandia.gov 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budget: $1,850K (SNL, carryover from FY 2008) 

____________________________________________________________________________________

Objectives

• Improve reliability and reduce cost of dish engine components and systems

• Support industry in commercialization of the technology

• Develop tools for industry to characterize and deploy their systems and components

• Perform research and development on dish engine system components and systems

• Test, evaluate, and improve performance of dish engine components and systems.

Accomplishments

• Participated in optical design and analysis of Stirling Energy Systems (SES) production SunCatcherTM

system, resulting in substantial weight and cost reduction

• Assisted with the installation and operation of four prototype production SES SunCatcherTM systems at 

SNL

• Developed and deployed rapid facet characterization system (Sandia Optical Fringe Analysis Slope 

Tool, SOFAST) on SES factory floor, instrumental in rapid improvement of manufactured facets

• Participated in controls development and refinement for SES production SunCatcher

TM systems

• Mentored new solar engineers through SNL programs and at industry partners

• Deployed and tested two Infinia 3-kW systems at SNL, and prepared for installation of four production 

units

• Enhanced CIRCE2 model to support direct facet measurements (SOFAST or VSHOT)

• Participated in Funding Opportunity Announcement projects (FOAs) team for dish Brayton system, 

particularly in dish optics consultation

• Completed a draft report of the CSP cost study, which is being reviewed by the CSP industry. 

Future Directions

Primary activities in fiscal year (FY) 2010 will support industry’s efforts toward commercialization:

• Support SES system refinement to address any outstanding performance and cost issues

• Develop rapid optical tools for alignment in a production setting, applicable to SES, Brayton, and 

others

• Continue to participate in reliability improvement and characterization of SES SunCatcherTM systems

• Support SES data reduction and analysis of Maricopa and Model Power Plant (MPP)systems leading 

to improved performance and reliability

• Install and operate four new Infinia systems at SNL

• Support Brayton in first system deployment in Phoenix, including optical characterization (VSHOT, 

Fluxmapping, alignment, tracking)

• Support Infinia operations, commercialization, and FOAs on dish engine storage and 30-kW free 

piston engine development

• Evaluate possible additional dish engine products, as needed

• Complete final CSP cost study

____________________________________________________________________________________

D R A F T
1. Introduction

Staff members work closely with the industry to 

improve dish Stirling system performance and 

reliability and to support industry deployment in 

the near term. The primary focus of SES this year 

was developing and deploying 60 production 

systems at Maricopa Solar in Peoria, AZ, which 

encompassed a significant and successful design 

for manufacture and cost phase. The MPP at SNL 

was expanded with four production systems, and 

SNL and SES continued to gain operational 

experience with the MPP.

SES is pursuing the aggressive deployment of 25 

kW dish Stirling systems for bulk power 

generation. The success of the MPP has led to 

agreements with Tessera Solar, SES’s sister

company responsible for project development, and

Southern California Edison for up to 850 MW of 

power and with San Diego Gas and Electric for up 

to 750 MW. 

Infinia, previously Stirling Technology Corporation 

(STC), has developed a system around a 3-kW 

free-piston Stirling engine. This system is 

hermetically sealed and requires no maintenance. 

Infinia plans both large and small deployments 

and has targeted photovoltaics as a competitor. 

SNL was involved in the conceptual design, 

detailed design, and deployment of the first 

prototype systems. SNL entered into a 

memorandum of understanding with Infinia to 

support several Infinia staff on SNL premises. Two

prototype dishes were set up and operated at 

SNL, and four additional preproduction systems 

are being installed. 

2. Technical Approach

The dish engine systems program is industry led 

as each company involved drives toward 

commercial deployments. The laboratories provide 

technical assistance, expertise, measurement, and 

support where significant experience can be 

leveraged to enhance the success of these 

companies. The laboratories have particular 

expertise in systems engineering, optical design, 

optical characterization, and controls. Often, the 

laboratories are able to identify needs and help 

with solutions before they become critical path 

needs, thanks to the experience of laboratory 

personnel.

A contract is in place for a CSP cost and market 

study. The purpose of this project is to develop 

engineering estimates of the current and projected 

cost of electricity from CSP power systems, 

troughs, molten-salt towers, and dish Stirling 

systems, as characterized by their installed costs 

and the cost of electricity (referred to as the 

levelized cost of energy, LCOE). In addition, this 

program supports FOAs, funded through the DOE 

Golden Field Office, for several dish-related 

projects. The laboratories monitor progress and 

provide consultation or test support as 

appropriate.

3. Results and Accomplishments

In 2009, SES designed, developed, and deployed 

a production version of the SunCatcherTM 25-kW 

dish system. This production version incorporates 

significant cost reduction features, and is simpler 

to install and commission. It features a steelefficient gore facet layout, a production engine 

with a substantial parts count reduction, and all 

new modernized controls for the dish and engine. 

The prototype systems are more than 4,000 

pounds (out of 17,500) lighter than the MPP 

systems. Four prototypes were erected and tested 

at SNL in the spring of 2009, and 60 production 

units (1.5 MWe total) were installed near Phoenix 

in the fall of 2009.

The SES engine was designed for manufacture 

with the assistance of their engine partner, 

Linamar/McLaren Performance Technologies, a 

Detroit, Michigan-area company. The significant 

parts count reduction speeds assembly and 

improves reliability. Many issues cataloged on the 

old engine during MPP operation were addressed 

in the design for manufacture. Several engines 

accrued more than 2,000 hours each in test cells 

at Linamar, and the durability of these engines is 

dramatically improved over the prior model.

SES and SNL continued to operate the enhanced 

model power plant, accruing a total of 29,300 dishhours on sun by the end of the FY 2009, including 

750 dish-hours on the new production prototype 

systems. The operational emphasis has shifted to 

the new systems, and operation of the six older 

systems has been largely phased out.

SNL completed development of and deployed the 

SOFAST at SES’s facet manufacturer. This rapid 

characterization system was instrumental in the 

rapid development of facet manufacturing 

techniques at Tower Automotive. The quality of 

the facets improved by about a factor of 3, and 

met specifications, in less than a year of 

development.

D R A F T
SNL continued to develop a facet alignment 

system based on SOFAST. This alignment system 

will automatically collect facet surface data, 

determine a representative pointing vector for 

each facet, and give automated tooling with 

updates to correctly orient the representative 

vector. This is a key to rapid deployments, and is 

seen as a possible solution to heliostat assembly 

and canting as well.

Fig. 1. A production prototype SunCatcherTM dish 

system deployed at SNL. 

SNL supported the installation and testing of two 

prototype 3-kW dish-engine systems at SNL. The 

Infinia system is a 3-kWe free-piston Stirling 

system. Infinia plans large and small installations 

throughout the world, and several demonstration 

plants are already operational. They are installing 

four production units at SNL for further operational 

and qualification testing. Infinia attained UL 

certifications of their electrical subsystems.

The Infinia 30-kW engine development FOA 

passed phase 1 completion and began phase 2. 

SNL continues to support this effort with monthly 

consultation and review.

SNL and NREL have supported the Brayton 

Energy FOA for developing a large Brayton cycle 

system. A prototype is slated for deployment in 

Phoenix in FY 2010. SNL gave a detailed tutorial 

workshop for alignment of dish system facets. In 

FY 2010, SNL will perform flux characterization 

support, and NREL will produce a VSHOT 

characterization of the dish reflector.

The CSP industry is reviewing the draft of the CSP 

cost study project report. After Sargent & Lundy 

evaluate the comments and recommended 

changes, the final report will be prepared and 

published by April 2010.

Fig. 2. Six Infinia 3-kW preproduction prototype 

dish systems at SNL.

4. Planned FY 2010 Activities

SES Field Operations: 

• Operate the MPP at SNL for reliability 

improvement, O&M operations definition, 

controls development, and system 

characterization

• Controls: Provide background knowledge, 

simulations, consultation, and expertise to 

facilitate the continued development and 

testing of next-generation dish and engine 

controls

• Production systems: Develop effective test 

plans, processes, and equipment to qualify

production prototypes

• Production systems: Perform critical optical 

design, analysis, and testing of prototype 

commercial systems

• Support completion and operation of 1.5-MW 

SES/Tessera Demonstration Plant near

Phoenix

• Engine testing. Complete Engine Test Facility 

upgrades to support continuous steady and 

cyclic operation of engines at full power 

• Development. Deploy and test field SCADA 

systems, engine parts alternatives, mirror 

modules, alignment tools, and field O&M 

systems such as wash vehicles. The labs and 

SES will do the developing, and SES will 

prioritize elements of the work.

SES Next-Generation Tools and Manufacturing 

Support: 

• Alignment systems: Complete hardware and 

software development and demonstrate 

operational system

D R A F T
• Optical design: Continue to support SES in 

optical and thermal design of dish, cavity, 

receiver, and engine

• Assist SES in developing predictive algorithms 

for engine and dish operation.

Infinia Site Support: 

• Furnish test support and logistics to test six 

systems at SNL

• Give assistance in problem solving as 

requested.

Dish FOA Support: 

• Support Brayton Energy in deploying and 

characterizing their first prototype dish engine 

system in Phoenix

• Support Infinia in the phase 2 design efforts 

and testing of the 30-kW free piston 

multicylinder engine.

CSP Cost Study: 

• Complete the CSP cost study report and 

publish in April 2010. 

5. FY 2009 Special Recognitions and Patents

• Technical Advance filed for SNL’s SOFAST 

facet characterization system.

6. Major FY 2009 Publications

C.E. Andraka, S. Sadlon, B. Myer, K. Trapeznikov, 

and C. Liebner, “Rapid Reflective Facet 

Characterization Using Fringe Reflection 

Techniques,” Proc. Energy Sustainability 

2009, San Francisco CA, July 2009.

C.E. Andraka, S. Sadlon, B. Myer, K. Trapeznikov, 

and C. Liebner, “SOFAST: Sandia Optical 

Fringe Analysis Slope Tool For Mirror 

Characterization,” Proc. Solar Paces 2009, 

Berlin, Germany, September 2009.

7. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal 

Investigator

Location/E-mail Description/Title of Research 

Activity

FY 2009

($K)

Sergeant & 

Lundy 

Engineering/ 

Robert Charles

robert.p.charles@sargentlundy.com

CSP Cost Study. The project involves 

three primary tasks. Task I is the factfinding part of the project where the 

contractor will review existing 

information and interview industry 

representatives to obtain available 

cost information and to identify any 

limitations on deployment caused by

the availability of equipment and/or 

near-term supplier constraints. The 

contractor will also establish the 

parameters for the cost estimates, 

financial assumptions, and federal and 

state incentives, and develop the 

methodology for the installed and 

LCOE cost estimates. The three 

deployment scenarios for each of the 

technologies will be developed in Task 

I. Task I will culminate in a report, 

which must be approved by the SCR

prior to starting Task II of the project, 

in which the initial costing parameters, 

financial assumptions, incentives, 

deployment scenarios, study 

methodology, and deployment 

scenarios are defined. 

250

D R A F T
Dish Industry Projects

Performing Organizations: Brayton Energy

Infinia Corporation

Key Technical Contacts: Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953,

carolyn.elam@go.doe.gov

Brad Ring, DOE/GO, 303-275-4930, brad.ring@go.doe.gov

DOE HQ Technology Managers:Frank (Tex) Wilkins, (202) 586-1684, frank.wilkins@ee.doe.gov

Tommy Rueckert, (202) 586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budget: $1,916K (DOE/GO)

____________________________________________________________________________________

Objectives

• Develop energy supply technologies that are reliable, affordable, and environmentally sound; 

expand national electricity generation portfolio to increase energy security by diversifying 

domestic energy supply options. 

• Perform preliminary exploration/feasibility analysis of new concentrating solar power (CSP)

approaches for electrical power production. 

Accomplishments

• Continued two CSP Advanced Systems and/or Component (Dish) awards

• Completed two phase I go/no-go reviews (both awardees received a “go” decision)

• Continued to assess CSP Advanced Systems and/or Component (Dish) awards against the Solar 

Energy Technologies Program (SETP) CSP subprogram goals and objectives.

Future Directions

• Evaluate the CSP Advanced Systems and/or Component (Dish) awards to ensure they are 

progressing to meet the SETP CSP subprogram objectives to identify concepts that can generate 

low-cost power (under 7¢/kWh) with storage (12–17 hours) by 2020.

____________________________________________________________________________________

1. Technical Approach

CSP is one of the most attractive renewable 

energy options in the southwestern United 

States, with a nominal levelized cost of energy 

(LCOE) target of 7¢–10¢/kWh by 2015 and 5¢–

7¢/kWh by 2020. In-depth systems analysis 

specifies characteristics of a system (e.g., size, 

components, operating temperature, component 

and system efficiencies, storage and heat 

transfer fluids), major technical barriers and 

proposed approaches to overcoming them, 

estimated system and component costs, and 

operation and maintenance (O&M) costs. The 

funding opportunity announcement (FOA) 

investigated three areas to resolve market 

barriers for utility-scale generation of CSP 

technologies: thermal storage, trough 

component manufacturing and advanced CSP 

systems or components (dish Stirling R&D). 

The selected projects are as follows:

Organization, Principal Investigator, and 

Agreement Title

FY 2009

Budget 

($K)

Brayton Energy—James Kesseli,

Brayton Solar Power Conversion System

1,000

Infinia Corporation—Qiu Songgang,

30-kW Maintenance Free Stirling Engine for 

High Performance Dish Concentrating 

Solar Power

D 

916

R A F T
Brayton Energy

Brayton Solar Power Conversion System

Total Award: $4,269K DOE/Recipient: $2,300K/$1,969K

Objectives

• Design and demonstrate novel dish Brayton hybrid concentration solar power module

• Achieve LCOE of $0.075 to 0.10/kWh with an engine lifetime of 40,000 hours

• Achieve low emissions in alternate modes using natural gas, ethanols, or bio-oils. 

Accomplishments

• Completed phase 1, delivering 232-page technical report

• Applied proven components and design principles to dish Brayton design

• Prepared novel solar receiver design, subjected to review by U.S. government labs

• Operated air-bearing turboalternator at full speed on bench-test rig, without heat.

Future Directions

• Fabricate and test purpose-built gas turbine engine with hydrocarbon fuels

• Integrate receiver and engine with purpose-built solar concentrator

• Test and characterize two subassemblies: 

o Turboalternator: Complete power conversion system in a laboratory setting with hybrid fuel 

systems but no solar receiver, measuring efficiencies and emission levels

o Solar receiver: In lab environment and 320-m2 dish, characterizing cavity and overall heat 

losses. 

____________________________________________________________________________________

1. Introduction

Brayton Energy performed extensive design and 

analysis of a novel CSP conversion system. It

uses a specialized recuperated gas turbine 

generator with a solar receiver. Prototype units will 

be fabricated at an assembly plant for volume 

manufacturing near Phoenix, AZ. The focus is on 

the engine/receiver module design and component 

tests. 

2. Technical Approach

The power module is designed to produce 84 kWe 

of net power on 850-W/m2

 insolation, which 

equates to a dish of nominally 320 m2

. DOE work 

is focused exclusively on the power conversion 

system, and the affiliate SolarCAT Inc. is 

developing and deploying a large dish that will be 

made available for receiver tests in this project. 

Several tasks were planned for this fiscal year.

The turbine and hot section will be fabricated and 

tested on the turboalternator test rig. The goal is to 

achieve an adiabatic turbine efficiency > 84%. The 

lab test rig at Brayton will be fired by customdesigned SolarCAT hybrid burners. For the 

second phase of fundingdecision, the early turbine 

efficiency target for the initial test trials in this 

phase has been set at 80%. 

The high-speed alternator will be fabricated and 

tested on the turboalternator test rig. The goal is to 

achieve an efficiency of > 96%.

Brayton will also validate efficiency prediction 

models to show that cycle efficiency varies less 

than +/-2 percentage points over the control range 

(200 to 1,000 W/m2

). The lab test rig will be built to 

measure overall turbine-alternator efficiency.

The overall integrity of the turbine and hot section

will be demonstrated. After testing for nominally 50 

hours, researchers will check for material distress.

Also, avoiding VAN galling caused by thermal 

distortion will be a key objective.

Researchers will conduct to correlate heat transfer 

and friction characteristics from testing, for a final 

receiver design. A receiver will be fabricated and 

delivered to a concentrator test facility at the 

SolarCAT Inc. facility near Phoenix.

Manufacturing trials will be conducted to qualify 

tube bending and joining procedures and to gain 

experience to establish greater confidence in the

cost estimate for the solar receiver. 

The DOE review board on December 18, 2008, 

recommended adding the following items:

D R A F T
1. Develop a test plan for the experimental solar 

receiver and dish module

2. Integrate the prototype component/system 

(dish integration with the solar receiver)

3. Test dish receiver on sun test and validation 

results, in accordance with the test plan. 

SNL, NREL, Brayton, and SolarCAT Inc. will 

collaborate on developing a dish and receiver test 

plan. Brayton will produce design information and 

documents at various stages of the design 

process for SNL and NREL for review and 

comment on both the preliminary and the final 

component and system designs.

3. Results and Accomplishments

Researchers completed designing the 

turboalternator and recuperator and continue to 

analyze the durability of critical design elements. 

The LCOE analysis is complete and has met 

objectives, based on performance analyses, 

capital cost, and life/maintenance expectations. 

The findings support the achievability of near-term 

DOE cost targets of $0.075 to $0.10/kWh. The 

final design employs intercooling and high levels 

of recuperation and reheat, enabling engine 

thermal-electric efficiency to exceed 37% at 

moderate turbine inlet temperatures. A detailed bill 

of materials has been prepared for the engine and 

receiver. 

4. Planned FY 2010 Activities

• Fabricate and test purpose-built gas turbine 

engine with hydrocarbon fuels

• Integrate receiver and engine with purposebuilt solar concentrator

• Test and characterize the turboalternator: 

complete power conversion system in a 

laboratory setting with hybrid fuel systems but 

no solar receiver, measuring efficiencies and 

emission levels; test and characterize the 

solar receiver in lab environment and 320-m2

dish, characterizing cavity and overall heat 

losses.

5. FY 2009 Special Recognitions and Patents

Brayton Energy received two patents, on power 

conversion systems and a variable position turbine 

nozzle. They submitted six other filings related to 

recuperators, turbomachinery, and solar receivers. 

6. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009. 

Organization/

Principal Investigator Location Description/Title of Research Activity FY 2009($K)

Cost Share

($K)

Oak Ridge National 

Labs/Dr. Bruce Pint Oak Ridge, TN High-temperature materials evaluation 26 0

University of New 

Hampshire/Chad 

Everbeck, Martin Wosnik

Durham, NH Advanced heat exchanger design and 

integration for Brayton solar power conversion 0 0 

SolarCAT Inc./ 

Herb Hayden Glendale, AZ

Dish design, fabrication, testing. Assembly 

factory deployment. 100-MWe site

development

0 73

D R A F T
Infinia Corporation

30-KW Maintenance Free Stirling Engine for

High Performance Dish Concentrating Solar Power System

Total Award: $3,196K DOE/Recipient: $2,062K/$1,134K 

Objectives

• Provide prototype engine preliminary design and preliminary LCOE estimate by the end of phase 

1 (FY 2008–FY 2009)

• Build and demonstrate a 30-kW engine laboratory prototype by the end of phase 2 (FY 2009– FY

2010)

• Deliver and field test a prototype 30-kW Stirling engine by the end of phase 3 (FY 2010–FY

2012). 

Accomplishments

• Completed detailed design, with projected performance expected to meet SETP and LCOE goals

• Initiated prototype fabrication 

• Completed Preliminary LCOE, initiated detailed LCOE analysis.

Future Directions

• Complete fabrication and assembly of engine

• Complete test station design and instrumentation

• Test and evaluate engine

• Complete detailed LCOE analysis

• Address any residual technical or cost barriers.

____________________________________________________________________________________

1. Introduction

For dish Stirling CSP, two critical issues are 

engine life/reliability and O&M costs. The primary 

objective of this program is to apply Infinia’s 

proven engine life and reliability to a maintenancefree 30-kW multicylinder free-piston Stirling engine 

(MCFPSE), greatly improving reliability and 

reducing overall levelized cost of energy. 

2. Technical Approach

Phase 1 was conducted during FY 2008 and FY

2009. FY 2009 activities focused on completing 

the preliminary design and cost analysis. Phase 2 

was initiated in FY 2009 and continues into FY

2010. During FY 2009, phase 2 activities focused 

on completing the detailed design of the engine 

and refining the preliminary cost analysis 

developed during phase 1. The general approach 

in phase 1 was to adapt proven free piston Stirling 

engine (FPSE) technology into an innovative, 

double-acting, multicylinder 30-kW design. To 

facilitate this process, SAGE (a Stirling engine 

simulation code) was used to simulate and support 

design of a six-cylinder engine.

This detailed SAGE analysis provided a basis to 

launch the detailed design of the test engine. A 

design for manufacturability and assembly (DFMA) 

analysis was conducted during the detailed design 

process to ensure that the engine would meet 

commercial manufacturing requirements. Changes 

for manufacturability were then added to the 

SAGE model, to assess any performance impact. 

Engine design was completed and all fabrication 

drawings were finalized. Initial fabrication of the 30 

kW engine began in late 2009. 

Using commercial component data from Infinia’s 

3-kW engine, and analysis by leading automotive 

industry experts, Infinia performed a preliminary 

cost analysis of a 30-kW dish Stirling system 

based on the engine designed here. This analysis 

indicated a, LCOE in the range of 6.5¢ to 

14.8¢/kWh, depending on subsidies and financing

alternatives. The phase 2 cost analysis, based on 

the detailed engine design, was initiated in late 

2009. 

3. Results and Accomplishments

Infinia achieved substantial progress in the design 

and costing of its 30-kW prototype during FY

2009. Figure 1 shows the prototype engine 

configuration. The prototype design consists of six

individual engine cylinders with interconnecting 

D R A F T
ducts that form two 15-kW engine modules. Each 

15-kW engine module cancels its own vibration 

but not its own nutating motion. The two integrated

15-kW engine modules cancel all vibration and

nutating motion. This results in a design with no 

theoretical vibration transmitted to the supporting 

structure. 

The 30-kW engine is designed such that each 

cylinder is rigidly connected to the others, which 

results in an exceptionally stiff and strong engine.

Fig. 1. 30-kW MCFPSE engine

A refined cost analysis for the engine and dish is 

ongoing with completion scheduled in FY 2010.

Infinia will develop a preliminary assessment of 

the high-volume production cost of the system and 

O&M costs as they relate to the engine’s effect on 

overall LCOE. Vendor information is being used

and manufacturability examined in relation to 

cost/performance trade-offs. Engine costing began 

with preliminary part drawings. Infinia enlisted 

automotive and manufacturing expert, Ricardo, 

LLC, to assist. Ricardo has experience with 

Infinia’s and other developers’ Stirling engines and 

routinely develops high-volume cost models for 

the automotive industry. 

4. Planned FY 2010 Activities

During FY 2010, phase 2 will be completed and

phase 3 will be started. Phase 2 activities to be 

completed early in FY 2010 include:

• Finish fabricating the prototype engine

• Test and evaluate prototype engine

• Perform manufacturing cost analysis for the 

engine and dish

• Determine and resolve any residual technical 

or cost barriers. 

Phase 3 objectives will be to fabricate and 

assemble an engine and balance of plant while 

incorporating any required improvements from 

phase 2. This will then be attached to an existing

dish for performance testing.

Specific phase 3 deliverables include:

• Complete engine and balance of plant design 

suitable for dish mounting

• Assemble dish-mounted 30-kW engine 

prototype 

• Conduct performance and characterization

testing on sun. 

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

Butler Sun Solutions/ 

Barry Butler

Solana Beach CA

barry@butlersunsolutions.com Sourcing of dish and dish costing analysis

Consultant/

Barry Penswick 

Stevenson WA

lbpeng@saw.net Stirling engine design

Ricardo, LLC/

Alan Munday

Detroit, MI

Alan.Munday@ricardo.com

D 

Cost analysis

R A F T
Thermal Energy Storage Summary

The concentrating solar power (CSP) storage project comprises two important areas of research 

and development - advanced heat transfer fluids and thermal energy storage systems. Both topic 

areas include specific research activities that are directed towards increasing the performance 

and lowering the cost of CSP technologies. Specifically, this project’s goals are to reduce the cost 

of thermal storage systems and increase CSP plant performance to meet the near-term CSP 

program goals of being cost-competitive with intermediate load markets by 2017 and carbonconstrained baseload markets by 2020.

Work within advanced heat transfer fluids seeks to improve the properties of heat transfer and 

storage fluids. Heat transfer fluids limit the maximum operating temperature of parabolic trough 

and power tower plants. 

Work within thermal energy storage systems seeks to increase the stored energy density of the 

systems, which reduces the required inventory and cost of the systems. In addition, identifying 

systems that use less expensive storage media is also a priority. Both of these efforts require the 

identification and development of new storage materials. 

Work within this project is performed at the U.S. Department of Energy’s (DOE’s) national 

laboratories – National Renewable Energy Laboratory (NREL) and Sandia National Laboratories 

(SNL) – and at various universities and companies. The work is a blend of near-term analysis and 

materials development that is intended to quickly advance the technology and long-term research 

that will produce more dramatic technical advances as the technology matures.

Thermal storage projects comprise the following areas:

• Storage Systems

• Advanced Heat Transfer Fluid Development

• Storage Industry Projects

• Storage/Heat Transfer Fluids Industry Projects.

NREL SNL Other Solar

Total $K Total $K Total $K Total $K

Thermal Storage R&D 965 1250 4128 6343

Storage Systems & 

Components 510 700 0 1210

Advanced Heat Transfer Fluid 

(HTF) Development 405 500 0 905

CSP Funding Opportunity 

Announcement #1 – 

Storage 50 50 2930 3030

CSP Funding Opportunity 

Announcement #2 – 

Storage/HTF

D 

0 0 1198 1198

R A F T
Storage Systems

Performing Organizations: National Renewable Energy Laboratory (NREL)

Sandia National Laboratories (SNL)

DOE Golden Field Office

Key Technical Contacts: Greg Glatzmaier (NREL), 303-384-0000, greg.glatzmaier@nrel.gov 

Nathan Siegel (SNL), 505-284-2033, npsiege@sandia.gov 

DOE HQ Technology Manager: Tex Wilkins, 202-586-1684, frank.wilkins@hq.doe.gov 

FY 2009 Budgets: $750K (SNL) and $510K (NREL)

____________________________________________________________________________________

Objectives

• Upgrade molten salt component test capability including central receivers. (SNL)

• Develop materials, methods, and hardware for deploying low melting point salt in parabolic 

troughs. (SNL)

• Provide computational fluids dynamics (CFD) modeling to assess and improve performance of 

thermal storage systems and their integration into Concentrating Solar Power (CSP) power 

plants. (NREL)

• Provide cost analysis to determine capital costs and levelized costs of energy (LCOE) impacts of 

thermal storage systems. (NREL)

• Design and establish a new thermal storage process and components integration laboratory to 

determine performance and operation of new storage concepts at laboratory scales. (NREL)

• Improve thermal energy storage (TES) systems to reduce the LCOE by $0.018/kW-h. (NREL)

Accomplishments

• Completed the conceptual design for upgraded molten salt component test facilities following a 

survey of industrial needs. (SNL)

• Experimentally identified a receiver failure mode for parabolic troughs using a molten salt heat 

transfer fluid (HTF). (SNL)

• Developed computational models of the freeze/thaw behavior of molten salt in a parabolic trough 

heat collection element (HCE). (SNL)

• Began construction of 650o

C molten salt corrosion system and the second generation 

freeze/thaw experiment. (SNL)

• Provided support to thermal energy storage contract awardees. (SNL/NREL)

• Conducted performance modeling of thermocline storage system with packed filler material. 

(NREL)

• Performed survey of tank manufacturers to determine largest practical size for storage vessels. 

(NREL)

• Performed cost analysis to determine the current LCOE for electricity from a 100 megawatt (MW) 

parabolic trough power plant with 6 hours of thermal energy storage using 2-tank molten salt 

storage system. (NREL)

Future Directions

• Develop molten salt mixtures stable to 650o

C. (SNL)

• Complete the design and construction of molten salt facility upgrades. (SNL)

• Identify additional failure modes related to salt freeze/thaw in parabolic troughs. (SNL)

• Complete CFD modeling of thermocline storage systems. (NREL)

• Complete cost analysis of thermocline storage systems. (NREL)

• Construct full-plant performance models in TRaNsient SYstem Simulation Program

TRNSYS for integrating thermal storage into power plants. (NREL)

D R A F T
• Specify and fabricate thermal storage test loops and supporting instrumentation for thermal 

storage process and components integration laboratory. (NREL)

____________________________________________________________________________________

1. Introduction

SNL

CSP plants, both parabolic trough and power 

towers, are being built or planned that will 

generate significant electrical power output in the 

near-term. TES incorporated into such plants 

would reduce the LCOE and provide 

dispatchability at the most valuable time of day. 

Commercially available nitrate salts can provide 

high capacity storage and have properties that are 

readily adaptable to the operating characteristics 

of both trough plants and power towers. However, 

realizing the lowest-cost energy production with 

CSP involves moving beyond the limits of current 

TES technology. The purpose of this project is to 

develop improved thermal storage media, 

hardware, and operational methodologies that can 

help reduce the cost of solar-generated electricity. 

NREL

This agreement focuses on systems analysis 

issues relating to evaluating and improving the 

performance and cost of thermal storage systems 

for parabolic trough power plants. 

Systems modeling and cost analysis dictate that 

thermal storage be integrated into the parabolic 

trough solar plant in order to operate efficiently 

and, most importantly, in a cost-effective fashion. 

This necessitates integrating thermal storage into 

cost and performance models to evaluate the 

sensitivities that result from changes in the storage 

system design, i.e., working fluid, fluid flow rates, 

heat exchanger designs, storage volume, etc.

 

2. Technical Approach

SNL

Technical work at SNL in FY09 was focused on 

the following tasks outlined below:

• Molten Salt Components and Receiver Test 

Facility – SNL is currently upgrading its 

capability to test salt-service components at 

the conditions necessary for operation in 

advanced parabolic trough plants and in 

central receivers. This work involves the 

design and construction of two facilities. The 

first will be used to test trough components, up 

to a complete module, at realistic flow rates 

and temperatures up to 500o

C. This same 

facility also will be capable of testing valves 

and other components for central receiver 

service up to a temperature of 580o

C. The 

second facility will support central receiver 

panel testing at SNL’s power tower facility as 

well as component development. This facility 

will be capable of 650o

C operation, consistent 

with the performance requirements of future 

advanced power towers operating with more 

efficient power cycles. Input was solicited 

from potential industrial users during the initial 

design stages for both facilities. 

• Corrosion Testing – In order to achieve the 

lowest cost electricity from CSP the 

temperature at which the power cycles 

operate must increase, possibly beyond 

650o

C. Currently there is little information 

available related to the corrosion of 

engineering materials in nitrate salts at this 

temperature. We have designed a corrosion 

test facility to evaluate both the stability of 

nitrate salts at 650o

C and the corrosion of 

engineering materials. The facility will be built 

in FY10.

• Freeze/Thaw Experiments and Analysis – 

Using nitrate salts as the heat transfer fluid in 

parabolic troughs offers some benefits with 

respect to performance and cost. However, 

the possibility of the salt freezing in heat 

collection elements (HCE) poses a significant 

technical challenge. In FY09 we conducted 

experiments to evaluate the behavior of 

molten-salt filled HCEs during phase change 

processes. We also developed computational 

thermo-mechanical models of the system in 

parallel with the experimental efforts. 

• Support of funding opportunity announcement 

(FOA) Awardees – Several researchers at 

SNL continue to serve as technical monitors 

and advisors for thermal energy storage 

FOAs. 

NREL

• This agreement is divided into two primary 

activities: performance modeling and cost 

analysis.

• Performance modeling is an internal NREL 

activity. It uses computational fluid dynamics 

(CFD) modeling techniques to estimate and 

predict heat transfer and fluid flow within 

complex flow geometries. This capability is 

used to characterize the performance of 

thermocline thermal energy storage systems. 

Modeling of thermocline performance is 

necessary because large temperature 

gradients exist within this storage system. 

D R A F T
These gradients generally occur axially along 

the direction of fluid flow but also exist

between the fluid and solid storage medium 

and within the solid medium itself. 

Thermocline operation is highly transient in 

nature. For these reasons, CFD modeling is 

necessary to characterize and understand the 

performance of thermocline storage systems 

for CSP applications.

• In contrast, performance characterization of 

the 2-tank molten salt storage system does 

not require CFD modeling because each tank 

is isothermal and operation is relatively simple 

compared with the thermocline.

• Performance modeling of either storage 

system considers the total storage 

requirements, charging and discharging power 

requirements, storage vessel size limitations, 

vessel orientation, and aspect ratio. The goal 

is to determine the optimum storage 

configurations for likely solar field sizes (or 

solar multiples) that minimize the levelized 

cost of electricity.

• Cost analysis was performed as part of a 

larger task that updated the costs for a 

parabolic trough power plant with 6 hours of 

thermal energy storage. This work was 

subcontracted to Worley Parsons, a large 

design & engineering firm with EPC 

management experience in parabolic trough 

power plants. Worley Parsons was able to 

contact component vendors and acquire cost 

information that was needed to perform the 

cost analysis.

3. Results and Accomplishments

SNL

The results of the technical work performed at 

SNL in FY09 are summarized below:

• Molten Salt Components and Receiver Test 

Facility – A decision was made to eliminate 

the support for testing long-shafted pumps 

from the original facility plan. A new facility 

configuration was developed after interviewing 

several potential industrial partners/users 

(9/09). Valves, instrumentation, and other 

components for salt service must be 

developed and demonstrated in realistic 

operating conditions in order to justify their use 

in CSP facilities. Our upgraded test facility will 

have two independent loops for providing 

flowing molten salt at a controlled temperature 

to three test segments. Two of the test 

segments accommodate parabolic trough 

components; the other accommodates central 

receiver components. An illustration of the 

facility is shown in Figure 1.

Figure 1. The molten salt component test facility 

at SNL

• Corrosion Testing – The design and heat 

transfer analysis of the 650o

C corrosion test 

facility was completed and the required 

hardware purchased (8/09).

Figure 2. Simulated HCE deformation during a 

freeze/thaw cycle for a fully filled tube.

• Freeze/Thaw Experiments and Analysis – 

Testing continued through FY09. During 

several tests we identified conditions under 

which salt-filled HCEs would plastically deform 

during impedance heating. Using molten salt 

as opposed to synthetic oil as the heat transfer 

fluid in a parabolic trough power plant offers 

performance and cost benefits. In FY09 we 

performed experiments and developed models 

to investigate strategies that may be used to 

recover a trough field should the molten salt 

heat transfer fluid freeze in the HCEs. We 

found that, using an impedance heating 

strategy, it is possible to cause permanent 

damage (plastic deformation) to receiver tubes 

during the thawing process if the conditions 

are such that the HCEs completely fill with salt 

during solidification. If liquid salt is not allowed 

to fill in the gaps upon freezing, the stress on 

D R A F T
the tube is reduced and plastic deformation 

can be avoided. Figure 2 shows magnified 

tube deformation during thaw for a completely 

filled HCE when heated from 80-140o

C. 

• Molten Salt Steam Generator Analysis – In 

FY09 SNL placed a contract with Texas Tech 

University to perform a CFD analysis of a 

molten salt steam generator proposed for 

central receiver applications by TEi-Struthers 

Wells. The purpose of the work is to evaluate 

the extent of salt cross-over between the hot 

and cold sides of the heat exchanger and seek 

ways to reduce its impact on performance. 

This work is still in progress.

• Support of FOA Awardees – SNL staff 

members support all of the DOE thermal 

energy storage FOAs.

NREL

During FY2009, we completed the following 

activities:

• Conducted performance modeling of 

thermocline storage system with packed filler 

material (results presented in publication list in 

section 6). 

• Performed survey of tank manufacturers to 

determine largest practical size for storage 

vessels. 

• Performed cost analysis to determine the 

current LCOE of electricity from a 100 MW 

parabolic trough power plant with 6 hours of 

thermal energy storage using 2-tank molten 

salt storage system. 

4. Planned FY 2010 Activities

SNL

• Finalize the design (9/2010) and begin 

construction of both the molten salt 

component test facility and the central receiver 

test loop. 

• Upgrade the HCE freeze/thaw test to include 

receiver tube mounted instrumentation. 

Complete the first round of testing (7/2010). 

Update computational models and identify the 

processes governing tube failure (8/2010).

NREL

• Complete a design basis for thermocline 

storage systems for parabolic trough and 

central receiver power plants. 

• Complete a CFD thermocline modeling effort 

that models heat transfer and fluid flow 

through structured packing. 

• Complete a cost estimation for thermocline 

storage systems for parabolic troughs and 

central receiver power plants. 

• Complete a design specification for the new 

thermal storage process and components 

integration laboratory. 

5. Major FY 2009 Publications

SNL

Kolb, G.J., Ho, C.K., Iverson, B.D., Moss, T.A., 

Siegel, N.P., “Freeze-Thaw Tests of Trough 

Receivers Employing a Molten Salt Working 

Fluid.” Submitted to Energy Sustainability 2010, 

ASME, 2010. 

NREL

D. Bharathan, G. C. Glatzmaier, Progress in 

Thermal Energy Storage Modeling, Proceedings of 

ES2009, ASME Energy Sustainability, San 

Francisco, California, July 19-23, 2009.

6. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

SNL

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Texas Tech University

Dr. Darryl James

Lubbock, TX

Darryl.james@ttu.edu

Analysis of molten salt steam 

generator design. 60

NREL

Organization/

Principal 

Investigator

Location/E-mail Description/Title of Research 

Activity

FY 2009

($K)

Worley Parsons Golden, CO/Rodney Gartner; 

Rodney.Gartner@WorleyParsons.com Cost analysis of 2-tank TES 75

 

D R A F T
Advanced Heat Transfer Fluids Development

Performing Organizations: Sandia National Laboratories (SNL) 

 National Renewable Energy Laboratory (NREL)

 DOE Golden Field Office

 

Key Technical Contacts: Robert Bradshaw (SNL), 925-294-3229, rwbrads@sandia.gov

Nathan Siegel (SNL), 505-284-2033, npsiege@sandia.gov

Greg Glatzmaier (NREL), 303-384-7470, greg.glatzmaier@nrel.gov

 

DOE HQ Technology Manager: Tex Wilkins, 202-586-1684, frank.wilkins@hq.doe.gov 

FY 2009 Budgets: $500K (SNL), $405K (NREL)

____________________________________________________________________________________

Objectives

• Develop cost-effective thermal energy storage (TES) for parabolic trough plants (TES cost 

objective: $20/kWh) (SNL)

• Formulate heat transfer fluid (HTF) for advanced parabolic troughs enabling higher operating 

temperatures than current fluids and thus higher efficiency (levelized cost of energy [LCOE] 

objective ~7¢/kWh, temperature objective 500°C) (SNL)

• Discover and characterize new HTFs with low freezing points, high temperature thermal stability, 

and increased thermal conductivity; new storage materials with improved heat capacity (NREL)

• Improve heat transfer fluids and storage materials to each reduce LCOE by $0.008–0.018/kWh

(NREL). 

Accomplishments

• Developed multicomponent molten nitrate salt mixtures that solidify below 90°C (SNL)

• Discovered molten nitrate/nitrite salt mixtures that solidify below 80°C (SNL)

• Demonstrated chemical stability of nitrate-only molten salts to 500°C (SNL)

• Determined physical properties and corrosion activity of molten salt HTF (SNL)

• Began computational chemistry studies (molecular dynamics, thermodynamics) to search for salt 

compositions (SNL)

• Expanded nanofluids research to include experimental synthesis of nanoclusters for incorporation 

into fluids; increased heat capacity of nanofluids will reduce LCOE by $0.018/kWh (NREL)

• Initiated thermodynamics modeling of salt formulations using FactSage to identify useful salt 

formulations that have components other than nitrates and nitrites; improved properties will 

reduce LCOE by $0.008/kWh (NREL)

• Established thermal storage materials laboratory for characterizing new heat transfer fluids and 

storage materials; this laboratory supports other R&D activities (NREL). 

Future Directions

• Complete property characterization studies of low-melting nitrate and nitrate-nitrite salt mixtures

(SNL)

• Evaluate maximum operating temperature possible with binary solar salt for central concentrating 

solar power (CSP) (SNL)

• Extend computational chemistry methods to search for better compositions and predict properties

(SNL)

• Assess properties of molten salt hydrates as low-melting HTFs (SNL)

• Evaluate concept for encapsulating a metallic phase-change material (SNL)

• Expand scope of nanofluids modeling and synthesis to include metal alloys and encapsulated 

nanoclusters (NREL)

• Develop laboratory protocols for new instrumentation; build thermal conductivity instrument 

(NREL)

D R A F T
• Identify and refine storage material formulations using FactSage software (NREL). 

____________________________________________________________________________________

1. Introduction

At SNL, parabolic trough solar concentrating 

plants are being built or planned that will generate 

significant electrical power in the near term. TES

incorporated into such plants would reduce the 

LCOE and ensure dispatchability at the most 

valuable time of day. SNL developed and 

evaluated novel inorganic molten salts that can be 

used at temperatures up to 500°C, increasing 

power cycle efficiency vs. oil-based HTFs, which 

are limited to 400°C. The molten salt HTF is 

amenable to use in large TES tanks because it is 

inexpensive relative to organic fluids and has 

negligible vapor pressure. 

The purpose of this agreement with NREL is to 

discover and characterize new HTFs and storage 

materials for CSP applications. This work consists 

of complementary efforts in molecular dynamics, 

thermodynamics modeling, experimental 

synthesis, and property characterization.

Development of new HTFs will increase the 

thermodynamic efficiency of CSP power plants.

New storage materials will increase TES density.

Both improvements will decrease the LCOE for 

CSP plants.

2. Technical Approach

The technical approach at SNL in FY 2009 was to 

expand the preliminary work performed in FY 2008 

to conduct a wide-ranging laboratory evaluation of 

the newly developed molten salt HTF. The 

strategy for developing improved molten nitrate 

salt HTF involved using a limited experimental 

matrix to observe low-melting mixtures and to 

estimate the direction of optimal composition for 

the next group of experiments. The candidate lowmelting salt mixtures were then subject to 

determinations of chemical stability, physical 

properties, and corrosion activity. Physical 

property measurements and corrosion tests were 

also performed on candidate mixtures.

In FY 2009, NREL focused on developing and 

establishing new research capabilities. Past work 

within this agreement was limited to molecular 

dynamics modeling of nanoscale particles for 

nanofluids applications. NREL initiated 

experimental work to synthesize and characterize 

nanoscale particles. These materials will be 

incorporated into fluids to determine improvements 

in the fluid properties. NREL also initiated a new 

thermodynamics modeling capability to explore 

salt formulations beyond the conventional 

nitrate/nitrite compositions to identify alternative 

formulations with improved properties. Finally, 

NREL established a thermal storage materials 

laboratory that includes instrumentation to fully 

measure and characterize the thermophysical 

properties of new heat transfer fluids and storage 

materials.

3. Results and Accomplishments

SNL

• Developed multicomponent molten nitrate salt 

mixtures that solidify below 100°C by limited 

combinatorial experiments

• Demonstrated chemical stability of these 

molten salts to 500°C

• Determined viscosity and density of molten 

salt HTF

• Completed analysis of corrosion test alloys

• Demonstrated multicomponent nitrate-nitrite 

salt mixtures that solidify near 80°C. 

This project developed a novel molten salt HTF 

capable of both low and high temperature 

operation. Nitrate-only and nitrate-nitrite mixtures 

were studied. The chemical stability limits of lowmelting nitrate mixtures were determined by 

chemical analysis of molten salts maintained at 

high temperatures. Further, SNL conducted 

corrosion tests for 3000 hours at 500°C without 

degradation of the salt. Viscosity measurements 

showed that adding calcium nitrate to the 

multicomponent molten salts significantly 

increased the viscosity but was still acceptable for 

trough operations. Density was determined 

against composition and temperature to 500°C. 

Corrosion tests were conducted for stainless 

steels, carbon steel, and alloy steels. Specimens 

were evaluated gravimetrically and 

metallographically to determine their performance. 

SNL conducted laboratory work to investigate the 

properties of mixtures of nitrate (NO3

-

) and nitrite 

(NO2

-1) salts using sodium, potassium, and lithium 

in varying proportions. Melting points near 80°C 

were observed with mixed anion compositions. 

Work is continuing to obtain a complete phasediagram and evaluate properties.

D R A F T
Molecular dynamics simulations and continuum 

(free-energy based) thermodynamics calculations 

were used to study solid-liquid phase equilibria for 

alkali nitrate salt mixtures. 

NREL 

• Modeled nanoparticles with encapsulating 

shells that stabilize the particle during phase 

transitions (06/2009)

• Initiated synthesis of nanoparticles (07/2009)

• Surveyed the open literature to establish a 

database of 900 references for relevant 

nanomaterials work (07/2009)

• Purchased and installed instrumentation for 

the thermal storage materials laboratory 

(02/2009)

• Initiated thermodynamics modeling using 

FactSage software (03/2009). 

4. Planned FY 2010 Activities

SNL 

• Extend physical property determinations of 

molten salt HTF to include heat capacity and 

thermal conductivity 

• Complete study of nitrate-nitrite molten salt 

system for low-melting HTF compositions

• Explore molecular dynamics and continuum 

thermodynamic computational methods to 

discover better low-melting salt compositions

• Establish lab capabilities with new instruments 

for TGA/MS and DSC

• Evaluate stability limits of binary solar salt for 

700°C use in central receivers

• Assess novel method for encapsulating 

metallic PCM.

NREL 

• Complete first round of nanoparticle synthesis

• Complete laboratory protocols for materials 

laboratory

• Design and build thermal conductivity 

instrument

• Use FactSage modeling to identify promising 

new storage materials. 

5. FY 2009 Special Recognitions and Patents

Patent awarded, USP #7,588,694, Low-Melting 

Point Inorganic Nitrate Salt Heat Transfer 

Fluid, R.W. Bradshaw and D.A. Brosseau,

Sept. 15, 2009. 

Patent application #12/336,657, Low-Melting 

Point Inorganic Nitrate-Nitrite Salts, J.G. 

Cordaro and R.W. Bradshaw, filed Dec. 17, 

2008. 

6. Major FY 2009 Publications

D.M. Blake, Nanomaterials for Heat Transfer Fluid 

and Thermal Storage Applications in 

Concentrating Solar Plants, NREL/SR-550-

46591, Golden, CO: NREL (September 2009). A 

Review of 206 References.

R.W. Bradshaw and N.P. Siegel, “Development of 

Molten Salt Nitrate Mixtures For Concentrating 

Solar Power Systems,” SolarPACES 2009, 

Paper 11583, Berlin, DE, Sept. 15–18, 2009. 

R.W. Bradshaw, J.G. Cordaro, and N.P. Siegel, 

“Development of Inorganic Molten Salt Mixtures 

for Solar Thermal Energy Systems,” ASME 

Energy Sustainability 2009, Paper ES2009-

90140, San Francisco, CA, July 19–23, 2009.

G.C. Glatzmaier, J. Kang, Y.-H. Kim, D.M. Blake, 

and C. Curtis, “Nanoscale Materials Modeling for 

Improved Heat Transfer and Storage Fluids,” 

Solar PACES 2009, Berlin, Germany, September 

15–18, 2009. 

J. Kang and Y.-H. Kim, “Half-Solidity of 

Tetrahedral-Like Al55 Clusters,” ACS Nano, in 

press.

H. Xiang, J. Kang, S.-H. Wei, Y.-H. Kim, C. Curtis, 

and D. Blake, “Shape Control of Al Nanoclusters 

by Ligand Size,” J. Am. Chem. Soc. 131, 8522 

(2009).

7. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity FY 2009($K)

Daniel M. Blake daniel.blake@nrel.gov Support nanofluids and thermal storage 

R&D for the CSP Program 60

.

D R A F T
Storage Industry Projects

Performing Organizations: Abengoa Solar Inc.

Hamilton Sundstrand Corporation

Key Technical Contacts: Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953,

carolyn.elam@go.doe.gov

Jim Payne, DOE/GO, 303-275-4756, jim.payne@go.doe.gov

Brad Ring, DOE/GO, 303-275-4930, brad.ring@go.doe.gov

DOE HQ Technology Managers:Frank (Tex) Wilkins, (202) 586-1684, frank.wilkins@ee.doe.gov

Tommy Rueckert, (202) 586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budgets: $0 (DOE/GO); funded in FY 2008, no additional funding to date

____________________________________________________________________________________

Objectives

• Develop energy supply technologies that are reliable, affordable, and environmentally sound.

Expand national electricity generation portfolio to increase energy security by diversifying 

domestic energy supply options. 

• Develop low-cost, high-temperature storage that enables concentrating solar power (CSP) trough 

systems to reach nominal levelized cost of energy (LCOE) target of 5-7¢/kWh with storage (12–

17 hours) by 2020. 

Accomplishments

• Continued two CSP Advanced Systems and/or Component awards 

• Completed one Phase I go/no-go reviews (awardee received “go” decision)

• Continued to assess CSP Thermal Storage awards against the Solar Energy Technologies

(SETP) CSP subprogram goals and objectives.

Future Directions

• Evaluate each CSP Thermal Storage award to ensure they are progressing to meet the 

SETP/CSP goals and objectives. 

____________________________________________________________________________________

1. Introduction

CSP is one of the most attractive renewable 

energy options in the southwestern United 

States, with a nominal LCOE target of 7-

10¢/kWh by 2015 and 5-7¢/kWh by 2020. The

CSP thermal storage R&D activities are 

expected to develop low-cost, high-temperature 

storage that enables trough technologies to 

reach the nominal LCOE target. To achieve this 

goal, a storage cost of less than $15/kWh 

thermal is desired with round-trip efficiencies at 

or greater than 93%. . 

Organization, Principal Investigator,

and Agreement Title

FY 2009 

Budget 

($K) 

Abengoa Solar Inc., Bruce Kelly, 

Development of Molten Salt Heat Transfer 

Fluid Technology for Parabolic Trough 

Solar Power Plants

0 

Hamilton Sundstrand Corporation,

Michael McDowell, Concentrating Solar 

Power Molten Salt Pump

D 

0 

R A F T
Development of Molten-Salt Heat Transfer Fluid Technology for 

Parabolic Trough Solar Power Plants

(Abengoa Solar, Inc.)

Phase 1 Award: $625K DOE/Recipient: $500K/$125K 

____________________________________________________________________________________

Objectives

• Determine economic potential of low freeze point molten salts

• Develop technologies required for use of molten salts

• Conduct field tests necessary for introduction of molten salts in commercial project. 

Accomplishments

• Investigated using current receiver tube technology with molten salt up to 500°C 

• Identified potential collector joint concepts and joint materials compatible with molten salt heat 

transfer fluid (HTF) to be tested in Phase II

• Determined an optimum collector geometry and associated field piping layout for use with molten 

salt HTF 

• Identified compatible instrumentation for use with molten salt HTF

• Developed specifications for freeze prevention/recovery systems for the entire field piping system

• Developed loop operations and maintenance procedures specific to molten salt HTF

• Developed transient performance models in TRNSYS of entire molten salt plant, including two 

options for direct thermal energy storage (2-Tank and Self-Supporting Bed Thermocline)

• Analyzed plant performance with TRNSYS models

• Received detailed preliminary engineering, procurement, and construction costs for molten salt 

plant with two thermal energy systems (TES) options. 

Future Directions

• Test prototype components for molten salt use (ball joints, high-temperature receivers)

• Use Phase 1 results to illustrate reduced LCOE and risk mitigation. 

____________________________________________________________________________________

1. Introduction

Commercial parabolic trough projects use an 

organic fluid as the HTF in the collector field and 

the steam generator. The high vapor pressure of 

this fluid requires an indirect thermal storage 

system. The project will determine whether 

inorganic fluids reduce LCOE enough to pursue 

further development and to develop the 

components required for molten salt use.

2. Technical Approach

Abengoa is developing sizing models in 

Engineering Equation Solver (EES) and transient 

performance models in TRNSYS to both assess 

plant performance and create a bill of materials 

necessary for engineering, procurement, and 

construction cost estimate.

3. Results and Accomplishments

Abengoa developed solar field piping layouts for 

both the baseline Therminol (organic HTF) and the 

reference molten salt plant, with an option to use 

molten salts with very low (~100°C) melting points. 

Preliminary analysis of the low melting point salts 

focuses on economic concerns, performing a 

design tradeoff between the higher cost of these 

salts and the lower equipment cost. Heat balances 

were also developed for the reference Therminol, 

and the baseline molten salt plants. An 

engineering assessment, using capital cost data, 

was developed for the reference Therminol and 

the baseline molten salt plants, based on half of 

the 250-MWe Solana project for Arizona Public 

Service. 

4. Planned FY 2010 Activities

• Produce Phase 1 final report

• Receivego/no go decision on Phase II

• Develop prototype and scale up if Phase II 

D 

approved.

R A F T
5. Major FY 2009 Publications

D.A. Arias, A. Gavilan, and R. Muren, “Pumping 

Power Parasitics in Parabolic Trough Solar 

Fields,” SolarPACES 2009, Berlin, Germany, 

September 15–18, 2009.

D.J. Chapman and D.A. Arias, “Effect of Solar 

Brightness Profiles on the Performance of 

Parabolic Concentrating Collectors,” Proc. ASME 

2009 3rd International Conference on Energy 

Sustainability ES2009, San Francisco, CA, July 

19–23, 2009. 

. 

D R A F T
Concentrating Solar Power Molten Salt Pump

(Hamilton Sundstrand Corporation) 

Total Award: $4,374K DOE/Recipient: $3,219K/$1,155K 

____________________________________________________________________________________

Objectives

• Develop molten salt pump requirements

• Evaluate existing hardware designs for necessary modifications

• Create a preliminary design of the pump concept

• Develop and refine cost estimates for Phase II and Phase III. 

Accomplishments

• Achieved all Phase I objectives

• Held Conceptual Design Review (CoDR) on November 4, 2009

• Submitted Phase I continuation report on December 22, 2009. 

Future Directions

• Begin Phase II (design, fabricate, build), DOE continuation evaluation under way

• Phase III testing at Sandia National Laboratory. 

____________________________________________________________________________________

1. Introduction

This project addresses the integration of advanced 

low-cost thermal storage with parabolic trough 

systems. The intent of this project is to design, 

build, and test a long-shafted (~50 feet) molten 

salt pump, capable of operation at 1,050°F. The 

design will be evaluated using parameters 

expected with the thermal storage system of a 

commercial-scale solar trough plant.

2. Technical Approach

The intention is to improve the technology of longshafted pumps to replace the sump-type of pump, 

and eliminate the associated valving, piping, and 

heat trace. The technical innovation necessary for 

this project reflects the need to expand the 

performance envelope of long-shafted molten salt 

pumps. The system for the pump application has 

been defined, and pump operations necessary for 

successful plant operation has been developed.

As part of Phase I, cost estimates for the design, 

build, and testing in Phase II and Phase III will be 

developed.

Rocketdyne has partnered with Friatec N.A., LLC 

to jointly develop a molten salt pump, creating top 

level specifications, a conceptual design, and 

detailed cost estimates. Friatec N.A., LLC will also 

support activities in Phase II and Phase III.

3. Results and Accomplishments

Phase I major accomplishments:

• Defined molten salt pump system 

requirements (07/09)

• Evaluated existing hardware for necessary 

modifications (10/09)

• Generated conceptual design, hold design 

review (11/09)

• Evaluated cost estimates of Phase II and 

Phase III (12/09)

• Submitted continuation report (12/09).

The pump design should support a 100-MWe 

power plant with 4 hours of thermal storage 

capacity. Although double the size of existing 

trough plants, this was considered to be a 

reasonable increase in capacity. Friatec examined 

its existing designs. Having significant involvement 

with molten salt applications in both the United 

States and Europe, the review covered 300 molten 

salt pump applications, including single- and 

multistage wet ends, 20 impeller sizes, 5 bearing 

pedestal sizes, and 7 different materials used for 

the columns, wet end, and pump discharge. All 

pumps were designed to operate in the same 

temperature range (~550°F to 1050°F) as required 

for this project, using motors up to 800 HP. Shaft 

lengths, however, were shorter (20 feet versus 50 

feet).

D R A F T
The pump will be designed for a two-tank plant 

(hot and cold). Focus will be on the hot tank 

design, with a vertical pump orientation and top 

entry specified. The result of this configuration will 

be a reduction in the necessary valving, piping, 

fitting and heat trace. The pump will operate at 

1,800 RPM, but will have variable speed 

capability.

The vendor evaluated its existing line of pumps, 

based on the current RFP requirements for solar 

trough plants with thermal energy systems (TES) 

using molten salt pumps. For reference, 68% of 

the time a pump with a 10-inch discharge, a 16.5-

inch impeller diameter, and an operating speed of 

less than 1,800 RPM met customer requirements.

The size of the pump selected for this application 

would be used in parallel with two pumps of the 

same size to provide redundancy within the TES 

system, to control equipment costs, and to reduce 

the risk of a complete system shut down because 

of a pump failure

It was determined that the pump required for the 

program is similar to the production pump model 

GVSO 250/355 (10-inch discharge, 16.6-inch 

diameter impeller, 1,800 RPM, 250 HP, single 

stage wet end). Finite element analysis (FEA) and 

computation fluid dynamic (CFD) analysis on a 

similarly sized 200/400 pump (8-inch discharge, 

18.3-inch diameter impeller, 1800 RPM, 2300 HP, 

4 stage wet end) have already been performed.

For this project, the only major change required to 

the existing design would be to increase the shaft 

length. This change would be significant, because

the planned application requires a shaft of greater 

than two times the existing design. 

Fig. 1. Pump cross section and major 

components. 

4. Planned FY 2010 Activities

Phase II of the project is scheduled for a period of 

18 months. During this period, the detailed design 

will be finalized. To minimize the chance of 

technical issues, FEA and CFD models will be 

generated to assist in understanding the effects of 

the necessary design changes. In the next period, 

the preliminary and critical design reviews will be 

held. This will be followed by the fabrication of the 

pump components, pump assembly, and shipment 

of the pump to the test facility. Testing of the 

prototype pump will be conducted in Phase III at 

the facilities of Sandia National Laboratories.

5. University and Industry Partners

Organization/

Principal Investigator Location Description/Title of Research Activity FY 2009 ($K)

Cost Share 

($K)

Friatec N.A., LLC / Jeff 

Kelly Odessa, FL Long Shafted Molten Salt Pump Development 236 47

D R A F T
Advanced Heat Transfer Fluids and Novel Thermal Storage Concepts for 

Concentrating Solar Power Generation 

Performing Organizations: Abengoa Solar, Inc. (2)

ACCIONA Solar Power, Inc. (2)

City College of New York (CUNY)

General Atomics

Infinia Corporation

Lehigh University

Symyx Technologies

Terrafore, Inc.

Texas A&M University (Texas Engineering Experiment Station)

University of Connecticut

The University of Alabama (UA), Tuscaloosa

University of Arkansas

US Solar Holdings, LLC

Key Technical Contacts: Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953,

carolyn.elam@go.doe.gov

Brad Ring, DOE/GO, 303-275-4930, brad.ring@go.doe.gov

Jim Payne, DOE/GO, 303-275-4756, jim.payne@go.doe.gov

Brian Hunter, DOE/GO, 303-275-4934, brian.hunter@go.doe.gov

DOE HQ Technology Managers:Frank (Tex) Wilkins, 202-586-1684, frank.wilkins@ee.doe.gov

Tommy Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Funding: $1,499K (DOE/GO)

____________________________________________________________________________________

Objectives

• Support long-term R&D and near-term demonstration in two areas that could increase the 

efficiency and reduce the cost of concentrating solar power (CSP) systems to make them cost 

competitive:

o Improved heat transfer fluids (advanced HTF): Identify and characterize novel fluids or 

fluid types that possess the physical and chemical properties required for an improved 

HTF and thermal storage fluid for CSP technologies. 

o Novel thermal energy storage (TES) concepts (novel TES systems): Generate and 

evaluate novel concepts for TES that have the potential to reduce the cost of TES to less 

than $15/kW thermal and achieve round-trip efficiencies greater than 93%.

Accomplishments

• Negotiated 15 CSP HTF/TES awards; held kick-off meetings with award recipients

• Defined roles and responsibilities of program management team, including technical advisors at 

the National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL)

• Continued to assess CSP HTF/TES awards against the Solar Energy Technologies Program 

(SETP)/CSP subprogram goals and objectives.

Future Directions

• Evaluate progress toward critical milestones; make go/no-go decisions at the end of the each 

project’s first phase, starting in FY 2009 and extending into FY 2010

• Evaluate each of the CSP Advanced HTF/TES awards to ensure they are progressing to meet 

the SETP/CSP subprogram objectives to identify concepts that can reduce the cost of TES to 

less than $15/kW thermal and achieve round-trip efficiencies greater than 93%.

____________________________________________________________________________________

D R A F T
1. Introduction

Funding Opportunity Announcement (FOA) DEPS36-08GO98032, titled “Advanced Heat 

Transfer Fluids and Novel Thermal Storage 

Concepts for Concentrating Solar Power 

Generation,” resulted in 15 FY 2008 awards in 

three topic areas: Advanced Heat Transfer Fluid 

Research and Development (1 award), Thermal 

Energy Storage Research and Development (10 

awards), and Thermal Energy Storage NearTerm Demonstration (4 awards). The financial 

assistance agreements are listed in the following

table. 

Recipient/Principal Investigator

Agreement Title

FY 2008 

Funding 

($K)

FY 2009 

Funding 

($K)

Advanced HTF Research and Development

Symyx Technologies/J. Raade

Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids 500 0 

TES Research and Development

Abengoa Solar, Inc./B. Kelly

Advanced Thermal Energy Storage for Central Receivers with Supercritical 

Coolants

303 0 

ACCIONA Solar Power, Inc./Newmarker

Sensible Heat, Direct, Dual-Media Thermal Energy Storage Module 100 0 

City College of New York/R. Shinnar

A Novel Storage Method for Concentrating Solar Power Plants Allowing 

Operation at High Temperature

445 0 

General Atomics/B. Wong

Thermochemical Heat Storage for Concentrated Solar Power 500 0 

Lehigh University/S. Neti

Novel Thermal Storage Technologies for Concentrating Solar Power 

Generation

350 20

Terrafore, Inc./A. Mathur

Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for 

Concentrating Solar Power Plants

469 0 

Texas A&M University (Texas Engineering Experiment Station)/M. Schuller

Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar 

Power Systems

543 0 

University of Connecticut/A. Faghri

Research and Development for Novel TES Systems for CSP 449 0 

The University of Alabama/R Reddy

Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power 

Generation 500 0 

University of Arkansas/P. Selvam

Development and Performance Evaluation of High Temperature Concrete for 

Thermal Energy Storage for Solar Power Generation

224 0 

TES Near-Term Demonstration

Abengoa Solar, Inc./B. Luptowski

Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar 

Power Plants

500 0 

ACCIONA Solar Power, Inc./M. Newmarker

Indirect, Dual-Media, Phase Changing Material Modular Thermal Energy 

Storage System

500 0 

Infinia Corporation/S. Qiu

Innovative Application of Maintenance-Free Phase-Change Thermal Energy 

Storage for Dish Engine Solar Power Generation

500 1479

US Solar Holdings, LLC/J. Stephens

CSP Energy Storage - Multiple Technologies Compared 236 0 

D R A F T
Deep Eutectic Salt Formulations Suitable as Advanced Heat Transfer Fluids 

Symyx Technologies

Total Award:$2,635K ($1,500K DOE / $1,135K nonfederal)

____________________________________________________________________________________

Objectives

• Develop an advanced HTF with a melting point below 80°C and thermal stability up to 500°C. A 

material with these properties could reduce the levelized cost of energy (LCOE) from CSP by 

$0.02/kWh. This project will focus on complex mixtures of inorganic salts that exhibit a high 

thermal stability, a low melting point, and other favorable characteristics. Symyx will conduct a 

high-throughput combinatorial research and development program in order to achieve the project 

objective. 

Accomplishments

• Screened more than 2,500 unique salt blends for melting point so far

• Discovered two distinct families of salt blends with melting points below the 80°C target

• Completed method development for the thermal stability measurement of salt blends; began to 

screen blends that passed the melting point target

• Assessed the utility of thermodynamic modeling software tools. 

Future Directions

• Complete the screening program of 5,000 unique blends by December 31, 2009

• Perform secondary screening and then field testing of candidate blends to arrive at a commercial 

candidate heat transfer fluid.

____________________________________________________________________________________

1. Introduction

Current CSP plants use a synthetic oil-based heat 

transfer fluid that limits their operating 

temperature to 400°C. Next-generation plants are 

targeting an operating temperature of 500°C to 

increase efficiency and reduce the LCOE. Molten 

salts exhibit many desirable heat transfer qualities 

within the range of the project objectives but 

typically have high melting points, preventing their 

application in commercial CSP plants.

2. Technical Approach

Symyx will investigate complex mixtures of 

inorganic salts to discover deep eutectic or low 

melting point formulations suitable as advanced 

HTFs. Eutectic mixtures of salts exhibit dramatic 

melting point reductions, but little experimental 

data exist for quaternary or higher order systems. 

3. Results and Accomplishments

Symyx developed a high throughput workflow 

capable of dispensing, melting/mixing, and 

characterizing up to 400 unique salt blends per 

week. The workflow consists of automated Symyx 

equipment such as the Powdernium powder 

dispensing robot and Parallel Melting Point 

Workstation. A thermogravimetric analysis (TGA) 

device measures the thermal stability of the salt 

blends.

4. Planned FY 2010 Activities

• Viscosity screening (lower viscosity of heat 

transfer fluid means lower parasitic pumping 

losses)

• Thermodynamic modeling with the FactSage 

software and databases; model eutectic 

behavior and high-temperature reactions

• Thermal stability enhancement. 

D R A F T
Advanced Thermal Energy Storage for Central Receivers with Supercritical Coolants 

Abengoa Solar, Inc.

Total Award: Phase 1 $379K ($303K DOE / $76K nonfederal)

Phase 2 $379K ($303K DOE / $76K nonfederal)

Phase 3 To Be Determined (TBD)

____________________________________________________________________________________

Objectives

• Determine if supercritical heat transport fluids in a central receiver power plant, in combination 

with ceramic thermocline storage systems, reduce the LCOE over a baseline nitrate salt concept

• If so, demonstrate a prototype thermocline storage unit.

Accomplishments

• Examined the following six plant designs:

o Two reference nitrate salt designs, each using a two-tank nitrate salt thermal storage system: 

 A subcritical design, using a Rankine cycle operating at 125 bar, with live and reheat 

steam temperatures of 540°C 

 A supercritical design using a Rankine cycle operating at 300 bar, with live and reheat 

steam temperatures of 590°C

o Two supercritical steam receiver designs: 

 A low-temperature variation, using a two-tank nitrate salt thermal storage system 

 A high-temperature design, using a packed bed thermocline storage system

o Two supercritical carbon dioxide receiver designs: 

 A low-temperature variation, using a two-tank nitrate salt thermal storage system 

 A high-temperature design, using a packed bed thermocline storage system

• Developed conceptual heliostat field layouts, together with optimum tower heights and receiver 

absorber dimensions, using the RCell computer program (Tietronix)

• Developed incident flux and temperature maps for each of the receiver concepts to estimate 

thermal efficiency and fatigue life

• Developed models of the temperature profiles in the high-temperature storage designs using a 

finite element approach for the solution of the Schumann simultaneous partial differential 

equations to model the heat transfer in a packed bed thermocline

• Developed annual plant performance calculations with the SOLERGY computer program

• Assembled plant capital cost estimates, and annual operation and maintenance cost estimates, 

from a range of earlier studies and an in-house estimating database

• Developed LCOE calculations using a 30-year cash flow analysis and financial parameters typical 

for an independent power producer. 

Future Directions

• Further research packed bed thermocline using supercritical H2O, found to be impractical due the 

wide range of fluid specific heats near the bottom (low temperature portion) of the vessels. 

• Further research packed bed thermocline using supercritical CO2,found to offer stable, and 

repeatable, temperature profiles. However, the high pressures characteristic of supercritical CO2

(~150 bar) require expensive pressure vessels to contain the ceramic storage media. 

• Recommend to DOE to conclude the study at the end of Phase 1 and not to proceed with the 

more detailed thermocline analyses planned for Phase 2, since neither of the thermocline storage 

designs offered a reduction in 

D 

LCOE compared to the reference nitrate salt storage designs. 

R A F T
Sensible Heat, Direct, Dual-Media Thermal Energy Storage Module 

ACCIONA Solar Power, Inc.

Total Award: Phase 1 $125K ($100K DOE / $25K nonfederal)

Phase 2 TBD

Phase 3 TBD

____________________________________________________________________________________

Objectives

• Design and validate, at prototype level, a sensible heat TES module with round-trip efficiency 

greater than 93%; 

the module will be part of a TES system that can facilitate a decrease in LCOE by 2020.

Accomplishments

• Derived several different configurations

• Began developing a heat transfer model that can be adapted to each design.

Future Directions

• Perform detailed heat transfer and fluid dynamic modeling

• Generate a basic design of the sensible-heat TES module.

____________________________________________________________________________________

1. Introduction

An unsophisticated, modular, and scalable TES

system could facilitate the attainment of an LCOE 

of $0.07/kWh by 2015. 

The proposed sensible-heat TES module is a 

direct heat transfer TES system in which HTF 

circulating through the solar field charges the 

storage and serves as limited storage media in 

itself. The direct, dual-media TES module consists 

of HTF and pressure containment vessels filled 

with a solid storage media.

2. Technical Approach

During FY 2009 researchers examined the design 

concept using value engineering criteria, 

consolidating the best configurations for the TES 

module. 

Also during FY 2009, ACCIONA created a heat 

transfer model with TRNSYS. This model will 

determine the heat storage capability and will be 

used as a key go/no go evaluation of the project.

2. Results and Accomplishments

The first achievement of this project was to 

consolidate all the design concepts examined for 

this project. Two different design concepts were 

derived. 

Next, TRNSYS was used to begin modeling the 

problem using standard program components. The 

current iteration can charge the storage system 

based on step functions and temperature 

dependent flow control.

3. Planned FY 2010 Activities

• Continue heat transfer modeling with standard 

components and add the ability to simulate 

discharge (03/10)

• Begin building proprietary components (04/10)

• Begin fluid dynamic analysis of the two 

designs; this modeling will be used as a key 

go/no go evaluation (06/10)

• Complete a basic design of the sensible-heat

D 

TES module (11/10).

R A F T
A Novel Storage Method for Concentrating Solar Power Plant Allowing 

Operation at High Temperature 

City College of New York

Total Award: $1,904K ($1,328K DOE / $576K nonfederal)

____________________________________________________________________________________

Objectives

• Develop a storage method for CSP plants that can operate without any practical constraints at 

both the lower or upper temperature extremes (from ambient to 2500°F), and be added to a CSP 

plant without affecting the cost of daily kilowatt-hours generated. 

Accomplishments

• Identified a filling material for the storage unit for both water/steam and CO2 storage

• Developed reduced models for CO2 and water/steam storage

• Designed a laboratory pilot plant to demonstrate heat storage using both CO2 and water/steam; 

contracted construction of the plant. 

Future Directions

• Focus on the pilot plant operation to demonstrate the concept of heat storage and produce data 

to improve the computer models

• Perform optimization studies of the filling material to reduce cost and storage volume.

____________________________________________________________________________________

1. Introduction

The main objective of the work is to develop and 

test a storage method that is able to completely 

remove both upper and lower operating 

temperature constraints, which currently strongly 

limit the efficiency of CSP plants, and to 

significantly reduce the costs well below the cost 

goals fixed by this FOA. 

2. Results and Accomplishments

An experimental setup to test the filler material 

was constructed. All testing will be conducted 

during FY 2010 and will be documented in the 

report for that year.

A model for CO2 storage was developed. Results 

show that the heat front advances as a sharply 

defined gradient, thus giving a total available 

volume for storage of about 80%.

A laboratory-size plant was designed. A company 

willing to work within our budget to optimize the 

design and build it was identified: Chemtech 

Services Inc. of Joliet, IL. The plant is being built 

and it is expected to be completed in February 

2010.

3. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Cost 

Share ($K)

Chemtech Services 

Inc./ 

John F. Hart

Joliet, IL

Jhart@chemtechservicesinc.com

D 

Fabrication of pilot plant 180 0 

R A F T
Thermochemical Heat Storage for Concentrated Solar Power 

General Atomics

Total Award: $2,434K ($1,500K DOE / $934K nonfederal)

____________________________________________________________________________________

Objectives

• Identify and assess solid oxide thermochemical cycles (TC) that can be used for TES in an openloop system in which air is used as both the heat carrier and the reactant

• Determine reaction thermodynamics of all solid oxide TC and evaluate their potential as TES 

candidates; carry out laboratory studies to verify the feasibility of using the potential TC 

candidates for TES and to establish a protocol for future experimental evaluation

• Establish a baseline process model for an electricity plant integrated with TES; apply all potential 

TES candidates to the model and estimate their process efficiency, chemical heat storage cost

(target: $15/kWh), and LCOE (target: $0.08/kWhe) 

• Down-select the potential candidates based on computed economics and preliminary 

experimental data; selected systems will undergo more detailed experimental characterizations. 

Use the data to support process component designs and modeling to obtain a more accurate 

economic assessment. Carry out a conceptual design for “on sun” demonstration if the economic 

viability of the selected TC is demonstrated. 

Accomplishments

• Surveyed pure and mixed oxides TC applicable to TES using thermodynamic calculations and 

literature data

• Completed the thermodynamic assessment of all single-component solid oxide systems using 

HSC Chemistry software; identified 15 pure oxide TC as potential TES candidates

• Developed a preliminary process flowsheet for an electricity plant incorporated with a solid oxide 

based TES system; estimated the chemical storage cost and LCOE with respect to each potential 

pure oxide TC

• Completed the construction of packed bed test systems for preliminary feasibility studies.

Future Directions

• Complete preliminary experimental evaluation of potential TES candidates

• Down-select potential solid oxide TES candidates

• Conduct a more detailed experimental characterization of the selected TES candidates

• Identify pathways and conduct experiments to modify the properties of the selected TES 

candidates

• Conduct thermochemical heat storage reactor and solar interface designs and establish a 

process model for a CSP power plant integrated with a solid oxide TES system.

D R A F T
Novel Thermal Storage Technologies for Concentrating Solar Power Generation

Lehigh University

Total Award: $1,497K ($1,103K DOE / $394K nonfederal)

______________________________________________________________________________

Objectives

• Establish technical feasibility of using specially made encapsulated phase-change materials 

(EPCM) at elevated temperatures and acquire engineering results that will lead to the 

demonstration of large-scale thermal storage systems.

Accomplishments

• Performed heat transfer analysis to transfer enthalpy into and out of storage material; heat 

transfer does not appear to be an impediment for solar thermal energy storage 

• Considered various methods for the encapsulation of phase-change material (PCM, zinc) have 

been considered; completed stress analysis of the encapsulating material for three geometries

• Evaluated the actual enthalpy into or out of the PCM using calorimetry; built and now testing a

precision calorimeter. 

Future Directions

• Explore further analysis of heat transfer into the PCM and in a bed full of EPCM; manufacture 

sample EPCM and build a heat transfer bed to test the TES concept; this will include issues 

related to the repeated thermal cycling of the EPCM.

_____________________________________________________________________________

1. Introduction

Solar power generation has proved to be an 

excellent source of renewable energy. CSP 

technology is recognized as an attractive option 

for solar power, for plants of 100 MW or greater 

capacity. Two key needs for this technology are 

improved HTF and improved methods for TES.

This project addresses the second need, with 

the objective of developing a novel TES 

technology that uses phase-change latent heat 

to increase thermal capacity, and offers energy 

storage at high temperatures (~400°

C) to 

improve thermodynamic efficiency.

Using latent heat thermal energy storage could 

have significant advantages. In the present work 

zinc is used as PCM for storing thermal energy. 

Because the melting point of zinc is 420°

C, it is

an ideal candidate for the storage of latent as 

well as sensible heat. It can enable the 

production of high-temperature steam from solar 

energy even during nondaylight hours.

The change material needs to be encapsulated 

to provide sufficient heat transfer surface during 

the energy storage and retrieval process. Nickel 

and stainless steel are being considered as 

encapsulation material to make up the zincnickel EPCM.

The TES will be accomplished in a large bed of 

EPCM through which the HTF from the solar 

field flows to charge and discharge the bed, thus 

storing and retrieving energy.

Heat transfer in the PCM modules is very 

important for the TES process. Transient onedimensional analysis in the PCM indicates that 

heat transfer into and out of the PCM is not likely 

to be a major impediment to TES. Work to 

further appreciate these concepts continues. 

The PCM material will expand as it is heated to 

the desired storage temperatures. The 

expansion could be as much as 10% to 11%, 

corresponding to as much as 3% strain in the 

encapsulating material. Researchers used the 

properties of nickel at 450°

C and finite element 

analysis that includes plastic deformation. 

Abaqus was used for this plastic deformation 

and stress analysis. With appropriate choice of 

the encapsulating material thickness and 

geometry for encapsulation, it is possible to 

construct EPCM modules that will result in 

stress under permissible values despite the 

high-temperature conditions. Sample EPCM 

modules will be built soon.

The amount of thermal energy stored is being 

verified using calorimetry. Because of the 

special nature of the materials used and 

because commercially available calorimeters 

D R A F T
were not adequate, researchers designed and 

built a precision calorimeter. Measurements with 

heated cylinders indicate that overall energy 

balances of about 2.5% are possible. 

Plans for the immediate future include additional 

calorimetry work and the design and 

development of an EPCM bed with hot/cold air 

flow through it to make TES measurements. We 

anticipate building a 25-kW system that can 

handle approximately 25-mm-diameter, 40-mmlong EPCM cylinders. This system will be 

capable of demonstrating thermal energy 

storage in zinc-nickel EPCM.

D R A F T
Heat Transfer and Latent Heat Storage in Inorganic Molten Salts for 

Concentrating Solar Power Plants 

Terrafore, Inc.

Total Award: $1,834K ($1,439K DOE / $395K nonfederal)

____________________________________________________________________________________

Objectives

• Develop a salt mixture composition based on a dilute eutectic and develop a coating material for 

heat transfer tubes that inhibits sticking

• Identify economical salt mixtures for use with CSP plants (power tower and linear Fresnel 

reflectors or parabolic troughs).

Specific benefits of using PCM TES include:

• A 30% reduction in amount of salt and a 60% reduction in container size compared to equivalent 

sensible heat TES

• Improved overall CSP system efficiency by 2% to 3% 

• Reduced TES costs by 30% over conventional sensible-heat TES, reducing LCOE costs by more 

than 6%. 

• 

Accomplishments

• Selected salt mixtures suitable for commonly used steam cycles (6 to 13 MPa steam pressures 

and 560°C) with various CSP plants

• Identified and characterized two candidate coating technologies for use with the heat exchanger

• Developed an experiment setup for qualifying coatings as “anti-stick” to selected salt mixture; in

the experiment rig, the salt mixture is pumped through an external heat exchanger with partial 

frozen salt slurry returning to tank

• Developed a mathematical model of the PCM storage system.

• 

Future Directions

• Continue tests with coatings and salt mixtures

• Develop mathematical models and empirical correlations and conduct simulation and economical 

analysis

• Demonstrate the concept with a scaled engineering model.

1. Introduction

CSP plants are being designed to generate power 

between 50 and 100 MW using high-pressure 

steam Rankine system cycles. In a typical CSP 

system, the heat transfer fluid is heated to 400°C 

to 565°C to provide heat for vaporizing and 

superheating steam at steam pressures from 5.9 

MPa (850 psia, saturated steam temperature of 

274°C) to 12.4 Mpa (1,800 psia, saturated steam 

temperature of 327°C). The collected heat is 

stored in a TES system to ensure heat on cloudy 

days and at times when the sun is not shining. In 

conventional systems, this heat is stored as 

sensible heat in salts or oil. Storing heat as latent 

heat of fusion in inorganic salts (PCM storage), 

however, significantly reduces the amount of salt 

required and the tank size. For PCM storage, this 

system has many challenges. DOE and Terrafore 

are jointly researching approaches to address 

these challenges in this project.

2. Technical Approach

Our innovative approach to solve this is to use 

inorganic salt mixtures that have a simple phase 

diagram, and the mixture is a dilute eutectic

composition. When a dilute eutectic freezes, an 

equilibrium liquid becomes associated with it. This 

solid with the associated liquid has the 

consistency of a slurry, which can be pumped to 

an external heat exchanger, thus forcing the 

molten salt over the heat exchanger tubes and 

causing the freezing solid particles to remain in the 

molten slurry. The forced convection heat transfer 

caused by flow velocity is significantly larger than 

conduction through solid. In addition to this, a 

“salt-phobic” coating on the heat exchanger 

surface can further prevent the salt from sticking to 

the tubes, and a nucleating agent and chemical 

added to the salt mixture can help with the flow 

and heat transfer properties. 

D R A F T
3. Results and Accomplishments

The project funded by DOE will affect the overall 

economics in three ways:

• Reduce total thermal storage cost in dollars per 

kilowatt-hour ($/kWh). We estimate a reduction 

of at least 6% over the conventional systems.

The amount of salt used is reduced by more 

than 30%. 

• Improve cycle efficiency because of the use of 

higher turbine cycle pressure such as 2,400 

psia. A 2% to 3% improvement in system 

efficiency is indicated.

• Introduce flexibility to charge storage when 

collection temperatures are lower than the 

design such as during partial cloud cover and 

early morning. During these times, the energy 

is collected at lower temperatures to melt the 

PCM salt in the tank. 

FY 2009 accomplishments include the following: 

• Selected salt mixtures suitable for commonly 

used steam cycles (7 to 16 MPa steam 

pressures and 560°C)

• Identified and characterized two candidate 

coating technologies for use with a heat 

exchanger

• Developed an experiment setup for qualifying 

coatings as anti-stick to a selected salt mixture; 

in the experiment rig, the salt mixture is 

pumped through an external heat exchanger 

with partial frozen salt slurry returning to tank

• Produced solids different from that of single 

salt using a qualified Terrafore proprietary 

composition of salt mixture (dilute eutectic). 

Solidification morphology

• Started measuring salt solidification 

morphology versus temperature using contact 

angle rig

• Started measuring viscosity of solid slurries

• Polished samples of frozen solids to view them

in the scanning electron microscope to study

the interface between solid and tube surface. 

Mathematical model

• Developed a mathematical model for predicting 

heat transfer coefficient in external heat 

exchangers as molten salt freezes on heat 

transfer tubes

• Developed a mathematical model for storing 

heat using thermal stratification in a tank with 

freezing slurry returning to the tank. 

4. Planned FY 2010 Activities

• Continue tests with coatings and salt mixtures

• Develop a heat exchanger and demonstrate 

on a laboratory-scale system.

5. FY 2009 Special Recognitions and Patents 

• Submitted patent on latent heat storage for 

CSP systems. 

• Presented at a CSP conference in San 

Francisco

• Interviewed on Radio Melbourne on 

challenges and benefits of PCM storage. 

6. University and Industry Partners

The following organizations partnered in the 

project’s research activities during FY 2009: 

• Terrafore, Inc., Riverside, CA

• University of California at Riverside, CA

• Jet Propulsion Labs, Pasadena, CA

• Pratt & Whitney Rocketdyne, Pasadena, CA

• H.V. Setty, University of Minnesota, MN.

D R A F T
Molten Salt-Carbon Nanotube Thermal Energy Storage for Concentrating Solar Power Systems 

Texas A&M University, Texas Engineering Experiment Station

Total Award: $1,875K ($1,500K DOE / $375K nonfederal)

____________________________________________________________________________________

Objectives

• Evaluate the ability of composite TES materials (nanoparticles in a molten salt) to:

o Reduce $/kWhth for TES system

o Increase specific heat of TES materials

o Increase thermal conductivity of TES materials

o Increase temperature range of TES materials

• Demonstrate that the composite material does not increase corrosion of stainless steel. 

Accomplishments

• Demonstrated 20%–75% improvement in specific heat of carbonate eutectic TES material by 

adding 0.1%–1.5% by weight concentration of nanoparticles

• Demonstrated 10% improvement in specific heat of nitrate TES material (75% transient 

improvement)

• Discovered a new way of synthesizing carbon “onion” nanoparticles in situ in the carbonate 

eutectic TES material by adding 1%–5% by weight of surfactant (SDS) that led to enhancement 

of specific heat by 16%–55%

• Demonstrated first-order freeze/thaw cycle stability of composite TES materials

• Developed numerical models (using molecular dynamics simulations) to optimize the size and 

concentration of nanoparticles

• Developing a theoretical model to explain the observed enhancement of specific heat of 

nanofluid-eutectics

• Demonstrated 15% improvement in specific heat of chloride eutectic TES material by adding 1% 

by weight concentration of nanoparticles.

Future Directions

• Identify and evaluate nanoparticle materials that will remain in suspension in nitrate TES material

• Demonstrate long-term freeze/thaw cycle stability of composite TES materials

• Demonstrate corrosion compatibility of composite TES materials with stainless steel

• Demonstrate improved thermal conductivity of composite TES materials

• Determine the optimum size and concentration of the nanoparticles for enhancing thermophysical

properties

• Develop a detailed cost and sizing model for a TES system using composite materials that 

balances cost and performance of nanoparticle composition and dimensions.

____________________________________________________________________________________

1. Introduction

Reducing the cost of TES systems can both 

reduce the cost of electricity produced by CSP 

plants and increase their income by shifting their 

electricity output into more lucrative time 

periods. One approach to achieving these goals 

is to improve the thermophysical properties of 

the TES material. Previous research indicated 

that adding small amounts of nanoparticles to a 

fluid could dramatically improve the 

thermophysical properties of that fluid. We are 

investigating applying these findings to improve 

the specific heat and thermal conductivity of 

TES materials for CSP plants. 

2. Technical Approach

The project team identified candidate materials, 

including the base materials (salts) and 

nanoparticles. We fabricated candidate 

materials using a variety of techniques, including 

dry mixing and aqueous solution mixing (using 

pool and film boiling techniques using a syringe 

pump). We measured the thermophysical 

properties of the candidate materials. The 

primary tool used in this task was a digital 

scanning calorimeter (DSC), which measures 

the specific heat of the material. We also used a 

laser flash analyzer for specific heat and thermal 

conductivity measurements. The main issue 

D R A F T
addressed in the first year of the program was 

demonstrating feasibility of the concept. 

3. Results and Accomplishments

• Demonstrated 25%–75% improvement in 

specific heat of carbonate eutectic material 

at 0.5%–1.5% loading of SiO2 nanoparticles

(12/09)

• Demonstrated 20%–70% improvement in 

specific heat of carbonate eutectic material 

at 0.05%–0.1% loading of carbon nanotubes 

(CNT) (12/09)

• Demonstrated 10%–75% improvement in 

specific heat of nitrate material when Al2O3

added; still need to stabilize composite

(11/09)

• Discovered a new way of synthesizing 

carbon onion nanoparticles in situ in the 

carbonate eutectic TES material by adding 

1%–5% by weight of surfactant (SDS) that 

led to enhancement of specific heat by 

16%–55%

• Demonstrated 15% improvement in specific 

heat of chloride eutectic material at 0.5%–

1.5% loading of SiO2 nanoparticles (12/09)

• Completed preliminary analysis of 

economics of improving TES material 

(11/09)

• Measured irregular results (up to 10%–20% 

improvement) for the specific heat of 

carbonates, chlorides, and nitrates at 0.1%–

1% loading of cellulose nanocrystals (CNC).

We demonstrated the feasibility of improving the 

specific heat of a molten salt by adding small 

amounts of nanoparticles. We were able to show 

improvements in the specific heat in both the 

solid and liquid phases of the material. Our 

preliminary economic analysis showed that 

improving the specific heat of the TES material 

by 50% reduces TES system cost by 30%. 

4. Planned FY 2010 Activities

• Refine and extend measurements of specific 

heat for composite materials (07/10)

• Demonstrate freeze/thaw cycling of 

composite materials (08/10)

• Demonstrate corrosion of stainless steel in 

composite material is no worse than it is in 

base salt (09/10)

• Demonstrate improvement in solid-phase 

thermal conductivity of composite materials 

(10/10)

• Identify means to stabilize nitrate-based 

composites (10/10)

• Reevaluate CNC nanoparticle composites 

(10/10)

• Improve economic model of TES system 

(11/10).

5. Major FY 2009 Publications

D. Shin and D. Banerjee, “Investigation of 

Nanofluids for Solar Thermal Storage 

Applications,” Paper No. ES2009-90465, 

ASME Energy Sustainability Conference, San 

Francisco, CA, July 20–25, 2009.

D R A F T
Research and Development for Novel Thermal Energy Storage Systems (TES) for 

Concentrating Solar Power 

(University of Connecticut)

Total Award: $1,687K ($1,290K DOE / $397K nonfederal)

____________________________________________________________________________________

Objectives

• Develop innovative heat transfer devices and methods for novel TES systems involving PCMs

• Develop new thermosyphons or heat pipes or both to reduce thermal resistances within the TES 

and improve performance of the CSP system

• Generate fundamental knowledge to enable system design through experimentation and 

modeling

• Enable reduction of LCOE by up to $0.06/kWh. 

Accomplishments

• Identified candidate heat-pipe working fluids

• Designed and fabricated low-temperature multiple heat-pipe experimental apparatus

• Developed system-level TES model, including PCM, heat pipes, and heat transfer fluid

• Developed fundamental heat transfer and fluid dynamics model for PCM melting and 

solidification, including periodic melting and solidification. 

Future Directions

• Identify specific PCM and heat-pipe working fluids

• Design and fabricate moderate/high-temperature heat pipes

• Design and fabricate moderate/high-temperature multiple heat-pipe experimental apparatus

• Finalize system-level and fundamental models

• Validate moderate/high-temperature models with experimental results

• Apply the system model to full-scale systems

• Optimize PCM/heat-pipe configurations. 

____________________________________________________________________________________

1. Introduction

The overall objective is to develop innovative heat 

transfer devices and methods for novel TES

systems involving PCMs. 

2. Technical Approach

The technical approach is to embed 

thermosyphons or heat pipes into PCMs to reduce 

thermal resistances between the PCM and the 

working fluid, to increase the overall efficiency of 

concentrating solar power generation plants. 

Experimental and modeling approaches are taken, 

and novel heat pipes and PCM modules will be 

fabricated to test their performance. Ultimately, 

computer programs will be made available to 

develop these components as well as to 

implement them in an optimal manner in actual 

concentrating solar power systems.

3. Results and Accomplishments

• Successfully identified a number of candidate 

working fluids for the heat pipes as well as 

candidate PCMs for incorporation in both 

current and future concentrating solar plants.

• Developed a system-level model, using a 

thermal element network approach, and used

it to identify tradeoffs in the TES system. The 

effectiveness of adding heat pipes to improve 

performance was clearly shown and 

quantified. Companion experimental work with 

low-temperature PCMs and heat pipes has 

commenced with promising preliminary 

results.

• Developed a detailed simulation model to 

predict melting and solidification of the PCM. 

The model is capable of predicting both 

charging and discharging of thermal energy 

storage system; it uses no empirical models or 

input. 

D R A F T
4. Planned FY 2010 Activities

• In FY 2010, we will continue to identify and 

test candidate PCMs and heat pipe working 

fluids. Both the system model and the detailed 

models will be finalized and validated with 

detailed experimental measurements. 

• High-temperature experiments will be 

designed and conducted for both the heat 

pipes and PCMs, individually as well as in an 

integrated module.

5. University and Industry Partners

• Virginia Polytechnic Institute and State 

University. 

D R A F T
Novel Molten Salts Thermal Energy Storage for Concentrating Solar Power Generation (The 

University of Alabama, Tuscaloosa)

Total Award: $1,895K ($1,500K DOE / $395K nonfederal)

____________________________________________________________________________________

Objectives

• Develop low melting point (LMP), molten salt, TES media with high TES density for sensible heat 

storage systems, with the following specific characteristics:

• Lower melting point compared to current salts (<222°C)

• Higher energy density compared to current salts (>756 MJ/m3

) 

• Lower power generation cost compared to current salts: 2020 goals are to reduce the cost of TES 

to less than $15/kWhthermal and achieve round-trip efficiencies greater than 93%. 

Accomplishments

• Confirmed the ternary eutectic mixture in the LiNO3-NaNO3-KNO3 system by thermodynamic 

calculations and experimental verification to meet/exceed the specific targeted characteristics, 

offering good heat capacity and thermal stability 

• Identified five additional salt mixtures that had the balance of properties to exceed the criteria; l 

identified 14 other novel mixtures that have attractive thermal properties 

• Found that the six salt mixtures have melting temperatures in the range of 80°–116°C, and 

energy storage density from 1,000 to 1,500 MJ/m3

, which is a 30%–90% improvement over the 

current salt. 

Future Directions

• Study the six proposed salt mixtures further; characterize all the necessary thermal and physical 

properties and optimize them for performance and cost based on their potential to meet the DOE 

2020 goals 

• Evaluate the additional identified salt mixtures to determine their thermal and physical properties, 

then optimize them for performance based on their potential. 

____________________________________________________________________________________

1. Introduction

Two key opportunities to reduce the cost of CSP 

plants are improved HTF and improved methods 

for TES. As part of this work, DOE awarded this 

contract to the University of Alabama (UA) to 

define and evaluate advanced HTF for CSP plant 

use.

The current molten salt, an HTF and thermal 

storage media, is a mixture of 60 wt% NaNO3 and 

40 wt% KNO3. The liquid temperature range is 

220°–600°

C. The main disadvantage of this salt 

mixture is the high melting point. The UA program 

objective is to develop LMP molten salt TES

media with high TES density for sensible heat 

storage systems. The media must also meet 

thermal stability criteria and be economically 

viable.

Preliminary work suggested that a ternary eutectic 

in the NaNO3-LiNO3-KNO3 system had the 

required properties of lower melting point and 

higher TES density than the current salt system. 

2. Technical Approach

To develop candidate LMP salt materials, the 

project team used thermodynamic calculations 

backed up by atomic and molecular modeling that 

estimated eutectic compositions melt points of 

mixtures, heat capacity, and density. From that 

work, energy storage density was calculated.

Material properties were validated by using 

experimental techniques, including DSC for melt 

point and heat capacity, TGA and DSC for thermal 

stability, Brookfield viscometer for viscosity, and 

other characterization techniques. The potential 

impact of LMP materials on the TES facility is 

being evaluated by modeling the TES using

MatLab®. Finally, costs are predicted by collecting 

current salt pricing and calculating salt mixture 

cost, and normalized mixture cost/energy stored 

($/kWht). System costs are estimated by 

comparative ratioing with material capability and 

D R A F T
cost predictions for an Andasol 1 TES-2 tank 

system as recently estimated by the Electric 

Power Research Institute (EPRI). 

Thermodynamic calculations involve the 

minimization of the Gibbs energy of fusion 

expression for temperature and composition in a 

given system. Standard thermodynamic databases 

were used to input the thermodynamic parameters 

for the calculations. Regular solution 

approximation, which deals with expressing the 

excess Gibbs energy as a function of composition, 

was used for all the systems studied. Calculated 

eutectic points in binary systems were compared 

with the data available in the literature (phase 

diagram). Calculating the melting points of higher 

order systems involved extending the regular 

solution approximation employed for binary 

systems. 

3. Results and Accomplishments

• Completed assessment of the base ternary 

eutectic system for melting point

• Predicted the melting point, density, heat 

capacities, and energy storage densities for 

more than 28 molten salt mixtures

• Completed the estimation of TES costs of the 

candidate LMP salt systems

• Completed identification of two or more 

potential salt system candidates that have 

lower melting points and higher energy density 

compared to current salts, and that are 

economically viable. 

Thermodynamic calculation and experimental 

verification confirmed that the novel baseline UA 

ternary material, shown as the second material in 

Table 1, meets and exceeds the go/no-go goals. 

Using extensive thermodynamic calculations to

predict melting point, density, and heat capacity, 

the project team identified 14 additional novel 

mixtures of molten salt with attractive thermal 

properties. 

Melting points for all of these materials are well 

below the baseline UA ternary of 116°C, with one 

mixture predicted in the 80°C region. In addition, 

energy storage density for each of these materials 

is well above the solar salt. HTF compound costs 

were estimated based on the current supplier’s

price quotation, and TES system costs for a twotank, direct approach were estimated for each of 

these materials. From the large set of qualifying 

materials, the team selected six specific mixtures 

further study; details are given in Table 1. 

As shown in Table 1, the current solar salt price 

estimate is $1.08/kg, less than novel mixture costs 

of $1.27 to $2.21/kg. Because these novel 

materials offer much higher energy storage 

densities, however, both HTF material inventory 

and equipment (tank) size can be significantly 

reduced. Figure 1 also shows the resulting system 

cost estimates. Systems using the proposed 

materials approach the 2020 goal of 

$15/kWhthermal. The UA baseline ternary showed a 

melting point significantly below the conventional

solar salt and the Hitec salts. The calculated 

density and heat capacity for the UA baseline 

ternary showed improvements over the solar and 

Hitec salts.

Fig. 1. Cost estimates for proposed HTF systems 

vs. solar salt baseline 

The experimental melting point was 117°C and the 

experimental heat capacity of 2.3184 J/g.K was 

obtained at 500°C. These properties turn into a 

significant advantage for the UA baseline ternary’s

energy storage density, at 1524 MJ/m3

, nearly 

100% greater than conventional solar salt (756 

MJ/m3

) and significantly greater than values for the 

Hitec salt (955 MJ/m3

).

Thermal stability, shown in Figure 2, is good at

500°C. Weight loss of the salt at 500°C was less 

than 0.1%.

D R A F T
Fig. 2. TGA-DTA data showing the thermal 

stability of UA baseline ternary salt

4. Planned FY 2010 Activities

• Synthesize the six candidate salt mixtures 

proposed from year 1; study and optimized all 

the necessary thermal and physical properties 

for performance and cost based on their 

potential

• Further pursue additional salt mixtures that 

were identified to determine the necessary 

thermal and physical properties.

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Cost Share 

($K)

The University of Alabama/ 

Ramana G. Reddy

Tuscaloosa, AL

rreddy@eng.ua.edu

Develop LMP molten salts 

thermodynamic and transport 

property model, and experimental 

validation of the property data.

Also develop LMP molten salt 

media with high TES system.

357.5 116

United Technologies 

Research Center/ 

James R. Irish

Hartford, CT

irishjr@utrc.utc.com

Contribute atomic/ molecular and 

thermal modeling of system. 

Collaborate with UA in component 

attributes to evaluate 

improvements and cost reductions 

available in TES system.

142.5 35.6

D R A F T
Development and Performance Evaluation of High Temperature Concrete for Thermal Energy 

Storage for Solar Power Generation 

University of Arkansas

Total Award: $770K ($616K DOE / $154K nonfederal)

____________________________________________________________________________________

Objectives

• For the 2020 DOE goal for TES systems , achieve costs of less than $15/kWhthermal and achieve 

round-trip efficiency greater than 93%. Concrete as a material is inexpensive and the media 

cost/kWhthermal is reported to be $1. Hence this is a viable sensible heat solid media technology for 

TES. The objective is to develop and test high-performance concrete that can withstand 

temperatures up to 600°C.

• Develop computer model to study the heat transfer rate with and without fins. 

• Test the developed concrete for TES using thermal cycling and evaluate the performance.

Accomplishments

• Developed a concrete mix that can withstand temperatures of greater than 600°C 

• Developed and validated a 3D FEM model to study the heat transfer rate

• Used the model to study different fin arrangement effects on heat transfer rate.

Future Directions

• Develop a heating system to heat the concrete blocks up to 600°C 

• Test the effect of heating rate on the performance of concrete as well as energy storage using 

concrete around a single steel tube

• Test a 4x4 steel tube system with concrete for energy storage and concrete performance.

____________________________________________________________________________________

D R A F T
Reducing the Cost of Thermal Energy Storage for Parabolic Trough Solar Power Plants 

Abengoa Solar, Inc.

Total Award: Phase 1 $625K ($500K DOE / $125K nonfederal)

Phase 2 TBD

Phase 3 TBD

____________________________________________________________________________________

Objectives

• Identify opportunities for cost reduction in near-term TES systems

• Identify two mid-term TES options with greater opportunities for cost reduction

• Demonstrate the TES options with the best cost reduction potential for parabolic troughs plants in 

the near term and midterm. 

Accomplishments

• Completed design and model of 125 MWe_net baseline Therminol plant with 6 hours of two-tank 

molten salt storage

• Completed preliminary assessment of several TES concepts and chose three for more detailed 

investigation (advanced molten salt, phase change material, concrete)

• Completed transient performance models of TES concepts in TRNSYS. 

Future Directions

• Finalize detailed technical and economic analysis of best three concepts

• Use Phase 1 results to illustrate reduced LCOE and make go/no go decision for further 

investigation. 

____________________________________________________________________________________

1. Introduction

State-of-the-art TES systems use a molten salt in 

a two-tank configuration. Although the two-tank 

systems are functional, the cost of such TES 

systems for parabolic trough plants must be 

reduced to be economically attractive. This work

focuses on two approaches for reducing the cost 

of TES for trough plants:

• Research cost reduction opportunities for the 

indirect two-tank molten-salt design

• Develop alternative TES options that might be 

applicable for trough plants for midterm 

projects.

2. Technical Approach

• Develop sizing models in Engineering 

Equation Solver (EES) and transient 

performance models in TRNSYS to both 

assess plant performance and create bill of 

materials necessary for engineering, 

procurement, and construction cost estimates.

3. Results and Accomplishments

Abengoa developed a TRNSYS performance 

model for the 125 MWe_net baseline Therminol 

plant with 6 hours of two-tank molten salt storage, 

and obtained a cost estimate for such a plant. 

Researchers completed a preliminary assessment

of several TES concepts, and selected three 

concepts for more detailed investigation 

(advanced molten salt, phase change material, 

and concrete). Transient performance models 

were developed in TRNSYS for each TES concept 

and attached to the plant model to account for 

system interactions and performance limitations. 

Performance analyses are being carried out for 

comparison with the baseline. Detailed cost 

estimates are also being obtained for each 

concept; these will be combined with performance 

results to calculate LCOEs for each concept.

4. Planned FY 2010 Activities

 

• Finalize detailed technical and economic 

analysis of best three concepts

• Select a concept and system development 

requirements for Phase 2 

• Make a go/No Go decision on Phase 2 

• Develop a prototype and scale-up if Phase 2 is 

D 

approved.

R A F T
5. Major FY 2009 Publications

D.A. Arias, A. Gavilan, and R. Muren, “Pumping 

Power Parasitics in Parabolic Trough Solar 

Fields,” SolarPACES 2009, Berlin, Germany, 

September 15–18, 2009. 

D.J. Chapman and D.A. Arias, “An Assessment of 

the Supercritical Carbon Dioxide Cycle for Use in 

a Solar Parabolic Trough Power Plant,” 

Proceedings of SCCO2 Power Cycle 

Symposium 2009, Troy, NY, April 29–30, 2009.

R. Muren, D. Arias, and B. Luptowski, 

“Performance Based Cost Modeling of Phase 

Change Thermal Energy Storage for High

Temperature Concentrating Solar Power 

Systems,” Proceedings of the AMSE 2009 

International Mechanical Engineering Congress 

& Exposition IMECE2009, Lake Buena Vista, FL, 

November 13–19, 2009.

D R A F T
Indirect, Dual-Media, Phase Changing Material Modular Thermal Energy Storage System 

ACCIONA Solar Power, Inc.

Total Award: Phase 1 $625K ($500K DOE / $125K nonfederal)

Phase 2 TBD

Phase 3 TBD

____________________________________________________________________________________

Objectives

• Design, validate at prototype level, and then demonstrate a full-size TES system based on PCM 

TES modules; the 

PCM TES module will be part of a TES system that can facilitate a decrease in LCOE by 2020.

Accomplishments

• Derived several different configurations

• Began developing heat transfer and fluid flow models that can be adapted to each design.

Future Directions

• Perform detailed heat transfer and fluid dynamic modeling

• Design the PCM TES module and the PCM TES system

• Fabricate and test a 100-kWht PCM TES module prototype.

____________________________________________________________________________________

1. Introduction 

An unsophisticated, modular, and scalable TES 

system could facilitate the attainment of a LCOE of 

$0.07/kWh by 2015. 

The proposed design uses the inherent 

characteristic of molten salt to solidify during 

discharge to gain access to its latent heat 

properties. As discharging of the system 

concludes, the vat of salt will be fully solidified.

2. Technical Approach

The research team examined the design concept 

using value engineering criteria, consolidating the

best configurations for the PCM TES module. 

Also during FY 2009, the team created heat 

transfer and fluid dynamic models. These models 

will determine the heat storage capability and 

pumping capacity needed for the system and will 

provide a key go/no-go evaluation of the project.

3. Results and Accomplishments

The first achievement was to consolidate all of the 

design concepts that were examined for this 

project. Four different design concepts were 

derived. Next, TRNSYS was used to begin 

modeling the problem with standard program 

components. The current iteration can charge and 

discharge the storage system based on step 

functions and temperature-dependent flow control.

4. Planned FY 2010 Activities

• Continue modeling with standard components 

to simulate the latent heat portion of discharge

(03/10)

• Begin building proprietary components (04/10)

• Begin translating the model elements into a 

physical design, which will segue into the lab 

unit design (06/10)

• Design the PCM TES module and the PCM 

TES system (11/10).

D R A F T
Innovative Application of Maintenance-Free Phase-Change

Thermal Energy Storage (TES) for Dish Engine Solar Power Generation

Infinia Corporation

Total Award: $9,361K ($5,423K DOE / $3,939K nonfederal)

____________________________________________________________________________________

Objectives

• Provide preliminary design for 1-hour TES/dish Stirling demonstrator and preliminary LCOE 

estimate by the end of Phase 1 (FY 2009)

• Build and demonstrate 1-hour storage prototype based on the 3 kW commercial CSP system by 

the end of Phase 2 (FY 2010)

• Manufacture, deliver, and field test a statistically significant number of 4- to 6-hour storage 

TES/CSP systems by the end of Phase 3 (FY 2011 through FY 2012). 

Accomplishments

• Completed the preliminary design of the 1-hour storage demonstrator 

• Completed the preliminary LCOE estimate 

• Finalized 50% of the design for the 1-hour storage demonstrator. 

Future Directions

• Complete final design of the demonstrator

• Initiate design of an increased capacity dish for a 4- to 6-hour TES/CSP system

• Build and test prototype the demonstrator in FY 2010. 

____________________________________________________________________________________

1. Introduction

Integrating TES modules with dish Stirling systems 

will enable operation during cloud transients and 

provide dispatchable power for 4 to 6 hours after 

daylight hours, at a net incremental cost that can 

be shown to add a higher incremental value to the 

system, reducing LCOE in volume production.

2. Technical Approach

The TES system uses a PCM salt with a high 

melting point to maximize energy storage density 

by using both the latent heat of fusion and the 

sensible heat capacity over a wide range of 

operating temperatures. Heat will be conducted 

into and out of the salt via heat pipes. Thermal 

modeling analysis was used to optimize the 

configuration of heat pipes in the device.

3. Results and Accomplishments

Infinia completed the preliminary design and 

started final design of the 1-hour demonstration 

prototype. Researchers determined the size of the 

TES device, as well as the size, number, and 

placement of the heat pipes, required for optimal 

performance. The strategy for integrating the TES 

device with a commercial CSP system was

defined, and a preliminary levelized cost of energy 

study was conducted. Figure 1 shows the 

demonstrator prototype.

4. Planned FY 2010 Activities

 

FY 2010 activities will focus on completing the 

final design of the demonstrator system, its 

fabrication, and testing. Preliminary design for a 

larger dish suitable for a 4- to 6-hour storage 

device will also be completed. Specific items 

include:

• Build the 1-hour TES demonstrator

• Demonstrate TES on-sun

• Complete larger dish design. 

Fig. 1. Demonstrator prototype

TES Module

D R A F T
5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location Description/Title of Research 

Activity

FY 2009

($K)

Cost 

Share 

($K)

Infinia Corporation/

Songgang Qiu Kennewick WA Principal investigator, Stirling design 457 117

Penn State University 

Applied Research Lab/ 

Tim Miller

State College, 

PA Thermal modeling and analysis 43

Consultant/

Barry Penswick Stevenson, WA Stirling engine performance modeling 11

Thermacore, Inc./

John Thayer Lancaster, PA Heat pipe design 74

D R A F T
CSP Energy Storage—Multiple Technologies Compared 

US Solar Holdings, LLC

Total Award: $4,084K ($2,038K DOE / $2,046K nonfederal)

______________________________________________________________________________ 

Objectives

• Provide a path to maximally cost-effective, commercially proven CSP energy storage technology

• Conduct further proof and cost reduction analysis for the thermocline TES technology

• Develop and prove a new, novel Sand Shifter TES technology.

Accomplishments

• Developed mathematical modeling tool for thermocline systems

• Detailed key design elements and identified the preferred design method for thermocline and 

Sand Shifter TES systems

• Generated initial cost estimates of the preferred design options for each technology.

Future Directions

• Validate design stage work through prototype construction, testing, and analysis

• Improve primary design approaches based on prototype testing and performance evaluation

• Refine cost estimates based on prototype performance analysis.

______________________________________________________________________________ 

1. Introduction

The goal is to develop and demonstrate TES 

systems that are competitive at the utility scale. To 

achieve this objective, the project examines

innovative design approaches to lower the cost of 

TES technologies.

2. Technical Approach

2.1 Thermocline TES

Phase 1 focused on identifying and evaluating key 

design parameters in order to converge on a 

preferred thermocline system design approach. 

Selecting the preferred design approach involved 

a detailed evaluation of existing thermocline 

designs and an assessment of all key design 

parameters. An ideal heat storage system was first 

modeled to determine baseline system parameters 

(i.e., transfer fluid mass flow rate, total tank 

volume). Heat storage analysis was conducted to 

model the heat transfer between the transfer fluid 

and the solid heat storage filler material. This 

model was then used compare various system 

configurations to converge on a preferred design 

approach.

2.2 Sand Shifter TES

The Sand Shifter is an innovative idea requiring 

much time spent on modeling, basic R&D, and 

preliminary design. Both system and component 

design development was necessary. A 

comprehensive list of critical issues was identified 

and design development and testing were directed 

at resolving these issues, none of which now 

appear to make the concept infeasible. Heat 

transfer performance has been a special concern. 

Many approaches and detailed information remain 

proprietary pending patent execution, but an 

overview of the results and accomplishments is 

given here. 

Attention has focused on the adverse capital cost 

and energy consumption of the auxiliary materials 

handing equipment (MHE). Design improvements 

explored and testing indicates that MHE energy 

consumption will be acceptable. Also, some 

structural design issues are critical and several 

promising designs are now under development. 

3. Results and Accomplishments

3.1 Thermocline TES

• Evaluated key design parameters and 

compared various system configurations to 

select a preferred design approach (07/09)

• Developed a model to predict heat storage 

performance for different thermocline 

conditions and configurations (05/09)

• Designed and partly constructed a lab-scale 

heat storage test loop prototype (09/09)

• Consulted expert vendors for initial cost 

estimate of preferred design approach (08/09). 

D R A F T
3.2 Sand Shifter TES

• Demonstrated basic concept with a 

preliminary 50-inch diameter prototype 

(12/08)

• Identified alternative mineral sand, which is 

under consideration (02/09+)

• Identified an alternative storage volume with 

multiple advantages (02/09)

• Continued sand erosion tests, which show 

negligible wear (03/09+)

• Completed preliminary designs, with 

favorable cost analyses (03/09)

• Verified heat transfer results (03/09+)

• Developed Various heat exchanger surface 

designs (02/09+)

• Performed sand distribution tests (09/09).

4. Planned FY 2010 Activities

3.1 Thermocline 

• Construct prototype system and perform 

testing plan

• Refine initial cost estimate incorporating 

design updates.

3.2 Sand Shifter 

• Construct a fully integrated Sand Shifter 

prototype system

• Perform testing plan to evaluate and update 

key design components

• Refine initial cost estimate incorporating 

design updates.

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research 

Activity

FY 2009

($K)

Cost 

Share 

($K)

US Solar Holdings LLC/ 

Jake Stephens

Tucson, AZ

jstephens@ussolarholdings

.com

Principal investigator and project 

manager providing industry 

perspective and business analysis

47.4 0 

Georgia Tech/ 

Sheldon Jeter

Atlanta, GA

Sheldon.jeter@me.gatech.

edu

Lead role in Sand Shifter 

subproject design, development, 

and prototyping efforts

131.8 0 

University of Arizona/ 

Perry Li

Tucson, AZ

peiwen@email.arizona.edu

Lead role in thermocline 

subproject design, development, 

and prototyping efforts

86.2 0 

Arizona Public Service/ 

Phil Smithers

Phoenix, AZ

phil.smithers@aps.com 

Project oversight, utility scale 

development perspective, and 

technical assistance

IroncCo Enterprises/

Jeff Krauss

Phoenix, AZ

jeff.krauss@ironco.net

Steel fabrication consultant, 

prototype construction 20.6 0 

Klondyke Construction/ 

Steve McClain

Phoenix, AZ

smcclain@klonykeinc.com Construction consulting 9.6 0 

Harris Group/ 

Steve McCormick

Denver, CO

Steve.mccormick@harrisgr

oup.com

Engineering analysis and cost 

estimating 33 0 

Arizona State/

Kenneth Sullivan Tempe, AZ

Kenneth.Sullivan@asu.edu

Construction management and 

project planning controls 9 0 

D R A F T
Advanced CSP Concepts Summary 

Advanced Concepts task is recognized by the solar industry as the world’s leader 

because of its work in optical characterization and accelerated and outdoor testing of 

advanced solar reflectors and its repository of material durability data. Optical 

characterization and accelerated and outdoor testing are not duplicated by private 

industry work.

Low-cost, high-performance, durable advanced optical materials are necessary to meet 

the demands of advanced system designs and to achieve the cost and performance 

goals that are needed to commercialize CSP technologies. The overall objective is to 

develop, validate, and aid the commercialization of advanced reflector systems that can 

dramatically reduce the cost of concentrating solar power. 

NREL SNL Other Solar

Total $K Total $K Total $K Total $K

Advanced CSP Concepts 725 900 2910 4535

Advanced Materials & 

Concepts 475 0 0 475

Power Tower R&D 0 850 500 1350

CSP Funding Opportunity 

Announcement – Advanced 

Concepts 250 50 2410 2710

D R A F T
Advanced Materials and Concepts

Performing Organizations: Sandia National Laboratories (SNL)

National Renewable Energy Laboratory (NREL)

Key Technical Contacts: Clifford K. Ho (SNL, Primary Contact), 505-844-2384, ckho@sandia.gov 

Cheryl Kennedy (NREL, Primary Contact), 303-384-6272, 

cheryl.kennedy@nrel.gov 

Gregory J. Kolb (SNL), 505-844-1887, gjkolb@sandia.gov 

Nathan P. Siegel (SNL), 505-284-2033, npsiege@sandia.gov 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budgets: $750K (SNL), $475K (NREL)

Objectives

• Develop advanced cross-cutting technologies and modeling and analysis tools that will aid in the 

development, validation, and commercialization of concentrating solar power (CSP) components and 

systems to increase performance and dramatically reduce costs to less than 10¢/kWh by 2015

• Create probabilistic performance model to assess levelized cost of energy (LCOE), validation of solid 

particle receiver model, and develop CAD models for detailed coupled-process evaluation (SNL)

• Reduce by half the cost of the mirrors by moving from heavy glass mirrors to lightweight front-surface 

reflectors that include surface coatings to reduce soiling (NREL)

• Develop advanced reflector materials that are low in cost (less than $2.50/ft2 or $26.90/m2

• Test the durability of optical materials to determine the lifetime of solar reflector materials (NREL). 

) and maintain 

high specular reflectance (90%–95% into a 4-mrad cone angle) for long lifetimes (20 to 30 years) under 

severe outdoor environments (NREL)

Accomplishments

• Performed review of existing codes and software for CSP technologies; identified deficiencies and needs

(SNL)

• Developed and implemented probabilistic methods to quantify uncertainties and sensitivity analyses for 

assessing the system performance and economics (LCOE) of a central-receiver power plant (SNL)

• Acquired tools and methods to develop integrated models to assess the impact of wind, gravity, and 

thermal loads on optical performance of collector/receiver systems (SNL)

• Developed and validated model of a solid particle receiver for advanced high-temperature power-cycle 

and thermal-storage capabilities (SNL)

• Worked with California Energy Commission (the Commission) to develop analyses for glint and glare 

hazard assessments of solar thermal power plants (SNL)

• Published five papers on these topics at international conferences (SNL)

• Performed durability testing and published results of optical materials that potentially reduce LCOE of 

CSP to less than 10¢/kWh by 2015 (NREL)

• Provided significant industry support to CSP and concentrating photovoltaic (CPV) industries on solar 

reflectors (NREL). 

Future Directions

• Implement probabilistic modeling into existing tools used by industry (e.g., Solar Advisor Model, or SAM) 

(SNL)

• Continue developing integrated models (CAD/fluid/thermal/structural/optical) to understand and optimize 

system design and performance under normal and off-normal conditions (SNL)

• Continue durability testing of optical materials to determine the lifetime of solar reflector materials (NREL)

• Continue optical characterization of advanced reflector materials and accelerated and outdoor testing of 

commercial and experimental reflector materials, as well as those developed under CSP funding 

opportunity announcements (FOAs), the CSP industry, and cooperative research and development 

agreements (CRADAs) to determine the lifetime of solar reflector materials and to support 

industry/program needs (NREL)

D R A F T
• Analyze and publish testing results of reflector materials applied to CSP technologies (NREL). 

1. Introduction 

Modeling and analyses are critical to 

understanding and improving the performance and 

economics of CSP systems. Because these 

systems are complex, multiple models of 

components at various scales are needed. 

Information from detailed smaller scale models 

and tests are often distilled into larger scale, totalsystem models. 

SNL’s work focuses on the need to develop and 

integrate rigorous models and analyses of detailed 

components and processes to make large-scale, 

total-system models more accurate and reliable. 

Probabilistic models are needed to quantify 

uncertainties and to identify parameters and 

processes that have the most impact on system 

performance and cost. In addition, coupled 

processes such as the impact of wind and gravity 

loads on optical performance of heliostats or other 

collectors are needed to better predict 

performance in normal and off-normal conditions. 

Finally, models of emerging technologies that can 

improve system performance (e.g., solid particle 

receivers for advanced high-temperature power 

cycles and thermal storage) and cross-cutting 

analyses that will enable certification of CSP 

systems are described.

NREL is conducting R&D to meet the DOE SETP

goal, which is for CSP technologies to be cost

competitive in the intermediate power market at 8–

9¢/kWh with six hours of storage by 2015. The 

long-term goal is for CSP systems to be cost 

competitive in the baseload power market with 12 

to 17 hours of thermal storage by 2020. CSP 

systems cannot hit these targets without 

aggressive cost reductions and revolutionary 

performance improvements from technology 

advances. The SETP Multi-Year Technical Plan

targets cost reductions of up to 50% for the solar

concentrator. Reducing the field labor and 

collector support structure costs will have a 

significant impact. Commercialization of CSP 

technologies requires the development of 

advanced reflector materials such as lightweight, 

easy-to-install, front-surface reflectors with

antisoiling coatings. The objective of NREL’s

research is to identify new, cost-effective 

advanced reflector materials that are durable with 

weathering.

2. Technical Approach

SNL performed a review of existing CSP codes 

and software to identify gaps and needs in 

modeling and analysis. Based on this review, 

researchers recommended and demonstrated 

probabilistic modeling. In addition, the 

investigators started using integrated CAD-based 

software (Solidworks®

), computational fluid 

dynamics software (FLUENT® and Cosmos 

FloWorks®

), stress analysis software

(Cosmosworks®

), and advanced optical modeling 

software (ASAP®

) to model detailed components 

and coupled processes. The results of these 

codes and models will enable a more thorough 

characterization of uncertainties and focus 

research on areas that are most important to 

enable more reliable total-system model 

predictions.

 NREL is working on the following:

• Developing advanced reflector materials that are 

low in cost (<$2.50/ft2

• Testing the durability of optical materials to 

determine the lifetime of solar reflector 

materials.

) and that maintain high 

specular reflectance (>95% into a 2- to 4-mrad 

cone angle) for long lifetimes (30 years) under 

severe outdoor environments 

Researchers identify candidate reflector materials 

based on their potential for high optical 

performance, long outdoor durability, and low cost. 

To assess their optical durability, materials are 

optically characterized at the outset and remeasured periodically as a function of exposure 

time after being subjected to real and simulated 

weathering environments. Candidate solar 

reflectors being tested include thick and thin glass, 

silvered polymer, aluminum, and front surface

reflectors. The optical materials database contains 

more than 20,000 samples encompassing more 

than 300,000 measurements over a 23-year time 

span of optical durability results.

3. Results and Accomplishments

SNL achieved the following accomplishments:

• Researchers developed probabilistic models 

of a 100-MWe power tower to quantify 

uncertainties associated with LCOE 

predictions. Stepwise linear regression 

sensitivity analyses revealed specific features 

and processes that were found to be important 

to the LCOE, including costs, component 

reliability, parasitics, receiver absorption, and 

heliostat performance. 

D R A F T
• SNL recently designed and tested a prototype 

solid particle receiver. Researchers 

developed computational fluid dynamics 

models to simulate the performance of a 

prototype solid particle receiver being 

operated at SNL. The simulations included 

irradiation from the concentrated solar flux, 

two-band re-radiation and emission within the 

cavity, discrete-phase particle transport and 

heat transfer, gas-phase convection, wall 

conduction, and radiative and convective heat 

losses. The investigators compared the 

simulated and measured temperatures of the 

particles and cavity walls and calibrated solar 

flux parameters. This validated model will be 

used to develop next- generation receivers 

that allow higher temperature power cycles 

and energy storage for increased efficiency. 

The solid particle receiver enables both hightemperature operation and low-cost thermal 

energy storage that can potentially meet DOE 

cost goals and generate baseload solar power 

for industry.

• Applications and certifications for solar thermal 

power plants often require an assessment of 

“visual resources” at the site, which include an 

evaluation of general health and safety issues 

associated with potential glint and glare. 

Rigorous and uniform treatment of glint and 

glare, however, is lacking. In FY 2009, SNL 

compiled safety metrics and developed a 

hazard evaluation method. Models are being 

developed to assess potential hazards 

associated with glint and glare in each of the 

primary CSP technologies: (1) power tower 

systems, (2) linear concentrator systems (e.g., 

parabolic troughs), and (3) dish/engine 

systems. Once developed, these crosscutting analyses can be used by applicants 

seeking certification of concentrating solar 

thermal power plants.

• The Advanced Concepts R&D project was 

awarded a rank of 3.7 at the March 2009 

SETP Peer Review meeting. The review team 

specifically recognized the work of NREL’s 

Advanced Materials task and its importance to 

industry. The team strongly recommended that 

the project be expanded with additional space, 

equipment, and personnel resources allocated 

for this activity.

Selected NREL accomplishments follow:

• Researchers provided significant industry 

support (i.e., technical assistance and data) to 

more than 180 CSP and CPV industry 

partners on solar reflectors.

• NREL signed a CRADA with Schott Solar in 

April 2009 to rapidly commercialize NREL’s 

solar selective coating for parabolic trough 

receiver tubes in CSP systems.

• NREL and 3M signed a CRADA in July 2009 

to develop silvered polymeric mirrors as lowcost replacements for glass mirrors in CSP 

systems.

• Capabilities that had been degraded after five 

years of significantly constrained budgets

continue to be restored. NREL is hiring new 

staff members and purchasing and installing 

new optical measurement and accelerated 

weathering equipment.

• A subcontract to modernize the optical 

materials database and make it accessible via 

the Web was placed with EMagnit, and 

development work has begun.

• NREL staff members participated in DOE 

Glass Standard committee meetings and 

assisted with inclusion of Solar Glass 

standards (for PV, CSP, and SH applications) 

into the ASTM E44 Solar Applications working 

group. 

• NREL scientists also participated (by 

presenting and chairing) in SolarPACES Task 

III meetings on reflectance characterization 

and standards, receiver characterization and 

standards, and lifetime and durability. NREL 

staff also attended a session on mirror/module 

characterization and standards. 

4. Planned FY 2010 Activities

SNL will work on the following:

• Advanced trough analysis

• Optical facet/method lab development

• Advanced modeling

• Solid particle receiver analysis

• Molten salt heat transfer for advanced power 

cycles

• Selective absorbers for power tower receivers.

NREL’s work in advanced reflectors will entail the 

following:

• Continue to perform durability testing of optical 

materials and publish results of durability 

testing of solar mirrors (09/10).

• Implement Web-accessible database (03/10).

• Build 2-mrad spectral specular reflectance 

laboratory instrument (09/10).

• Demonstrate and report on low-no H2O 

cleaning design project by CU team (06/10).

D R A F T
• Complete and document review of existing 

procedures to form basis for identifying and 

developing CSP testing standards. Perform 

round robin reflectance measurements for 

standard development (03/10). 

In the area of advanced reflector FOA support, 

NREL will perform the following tasks:

• Report on application of SLP methodology to 

3M silvered polymer and glass mirror samples 

(09/10).

• Report on status of FOA projects (09/10).

• Report on VSHOT and two-axis tracking for 

Alcoa and PPG collector (09/10).

NREL’s work in advanced absorbers will include 

the following:

• Report on optimized NREL coating generated 

by sputtering and test optical properties and 

results of stability tests (03/10).

• Generate Ashby diagrams and report on 

potential systems (09/10).

• Complete and document review of existing

procedures for receiver testing to form basis 

for identifying and developing CSP testing 

standards (03/10).

5. FY 2009 Special Awards

The SkyTroughTM Parabolic Trough Solar 

Concentrating Collector was awarded an R&D 100 

award (bestowed by R&D Magazine) in August 

2009. The SkyTroughTM uses ReflecTech® Mirror 

Film, a lightweight, weatherproof, glass-free, slidein mirror developed by NREL Advanced Materials 

task members and SkyFuels.

6. Major FY 2009 Publications 

SNL published the following in FY 2009:

C.K. Ho, Software and Codes for Analysis of 

Concentrating Solar Power Technologies. 

SAND2008-8053. Albuquerque, NM: SNL (2008).

C.K. Ho and G.J. Kolb. “Incorporating Uncertainty 

into Probabilistic Performance Models of 

Concentrating Solar Power Plants.” Proc. 2009

ASME 3rd International Conference on Energy 

Sustainability, San Francisco, CA, July 19–23, 

2009.

C.K. Ho, C.M. Ghanbari, and R.B. Diver, “Hazard 

Analyses of Glint and Glare from Concentrating 

Solar Power Plants.” Proc. SolarPACES 2009, 

Berlin, Germany, September 15–18, 2009.

C.K. Ho, S.S. Khalsa, and G.J. Kolb, “Tools for 

Probabilistic Modeling of Concentrating Solar 

Power Plants.” Proc. SolarPACES 2009, Berlin, 

Germany, September 15–18, 2009.

C.K. Ho, S.S. Khalsa, and N.P. Siegel, 2009, 

“Modeling On-Sun Tests of a Prototype Solid 

Particle Receiver for Concentrating Solar Power 

Processes and Storage.” 2009 ASME 3rd 

International Conference on Energy Sustainability, 

San Francisco, CA, July 19–23, 2009.

C.K. Ho, M. Roeger, S.S. Khalsa, L. Amsbeck, R. 

Buck, N. Siegel, and G. Kolb, “Experimental 

Validation of Different Modeling Approaches for 

Solid Particle Receivers.” Proc. SolarPACES 

2009, Berlin, Germany, September 15–18, 2009.

NREL published the following in FY 2009:

C.E. Kennedy, “The Potential of Concentrating 

Solar Power.” Association of Industrial 

Metallizers, Coaters and Laminators (AIMCAL) 

Fall Technical Conference 2008 and 22nd 

International Vacuum Web Coating 

Conference, Myrtle Beach, SC, Oct.22, 2008. 

C.E. Kennedy, “Reliability Testing of Optical 

Materials.” 5th International Conference on 

Solar Concentrators for the Generation of 

Electricity (ICSC5), Palm Desert, CA, Nov. 18, 

2008.

C.E. Kennedy, “Requirements & Potential for 

Concentrating Solar Power Mirrors.” Glass 

Week 2009 for the Glass Association of North 

America (GANA), Las Vegas, NV, Feb.13, 

2009.

C.E. Kennedy, “CSP Applied Research.” DOE 

SETP Peer Review Meeting, Denver, CO, 

March 9, 2009.

C.E. Kennedy, “Market Potential for Concentrated 

Solar Power and Photovoltaics.” 2009 

SEMICON West & Intersolar North America 

Analytical Symposium: Analysis of Photovoltaic 

& Semiconductor Materials, San Francisco, 

CA, July 15, 2009.

C.E. Kennedy, “Development Path for an 

Advanced Solar Selective Coating.”

SolarPACES 2009 Symposium, Berlin, 

Germany, Sept. 16, 2009. 

C.E. Kennedy, “Advanced Mirrors for 

Concentrating Solar Power.” SolarPACES 

2009 Symposium, Berlin, Germany, Sept.16, 

2009.

7. University and Industry Partners

The following institutions provided in-kind 

participation in the Advanced Concepts activities: 

DLR, U. Wisconsin-Madison, UNLV, California 

Energy Commission, and NREL. 

D 

SNL

R A F T
During 2009, a partial list of industry interactions 

occurred with CSP reflector manufacturers and 

CPV manufacturers on the durability of solar 

mirrors includes: 3M, A Better Focus, Abengoa, 

ACA, Acciona, AGC (AFG, Glaverbel), Ahuru 

Energy, Airlight Energy, AIST-NEDO-METI, 

Alanod, Alcan, Alcoa, Ammonix, Arch Aluminum & 

Glass, Arontis, Atlas, Ausra, Bayer Material 

Science, BEI Space, Blach & Vetch, Boeing, 

BrightSource, Capitol Sun Group, Cardinal Glass, 

CENIM/CSIC, Ceplast Metallized Product, 

Chevron, Chisso, CNRC, Concentrator Optics, 

Convergent Solar, Cool Earth, Cooper Lighting, 

Copeland, Corning, Cosmo Films, Cyanto, 

Depostion Systems, Dow Chemical, Dow Corning, 

Energy Innovations, Enfocus, ESG, eSolar, 

Evonik, Fenzi, Flabeg (Naugatuck), Gardner 

Glass, Gear Solar, GE Energy, General Atomics, 

GlassTech, Google, Gossamer Space Frame, 

GreenVolts, Guardian, Honeywell, Hydro 

Aluminum, Imat SpA, Infinia, International Solar 

Technologies, ITRI, JDS Uniphase, Kearney & 

Assoc., KERI, Light Prescription Innovators, LLNL, 

Lockheed Martin, Lux Research, Luz II, Magna 

Mirrors, Micro Engineered Metals, McKinsey & 

Co., MegaWatt Solar, Mohave Sun Power, 

Momentive Performance, Nanotron, Naugatuck, 

Nitinol, Northside, Olymco, Pent-ht-optics, 

Pilkington, PPG, Pratt & Whitney, Praxair, QPanel, 

RAflector, RavenBrick LLC, Raytheon, 

ReflecTech, Replex, Rio Glass, Rocky 

Development, Rohm & Haas, SAES Getters, 

SAIC, Saint Gobain, Sandia, Sandvik, Schott 

Solar, SEIA, SkyFuel, Skyline Solar, Spraylat, 

SolarGenix, Solaria, SolarReserve, Solar 

Systems, SolarTech USA, Solarversa, Solel, 

SolFocus, Soliant, Solucar, Solyndra, Southwall, 

SPAWAR, Spinnaker Energy, Spraylat, SRI 

International, Stanford, Stirling Energy Systems, 

Sub-One, SunCube, SunPower, Sunray, 

SunTechnics, Surface Optics, Symmorphix, Texas 

A&M, The Boston Consulting Group, The Winslow 

Group, Uniaxis, United Solar, University of Baleric 

Islands, University of California Merced, University 

of Colorado, University of Hartford, University of 

Minnesota, Valspar, VaporTech, Veridian, Vitro 

America, Von Ardenne, Vulvox, Wavefront 

Technologies, West Virginia University, Wooly 

Parsons, Xandex, Xcel Energy, and Xerocoat. 

NREL

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail

Description/Title of Research 

Activity

FY 2009

($K)

Cost Share 

($K)

3M

Dr. Susannah Clear

St. Paul, MN 

scclear@mmm.com 

To replicate SLP with 3M’s new 

improved “Solar Reflector 1000” 

and perform 250 hour of on-sun 

ultra-accelerated natural sunlight 

testing

90 640

Schott Solar

Dr. Alex Marker

Duryea, PA

alex.marker@us.schott.com 

To rapidly commercialize NREL’s 

advanced solar selective coating

435 

(TCD) 1,085

D R A F T
Power Tower R&D

Performing Organization: Sandia National Laboratories (SNL)

 

Key Technical Contacts: Gregory J. Kolb, 505-844-1887, gjkolb@sandia.gov

Cheryl M. Ghanbari, 505-845-3426, cghanba@sandia.gov 

Clifford K. Ho, 505-844-2384, ckho@sandia.gov

 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budget: $900K (SNL) 

____________________________________________________________________________________

Objectives

• Perform R&D to support development of power tower systems. 

Accomplishments

• Supported the development and test of Rocketdyne’s first-generation heliostat 

• Developed and tested a heliostat beam-characterization system 

• Updated SOLERGY software to better predict annual performance of steam receivers

• Replaced NSTTF heliostat software and developed an algorithm to improve tracking accuracy

• Worked with the National Renewable Energy Laboratory (NREL) to release the first power tower 

model, NREL’s Solar Advisor Model (SAM).

Future Directions

• Work with industry to develop and test components to be used in commercial projects

• Perform studies of next-generation power towers. 

____________________________________________________________________________________

1. Introduction

Five companies are pursuing commercial powertower projects: Solar Reserve, eSolar, 

BrightSource, Abengoa, and SENER. Two new 

commercial projects (25 MW total) began 

operation in 2009, and power purchase 

agreements to build thousands of future 

megawatts were established. Most of SNL’s power 

tower R&D supports industries efforts to develop 

successful near-term projects with the remainder 

devoted to R&D on next-generation technology. 

2. Technical Approach

SNL interacts with the U.S. power tower 

developers to determine critical technology needs.

Tasks that could be performed within the limits of 

the DOE budget allocation were defined. 

3. Results and Accomplishments

3.1 Help Rocketdyne Develop a Prototype 

Heliostat 

Solar Reserve and Rocketdyne are 

commercializing Solar-Two-type power tower 

technology. Rocketdyne has a long history in 

power tower development and were responsible 

for the construction of the Solar One steam 

receiver and Solar Two salt receiver. In 2008 

Rocketdyne made a business decision to expand 

their scope of supply to include heliostats. 

In FY 2009, SNL performed tech transfer activities 

with the Rocketdyne heliostat team. We made 

sure they were aware of the main conclusions of 

the heliostat R&D conducted over the years. SNL

also sent Rocketdyne several mirror facets and 

loaned them two azimuth drives to help them 

evaluate heliostat technology options. 

In late FY 2009, Rocketdyne installed their initial 

62-m2 prototype at the NSTTF and successfully 

tracked its beam on the solar tower for several 

days.

3.2 Develop a Heliostat Beam-Characterization 

System

SNL developed a user-friendly beamcharacterization system that will allow industry to 

evaluate the optical quality of their heliostats and

determine tracking accuracy. Lab-view-based 

D R A F T
software reads inputs from a digital camera and 

solar-flux gauge. Flux contours and beam 

centroids are displayed in real time and recorded 

for further analysis.

The system is now routinely used at the NSTTF.

Rocketdyne also ran the software to evaluate their 

prototype heliostat. The system is relatively 

portable and could be moved to non-SNL test sites 

selected by industry.

3.3 Update SOLERGY to Better Predict the 

Performance of Steam Receivers

SNL’s SOLERGY code is used to simulate a 

power tower for a full year. SOLERGY uses 15-

minute weather data and plant performance 

models to calculate the power flowing through 

each part of the solar plant. 

Code predictions were compared with data from 

the Solar One steam receiver plant and the Solar 

Two salt receiver plant. The code does a better job 

of simulating a salt plant because the receiver and 

turbine-generator are able to operate during partly 

cloudy weather and using 15-minute average 

direct-normal insolation (DNI) data adequately

represents insolation transients. Steam receivers, 

on the other hand, typically trip offline within a few 

minutes during partly cloudy conditions because of

rapid degradation of steam temperature and 

pressure. Receiver trip leads to a turbine trip 

because there is no buffer storage between the 

receiver and turbine. During our validation effort 

conducted in the late 1980s we found that using

15-minute average DNI data caused SOLERGY to 

overpredict Solar One’s actual annual 

performance by 16%. We showed that using 3-

minute data gave a much better estimate, but 3-

minute data are not generally available for many 

sites. 

Because eSolar and Brightsource are resurrecting 

water-steam receiver technology, SNL improved

SOLERGY’s model of steam receiver plants and 

revalidated this new model with Solar One data.

The new model will trip the receiver when 

insolation within a given time step is less than 

XX% of the clear-sky value that is predicted for 

that time step. We found that a value of 60% 

allows SOLERGY to achieve a much better 

prediction of actual Solar One performance. The 

new model was used during an evaluation of 

eSolar’s distributed power tower system under a 

work-for-others contract that SNL established with 

eSolar.

3.4 Improved Heliostat Software

All of the controls for the heliostats at the NSTTF

were replaced. This involved deploying software 

for sun tracking of each heliostat at each heliostat.

Heliostat aiming, scram, and failsafe commands 

are sent from computers in the control room. The 

software deployment at each heliostat was 

completed as well as about a third of the software 

required for operation in the control room. 

 

Ten of the dish Stirling systems currently operating 

at the NSTTF employ advanced tracking software 

that eliminate sun-tracking errors caused by 

several potential installation and manufacturing 

errors (e.g., a tilted pedestal). These algorithms 

were adapted for heliostat application during FY

2009.

3.5 Support Development of SAM Power Tower 

Model

A power tower module was incorporated into 

NREL’s SAM in FY 2009. SNL’s DELSOL code is 

used by SAM to define the optical design of a 

power tower. SNL worked with NREL to integrate 

DELSOL into SAM. SNL also performed detailed 

computational fluid dynamics modeling to evaluate 

the heat loss model implanted in SAM.

4. Planned FY 2010 Activities

• Rocketdyne will complete testing of their 

prototype heliostat and test three additional 

second-generation models. 

• Improved heliostat tracking software will be 

tested on several heliostats at the NSTTF. 

• We will evaluate next-generation power towers. 

5. Major FY 2009 Publications/Presentations

G.J. Kolb, “Point-Focus Systems,” Plenary 

Session of SolarPACES 2009, Berlin, Germany, 

September 15-18, 2009. 

6. University and Industry Partners

Solar Reserve/Rocketdyne and eSolar were SNL’s 

industry partners in FY 2009. A $30K work-forothers contract was established with eSolar.

Rocketdyne worked side-by-side with SNL at the 

D 

NSTTF under a user-facility agreement.

R A F T
Advanced CSP Concepts Industry Projects

Performing Organizations: PPG Industries, Inc.; SkyFuel, Inc.; 3M Company; Hamilton Sundstrand 

Corporation; Solar Millennium, LLC

Key Technical Contacts: Carolyn Elam, DOE Golden Field Office (DOE/GO), 303-275-4953,

carolyn.elam@go.doe.gov 

Brad Ring, DOE/GO, 303-275-4930, brad.ring@go.doe.gov 

DOE HQ Technology Managers:Frank (Tex) Wilkins, (202) 586-1684, frank.wilkins@ee.doe.gov 

Tommy Rueckert, (202) 586-0942, thomas.rueckert@ee.doe.gov 

FY 2009 Budget: $2,881K (DOE/GO)

Objectives

• Develop reliable, affordable, and environmentally sound energy supply technologies to expand 

national electricity generation options and increase energy security by increasing domestic 

energy supply options. 

• Identify advanced systems or components that can generate low-cost power (less than 7¢/kWh) 

with storage (12–17 hours) by 2020.

Accomplishments

• Continued five Concentrating Solar Power (CSP) Advanced Systems and/or Component awards 

• Completed two Phase I go/no-go reviews (both awardees received “go” decision)

• Continued to assess CSP Advanced Systems and/or Component awards against the Solar 

Energy Technologies Program (SETP)/CSP subprogram goals and objectives.

Future Directions

• Evaluate each of the CSP Advanced Systems and/or Component awards to ensure they are 

progressing to meet the SETP/CSP objectives.

____________________________________________________________________________________

1. Introduction

CSP is of the most attractive renewable energy 

option in the southwestern United States.

Advanced CSP concepts activities are expected 

to identify concepts that can generate low-cost 

power with a nominal levelized cost of energy 

(LCOE) target of under 7¢/kWh with storage 

(12–17 hours) by 2020. The funding opportunity 

announcement (FOA) investigated three areas 

to address market barriers for utility-scale 

generation of CSP technologies: thermal 

storage, trough component manufacturing, and 

advanced CSP systems and/or components.

The selected projects are:

Organization, Principal Investigator, 

and Agreement Title

FY 2009 

Budget 

($K)

PPG Industries, Inc., James McCamy,

High Performance Reflector Panels for 

531

Organization, Principal Investigator, 

and Agreement Title

FY 2009 

Budget 

($K)

Concentrating Solar Power Assemblies

SkyFuel, Inc., Randy Brost/Randy Gee,

Commercial Development off an Advanced, 

High-Temperature, Linear-Fresnel Based 

Concentrating Solar Power Concept

0* 

3M Company, Susannah Clear, Cleanable 

and Hardcoat Coatings for Increased 

Durability of Silvered Polymeric Mirrors

996

Hamilton Sundstrand Corporation, Michael 

McDowell, Solar Power Tower Receiver

Development

795

Solar Millennium, LLC, Ray Dracker, 

Advanced High Temperature Trough 

Development

559

*Funded in FY 2008 with additional funding 

D 

planned in FY 2010.

R A F T
PPG Industries, Inc.

High Performance Reflector Panels for Concentrating Solar Power Assemblies

Total Award: $3,639K: $2,185K (DOE), $1,453K (Recipient)

____________________________________________________________________________________

Objectives

• Develop and commercialize large-area high value mirrors (HVM) with lower cost and higher 

performance, resulting in reduced LCOE

• Develop one or more Pb-free protective coatings and associated application process for long-life 

field deployments

• Develop mirrors with different (flat/bent) geometries and mechanical strengths for deployment in 

power tower, CLFR, and trough CSP applications.

Accomplishments

• Demonstrated feasibility of large-area mirror fabrication with PPG’s technology for both bent and 

flat geometries

• Identified Pb-free coating and encapsulant materials and stack design for significantly improved 

durability under exposure to damp heat (85°

C/85% relative humidity [RH]) and CASS accelerated 

testing conditions

• Completed 60 weeks of exposure to damp heat accelerated testing conditions, for mirror samples 

with no loss of reflectivity

• Completed initial fabrication process design and engineering study

• Completed initial cost study and validated SAM inputs supporting LCOE reduction of more than 7%.

Future Directions

• Focus on process development for low-cost manufacturing of large-area mirrors with differing 

geometries and mechanical strengths.

____________________________________________________________________________________

1. Introduction

PPG plans to develop and commercialize largearea mirrors that are superior in value, in terms of 

cost and performance, to mirrors available on the 

market today. The expected outcomes are a 

design and fabrication process for a mirror having 

a high solar-weighted specular reflectance, 

minimal optical performance degradation over the 

service lifetime, and a cost reduction to the CSP 

systems builder of the overall capital expenditure. 

2. Technical Approach

PPG is investigating alternate materials, 

structures, and fabrication processes for reflector 

components. PPG is evaluating various materials 

and stack designs for the reflecting layers with 

protective back coatings and whether it is possible 

to bend the resulting mirror into parabolic or other 

advantageous shapes. 

3. Results and Accomplishments

PPG completed the use of damp heat 

(85°

C/85%RH) testing as the initial screening to 

determine potential materials candidates and 

moved to CASS accelerated as the primary tool 

for determining durability. This change in test 

protocol focus was confirmed with outdoor field 

testing at our research facility. Progress was made 

in new coating stack designs and materials for the 

reflective layer and encapsulant back coat.

Researchers also investigated and demonstrated 

several different application methods and 

fabrication techniques using standard industrial 

equipment, as well as new methods for applying 

the back protective coating. These fabrication 

subprocesses were included in an initial process 

design and engineering study that investigated all 

the unit operations necessary to fabricate mirrors 

of different geometries. The study results confirm 

this approach is viable as a method for producing

a high-value reflector for the CSP solar field. 

During 2009, we demonstrated the feasibility of 

large-area mirror fabrication for both bent and flat 

geometries, using commercially available 

industrial-scale equipment. With this equipment 

we were successful in bending 20 samples with a 

18 x 24 in. size, 10 samples with 36 x 48 in. size, 

and 6 samples with an LS-4 (61.8 x 74.8 in.) size.

D R A F T
All were bent with a cylindrical radius of 160

inches. Figure 1 shows an LS-4 size mirror 

produced using this approach.

Fig. 1. Six samples of mirror coated glass bent 

to the LS-4 geometry (61.8 x 74.8”; 160” 

radius).

Gen 3 mirror samples completed more than 60 

weeks of testing under damp heat conditions with 

no reduction in reflectivity. Figure 2 shows the 

front surface of these mirrors. The mirror on the 

left had no back protective coating, and the one on 

the right had a two-layer organic back protective 

coating that was developed by PPG. 

Fig. 2. Glass side physical appearances of 

encapsulated (right) and unencapsulated (left) 

mirrors after 60 weeks of exposure under 85°

C 

/ 85% RH conditions. The straight line on the 

left of each sample is a scratch made in the 

mirror layers. 

Substantial progress was made in improving the 

durability of the mirror when exposed to CASS 

accelerated testing conditions. This was achieved 

by improving the intrinsic durability of the reflective 

coating stack and the protection of the back 

protective coating. This protective coating was a 

two-layer, Pb-free paint system with a 

heterogeneous organic/inorganic base layer.

Figure 3 shows the improved CASS durability with 

this system compared with an earlier (85/85 

durable) material.

Fig. 3. Comparison of an all-organic back 

encapsulant system (top) and two-layer 

encapsulant system developed this period 

after 120 hours of exposure to CASS.

4. Planned FY 2010 Activities

• Down select the coating materials and designs 

for development in Phase 3

• Develop these materials and focus on low-cost 

processing for both flat and bent geometry 

mirrors

• Demonstrate all the fabrication unit operations 

for a set of large-area prototype mirrors

• Field test large-area prototype mirrors at 

multiple outdoor locations.

5. FY 2009 Special Awards and Patents

The High Performance Reflector Panels for 

Concentrating Solar Power Assemblies project 

won the 2009 PPG INNOVA award. This award is 

the highest recognition for an early-stage project 

and recognizes both technical achievement and 

expected market impact. 

6. Major FY 2009 Publications

Product development results were presented to 

the solar community at the Solar Power 

International Conference 2009 meeting.

D R A F T
SkyFuel, Inc.

Commercial Development off an Advanced, High-Temperature, Linear Fresnel Concept

Total Award: $4,139K: $2,423K (DOE), $1,716K (Recipient)

____________________________________________________________________________________

Objectives

• Develop advanced CSP system using linear Fresnel reflective technology

• Enable use of molten salt as a heat transfer fluid (HTF) in linear concentrator systems and as 

direct thermal energy storage. 

Accomplishments

• Completed analysis and optimization of linear power tower collector design and power plant 

configuration using linear Fresnel reflectors and direct molten salt thermal energy storage

• Produced conceptual designs of key collector hardware components

• Assessed overall performance and economic efficacy of the linear power tower design relative to 

a state-of-the-art parabolic trough concentrator. 

Future Directions

• Implement and test collector components using the low-cost, high-performance designs 

developed in Phase 1

• Demonstrate efficient fabrication and installation processes for the linear power tower collector

• Estimate expected linear power tower economic performance, based on measured results

• Implement pilot linear power tower power plant in Phase 3.

____________________________________________________________________________________

1. Introduction

The objective of SkyFuel’s proposed 

multiphased project is to develop an advanced 

CSP system, using linear Fresnel reflective 

technology, to achieve significantly lower 

delivered electricity costs from utility-scale solar 

thermal power plants. The design uses moltensalt HTF to enable higher operating 

temperatures and direct thermal storage,

eliminating the need for heat exchangers. 

2. Technical Approach

The linear Fresnel collector architecture allows 

the design of solar collectors with large 

apertures, while keeping the bulk of the collector 

low to the ground. This reduces wind loads, 

which in turn allows the design of mirrors with 

significantly reduced material content. A key 

component of our design approach is to use 

ReflecTech® polymer film to produce low-cost 

yet high-performance mirror components.

Although Fresnel collector architecture offers 

inherent structural advantages allowing low-cost 

mirrors, it also entails numerous configuration 

options and design freedoms, leading to 

increased complexity. SkyFuel uses advanced 

computational optimization methods.

3. Results and Accomplishments

SkyFuel explored several different design 

concepts for key linear power tower collector 

components and developed efficient designs for 

each component, with two leading mirror 

concepts carried forward for competitive testing 

in Phase 2. Both designs substantially reduce 

material content compared to parabolic trough 

while avoiding the high part count and 

complexity characteristic of central receiver 

technologies.

SkyFuel developed in-house optimization 

software to generate and evaluate thousands of 

candidate collector and solar plant designs. 

These models were used to identify optimum 

designs for the collector geometry, plant layout, 

and storage system, using economic return as 

the optimization criterion. The models predict 

that a linear power tower using molten salt HTF 

will produce economic performance substantially 

higher than state-of-the-art parabolic troughs, 

and will support energy storage capacities in 

excess of 10 hours.

4. Planned FY 2010 Activities

Construct prototype LPT collector components 

and evaluate their cost and performance. 

D R A F T
3M Company

Cleanable and Hardcoat Coatings for Increased Durability of Silvered Polymeric Mirrors

Total Award: $3,614K: $2,312K (DOE), $1,302K (Recipient)

____________________________________________________________________________________

Objectives

• Develop durable and cleanable coatings specifically for silvered polymeric mirrors with

polymethylmethacrylate (PMMA) front surfaces

• Demonstrate manufacturing processes for these durable and cleanable coatings

• Evaluate and validate the performance of these mirrors and associated effect on LCOE. 

Accomplishments

• Passed go/no go decision at end of Budget Period 1

• Identified, from accelerated weathering, three classes of coating chemistries compatible with 

PMMA substrates with good balance of abrasion resistance and durability that significantly 

improve abrasion resistance of PMMA

• Identified critical process spaces for coating chemistries that affect durable adhesion of coating 

after accelerated weathering

• Established preliminary understanding of coatings as technology that plays a role in enabling 

15%–25% LCOE reduction. 

Future Directions

• Optimize coating formulations and process conditions for durability, optical properties, 

cleanability, and adhesion

• Optimize coating conditions on a roll-to-roll coater for the top candidates based on accelerated 

aging and performance testing

• Develop LCOE model to evaluate performance of coated versus uncoated PMMA mirrors. 

____________________________________________________________________________________

1. Introduction

Silvered polymeric mirrors with protective acrylic 

front surfaces are promising alternative low-cost 

replacements for thick glass mirrors in parabolic 

trough CSP installations, with the potential to 

reduce the installed system cost and LCOE for a 

trough installation. 3M is studying two aspects of 

silvered polymeric mirror films related to longterm durability–abrasion and soiling resistance

of the acrylic protective layer.

2. Technical Approach

3M’s approach in Budget Period 1 was to screen 

candidate hardcoat and cleanable coatings, use 

accelerated aging to test for durability and 

performance, and develop process optimization 

on samples with the best balance of abrasion 

and soiling resistance, optical properties, 

durability, and durable adhesion. Researchers 

evaluated top candidates to determine their 

feasibility for manufacturing and roll-to-roll 

coating processes. During Budget Period 2, 3M 

is optimizing formulations and pilot-scale 

processes for selected coatings. Results from 

bench and pilot work will be incorporated into an 

economic model. Final candidates will be 

selected for scale-up to large width, 

manufacturing scale, mirror coating in Budget 

Period 3. Coated mirror film from this phase will 

undergo field trial weathering, and results will be 

analyzed and incorporated into LCOE 

calculations.

3. Results and Accomplishments

3M successfully passed the Budget Period 1 

go/no-go decision. Screening work and 

performance testing, both before and after 

accelerated weathering, narrowed a list of 

suitable coating chemistries to three classes of 

materials. Optimal classes of chemistry 

completed a minimum of 2,000 hours of 

accelerated weathering, and top coating 

candidates completed more than 3,000 hours. 

Preliminary pilot-scale process settings were 

demonstrated for top candidates. Continued 

optimization to improve the durability of 

adhesion, abrasion resistance, and cleanability 

is ongoing in parallel with pilot-scale process 

optimization. Preliminary cost analysis 

D R A F T
demonstrated the value of coatings as enabling 

technology for silvered polymeric mirrors, which 

in turn are enabling technology for advances in 

trough size and system heat load that have the 

potential to decrease LCOE by 15%–25%.

4. Planned FY 2010 Activities

• Optimize formulations and process 

conditions for best abrasion resistance, 

cleanability, and durable adhesion

• Test field and accelerated aging of pilotscale coated silvered polymeric mirrors

• Incorporate field results into LCOE 

evaluation.

D R A F T
Hamilton Sundstrand Corporation 

Solar Power Tower Receiver Development

Total Award: $2,881K: $1,856K (DOE), $1,025K (Recipient)

____________________________________________________________________________________

Objectives

• Complete the following in Phase 1: panel sizing, preliminary design, cost evaluation, and goforward plan

• Work on Phase 2 objectives: comprehensive panel design, cost estimates, manufacturability 

assessment, roadmap, and procurement.

Accomplishments

• Completed preliminary design review (PDR) and Phase 1 report

• Achieved a preliminary design that reduced the LCOE of solar power plants

• Received go ahead to proceed to Phase 2.

Future Directions

• Complete Phase 2 objectives

• Start Phase 3: panel fabrication, panel testing, and production scenarios

• Apply lessons learned from this receiver development to production-level CSP receivers. 

____________________________________________________________________________________

1. Introduction

The objective is to validate the manufacturability of 

a large-scale molten salt receiver panel and then 

confirm its operation in prototypic solar flux to 

reduce the LCOE from a central receiver solar 

power plant. The key technical risk to building 

larger power towers is in building the larger 

receiver systems, specifically the issues involved 

with key receiver panel features such as the large 

headers and longer tubes. This work involves 

designing, fabricating, and testing an advanced, 

molten salt, prototypic, subscale receiver panel for 

a large receiver system. 

2. Technical Approach

Phase 2 of this three-phase project is ongoing. 

During Phase 1, researchers completed the 

preliminary design and cost evaluation. In Phase 

2, the preliminary design is moving to critical 

design drawings. Long lead hardware has been 

ordered and the design is being reviewed for 

manufacturability, along with a final cost 

breakdown and a roadmap to reach 2020 cost 

goals. During Phase 3, the receiver will be 

fabricated and tested at the National Solar 

Thermal Test Facility (NSTTF) at Sandia National 

Laboratories. 

Specific tasks completed during FY 2009 were 

panel sizing, preliminary design, cost evaluation, 

and go-forward plan. A PDR was held on March 5, 

2009.

Phase 2 was delayed until October 2009 while 

Phase 1 progress was reviewed and verified. The 

Phase 2 schedule now extends into the summer of 

2010.

3. Results and Accomplishments

The first major accomplishment of Phase 1 was 

the PDR completion. The PDR was presented to a 

panel of senior members of Pratt & Whitney 

Rocketdyne, responsible for supplying technical 

critique on the receiver design. They reviewed all 

aspects, including design requirements and 

features; manufacturing techniques; structural, 

thermal and materials analysis; electrical system 

details; quality plan details; risk analysis; and 

schedules/plans for the remaining phases. The 

PDR was well received and all attending believed

the review was a comprehensive summary of the 

design to date. 

Five actions were submitted that indicated areas 

for further iteration on the design. The main area 

of the design that the review board did not like was 

the tube clip retention system. The design 

presented in the PDR featured a snap-in feature 

that upon further reflection makes it inconvenient 

for easy installation and assembly. Therefore, the 

snap-in idea will not be incorporated and the 

design evaluated for a more technically sound and 

D R A F T
easily installed clip assembly. Other 

recommendations were questions about the 

headers, tubes, and structural analysis. Five 

actions are entered into an action control system 

to track and manage each item.

The second major accomplishment of Phase 1 

was completing the Phase 1 report. The report 

covered a summary of the work completed, 

including a discussion of the design and a 

summary of the cost evaluation of the project and

the receiver hardware. 

Fig. 1. Group of pictures showing fabrication and 

installation of a Solar II receiver at Daggett, CA.

The pictures in Figure 1 represent the progression 

and growth of the CSP receiver from the Solar II 

project in the 1990s to this current development 

receiver. The current design has larger tubes and 

headers to enable increased flow rate and a lower 

chance of tube blockage. Note that the DOE 

receiver is shorter than Solar II, on purpose, so 

that it can fit into the Sandia test facility. The fullscale receiver will be more than twice the size of 

the Solar II version. 

Fig. 2. Receiver being developed on this contract 

for testing at NSTTF. 

4. Planned FY 2010 Activities

FY 2010 activities include completing Phase 2 

tasks. The highlights of the schedule are as 

follows:

• Complete the 3D model (02/10)

• Order long lead hardware (04/10)

• Complete all the drawings (06/10)

• Perform Critical Design Review (06/10)

• Complete the Phase 2 final report (07/10) 

• Expose the receiver to a heat flux of 1050 

suns from the Sandia facility to reach the 

maximum temperature of 1050°F.

D R A F T
Solar Millennium, LLC

Advanced High Temperature Trough Development

Total Award: $5,919K: $3,311K (DOE), $2,608K (Recipient)

Objectives

• Design, construct, and demonstrate an advanced parabolic trough collector loop at Kramer 

Junction Power Plant

• Modify test loop to be a molten salt parabolic trough test system

• Evaluate benefits and costs of molten salt as an HTF in a full-sized solar field.

Accomplishments

• Completed detailed design of all components and systems for the Kramer Junction HelioTrough 

loop.

• Successfully organized a large, international, competitive procurement process for all the 

collector and loop components. Schott and Flabeg were chosen vendors for solar components. 

Schott was selected as the HCE vendor because they can produce the larger diameter (89 mm) 

heat collection element (HCE) tube required for the HelioTrough. Likewise, Flabeg was the only 

mirror vendor that could manufacturer mirrors large enough for the HelioTrough design. Baotou 

Hydraulics Machinery Co. Ltd. was the low-cost bidder and therefore selected as the steel 

vendor.

• Determined from photogrammetry and deflectometry results that the collector has an intercept 

factor range of 98.9%–99.1% for 89.9 diameter HCEs

• Successfully built and commissioned the new HelioTrough loop. 

Future Directions

• Conduct detailed tests of the full loop in 2010. 

____________________________________________________________________________________

1. Introduction

Flagsol designed a new high-temperature 

parabolic trough collector, the HelioTrough, to 

operate with a variety of HTFs. The HelioTrough 

has a larger collector aperture and HCE tube 

diameter compared to that of the Skal-ET. Also, 

the HelioTrough has a metal structure significantly 

different from the previous Skal-ET collector. 

Unlike the torque box design of the Skal-ET, the 

HelioTrough uses a flanged torque tube for 

supporting the cantilever arms. These 

improvements allow for a smaller solar field design 

with a larger thermal output.

To achieve high optical efficiency, the geometry of 

the reflector surface and position of the HCE tube 

must be extremely precise. To achieve such tight 

tolerances, the HelioTrough collector was built on 

a series of high precision aligned jigs. Before the 

work in Kramer Junction, the first HelioTrough 

prototype was erected in a warehouse in 

Dortmund, Germany. The work in Dortmund tested 

the drive pylon and offered jig and collector 

erection experience. This was to validate the 

construction of 40 HelioTrough collectors in 

Kramer Junction.

2. Technical Approach

This project is divided into four phases. Phase 2 

highlights were procurement, erection, and 

commissioning in 2009. Phase 2 consisted of the 

completing the detailed engineering of the

HelioTrough-VP1 Reference Loop, new assembly 

tools, and procurement, erection, and 

commissioning. 

3. Results and Accomplishments

In addition to successfully constructing and 

commissioning the advanced HelioTrough loop, 

CSP Services conducted photogrammetry and 

deflectometry during HelioTrough construction to 

evaluate the optical precision of the collector and 

assembly jigs. 

3.1 Photogrammetry and Deflectometry 

Photogrammetry evaluates the alignment quality 

of the mirror assembly jig and twist of the 

HelioTrough. deflectometry evaluated the 

D R A F T
parabolic shape and alignment of SCE 3 (before 

mirror jig realignment) and SCE 27 (after 

realignment). The deflectometry results indicate:

• Deviation from the ideal shape RMS 2.1–2.2 

mrad

• Intercept factors: 98.9%–99.1% for 89.9 

diameter HCE. 

Tests indicated that the RMS deviation values for 

each mirror of SCE 3 (before mirror jig 

realignment) are low except in Row 2. Higher 

deviations in Row 2 can be attributed to 

gravitational influences in the measurement 

position of SCE 3. Figure 1 shows the local 

intercept factor (in percent) for SCE3. Green 

indicates all reflected rays hit the absorber tube. 

Red indicates part of the reflected rays miss the 

absorber tube, and blue indicates reflected rays 

will most likely miss the absorber tube. Total 

intercept factor with the sun-shape is calculated to 

be 98.9%.

Fig. 1. Local intercept factor (in percent) for SCE3.

Similarly, deflectometry was performed on SCE 27 

after realignment of the mirror jig. According to 

CSP results, the RMS deviation values for each 

mirror of SCE 27 are low except in Row 3. The 

lower edges of Row 3 were bowed, which most 

likely was caused by gravitational influences. 

Figure 2 depicts the local intercept factor (in 

percent) for SCE27. The color reference remains 

the same. Total intercept factor with the sun-shape 

is calculated to be 99.1%. 

The optical design goals were fully achieved. In 

addition to these results, the jig assembly line is

highly efficient with simple construction. 

Fig. 2. Local intercept factor (in percent) for 

SCE27

3.2 Phase 2 Hydro, Electrical, and Mechanical 

Test

After all collectors were installed, researchers 

performed a hydro test to check for leaks and 

ensure the system is mechanically sound. A 

mechanical checkout package was completed and 

includes:

• Hydro completion report

• Weld map

• Pneumatic testing report

• 10% x-ray including film. 

Additionally, an electrical completion package 

includes:

• Continuity report for every wiring run to ensure 

proper functionality

• Calibration data documents for all instruments

• Flow meters 100% tested and fully installed

• RTDS 100% tested and fully installed

• Differential pressure transmitters 100% tested 

and calibrated, tubing connection fully 

installed. 

4. Planned FY 2010 Activities

Detailed test and evaluation of the full loop will be 

conducted. Advanced HCE tubes will be installed 

and performance metrics measured. 

5. Major FY 2009 Publications

K.-J. Riffleman, “HelioTrough—A New Collector 

Generation for Parabolic Trough Power Plants,” 

D 

presented at Solar Paces 2009.

R A F T
Southwest Stakeholder Outreach

Performing Organization: Sandia National Laboratories (SNL)

 

Key Technical Contact: Thomas R. Mancini, SNL, 505-844-8643, trmanci@sandia.gov 

DOE HQ Technology Manager: Charles Hemmeline, 202-586-6646, charles.hemmeline@ee.doe.gov

FY 2009 Budget: $250K (SNL) 

____________________________________________________________________________________

Objectives

• Act as an information resource to concentrating solar power (CSP) stakeholders in accordance 

with the U.S. Department of Energy (DOE) Southwest stakeholder outreach activity. Stakeholders 

include federal/state/local governments, utilities, regulatory commissions, the Western Governors’ 

Association (WGA), the Bureau of Land Management (BLM), and various transmission groups. 

Accomplishments

• Presented a workshop for the SEPA Conference in San Jose, CA, Oct. 13–15, 2008

• Presented at the U.S. Environmental Protection Agency Brown to Green Conference in Santa Fe, 

NM, Dec. 10–12, 2008

• Presented at Green Energy Conference on CSP, Las Vegas, NV, Jan. 21–22, 2009

• Presented at Solar Today CSP Conference, Barcelona, Spain, Feb. 20–26, 2009

• Presented at World Bank CSP meeting, Washington, DC, Apr. 8–9, 2009

• Participated in SEIA Utility Scale Division Meeting, Washington, DC, Apr. 26–28, 2009

• Attended Schott Solar Dedication, Albuquerque, NM, May 11, 2009

• Presented at Concentrating Solar Thermal Conference, San Francisco, CA, June 3–5, 2009

• Presented on at ASME HT and Renewable Conference, San Francisco, CA, July 27–29, 2009

• Presented at SEPA Utility Scale Conference, San Jose, CA, July 31, 2009

• Presented at EUCI CSP Conference, Denver, CO, Aug. 24–26, 2009

• Presented at BLM Renewables Conference, Las Vegas, NV, Aug. 31, 2009

• Reviewed more than 20 proposals for CSP projects on BLM land in Arizona.

Future Directions

• Support outreach activities; include accelerated support of the BLM land lease evaluations.

____________________________________________________________________________________

1. Introduction

The long-term goal of the CSP subprogram is to 

develop CSP systems that produce electricity that 

is competitive with electricity from conventional 

fossil-fuel power technologies in identified 

markets, e.g., intermediate and base load power. 

Detailed systems analyses have shown that major 

factors contributing to cost reduction include 1) 

technology research and development to improve 

performance and reduce component costs, 2) 

solar plant scale-up to minimize project 

development and operations and maintenance 

costs, and 3) deployment to take advantage of 

volume production and learning. The work 

performed within the Southwest stakeholder 

outreach agreement supports outreach efforts 

intended to encourage these last two avenues for 

cost reduction. The outreach efforts rely on work 

funded under the market analysis/grid integration, 

resource assessment, and solar advisor support 

within the CSP market transformation activities. 

2. Technical Approach

The general approach involves presenting at CSP 

conferences and supporting the Bureau of Land 

Management with deployment of CSP projects on 

public lands.

 

3. Results and Accomplishments

• Presented at more than 12 conferences

• Supported of reviews of more than 20 BLM 

proposals for CSP Projects in Arizona.

D R A F T
CSP Resource Assessment

Performing Organization: National Renewable Energy Laboratory (NREL)

 

Key Technical Contact: Mark Mehos (NREL), 303-384-7458, mark.mehos@nrel.gov 

 

DOE HQ Technology Manager: Tex Wilkins, 202-586-1684, frank.wilkins@hq.doe.gov

FY 2009 Budget: $950K (NREL)

____________________________________________________________________________________

Objectives

• Obtain high-quality, site-specific measurements for model validation studies

• Develop best practices in using solar data for system siting and operations

• Develop satellite-based, large-area, direct normal solar irradiance (DNI)data sets

• Evaluate solar resource forecasting schemes.

Accomplishments

• Installed 11 SOLRMAP stations in the southwestern United States

• Hosted Concentrating Solar Power (CSP) Resource Assessment Workshop, and started writing 

Best Practices Handbook

• Further developed in-house capability of modeling solar resources using satellite imagery at high 

spatial resolution (5–10 km)

• Through IEA/SHC Task 36, continued to evaluate various methods for determining 1–3 day 

ahead solar resource (DNI) forecasting

• Made a strategic new hire (Manajit Sengupta) to lead our in-house capabilities in resource 

modeling, forecasting, and benchmarking.

• 

Future Directions

• Finalize Best Practices Manual and update as required

• Develop various empirical and physically based satellite modeling and solar resource forecasting 

capabilities (in combination with photovoltaics [PV] task)

• Continue to provide technical and OA support to IEA/SHC Task 36 and future tasks

• Produce periodic updates to the NSRDB (in combination with PV).

____________________________________________________________________________________

1. Introduction

Assessing the amount and characteristics of DNI, 

including historical values as well as predicted 

future values, has been identified as a priority for 

CSP developers and utilities alike. Developers are 

becoming increasingly dependent on highresolution hour-by-hour DNI data derived from 

satellite imagery. Although annual maps have 

been useful for identifying potential locations for 

near-term projects, accurately predicting the hourby-hour (resource forecasting), month-by-month, 

and year-by-year (performance/revenue 

forecasting) DNI at locations of interest to 

developers and utilities is critical to large-scale 

deployment of CSP.

2. Technical Approach

Bankable Data and GIS Support: NREL works with 

interested developers and utilities through its 

SOLRMAP program to install up to 12 additional 

ground-based stations at targeted locations for site 

selection and system performance evaluation. The 

data support stakeholders and are available for 

NREL’s further validation of satellite remote 

sensing model estimates of DNI, for producing

high temporal resolution (up to 1-minute) 

measured solar and meteorological data needed 

for resource model development, and for use in 

projecting short-term in-situ data sets to long-term 

data that address seasonal and interannual 

variability of the solar resources. 

Resource Data Modeling and Forecasting: NREL 

evaluates several solar resource forecasting 

methods that could meet the needs of CSP plant 

operators. In parallel with a task within the NCPV, 

D R A F T
this task develops an in-house capability for 

producing site-time specific estimates of DNI solar 

resources using satellite imagery. This task also 

benchmarks various modeled DNI data sets 

against ground data stations to achieve several 

purposes. These procedures will be documented 

in a Best Practices Manual.

3. Results and Accomplishments

We installed 11 SOLRMAP stations, using the 

rotating shadowband radiometer configuration, in 

the southwestern U.S. SOLRMAP involves using 

cooperative research and development 

agreements to partner with industry to establish 

high-quality ground measurement stations in 

targeted locations. NREL uses the data for model 

development and other research; industry benefits 

from credible data sets validated by NREL solar 

resource assessment experts. Installing 11 

stations completes an FY 2009 milestone.

NREL hosted a CSP Resource Assessment 

workshop to show stakeholders the quality, 

completeness, and bankability of data sets being 

produced. About 80 participants attended the 2-

day meeting, and the outcome was a plan to 

develop a Best Practices Manual for applying solar 

resource data to CSP project design and 

implementation. A first draft of this manual is 

planned for completion in early FY 2010.

In collaboration with the PV task, we established 

procedures to access geostationary satellite data 

(both visible and IR channels), and are finalizing a 

procedure for converting this imagery into high 

resolution (5—10 km and 15—30 min) solar 

resource estimates, both GHI and DNI. The 

empirical modeling approach is nearing 

completion and will be tested in FY 2010. We are 

also developing a more physically based satellite 

model, to be used for research and benchmarking, 

through collaboration with NOAA, University of 

Wisconsin, and Colorado State University. Our 

efforts in FY 2009 focused on developing a scope 

of effort and establishing partnerships with the key 

researchers involved in NOAA’s Geostationary 

Satellite Insolation Program.

Through IEA/SHC Task 36, we are gaining critical 

information and data on DNI solar resource 

forecasting techniques being examined in several 

regions around Europe. NASA/LaRC previously 

evaluated some of these techniques, and this work 

will continue under SETP support in FY 2010. 

Although mesoscale model input improves the 

result of solar resource forecasts using National 

Weather Service forecast products, considerable 

work needs to be done to obtain sufficient 

reliability of these forecasts for utility-scale 

operations. This task is cost-shared with the PV 

program.

4. Planned FY 2010 Activities

The CSP and PV tasks will be consolidated. CSP 

work will focus on four areas:

• Continue SOLRMAP station installations and 

data processing

• Finalize the Best Practices Manual, and 

periodically update the manual based on R&D 

results and user feedback

• Further develop high-resolution satellite-based 

DNI models, taking into consideration physical 

processes in the atmosphere; these models 

will be used to guide R&D efforts in resource 

assessment methods, benchmarking against 

other methods, and analytical studies at NRE. 

• Continue further benchmarking and 

identification of research priorities of solar 

resource forecasting schemes.

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal 

Investigator

Location/E-mail Description/Title of Research Activity

FY 

2009

($K)

Cost 

Share 

($K)

Solar Consulting 

Services/Dr. Christ 

Gueymard

New Hampshire

chris@solarconsultingservices.

com

Develop high-quality spatial and temporal 

aerosol optical depth data for use in 

NREL-developed and external satellitederived models 

50

State University of 

New York, Albany/: 

Dr. Richard Perez

Albany, NY

perez@asrc.cestm.albany.e

du

Test and evaluate various 1–3 day ahead 

solar forecasting methods 25 50**

* To be awarded in FY 2010.

** Cost share with PV Solar Resource Characterization task.

D R A F T
Market Analysis & Grid Integration

Performing Organization: National Renewable Energy Laboratory (NREL)

 

Key Technical Contacts: Craig Turchi (NREL, Primary Contact), 303-384-7565, 

craig.turchi@nrel.gov

Mark Mehos, 303-384-7458, mark.mehos@nrel.gov

 

DOE HQ Technology Manager: Tex Wilkins, 202-586-1684, frank.wilkins@hq.doe.gov

FY 2009 Budget: $1,418K (NREL) 

____________________________________________________________________________________

Objectives

• Support development and use of tools for analyzing concentrating solar power (CSP) market 

penetration and grid integration to promote deployment of utility-scale CSP in the southwestern 

United States For FY 09 the agreement includes the following tasks: (i) CSP Market Analysis, (ii) 

Grid Integration and Optimized Dispatch Analysis, (iii) Transmission and Policy Support

• Support western transmission analysis and renewable energy study groups with CSP-specific 

analysis

• Support U.S. Department of Energy and Energy Information Administration analysis requests. 

Accomplishments

• Updated Renewable Energy Deployment System (ReEDS) code to maintain current system costs 

for CSP technologies 

• Used ReEDS model to produce a correlation map of solar generation potential, wind generation 

potential, and load for the 356 ReEDS regions

• Completed and published a life-cycle assessment (LCA) of the state-of-the-art thermal energy 

storage systems for parabolic trough plants 

• Estimated the water consumption for wet-cooled parabolic trough plants and modeled the 

performance and cost of dry-cooled alternative designs

• Completely revised and updated the cost model for NREL’s representative parabolic trough plant

• Assisted Bureau of Land Management (BLM) and Western Governors’ Association (WGA) with 

identifying and mapping potential solar energy zones

• Analyzed the role and value of thermal energy storage for maximizing revenue from 

representative CSP plants in different utility markets

• Added U.S. Environmental Protection Agency brownfield sites and proposed renewable energy 

zones to Solar Power Prospector

• Modeled CSP with storage contribution in Western Wind and Solar Integration Study (WWSIS), 

demonstrating optimum storage capacity and showing increased CSP plant revenue when 

storage is used to match dispatch to load. 

Future Directions

• Separate this project into CSP System Analysis, Market Transformation, and Grid Analysis 

activities to better focus activities and match staff expertise 

• Complete and publish the parabolic trough LCA, followed by initiation of a similar activity for 

power towers 

• Publish parabolic trough cost update and cooling studies

• Support Solar Vision Study

• Develop financial models representing current or proposed financial vehicle for utility-scale solar 

plants; incorporate the best models in the Solar Advisor Model (SAM)

• Investigate the potential of solar/fossil hybrid plant designs to reduce project risk and facilitate 

deployment of CSP technologies; this work will be undertaken with the Electric Power Research 

Institute (EPRI).

____________________________________________________________________________________

D R A F T
1. Introduction

The goal of the CSP subprogram is to develop 

CSP systems that produce electricity that is 

competitive with electricity from conventional fossil 

fuel power technologies in identified markets, e.g., 

intermediate and baseload power. Detailed 

systems analyses have shown that major factors 

contributing to cost reduction include technology 

R&D to improve performance and reduce 

component costs, solar plant scale-up to minimize 

project development and O&M costs, and 

deployment to take advantage of volume 

production and learning. The CSP Market 

Transformation Project supports outreach and 

analysis intended to encourage the last two 

avenues for cost reduction.

2. Technical Approach

Task 1, CSP Market Analysis, includes continued 

development of ReEDS and use of the model to 

support internal and external requests for analysis. 

Additional activities include updating and tracking 

CSP system costs, examining the correlation of 

CSP and wind energy generation, and 

investigating environmental impacts of CSP 

deployment. 

Task 2, Grid Integration and Optimized Dispatch 

Analysis, examined the optimum storage amount 

and dispatch plan for CSP plants with thermal 

energy storage. 

Task 3, Transmission Policy Support, includes 

CSP support of regional transmission study 

groups, including the WGA/Western Renewable 

Energy Zone (WREZ) analysis teams.

3. Results and Accomplishments

• The ReEDS model was maintained with 

updated cost and configuration data for CSP 

technologies and used to produce a 

correlation map of solar energy potential, wind 

energy potential, and load for the 356 regions 

that represent the United States. This 

spreadsheet-based model can be used to 

show regions where solar and wind power are 

complementary in their ability to cover the 

regional load. Such interaction can offset the 

variable nature of both technologies, 

promoting higher renewable energy 

penetration.

• NREL analysts completed a life-cycle 

assessment of the thermal storage systems 

within a state-of-the-art parabolic trough plant. 

A large mass of nitrate salt is required for 

current thermal storage designs. The source 

of the nitrate salt has a significant effect on its

carbon footprint, with mined salt producing 

much less greenhouse gas emissions than 

synthetically produced salt. The estimated 

carbon payback time for a thermal storage 

system with mined salt is approximately two 

months.

• Parabolic trough and power tower plants can 

be dry-cooled to reduce water consumption by 

more than 90%. However, dry-cooling is less 

efficient and leads to higher capital costs and 

levelized cost of electricity (LCOE). Analysis of 

wet-cooled and dry-cooled parabolic trough 

plants by subcontractor WorleyParsons 

indicated that larger than normal air-cooled 

condensers can minimize the efficiency 

penalty for dry-cooling and reduce the LCOE 

impact to 1¢/kWh or less.

• NREL also worked with WorleyParsons to 

update the cost estimates for parabolic trough 

power plants. The cost study used a reference 

plant with a 100-MWe capacity and 6 hours of 

thermal energy storage. Wet-cooling and drycooling configurations were considered. NREL 

developed a spreadsheet model that includes 

capital and operating costs by component, 

e.g., mirrors, heat transfer fluid, and operators, 

to allow users to estimate the effect of 

changes in component costs. Costs estimated 

by WorleyParsons were adjusted for a slight 

change in plant size and relocation to 

southwestern Arizona. The spreadsheet also 

allows users to estimate the costs of differentsize plants and to take into account changes 

in commodity prices. The model is designed to 

work with SAM.

• NREL’s analysts continued to assist working 

groups on the WGA/WREZ team and with the 

Solar Environmental Impact Statement. Both 

programs issued maps of proposed renewable 

energy zones to promote the siting of solar 

projects in locations that have better access to 

transmission and minimize the environmental 

impact of the facilities.

• NREL examined the value of thermal energy 

storage with respect to revenue generation for 

hypothetical trough plants in three different 

utility power markets. The analysis examined 

plants selling power into Arizona, Texas, and 

California markets and used historical 

D R A F T
electricity price data to estimate the revenue 

from different dispatch schemes. Locational 

profit differences were shown to be mainly 

caused by differences in energy prices in the 

different system operator and utility systems 

considered, with differences in solar resource 

being a smaller determinant of CSP value. For 

example, a CSP plant in Texas was estimated 

to have higher profitability than a similar plant 

in Arizona or California despite the lesser solar 

resource in Texas. We showed that TES can 

increase CSP value both by allowing 

generation to be shifted to higher-priced hours 

and by increasing the use of thermal energy 

from the solar field. The operating profits of 

the CSP plant seemed relatively insensitive to

the assumption that TES dispatch decisions 

are made a day at a time, which suggests that 

most generation shifting is done within a day 

or between adjacent days. A simple 

backcasting dispatch technique achieved at 

least 87% of the revenue that are possible 

with perfect foresight of energy prices and 

solar availability, indicating day-ahead 

forecasting will not be too challenging and 

including price and weather forecasts in the 

dispatch process can further improve the 

profitability of a real CSP plant. Despite these 

benefits, our analysis suggested that with 

current capital costs TES cannot be justified 

on the basis of energy value alone and further 

improvement in TES cost and performance 

are necessary. As overall CSP costs fall, the 

benefits of TES will be instrumental in helping 

CSP achieve higher market penetration and 

eventual cost parity with other generation 

sources.

• Analysis under the WWSIG resulted in similar 

conclusions with respect to CSP storage 

value, with the significantly higher capacity 

value of CSP highlighting the benefits of the 

CSP with thermal storage in meeting peak 

demand. 

4. Planned FY 2010 Activities

• Divide this topic area into separate projects 

focusing on CSP System Analysis, Market 

Transformation, and Grid Analysis. This 

separation will clarify the activities and allow 

staff with relevant expertise to be engaged. 

For example, transmission experts from 

NREL’s wind program area will be tapped to 

support analysis of CSP transmission issues. 

• The LCA for an entire parabolic trough plant 

will be completed, adding to the TES analysis 

performed in FY 2009. NREL will leverage the 

plant design information compiled under the 

FY 2009 WorleyParsons contract to update 

trough plant costs. The detailed data used to 

estimate plant size and cost will produce much 

of the information necessary to accurately 

estimate facility LCA. Following completion of 

the trough plant LCA, NREL will begin a 

similar activity for power towers, with a 

planned completion in FY 2011.

• The parabolic trough cost update, trough plant 

LCA, and trough plant cooling studies will be 

published.

• The NREL CSP analysis team will support the 

Solar Vision Study by providing insight and 

information on CSP costs, CSP generation 

potential, and CSP environmental impact. The 

Solar Vision Study will assess the potential of 

solar power to produce 10% and 20% of the 

nation’s electricity needs by 2030.

• Members of NREL’s financial analysis group 

will examine financial vehicles being proposed 

for utility-scale solar power projects, develop 

spreadsheet models to assess the value of 

each approach. and incorporate the best 

models in SAM. 

• NREL will release the first non-beta version of 

the Solar Power Prospector, incorporating 

enhanced data download capability, CSP plant 

data, and updated renewable energy zone 

information.

• Building on a relationship developed in FY

2009, NREL will work with EPRI to determine 

the potential of solar/fossil hybrid plant 

designs. Such designs can reduce the cost 

and project risk associated with large CSP 

projects. Solar/fossil hybrids are viewed 

favorably by the utility sector and can expand 

the deployment of CSP technologies, thereby 

accelerating learning rates and reducing CSP 

costs. NREL and EPRI will jointly develop a 

database of existing fossil plants that ranks 

suitability for solar augmentation. The team 

will also explore greenfield solar/fossil hybrid 

designs.

5. Major FY 2009 Publications

G.C. Glatzmaier and C.S. Turchi, “Supercritical 

CO2 as a Heat Transfer and Power Cycle Fluid 

for CSP Systems,” Paper ES2009-90332, ASME 

Energy Sustainability 2009, San Francisco, CA, 

July 19-23, 2009.

H. Garvin, C.S. Turchi, T. Decker, J. Burkhardt, 

and C. Kutscher, “Life Cycle Assessment of 

Thermal Energy Storage: Two-Tank Indirect and 

D R A F T
Thermocline,” Paper ES2009-90402, ASME 

Energy Sustainability 2009, San Francisco, CA, 

July 19-23, 2009. 

D. Lew, M. Milligan, G. Jordan, L. Freeman, N. 

Miller, K. Clark, and R. Piwko, “How do Wind and 

Solar Power Affect Grid Operations: The 

Western Wind and Solar Integration Study,” 

NREL/CP-550-46517, Golden, CO: NREL 

(2009). 

Western Renewable Energy Zones—Phase 1 

Report, Western Governors’ Association and 

U.S. DOE (June 2009). 

6. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of 

Research Activity

FY 2009

($K)

Cost 

Share 

($K)

WorleyParsons/

Rodney Gartner

Golden, CO

Rodney.Gartner@WorleyParsons.com

Parabolic Trough Plant 

Cost Model 181 0 

WorleyParsons/ 

Ryan Bowers

Golden, CO

ryan.bowers@WorleyParsons.com

Parabolic Trough Cooling 

Studies 100 0 

University of Colorado/ 

Dr. Jana Miford Boulder, CO CSP life Cycle Assessment 22 0 

Ohio State University/

Ramteen Sioshansi

Columbus, OH

sioshansi.1@osu.edu

Energy Storage and CSP 

Penetration Analysis 22 0 

Western Governors 

Association

Support for Western 

Renewable Energy Zones 

Initiative

313

D R A F T
Solar Advisor Support

Performing Organization: National Renewable Energy Laboratory (NREL)

 

Key Technical Contact: Nate Blair (NREL), 303-384-7426, nate.blair@nrel.gov 

 

DOE HQ Technology Manager: Tex Wilkins, 202-586-1684, frank.wilkins@hq.doe.gov

FY 2009 Budget: $380K (NREL)

____________________________________________________________________________________

Objectives

• Enhance the Solar Advisor Model (SAM) to develop capabilities to calculate energy output, 

energy costs, and cash flows using up-to-date component and system data while enabling 

parametric analysis with the best available concentrating solar power (CSP) models. 

Accomplishments

• Reconstructed the entire SAM core code in C++ for several reasons:

o Is significantly faster

o Allows greater interaction with risk-assessment tools such as @Risk and CrystalBall

o Incorporates Monte Carlo analysis (in conjunction with Sandia National Laboratories)

o Enables SAM as a WebApp and an Apple Mac Version

o Allows easier interaction with Excel, Matlab, and other web tools

o Has improved maintainability.

• Released new SAM versions with:

o Power tower model (based on sponsored university research) incorporated 

o Improved dispatch model for trough systems added

o Enhanced GUI and greater graphical output capability, including tornado-chart analysis

o Added time-of-use utility rates and automated IPP financing optimization. 

• Conducted multiple in-person and web-based trainings for SAM.

Future Directions

• Continue DOE and user support and hold a full-day user forum

• Add additional CSP technologies to SAM, including a detailed, thermodynamic trough model and 

a generic optical model.

____________________________________________________________________________________

1. Introduction

The objective of this project is to combine 

photovoltaics (PV), CSP, and thermal solar 

technologies into a single model using high-quality 

performance models developed by NREL, Sandia, 

and other partners. This will facilitate comparison 

by handling performance, costs, and financing 

consistently across technologies. Emphasis will be 

on a quality user interface to promote greater 

usage of quality tools by industry and the U.S. 

Department of Energy (DOE). 

2. Technical Approach

The system modeling task consists of systems 

performance and cost modeling and validation 

projects. The primary function of SAM is to allow 

users to investigate the effect of variations in 

physical and financial parameters to better 

understand their effect on key figures of merit for 

solar power systems. Figures of merit related to 

the cost and performance of these solar power 

systems include, but are not limited to, system

output, peak and annual system efficiency, 

levelized cost of energy, and system capital and 

O&M costs. SAM is used not only by DOE, 

laboratory management, and research staff, but 

also throughout the solar community. Its 

combination of robust performance models for 

multiple solar technologies with detailed financial 

D 

models in a publicly available package is unique. 

R A F T
3. Results and Accomplishments

A great deal of SAM development was 

accomplished in FY 2009. The primary activity 

was developing and releasing a rebuilt code base 

for SAM, which was done for a variety of reasons, 

including ongoing problems with the original 

platform chosen and its speed. Although not a 

planned deliverable, this activity was completed 

while still accomplishing the other planned 

deliverables (and some originally slated to be 

enhanced activities). 

With more than 11,000 individuals having 

downloaded SAM, user support continues to be a 

growing issue, especially as some long-time users

delve ever deeper into the capabilities. 

Specific CSP SAM Accomplishments:

• Held a specific annual one-day workshop at 

Solar Power International covering CSP and 

PV

• Incorporate detailed modeling of a power 

tower system into the SAM model

• Added a significantly enhanced dispatch 

model SAM as well for trough systems

• Enhanced IPP financing and other utility-scale 

issues.

4. Planned FY 2010 Activities

Task #1: DOE and Industry User Support-SAM. 

• Maintain user support for SAM via an email 

address supported by a subcontractor, a

significant effort with more than 11,000 users 

• Rework the SAM website to incorporate 

capabilities of our current Google Group site. 

Task #2: SAM Model Enhancement (Core).

• Incorporate direct access to DSIRE incentive 

web feed. 

• Complete SAM code restructuring:

Task #3: This task contains activities that are 

specific to CSP modeling within SAM: 

• Debug and update CSP portion of model

• Incorporate thermodynamic model of steam 

Rankine cycle into parabolic trough 

• Improve data exchange between SAM and 

Solar Power Prospector to facilitate CSP 

system feasibility studies 

• Improve SAM interface for modeling integrated 

solar-fossil plants

• Develop generic optical efficiency model to 

allow for analysis of nonstandard CSP designs 

and importation of SolTrace model outputs.

• Incorporate enhancements to power tower 

model (DSG and cavity receiver)

• Collaborate with Cliff Ho at Sandia on their 

stochastic modeling efforts (using SAM as the 

engine)

• Integrate NREL cost model into SAM as a 

standard option.

5. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Cost Share 

($K)

Janzou Consulting/ 

Steve Janzou

Evergreen, CO

Steve_janzou@nrel.gov

program the front-end and basic 

engine of the Solar Advisor Model 40 0 

University of WisconsinMadison/ 

Prof. Sanford Klein

Madison, WI

Klein@engr.wisc.edu

Development of Cavity Receiver 

Model 105 0 

Paul Gilman/

Paul Gilman

Chicago, IL

PaulGilman@earthlink.net

user support and technical writing 

support 20 0 

D R A F T
Solar Energy Development 

Programmatic Environmental Impact Statement (PEIS)

Performing Organization: Argonne National Laboratory (ANL)

National Renewable Energy Laboratory (NREL)

Key Technical Contacts: Heidi Hartmann (ANL, Primary Contact), 630-252-6487, 

hmhartmann@anl.gov 

Doug Dahle (Primary Contact), 303-384-7513, 

doug.dahle@nrel.gov 

Craig Turchi, 303-384-7565, craig.turchi@nrel.gov 

DOE HQ Technology Manager: Frank (Tex) Wilkins, 202-586-1684, Frank.wilkins@ee.doe.gov

FY 2009 Budgets: $2,081K (ANL), $125K (NREL)

____________________________________________________________________________________

Objectives

• Develop environmental strategies and mitigation measures applicable to DOE-supported solar 

energy development projects, and utility-scale projects to be located on lands administered by the 

Bureau of Land Management (BLM) in six southwestern states (Arizona, California, Colorado, 

Nevada, New Mexico, and Utah)

• Evaluate and compare environmental impacts of utility-scale solar technologies, including 

parabolic trough, power tower, dish engine, and PV systems

• Identify BLM-administered lands suitable for utility-scale solar energy development from an 

environmental impact perspective

• Meet regulatory requirements of National Environmental Policy Act (NEPA). 

Accomplishments

• Conducted second scoping period to solicit public comment on 24 solar energy study areas on 

BLM-administered lands; expanded scope of the PEIS to include detailed environmental impacts 

analyses in these areas (ANL)

• Distributed drafts of introductory chapters, affected environment description, impact analyses, 

and technical appendices for DOE, BLM, and Cooperating Agency review (ANL)

• Compiled extensive geographic information system (GIS) dataset (ANL)

• Participated in ongoing work with Cooperating Agencies and staff of related projects (Western 

Governor’s Association Renewable Energy Zones [WREZ] study; California Renewable Energy 

Transmission Initiative [RETI] study) to coordinate analyses (ANL)

• Provided GIS solar data and recommended exclusions for ANL development of maps (NREL)

• Performed technical review of PEIS Solar Technology Overview appendix (NREL)

• Provided consultation and advice for Argonne/BLM/DOE solar project planning meetings and 

solar power plant tours. Ran ReEDS model simulations for proposed solar energy study areas

(NREL)

• Maintained Solar PEIS Information Center website at http://solareis.anl.gov (ANL). 

Future Directions

• With DOE and BLM, establish suite of strategies and mitigation measures applicable for DOEsupported projects (ANL)

• Publish PEIS Draft for public comment December 2010 (ANL)

• Respond to public comments; publish Final PEIS December 2011 (ANL). 

____________________________________________________________________________________

1. Introduction

Executive Order 13212 requires that federal 

agencies and executive departments take 

appropriate actions “to expedite projects that will 

increase the production, transmission, or 

conservation of energy.” Executive Order 13514 

requires that federal agencies take efforts to 

D R A F T
align their policies to advance local planning 

efforts for energy development, including 

renewable energy. Both DOE and BLM are 

undertaking various actions to comply with these

orders. As part of these efforts, DOE and BLM 

are jointly preparing the Solar Energy 

Development PEIS to assess the environmental, 

social, and economic impacts associated with 

utility-scale solar energy development. Through 

the PEIS, the agencies will develop a 

comprehensive set of mitigation strategies and 

measures for various resources that will be 

applicable for utility-scale solar energy 

development projects supported by DOE, or on 

BLM-administered lands. The PEIS will also 

result in the amendment of BLM land use plans, 

a prerequisite for the granting of right-of-way 

(ROW) authorizations for solar developments on 

BLM-administered lands (see below). 

The BLM administers approximately 256 million 

acres (1 million km2

) of public lands. As of 

March 1, 2010, the BLM was processing about 

130 active applications (totaling about 74,000 

MW of power) for ROW authorizations for utilityscale solar energy projects on BLMadministered lands; additional applications are 

being received and evaluated. For any of these 

projects to proceed, the BLM must issue ROW 

authorizations in accordance with the 

requirements of the Federal Land Policy and 

Management Act of 1976 (FLPMA). Prior to 

issuance of ROW authorizations, BLM land use 

plans must be amended to designate specific 

areas as available for application for solar 

developments. 

2. Technical Approach

ANL

Environmental impact statements compare the 

impacts of various alternatives that the lead 

agency or agencies are considering 

implementing. For the Solar Energy 

Development PEIS, DOE’s proposed action 

alternative is to amend its current investment 

and deployment strategy to more effectively 

integrate environmental considerations into 

technology investment and technical assistance 

decisions. Elements of this include (1) 

establishing technology performance program 

goals and prioritizing investments that minimize 

environmental impacts; (2) preferentially 

investing in grouped (such as state and regional 

focused renewable energy zone efforts) or 

dispersed solar projects based on the potential 

for minimizing environmental impacts; and 3) 

amending the current financial assistance 

strategy to incorporate environmental 

considerations earlier in the process, by 

developing and implementing a program of 

policies and mitigation requirements that DOE 

financial assistance recipients would be required 

to adopt when applying for DOE funding. 

Alternatives being evaluated by BLM involve the 

identification of specific lands as available for 

ROW application, including potential designation 

of solar energy zones (SEZs) within which solar 

energy development would be prioritized over 

other land uses. In addition, BLM proposes to 

implement a program of policies and mitigation 

measures applicable to ROW authorizations for 

solar energy development. Certain BLMadministered lands would be excluded from 

solar development under all alternatives, 

including specially-designated lands (e.g., 

federally designated wilderness areas, 

wilderness study areas, national monuments, 

national conservation areas, national trails, and 

wild and scenic rivers) and lands with slope of 

greater than 5%.

In the PEIS, the impacts of the alternatives are 

assessed for the following resource areas and 

values: land use, water resources and 

availability, air quality (including emissions 

avoided), ecological resources and threatened 

and endangered species, visual resources, the 

acoustic environment, socioeconomics, 

environmental justice, paleontology and cultural 

resources, geologic setting and seismic hazard, 

transportation impacts, and health and safety. 

Assessments consider applicable regulations 

and BLM guidance, and compare the impacts of 

parabolic trough, power tower, dish engine, and 

PV technologies. Two parameters that are key 

for the comparison of impacts are land use (and 

associated habitat disturbance) and water use.

Potential mitigation measures for impacts are 

identified. Some potentially applicable mitigation 

measures will be recommended for 

consideration on a project-specific, locationspecific, or technology-specific basis. 

Additionally, a subset will be identified as 

applicable and reasonable for all solar energy 

development projects; this subset will be 

identified as the agencies’ environmental 

strategy, and included as requirements for 

projects over which each agency has 

jurisdiction. This set of mitigation measures will 

D R A F T
be comprehensive and will be consistently 

applicable for utility-scale solar energy 

development projects supported by DOE or on 

BLM-administered lands.

The PEIS will also evaluate the potential 

cumulative impacts of solar energy development 

over the twenty year period through 2030. NREL 

is aiding in this task, through the provision of 

state-specific projected development levels (in 

megawatts).

NREL

Under this agreement, NREL staff support the 

needs of the PEIS team at ANL. NREL activities 

include providing information related to solar 

technology operating conditions, operating 

requirements, and performance, as well as 

modeling potential solar deployment using the 

Renewable Energy Deployment System model 

(ReEDS). NREL staff have attended public 

scoping meeting and continue to attend project 

meetings as requested by DOE and ANL. NREL 

GIS experts assist the Argonne team and BLM 

with mapping of potential solar energy study 

areas. NREL provides technical review of PEIS 

documents and assists the team with questions 

and concerns related to the operational needs of 

solar power plants.

3. Results and Accomplishments

ANLThe PEIS public involvement process is 

driven by NEPA regulatory requirements. To 

date, the Solar Energy PEIS effort has met and 

exceeded these requirements.

Drafts of a significant portion of the PEIS were 

delivered to DOE, BLM, and their Cooperating 

Agencies for review. These included the 

introductory chapters, description of the affected 

environment in the six-state study area, 

description of potential impacts and mitigation 

measures for each technology, and technology 

overviews. Review comments were incorporated 

into revised drafts.

In March 2009, BLM initiated changes to the 

scope of the PEIS in response to Secretarial 

Order 3285 issued by the Department of the 

Interior Secretary Salazar. This order 

established a goal of identifying which BLMadministered lands are best suited for utilityscale solar energy production and prioritizing 

development in these areas. This change in 

scope included the identification of 24 solar 

energy study areas, a second public scoping 

period (from June 30 to Sept. 14, 2009), and the 

addition of detailed impact assessments of these 

areas. Based on public comment, the 24 solar 

energy study areas have been modified slightly 

and are now being assessed as potential SEZs.

Work is under way to revise earlier draft sections 

of the PEIS to incorporate these changes in 

scope and to include the detailed impact 

assessments.

4. Planned FY 2010 Activities

ANL

PEIS staff will complete analysis of the impacts 

of the 24 SEZs and revisions to the previously 

drafted sections of the PEIS. In addition, 

analysis of the agency proposed actions and 

alternatives will be prepared. The preliminary 

draft PEIS is scheduled for completion at the 

end of August 2010, at which time it will be 

reviewed and commented on by the Agencies

and by Cooperating Agencies. Comments will be 

incorporated as appropriate for release of the 

Draft PEIS in FY11 (12/10).

NREL

NREL will continue to assist the PEIS team as 

the activity continues in FY 2010 through FY

2012. Public comments will be posted in 

October 2009, and NREL will assist with 

reviewing and addressing these concerns, 

specifically as they relate to technology issues. 

NREL analysts will provide deployment 

modeling support via the ReEDS model to 

estimate where solar power plants are likely to 

be built and assess the value of proposed solar 

energy study areas with respect to transmission 

availability. A draft EIS that addresses public 

comments will be issued by Argonne in 

December 2010. This will be followed by another

90-day public comments period. NREL will again 

assist with addressing public comments prior to 

release of the final EIS in FY 2012 (12/11). 

5. Major FY 2009 Publications

Solar Energy Study Area maps published. 

Announcement in Federal Register 74, 124, 

June 30, 2009. Available at 

http://solareis.anl.gov/eis/maps/index.cfm.

D R A F T
Operations & Planning Overview

The operations and planning section includes activities that cut across all subprograms. The 

activities reflected below support the funded subprograms to achieve the program’s goals. 

The Program Management project includes all of the management oversight at the national 

laboratories – National Renewable Energy Laboratory (NREL) and Sandia National Laboratories 

(SNL) - as well as the support service efforts that are provided by New West and Sentech.

Equipment and Facilities includes equipment purchases at the labs that need to be funded 

through specially marked capital equipment accounts, as well as operations and maintenance 

(O&M) support for the National Solar Thermal Test Facility at SNL. The equipment purchase at 

NREL included an Atlas Weatherometer and an Oxygen Permeation device used for 

concentrating solar power (CSP) research and development (R&D). 

Communications efforts include laboratory support for the solar communications as well as 

various communications tasks funded directly through HQ. These include several solar-related 

studies by the National Academy of Sciences (NAS), support for the American Solar Energy 

Society (ASES) Solar Tour, and the Solar Electric Power Association (SEPA) Conference.

International activities include both PV & CSP International Energy Agency (IEA) efforts 

(SolarPACES), as well as direct support for a project in India.

PBA Crosscut activities are managed by the U.S. Department of Energy (DOE) Office of Energy 

Efficiency and Renewable Energy’s (EERE’s) Office of Planning Budget and Analysis, which 

totaled 3.3% of solar program funding. Activities include cross-cutting analysis, the Renewable 

Electricity Futures Study, Green Power, and projects in Hawaii, Alaska, Brazil, and Israel.

The DOE SBIR activity funds Small Business Innovative Research projects that are managed by 

DOE’s Office of Science. This came to 1.5% of Solar Program funding in FY 2009, however, the 

Solar Program benefits from specific solar projects that are selected under this solicitation. 

Operations & Planning NREL SNL Other Total

Program Management 1417 1531 3560 6508

PV Program Management 1112 811 0 1923

CSP Program 

Management 305 720 0 1025

HQ Support Services 0 0 3560 3560

Equipment & Facilities 202 800 0 1002

CSP Equipment & 

Facilities 202 800 0 1002

Communications & 

International 1247 200 1461 2908

Lab Communications 834 200 0 1034

HQ Communications 0 0 1461 1461

International 413 0 0 413

PBA Crosscut 0 0 5748 5748

DOE SBIR 0 0 2586 2586

Total 2866 2531 13355 18752

D R A F T
CSP Program Management

Performing Organizations: Sandia National Laboratories (SNL)

National Renewable Energy Laboratory (NREL)

 

Key Technical Contacts: Thomas R. Mancini (SNL) 505-844-8643, trmanci@sandia.gov

Mark S. Mehos (NREL) 303-384-7458, mark.mehos@nrel.gov 

DOE HQ Technology Manager: Tommy Rueckert, 202-586-0942, Thomas.Rueckert@ee.doe.gov 

FY 2009 Budgets: $750K (SNL), $305K (NREL)

____________________________________________________________________________________

Objectives

• Effectively plan, administer, manage, and review the NREL and SNL Concentrating Solar Power 

(CSP) budgets 

• Provide technical analysis and support services to the Department of Energy’s (DOE’s) Solar 

Energy Technologies Program (SETP or the Solar Program)

• Provide technical support for grid integration activities.

Accomplishment

• Successfully implemented CSP R&D and market transformation activities, as directed by DOE 

through the fiscal year (FY) 2009 Annual Operating Plan (AOP). 

Future Directions

• Support SETP management of the CSP efforts 

• Plan, administer, manage, and review the Solar Program at the national labs (NREL/SNL)

• Continue to support market transformation and grid integration activities, risk analysis, and 

CSP/Bureau of Land Management support.

____________________________________________________________________________________

1. Introduction

The CSP activities are managed collaboratively. 

SETP leads the CSP work, which is carried out 

through SNL and NREL. 

2. Technical Approach

At SNL, all CSP activities are overseen by Jeffrey 

Nelson. Thomas Mancini and Joe Tillerson are 

responsible for day-to-day CSP management and 

Charles Hanley manages the PV activities. Mark 

Mehos manages CSP activities at NREL. 

3. Results and Accomplishments

• Completed development of the FY 2009 AOP

and ensured that all FY 2009 CSP milestones

were completed

• Provided SETP support to evaluation, 

validation, and analysis activities, as well as 

other general program support, through onsite assignment of Joe Tillerson

• Contributed to the planning and 

implementation of all appropriate program 

meetings, such as the annual review, the FY 

2010 AOP development meetings, and other 

related events.

4. Planned FY 2010 Activities

SNL and NREL will continue to support DOE’s 

management of the CSP Program by providing 

analysis and recommendations for future direction.

Specifically, we will

• Participate in all future program management 

activities in close coordination with SETP

• Work with DOE CSP leadership to develop 

strategic and near-term plans that support 

accelerated commercial development and 

deployment of CSP systems

• Hire new staff to support expanded R&D, 

systems integration, market transformation 

funding and testing at the SNL and NREL test 

facilities, as well as to meet current and future 

program commitments. 

.

D R A F T
New West Technologies Programmatic Support

Performing Organization: New West Technologies, LLC (NWT)

Key Technical Contacts: John Bartlett (NWT), 202-586-8196, john.bartlett@ee.doe.gov 

Charlie Coggeshall (NWT), 202-470-6375, ccoggeshall@nwttech.com 

DOE HQ Technology Manager: John Lushetsky, 202-287-1685, john.lushetsky@ee.doe.gov 

FY 2009 Budgets: $2,572K (Task #3); $150K (Task #16); $216K (Task #29); $131.5K (Task

#31); $120K (Task #33) 

__________________________________________________________________________________

 

Objectives

• Provide technical, engineering, analytical, and management support to the U.S. Department of 

Energy’s (DOE’s) Solar Energy Technologies Program (SETP, or Solar Program) by developing 

program plans and evaluations, coordinating meetings and documents, reviewing scientific and 

engineering studies and analyses, offering technical expertise in various program and project 

evaluations, and managing projects (Task #3)

• Provide technical and programmatic support for the Solar Program’s Grid Integration Program 

activities (Task #16)

• Provide technical support for the Solar Program’s 2009 peer review (Task #29)

• Provide support for the Solar Program’s headquarters (HQ) communications (Task #31) 

• Support the Solar Program in monitoring technical progress and project costs (Task #33). 

Accomplishments

• Provided the Solar Program with technical, engineering, analytical, and management support in 

all efforts related to the program goal of achieving cost competitiveness for photovoltaic (PV) and 

concentrating solar power (CSP) technologies by 2015;this task (#3) was supported through the 

accomplishment of seven subtasks

• Provided technical support for stakeholder engagement activities and assisted in strategic 

planning activities for the Solar Program’s Grid Integration Program, as well as a DOE strategy 

document on interconnecting renewable energy systems onto the grid (Task #16)

• Provided technical support to the peer review organizer at HQ in achieving a well-organized, wellrun, technically superior Solar Program Peer Review (Task #29)

• Provided a marketing communication manager who met all Solar Program HQ communications 

needs and developed and identified communications and marketing opportunities (Task #31)

• Enabled Solar Program staff members to more effectively monitor project information via access 

to critical, real-time information about their projects in EERE’s Corporate Planning System (CPS; 

Task #33).

Future Directions

• Continue supporting the Solar Program’s goal of achieving cost-competitiveness for PV and CSP 

technologies by 2015

• Continue providing technical support for stakeholder engagement activities

• Support development of the DOE Solar Vision Study

• Continue providing strategic planning support and analyses for all subprograms (Grid Integration, 

Market Transformation, and PV and CSP technology programs) 

• Provide technical support for the Solar Program’s 2010 peer review.

____________________________________________________________________________________

D R A F T
1. Introduction

DOE’s Solar Program contracted with NWT to 

support five separate tasks with a cumulative 

budget of $3,189.5K. This report summarizes 

basic points in the agreements for each task and

the corresponding results of those tasks as of the 

end of FY 2009, and looks forward at directions 

and expectations for FY 2010.

2. Technical Approach

The Technology Development (TD) support (Task 

#3) accounted for the bulk of the total contract 

work budgeted for NWT. NWT subcontracted 

much of this work to SENTECH, Inc. The wide 

spectrum of support provided by NWT and 

SENTECH is broken down into the following seven 

subtasks, which the Solar Program identified as 

key areas requiring assistance: 

• Subtask #1: Solar Program working group 

activities

• Subtask #2: Simulation-based risk analysis 

development

• Subtask #3: Promotion of solar energy 

production capacity in the United States

• Subtask #4: Various policy, economic, and 

engineering analyses

• Subtask #5:2009 Solar Program Peer Review

• Subtask #6: All major market transformation 

activities

• Subtask #7: All CSP Program activities.

Task #29, which required support for the 2009 

peer review, was subcontracted to Kevin DeGroat 

of Antares.

Task #33, which required support for monitoring 

Solar Program technical progress and project 

costs, was subcontracted to BCS, Inc. 

3. Results and Accomplishments

3.1 Task #3

Successfully supported the Solar Program’s goal 

of achieving cost competitiveness for PV and CSP 

technologies by 2015. This task (#3) was 

addressed through the following subtask 

accomplishments: 

• Subtask #1:Assisted in the planning, 

facilitating, and implementing of Solar 

Program working group activities 

o Led Workforce Development activities 

(04/09)

o Provided technical assistance to the 

General Services Administration 

(GSA) throughout the year. SENTECH 

provided input on GSA’s solar request 

for proposals and supporting 

documentation, reviewed solar 

installation plans, and performed and 

provided oversight for site feasibility 

studies.

• Subtask #2: Assisted DOE in conducting 

detailed, systems-level simulation-based 

risk analysis

o Wrote content for the final report of 

the 2009 Solar Technical Risk and 

Uncertainty Analysis (09/09). 

• Subtask #3: Assisted in implementing the 

Solar Program’s plan for promoting 

America’s solar energy production 

capacity

o Established communication with 

principal solar analysts on Wall Street 

to facilitate flow of research from DOE 

to Wall Street (11/08)

o Wrote sections and edited all of 

Appendix B of the IRS 48C Notice 

(07/09)

o Successfully launched and maintained 

development of the Solar Vision Study 

(06/09–present) 

o Offered leader and member 

contributions to Solar Vision Study 

chapters (09/09)

o Provided background research on PV 

manufacturing consortia in support of 

PV Manufacturing Initiative (07/09)

o Contributed to the Annual Report on 

US Solar Energy Markets: 2008 

o Participated in numerous solar 

conferences including the following: 

Solar Energy Consortium Solar 

Summit in New York City, NY (10/08); 

Solar Power International in San 

Diego, CA (10/08); IREC Annual 

Meeting in San Diego, CA (10/08);

ASES Annual Conference in Buffalo, 

NY (05/09); SolarTech Performance 

Symposium/Intersolar in San 

Francisco, CA (07/09); National 

Association of State Energy Offices 

(NASEO) Annual Meeting (09/09);

USGWPC Water/Energy Sustainability 

D R A F T
Symposium in Salt Lake City, UT

(09/09); and Solar ABCs stakeholder 

meetings (throughout FY 2009). 

• Subtask #4: Assisted in preparation and 

drafting of policy, economic, and engineering 

analyses in response to administration, 

congressional, and stakeholder requests

o Analyzed the financial assumptions in the 

Solar Advisor Model (SAM; 12/08)

o Modeled and analyzed costs and benefits 

from SEIA’s stimulus proposals (01/09)

o Modeled number of applications 

Department of Treasury should expect 

from solar projects (2009–2011) for 

Section 1603 grants in lieu of tax credits 

(05/09)

o Completed the internal and external 

reviews for an NREL technical report, The 

Effects of the Financial Crisis on 

Photovoltaics: An Analysis of Changes in 

the Market Forecasts from 2008 to 2009

o Developed a gap analysis for the market 

transformation analysis effort with NREL. 

• Subtask #5: Assisted the Solar Program in 

planning the scope, schedule, and technical 

requirements of the 2009 Program Peer 

Review

o Finalized contact list for principal 

investigators (PIs)

o Prepared project feedback summary 

reports

• Subtask #6: Provided support for major market 

transformation activities including Solar 

America Cities, Education and Training, 

Codes and Standards, Solar America 

Showcase, and State and Utility Outreach

o Completed guide for Solar America Cities: 

Managing Solar in America’s Cities 

(12/08)

o Provided a speaker at the Intersolar 

Conference, who discussed the effect of 

codes and standards on the LCOE of 

solar systems (07/09)

o Led coordination of Solar America Cities 

2nd Annual Meeting 

o Led weekly calls on Cities and Showcase 

work (03/09)

o Participated in the Edison Electric Institute 

Annual Convention (06/09)

o Issued a notice of technical assistance for 

Solar America Showcase awards each 

quarter and reviewed project applications.

o Assisted the Market Transformation team 

and the National Association of 

Regulatory Commissioners (NARUC) with 

selection and management of technical 

assistance NREL provided to NARUC 

members (NARUC made nine awards in 

05/09). 

o Supported the Market Transformation 

team in issuing a funding opportunity 

announcement (FOA) for Solar America 

Cities Special Projects and Solar 

Workforce Development released 05/09–

08/09; reviewed subsequent responses to 

FOA.

• Subtask #7:Supported major CSP Program 

activities including the development of a 

Programmatic Environmental Impact 

Statement (PEIS), the development of a 

Congressionally directed Water Usage study, 

participation and review of the Western 

Governors’ Association activities, and 

development of the Program’s Technology 

Roadmap

o Created two CSP technical risk and 

uncertainty analysis documents for trough 

and tower technology (06/09)

o Participated in kickoff meeting for the 

ASME Performance Test Code for 

Concentrating Solar Power (07/09)

o Reviewed the Solar Program’s purpose 

and needs statement about the solar 

PEIS (03/09)

o Reviewed and provided feedback on the 

U.S. Bureau of Land Management (BLM) 

on solar companies’ development plans

for constructing utility-scale plants in the 

southwestern United States

o Supported the Solar Program’s

preparation and presentation to EERE 

management on the expanded initiative 

for the CSP Demonstration Project 

o Provided technical review for several 

funding opportunities for CSP 

technologies including ARPA-e, Loan 

D R A F T
Guarantee Program, Community Block 

Grants, and Small Business Innovation 

Research (SBIR) program.

3.2 Task #16

Provided technical support for stakeholder 

engagement activities and assisted in strategic 

planning activities for the Solar Program’s Grid 

Integration Program, as well as a DOE strategy 

document on interconnecting renewable energy 

systems onto the grid. Specific examples of some, 

but not all, accomplishments achieved under this 

task follow:

• Developed Renewable Systems Integration 

Program white paper (01/09)

• Conducted DOE Workshop on High 

Penetration of PV into the Distribution Grid 

(02/09)

• Prepared presentations for SEGIS-ES 

workshop (06/09)

• Completed draft report summarizing SEGISES workshop (07/09). 

3.3 Task #29

Provided technical support to the Solar Program 

2009 peer review organizer at HQ to achieve a 

well-organized, well-run, technically superior Solar 

Program peer review. Specific examples of some, 

but not all, accomplishments achieved under this 

task follow:

• Selected and confirmed chairperson and 

reviewers (01/09)

• Developed agenda and logistics for process 

(01/09–03/09)

• Facilitated and recorded peer review sessions 

(03/09)

3.4 Task #31

• Provided a marketing communication manager 

who met all Solar Program HQ 

communications needs and developed and 

identified communications and marketing 

opportunities. Specific examples of some, but 

not all, accomplishments achieved under this 

task follow: Directed Solar America Cities

(SAC) logo creation and development process 

(01/09)

• Provided SAC team members with new 

PowerPoint template slides (03/09)

• Collaborated with NREL and the DOE Golden

field office on development of the Solar 

Program’s Recovery page (04/09)

• Wrote numerous press releases for AARA 

FOAs (04/09)

3.5 Task #33

• Supported the Solar Program in monitoring 

technical progress and project costs. Enabled 

Solar Program staff members to more 

effectively monitor project information via 

access to critical, real-time information about 

their projects in EERE’s CPS. Specific 

examples of some, but not all, 

accomplishments achieved under this task 

follow: Provided technical input to Solar 

Program to coordinate and execute legislative 

requirements (05/09)

• Facilitated use of contacts database and 

provided training on its use (05/09)

• Provided program management and budget 

support to the Solar Program, including 

technical inputs for FY 2010 and ARRA 

financial planning and budget execution effort 

(09/09). 

4. Planned FY 2010 Activities

• Continue supporting the Solar Program’s goal 

of achieving cost competitiveness for PV and 

CSP technologies by 2015

• Continue providing technical support for 

stakeholder engagement activities

• Continue providing support for the DOE Solar 

Vision Study

• Continue providing strategic planning support 

and analyses for all subprograms Provide 

technical support for the Solar Program’s 2010 

peer review.

5. Major FY 2009 Publications

M. Coddington, B. Kroposki, T. Basso, K. Lynn, D. 

Sammon, M. Vaziri, and T. Yohn, “Photovoltaic 

Systems Interconnected onto Secondary 

Network Distribution Systems—Success 

Stories,” 34th IEEE Photovoltaic Specialists 

Conference, Philadelphia, June 7-12, 2009.

J.E. Bartlett, R.M. Margolis and C.E. Jennings, 

The Effects of the Financial Crisis on 

Photovoltaics: An Analysis of Changes in Market 

Forecasts from 2008 to 2009. Golden, CO: 

National Renewable Energy Laboratory 

D 

(September 2009).

R A F T
6. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal Investigator Location/E-mail Description/Title of Research Activity

FY 2009

($K)

Cost Share 

($K)

SENTECH Bethesda, MD 

jmcveigh@sentech.org Task #3/Assistance to SETP 2,256 0 

Antares Group, Inc. Landover, MD

kdegroat@antares.org

Task #29/SETP 2009 Peer 

Review 216 0 

BCS, Inc. Laurel, MD

kboras@bcs-hq.com

Task #33/Monitoring Technical 

Progress & Cost Support 120 0 

D R A F T
Sentech Programmatic Support

Performing Organization: Sentech, Inc.

Key Technical Contacts: Jim McVeigh, 240-223-5528, jmcveigh@sentech.org, 

Sarah Truitt, 240-223-5571, struitt@sentech.org

DOE HQ Technology Manager: John Lushetsky, 202-287-1685, john.lushetsky@ee.doe.gov

FY 2009 Budget: $615K on Business Administration support contract

____________________________________________________________________________________

Objectives

• Provide marketing and outreach support to the U.S. Department of Energy (DOE) Solar Energy 

Technologies Program (SETP) by preparing presentations and speeches, responding to 

controlled correspondence, updating Web sites, developing Webinars, creating outreach 

materials, supporting event logistics, and preparing for meetings and other outreach related 

activities. 

Accomplishments

• Supported the SETP Market Transformation team in addressing key industry issues to technology 

deployment with critical stakeholder audiences including state and local governments, workforce 

training and educational institutions, nationally recognized testing laboratories, and utilities

• Coordinated many internal and external SETP events and meetings including Solar Program 

Peer Review, Solar America Cities Annual Meeting, Tiger Team Retreats, and High Penetration 

Workshops. 

Future Directions

• Continue to support SETP in its endeavor to reduce solar technology system costs, increase 

efficiency, and address barriers to the widespread adoption of solar energy technologies

• Continue to provide logistical support for SETP meetings and events. 

____________________________________________________________________________________

1. Introduction

In fiscal year (FY) 2009, SENTECH provided 

administrative, programmatic, technical, and 

analytical support services to DOE’s SETP. In 

addition to providing overall support for SETP 

program management, communications, and 

administration, SENTECH supported multiple 

areas of SETP, including Budget and Operations, 

Market Transformation, and Concentrating Solar 

Power (CSP). 

2. Technical Approach

SENTECH provided turnkey support services in 

the areas of program administration, Web site 

development, meeting and event coordination, and 

communications and outreach. 

SENTECH partnered with Project Performance 

Corporation (PPC) to provide Web development 

services, Courtesy Associates for meeting and 

event logistics, and Christina VanVleck for 

graphics design services. 

SENTECH provided six full-time staff members 

dedicated to supporting various areas of SETP, 

including Budget, Planning and Operations, CSP, 

and Market Transformation. SENTECH also 

provided four part-time staffers to support SETP 

communications and analyses tasks. Half of the 

contractors who provided support hold an 

advanced degree in engineering, business, or 

public administration and policy. A majority of 

SENTECH contractors were co-located at DOE to 

facilitate responsive, on-site support to federal 

staff. 

3. Results and Accomplishments

Because SENTECH staff members assist DOE in 

carrying out activities to meet programmatic goals, 

our major accomplishments mirror those of 

SETP. Highlights from our support in FY 2009 are 

listed below:

D R A F T
3.1 Technical Outreach Support 

• Coordinated the peer review process for the 

American Recovery and Reinvestment Act of 

2009 (the Recovery Act) FOAs and SBIR 

phase I funding round 

• Provided content development, review, and 

project management for publications 

throughout the year, including Use of 

Municipal Assistance Programs to Advance 

the Adoption of Solar Energy Technologies,

published by the American Solar Energy 

Society (ASES) in May 2009 and Solar 

Powering Your Community: A Guide for Local 

Governments, published by SETP in July 2009

• Provided volunteer assistance as technology 

experts and VIP tour guides for the 2009 Solar 

Decathlon

• Represented SETP at numerous Solar 

America Cities (SAC) Program ribbon cutting 

and media events and staffed exhibit booths at 

numerous conferences.

3.2 Communications and Administrative Work

• Developed or modified Web site content for 

Market Transformation pages on EERE Web 

site 

• Compiled, edited, and distributed the SETP 

quarterly newsletter and SAC e-bulletin 

• Developed and maintained SAC public Web 

site and intranet portal

• Wrote press releases and progress alerts for 

SETP, assisted with controlled 

correspondence and budget tracking. 

3.3 Meeting and Event Coordination 

• High Penetration Workshop (02/09)

• Solar Program Peer Review (03/09)

• SAC Annual Meeting (04/09) 

• SAC Train the Trainers Workshop (07/09)

• Market Transformation Analysis Meeting 

(09/09)

• Workforce Development/SAC Special Projects 

Merit Review (08/09).

4. Planned FY 2010 Activities

SENTECH will continue to support SETP in 

advancing solar technology, industry, and market 

development. SENTECH will provide 

administrative, analytical, and technical support to 

federal staff. 

5. Major FY 2009 Publications

K. Lynn and S. Truitt, Use of Municipal Assistance 

Programs to Advance the Adoption of Solar 

Technologies, American Solar Energy Society 

(ASES) May 13-15, Buffalo, NY, 2009. 

6. University and Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Organization/

Principal 

Investigator

Location/E-mail Description/Title of 

Research Activity

FY 2009

($K)

Courtesy 

Associates

Washington, DC

lthornton@courtesyassociates.com

Meeting and event 

logistics coordination 235

PPC McLean, VA

Janis.adkins@ppc.com

Web site development 

services 200

Christina 

VanVleck (Graphic 

Designer)

Boston, MA

vanvleck@rcn.com 

Graphics design 

services.

D 

20 

R A F T
CSP Capital Equipment & Facilities

Performing Organizations: Sandia National Laboratories (SNL)

National Renewable Energy Laboratory (NREL)

 

Key Technical Contacts: Mark S. Mehos (NREL), 303-384-7458, mark.mehos@nrel.gov

Thomas Mancini (SNL), 505-844-8643, trmanci@sandia.gov

Joe Tillerson (SNL), 505-844-1806, jrtille@sandia.gov 

DOE HQ Technology Manager: Tommy Rueckert, 202-586-0942, Thomas.Rueckert@ee.doe.gov 

FY 2009 Budgets: $800K (SNL), $200K (NREL)

____________________________________________________________________________________

Objectives

• Maintain core capabilities of the Concentrating Solar Power (CSP) Program through operation 

and maintenance of the NREL and SNL CSP research facilities

• Maintain safe operational conditions for the test facilities at NREL and SNL

• Build advanced capabilities at NREL and at SNL’s National Solar Thermal Test Facility (NSTTF) 

using funding from the American Recovery and Reinvestment Act of 2009 (the Recovery Act). 

Accomplishments

• Achieved Nationally Recognized Testing Laboratory (NRTL) compliance for 95% of the NSTTF

site (SNL)

• Developed a detailed plan for Recovery Act funding (SNL)

• Awarded Recovery Act funds through competitive call for laboratory test and evaluation and 

storage concepts (NREL). 

Future Directions

• Begin major upgrades in facilities at the NSTTF in fiscal year (FY) 2009 (SNL)

• Complete NRTL compliance for Central Receiver Test Facility (CRTF) heliostat field and a few 

other outstanding pieces of equipment (SNL)

• Expand recapitalization plan from equipment to cover facilities, ensuring preparedness for 

upcoming R&D opportunities and challenges (SNL)

• Continue to replace aging and largely unserviceable equipment (SNL and NREL)

• Complete fabrication of optical test and thermal storage test labs at Energy Systems Integration 

Facility (ESIF;NREL)

• Complete construction of pilot-scale thermal energy storage test facility at SolarTAC (NREL)

• Complete upgrade of High Flux Solar Furnace (HFSF) test facility (NREL). 

____________________________________________________________________________________

1. Introduction

DOE uses the test facilities at SNL and NREL 

extensively for evaluating CSP components and 

systems. SNL’s facilities include a 5-MWth CRTF,

a 75-kWth solar furnace, a rotational facility for 

testing trough collectors over their operating 

temperature range, an engine test facility, a dish 

test facility, and associated data acquisition and 

technical test equipment needed by the 

technicians who support the evaluations. NREL’s

facilities include several optical materials research 

laboratories, an optical systems characterization 

laboratory, a thermal storage materials laboratory, 

a large-payload two-axis tracker for testing 

parabolic trough performance, and an HFSF. SNL 

and NREL are responsible for maintaining worldclass testing and evaluation capabilities for use by 

DOE and the CSP industry. 

2. Technical Approach

2.1 Operations

Ongoing activities at the NSTTF and NREL 

laboratory and test facilities include safety and 

readiness testing and inspection associated with 

chemicals, confined spaces, cranes and rigging, 

electricity, environmental management and 

D R A F T
regulations, evacuation, fire, hazardous waste, 

hoisting and rigging, lasers, local exhaust 

ventilation, lockout/tagout, machine shops, 

respiratory and hearing protection, compliance 

reviews, corporate stand-downs, and property 

inventory. General activities include maintaining

OUO, site and computer security, safety, monitor 

site access, coordinate maintenance and 

deliveries, Foreign Corrupt Practices Act, 

counterintelligence, EEO/AA, ethics, drug free 

workplace, export control, property, diversity, 

annual review of site security plan, SNL satellite 

badge office, process foreign national requests, 

coordinate tours, and process after-hours access. 

2.2 NRTL Certification at the NSTTF

All NREL and SNL facilities must be certified as 

NRTL compliant. Much of the equipment installed 

at the NSTTF is one of a kind or built specifically 

to meet a particular test requirement. 

Consequently, a large part of test and operations 

equipment had never been tested or certified by 

an NRTL. At this point, however, virtually all of the 

equipment has been evaluated and certified as 

compliant.

3. Results and Accomplishments

SNL accomplished the following at the NSTTF: 

• Upgraded motors and controls on the heliostat 

field

• Continued testing ten 25-kW Stirling Energy 

Systems (SES) dish Stirling systems

• Continued testing of four 3-kW Infinia dish 

Stirling systems

• Disassembled old molten-salt test facility

• Started testing the SkyFuel SkyTroughTM

• Installed and tested PWR heliostat 

NREL accomplished the following facilities-related 

work:

• Completed advanced thermal storage 

materials characterization laboratory 

• Awarded Recovery Act funds through 

competitive call for laboratory test and 

evaluation and storage concepts

• Tested SkyFuel and Acciona collectors

• Tested Schott and Solel heat-collection 

elements

• Tested advanced polymer and glass mirror 

samples and facets. 

4. Planned FY 2010 Activities

NREL and SNL will continue ongoing testing and 

facilities upgrades: Specifically, we will

• Continue testing of SES and Infinia dish 

Stirling Systems

• Continue testing of the PWR heliostat

• Complete testing of the SkyTrough

• Conduct design testing of PWR receiver panel

• Complete testing of SkyFuel, Alcoa, and 

Abengoa advanced collector designs 

• Complete testing of alternative mirror facets 

designs supplied by Rioglass, Guardian 

Industries, and PPG.

• Implement upgrades associated with 

Recovery Act funding. 

D R A F T
Communications

Performing Organization: National Renewable Energy Laboratory (NREL)

 

Key Technical Contact: Terri Jones (NREL), 303-275-4217, terri.jones@nrel.gov

 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, thomas.rueckert@ee.doe.gov

FY 2009 Budget: $834K (NREL)

____________________________________________________________________________________

Objective

• Provide communications strategy, execution, production, and evaluation to meet the 

communications needs of the Solar Energy Technologies Program (SETP). 

Accomplishments

• Made improvements to, updated, and maintained SETP Web site (approximately 300 pages and 

1,000 files) with changes to better reflect the current activities and increase usability. 

• Produced eight new documents, including the FY 2008 SETP Annual Report, and contributed to 

programmatic documents, such as the quarterly newsletter. 

• Represented the program at the International Builders’ Show (IBS) and the National Conference 

of State Legislators, completed all preparations for the Solar Power International conference, and 

provided communication support for the first annual Utility Solar Conference. 

Future Directions

• Conduct strategic planning to ensure communications tactics meet the most current and essential 

needs of the program. 

• Conduct usability studies with key stakeholders within the industry to assess their needs and 

subsequently make significant changes to the Web site to better meet those needs. 

• Evaluate efficacy of and make changes to exhibiting activities to ensure current needs of the 

program are being met. 

• Support Market Transformation to ensure that critical information about these activities is 

captured and available to its stakeholders, so they can better emulate these activities within their 

sphere of influence.

• Enhance support of Photovoltaic, Concentrating Solar Power, and Systems Integration

subprograms: target specific conferences, develop new exhibits, and create outreach materials.

____________________________________________________________________________________

1. Introduction

NREL provides comprehensive communications 

services to SETP including: 

• Strategic planning to ensure specific activities 

are necessary and conducted in the most 

cost-effective and efficient way possible. 

• Writing, designing, and producing print 

products for programmatic, technical, and 

outreach audiences. 

• Exhibit planning, design, and staffing. 

• Web site development and maintenance. 

• Communications consulting for partners who 

do not have expertise available.

2. Results and Accomplishments

Core/Cross-Cutting

• Produced FY 2008 SETP Annual Report, 

coordinating individual reports on all SETP 

activities. Edited, produced, printed, and 

distributed the report.

• Developed a new fact sheet for utilities and 

distributed an e-blast to attendees of the first 

annual Solar Energy Power Association's 

Utility Solar Conference, which the Solar 

Program co-sponsored.

• Managed program presence at Solar Power 

International, which included creating new fact 

sheets, producing an updated exhibit, and 

coordinating booth staffing. 

• Added a new rotating flash feature on the 

SETP home page to promote key activities.

D R A F T
• Established two new mechanisms to increase 

awareness of solar financial opportunities on 

the Web site: an RSS feed and email 

subscription. 

• Responded to ~100 Webmaster inquiries from 

a wide range of users and developed a 

comprehensive maintenance plan to ensure 

every Web page is updated regularly. 

Completed ongoing posting requests such as 

funding announcements.

• Developed new Systems Integration content 

on the SETP Web site to better represent the 

program activities. 

• Launched two new Web pages, under the 

direction of EERE, on the solar projects 

funded by the American Recovery and 

Reinvestment Act and the Solar Program’s 

Planning, Implementation, and Results. 

• Provided editorial and graphical support to

technical publications, concept papers, and 

reports.

Market Transformation

• Promoted benefits of incorporating solar in 

new home construction at IBS. SETP 

exhibited along with other federal agencies in 

a larger pavilion, entitled “Ask the Experts.” 

With more than 60,000 IBS attendees, the 

pavilion garnered new leads from attendees 

interested in solar. One new publication was

produced for the builder audience. 

• Supported Solar America Cities (SACs) and 

Solar America Showcases (SASs) in a variety 

of ways. Updated Web content timed to go live 

with the Secretary’s announcements of solar 

awardees. Developed publications to assist 

cities in understanding the technical 

assistance process.

• Collaborated with other SETP staff and 

contractors to develop a unique brand/identity 

for SACs, produced guidance for use of the 

brand both internally and externally, and 

presented the brand at SAC’s Annual Meeting.

• Produced a 100-page guide, in collaboration

with the Market Transformation Team, that 

helps state and local governments develop 

and implement solar programs, titled “Solar 

Powering Your Community: Guide for Local 

Governments.” 

• Collaborated with Market Transformation 

partners to develop “histories” publications to 

highlight the evolution of the Solar Program’s 

involvement in each of the 25 SACs (i.e., one 

for each city and one for SACs overall). 

• Served as a solar expert for the program 

booth at the National Conference of State 

Legislators. 

Fig. 1. The Annual Report was a key publication.

3. Major FY 2009 Products

Web site: www.solar.energy.gov 

Publications: 

• “A Homebuilders Guide to Going Solar,” 

www.solar.energy.gov/pdfs/44792.pdf 

• “Advancing Clean Energy,”

www.eere.energy.gov/office_eere/pdfs/solar_f

s.pdf 

• “Solar Energy Technologies Program: 

Photovoltaics” fact sheet, 

www.solar.energy.gov/pdfs/46660.pdf 

• “Solar Energy Technologies Program: 

Concentrating Solar Power” fact sheet, 

www.solar.energy.gov/pdfs/46661.pdf 

• “Solar Energy Technologies Program: Market 

Transformation” fact sheet, 

www.solar.energy.gov/pdfs/46662.pdf 

• “Solar Energy Technologies Program: 

Systems Integration” fact sheet, 

www.solar.energy.gov/pdfs/46663.pdf 

• “Solar: A Clean Energy Source for Utilities” 

fact sheet, 

www.solar.energy.gov/pdfs/46259.pdf

• “Solar America Cities Awards” fact sheet; 

DOE/GO-102009-2825. 

• “Solar Powering Your Community: Guide for 

Local Governments,” 

www.solaramericacities.energy.gov/pdfs/Solar

-Powering-Your-Community-Guide-For-LocalGovernments.pdf

D R A F T
International Activities

Performing Organizations: National Renewable Energy Laboratory (NREL)

 Sandia National Laboratories (SNL)

 

Key Technical Contacts: Carol Anna (NREL), 303-275-3655, carol.anna@nrel.gov 

Tom Mancini (SNL), 505-844-8643, trmanci@sandia.gov

 

DOE HQ Technology Manager: Kathleen Bolcar, 202-586-2820, kathleen.bolcar@hq.doe.gov 

FY 2009 Budgets: $188K (NREL), $100K (SNL) 

____________________________________________________________________________________

Objectives

International Energy Agency (IEA) Photovoltaic Power Systems (PVPS) Programme

• Act as operating agent for Task 10, Urban Scale PV Applications

• Represent the United States in Task 1, Exchange and Dissemination of Information on PVPS

• Organize or participate in meetings and workshops and submit deliverables as required by the 

membership agreement. 

IEA Concentrating Solar Power (CSP) Solar Power and Chemical Energy Systems (SolarPACES) 

• Provide operating agent for implementing agreement

• Coordinate activities of Task 1, CSP Electric Power Systems

• Organize and chair two meetings.

Accomplishments

PVPS Programme

• Produced the U.S. content for the Photovoltaic Power Systems Programme Annual Report 2008

and the National Survey Report of PV Power Applications in the United States 2008 (Task 1)

• Represented the United States at the Task 1 Experts Meeting in Kota Kinabalu, Sabah, Malaysia

(Task 1) 

• Represented the United States at Executive Committee and operating agent meetings in Vienna, 

Austria, and Lisbon, Portugal; and technical expert meetings in Sydney, Australia, and Rome, 

Italy (Task 10). 

CSP SolarPACES

• Completed and submitted annual report

• Completed the IEA’s midterm review of SolarPACES. 

Future Directions

• Complete 2009 IEA PVPS Annual Report and 2009 National Survey Report (Task 1) 

• Support IEA PVPS Web site activities and disseminate information to U.S. audiences (Task 1)

• Attend Task 1 meetings in Seville, Spain

• Close out Task 10 activities

• Complete review and revision of the implementing agreement. 

____________________________________________________________________________________

1. Major FY 2009 Publications

IEA PVPS. Photovoltaic Power Systems 

Programme Annual Report 2008 (April 2009). 

Available at http://www.ieapvps.org/products/download/rep_ar08.pdf, 

accessed March 2010.

. 

IEA PVPS. National Survey Report of PV Power 

Applications in the United States 2008 (June 

2009). Available at http://www.ieapvps.org/countries/download/nsr08/NSR%20US

A%202008.pdf, accessed March 2010.

SolarPACES Semi-Annual Review, October 

D 

2009, Stockholm, Sweden.

R A F T
Small Business Innovation Research

Performing Organization: DOE Solar Energy Technologies Program (SETP) 

DOE HQ Technology Manager: Alec Bulawka, 202-586-5633, alec.bulawka@ee.doe.gov

FY 2009 Budget: $12,000K

____________________________________________________________________________________

Objectives

• Support small business energy R&D

• Implement Executive Order 13329, which involves assisting the private sector in manufacturing 

innovation

• Continue to pursue wise cost/benefit investments

• Augment the core research of the U.S. Department of Energy (DOE) SETP

• Effectively support American Recovery and Reinvestment Act of 2009 (Recovery Act) initiatives.

Accomplishments

• Increased the efficiency of existing multijunction (MJ) cells with a solar concentrating coating that 

focuses incoming sunlight to the appropriate junction

• Solved the problem of encapsulation coatings with a material matrix, resulting in a polymer-based 

glass-like sol-gel high barrier coating against oxygen and water penetration

• Recycled swarf from slicing silicon using fixed abrasive slicing technology (FAST) to reduce 

waste and increase silicon supply

• Developed lightweight, mechanically robust, highly reflective membrane materials and 

environmental coating materials for antireflective, self-cleaning mirror surfaces

• Developed a photovoltaic (PV) manufacturing diagnostic system using hyperspecial imaging 

techniques enabling fast, in-line PV diagnostics

• Developed fast, real-time diagnostics of mechanically fragile silicon (Si) wafers and cell for PV 

production

• Using Al, Cu and Ni nanoparticle inks; increased control over film thickness and conductivity 

compared with conventional screen-print pastes

• Developed first-of-a-kind “flat-plate” high-concentration PV panel based on III-V cells with novel 

optical design and flattening concentrator structure to a panel

• Synthesized and tested new fullerene derivatives for use in bulk heterojunction organic PV (BHJ 

OPV), incorporation of electron-rich atoms to increase power conversion efficiency.

Future Directions

• Enter solar cell original equipment manufacturing (OEM) market in 2012

• Develop promising coating technology that will prolong the life of existing and future flexible solar 

cells without impeding efficiency

• Demonstrate ability to convert FAST swarf to high-quality Si feedstock, and demonstrate FAST

ability to slice Si

• Improve reflectivity of flexible mirrors by 2% and increase spectral bandwidth to include ultraviolet

• Achieve a 5% improvement in PV yield (through diagnostics) with a potential annual savings of 

about $300 million 

• Continue to study ultrasonic resonance vibrations diagnostic methodology, which will improve 

solar cell and module manufacturers 

• Expect potential increases in efficiency through reduced front shadowing and lower Si-PV cost 

through material waste reduction, thinner substrates, and increased yield

• Create a prototype CPV system with a potential of lowest levelized cost of energy (LCOE) on the 

market with higher efficiency and lower cost/footprint than conventional PV panels, utility-scale 

and rooftop potential

D R A F T
• Develop new fullerene derivatives in bulk heterojunction OPV, approaching an 8% to 10% 

efficient laboratory device. 

____________________________________________________________________________________

1. Introduction

Solar energy is our largest energy resource and 

can provide clean, sustainable energy supplies, 

including electricity, fuels, and thermal energy. 

The Recovery Act) emphasized solar energy, 

among others, as a key element in combating 

global climate change. The cost-effective capture 

of the enormous solar resource is, however, 

problematic. The Small Business Innovation 

Research (SBIR) Program seeks to develop novel, 

commercially feasible solar systems and 

production techniques. As such, SETP is 

submitting an unprecedented extensive topic and 

subtopic opportunity to the small business 

community. These topics emphasize novel, 

previously untried but commercially feasible solar 

concepts and devices.

Each year, 10 federal departments and agencies, 

including DOE, are required by the SBIR Program 

to reserve a portion of their R&D funds for award 

to small, U.S.-owned businesses. Over the life of 

the SBIR Program, the DOE Solar Energy 

Technologies Program has contributed $20 million 

and received $53 million in research funding. Last 

year, because of ARRA funding, the return on 

investment was exceptionally significant.

As in the past, the Solar Program also benefited to 

a large extent this past year from the Office of 

Basic Energy Sciences contribution, again mostly 

in nanotechnology topics for PV in 2008. The 2009 

Solar Program is nested mainly in the Advanced 

Solar Technology (Topic 8) SBIR-Recovery Act 

category as well as the conventional annual 

solicitation. Once again, the SBIR activities 

complement the DOE Solar Program multi-year 

technical plan because they continue to augment 

and support the core program, in all respects, with 

integrated solutions from the vast U.S. small 

business community. Based on an unprecedented 

return response volume to the ARRA solicitation, 

the community is involved very actively in the 

President’s ARRA Initiative.

2. Technical Approach

Renewable energy technologies, as before, have 

achieved significant advances in recent years, but 

further improvements are needed if they are to 

reach their full potential. The solar technologies 

included in the scope of this SBIR work involve 

solar electric, PV, and concentrating solar power 

(CSP) systems as well as solar-assisted alternate 

fuel generation. Much activity has also focused on 

organic material improvement. Grant applications 

for FY 2009 (in two separate solicitations) were 

required to clearly demonstrate the applicants’ 

ability to proceed to hardware development 

fabrication, testing, and manufacture of 

technologies.

3. Results and Accomplishments

More than ever before, SBIR awards advanced 

their goals and produced very encouraging results 

of their R&D to date (see Section 6 table).

4. Planned FY 2010 Activities

Further development of PV and CSP systems, as 

well as systems integration, will be accomplished 

through creative and innovative approaches in 

engineering and design, new materials, alternative 

fuels, and new processes. Much attention has 

been given to accelerate the idea of production 

and manufacture.

4.1 Hybrid Solar Energy Systems —Combination 

of PV, Solar Heat, and/or Solar Cooling

Hybrid solar technologies, which combine 

electrical and thermal power generation, promise 

to significantly increase the total operating 

efficiency of solar panels and reduce system costs 

and size where the cogeneration of heat and 

electrical power is needed. This approach also 

offers a variety of secondary benefits such as load 

shifting (e.g., thermal cooling, electrical/thermal 

ratio adjustment) and synergistic performance 

benefits (e.g., allowing cells to run cooler, 

removing snow melting). Currently, solar water 

heating is funded in the Building Technologies 

Program and PV technologies are funded through 

the Solar Program. This category enables crosscutting applications, which are currently not 

fundable under EERE.

4.2 Innovative Applications of Solar Energy for 

Fuels and Industrial Processes, Not Electricity, 

HVAC, or Residential Water Heating 

Solar energy can be used to produce fuels or to 

power industrial processes. Production of fuels 

allows solar energy to be stored and used at 

D R A F T
controlled times and places. Much research has 

been done by the international community in such 

production, with, as yet, no cost-effective 

technology found. For industrial processes, only a 

few large solar-powered systems are in use 

worldwide, even though among industry, 

transportation, household, and service sectors in

the developed world, industry has the highest 

share of energy consumption. Innovative design 

and development of solar-powered systems that 

either produce fuels or power industrial processes 

is highly desirable.

4.3 CSP Systems for Distributed Applications 

The CSP subprogram focuses on large-scale 

systems that can supply power on demand. There 

is also a market for smaller scale CSP 

technologies, however, that can supply power for 

residential and commercial applications. These 

could be either rooftop community based systems 

that do not require a lot of land and can be sited 

close to load centers. System design would be 

undertaken in Phase 1 and move on to prototype 

scale in Phase 2.

4.4 Organic PV and Nanotech/Photonics 

Concise methods and subassemblies for largescale, molecular manufacturing of fullerenic and 

other dopant material for organic semiconductors, 

specifically for PV, are being pursued. Variations 

on the theme are welcome whereby 

nanotechniques will also be explored and pursued 

that contribute to increasing the efficiency of 

organic PV beyond the 10% level, thereby leading 

to cost-effectiveness and commercial viability. 

Material nanotransformational contributory 

techniques and passive photonic nanoparticle/crystal augmentation are sought likewise.

4.5 Manufacturing Tools for Reliability Testing

Tools to conduct reliability testing in PV module 

manufacturing environments can be developed. 

For example, tools such as light soaking 

equipment are used to prepare modules or 

components for accelerated lifetime testing, which 

is frequently conducted in-house at the module 

manufacturing facility or by service companies 

before sending for official third party certification. 

New tools are needed for the testing components 

(e.g., modules, inverters) or subcomponents (e.g., 

cells, microinverters, individual layers of a 

module), and should combine high performance, 

low cost, and a small floor footprint.

4.6 Module and System Manufacturing Metrology 

and Process Control

The rapid scale-up of the manufacturing of PV, 

particularly for new thin-film technologies, is 

challenging the possibility of using conventional 

technologies to make real-time non-destructive 

measurements of material characteristics in highvolume, high-production-rate environments and 

then using this information to implement real-time 

process control of the manufacturing process. The 

development of novel, advanced, real-time nondestructive materials characterization tools for use 

in high-volume manufacturing lines for PV systems 

is thus essential.

4.7 PV System Diagnostic Tools 

The current rapid growth of the PV industry has 

led to diverse and innovative product designs, 

which frequently require non-traditional tests for 

reliability and performance. Examples of these 

non-traditional tests include performance testing 

and tracking requirements for concentrating PV 

modules, and software-based system diagnostic 

tools. Innovative methods are needed to monitor 

PV system and component performance in order 

to identify failures and loss mechanisms and to 

minimize system down time. Approaches of 

interest include the development of diagnostic 

tools that are process-oriented and internal to the 

system components, or those that can be 

integrated—i.e., “piggy-backed”—through ancillary 

application.

5. Major FY 2009 Publications

SBIR holds the awardees responsible for a final 

report at the end of both Phase 1 and Phase 2. 

The SBIR Office in Germantown, MD, has the final 

reports for all projects awarded in the past.

6. Industry Partners

The following organizations partnered in the project’s research activities during FY 2009.

Company Name Company Address Amount PI Title

Nanosolar, Inc. 2440 Embarcadero Way,

Palo Alto, CA 94303

750,000 Chris Eberspacher Printed Solar Cell Using 

Nanostructured Ink

D R A F T
Company Name Company Address Amount PI Title

TDA Research, 

Inc.

12345 W. 52nd Ave., Wheat 

Ridge, CO 80033-1916

750,000 Michael D. Diener Improved Fullerenes for OPV

NanoSonic, Inc. 1485 South Main Street,

Blacksburg, VA 24060-5556

750,000 Michelle Berg High Performance, Low-Cost 

Nanostructured Mirror 

Surfaces

Midwest 

Optoelectronics, 

LLC

2600 Dorr Street, Toledo, 

OH 43607

746,325 Aarohi S. Vijh Novel Interconnection Process 

for Lightweight Flexible 

Photovoltaic Modules

Luminit, LLC 1850 W. 205 Street,

Torrance, CA 90501-1526

750,000 Kevin Yu Flexible Spectrum Splitting 

Holographic Concentrator

SVV Technology 

Innovations, Inc.

10027 E. Taron Dr., Elk 

Grove, CA 95757-8190

749,882 Sergiy Vasylyev High Performance PV 

Concentrator

Luna Innovations 

Incorporated

1 Riverside Circle, Suite 

400, Roanoke, VA 24016-

4962

749,993 Kevin Flanagan High-Throughput In-Line PV 

Manufacturing Diagnostic 

System

Ultrasonic 

Technologies, 

Inc.

3650 Spectrum Boulevard,

Suite 170, Tampa, FL 

33612-9446

737,279 Sergei Ostapenko In-line Crack Detection in 

Silicon Solar Cell Production 

Using Resonance Ultrasonic 

Vibrations

Applied 

Nanotech, Inc.

3006 Longhorn Blvd., Suite 

107, Austin, TX 78758-7631

749,997 James Novak Non-Contact, Printable Metallic 

Inks for Silicon Solar Cells

Luminit, LLC 1850 W. 205 Street, 

Torrance, CA 90501-1526

750,000 Kevin Yu Multifunctional UV Curable 

Sol-Gel Organic Hybrid 

Nanocomposite Encapsulation 

System

Crystal Systems, 

Inc.

27 Congress Street, Salem, 

MA 01970

745,586 David Brian Joyce Material Utilization and Waste 

Reduction through Kerf 

Recycling

Gratings, Inc. 2655A Pan American 

Freeway NW, Albuquerque, 

NM 87107-1639

100,000 Saleem H. Zaidi Microstructured Crystalline 

Silicon Thin-Film Solar Cells

Luna Innovations 

Incorporated

1 Riverside Circle, Suite 

400, Roanoke, VA 24016-

4962

99,981 Martin Drees Highly Efficient Organic Solar 

Cells Using Low Band Gap 

Polymers and Novel Acceptor 

Materials

TDA Research, 

Inc.

12345 W. 52nd Ave., Wheat 

Ridge, CO 80033-1916

100,000 Michael D. Diener A New Three-Part Architecture 

for Efficient and Stable Bulk 

Heterojunction OPV Devices

Aspen Aerogels, 

Inc.

30 Forbes Road, Bldg, B,

Northborough, MA 01532-

2501

100,000 Roxanna Trifu Transparent Aerogel Insulation 

for Solar Heat Concentration 

Elements

NanoSonic, Inc. 1485 South Main Street, 

Blacksburg, VA 24060-5556

100,000 Michelle Berg Low-Cost Solar Coatings for 

Improved Thermal 

Performance of Components 

in Concentrating Solar Power 

Systems

ReflecTech 18200 West Highway 72,

Arvada, CO 80007

99,964 Randy Gee Low-Cost, Durable, HighPerformance Reflectors for 

Utility-Scale Solar Thermal 

Energy Collection

D R A F T
Company Name Company Address Amount PI Title

SVV Technology 

Innovations, Inc.

10027 E. Taron Dr., Elk 

Grove, CA 95757-8190

99,997 Viktor Vasylyev Concentrator PV Receiver 

Based on Crystalline Si Cells

MicroLink 

Devices

6457 West Howard St.,

Niles, IL 60714-3301

100,000 Chris Youtsey Backside Contact Multijunction 

Solar Cells for Concentrator 

Applications

Fractal Systems 

Inc.

108 4th Street, Belleair 

Beach, FL 33786-3213 

149,718 Matt Aldissi Recovery Act— Enhanced 

Charge Transport towards 

High Efficiency Organic 

Photovoltaics 

SVV Technology 

Innovations, Inc.

10027 E. Taron Dr., Elk 

Grove, CA 95757-8190 

95,929 Viktor Vasylyev Recovery Act—Hybrid SlatArray PV System with Thermal 

Co-Generation 

Plextronics, Inc. 2180 William Pitt Way, 

Pittsburgh, PA 15238-1357 

150,000 Shawn Williams Recovery Act—High 

Performance Organic 

Photovoltaics via Novel 

Materials Combinations 

Cobb Design Inc. 2595 27th Avenue. North 

Saint Petersburg, FL 33713-

3934

145,472 William Cobb, Jr. Recovery Act— Design and 

Demonstration of a Solar Array 

for a Modular Distributed 

Concentrating Solar Power 

(CSP) System

Weidlinger 

Associates, Inc.

375 Hudson Street. New 

York, NY 10014-3656 

149,041 Huiming Yin Recovery Act—Hybrid Building 

Integrated Solar Energy 

System for Photovoltaic, 

Thermoelectric, and Heat 

Utilization

Versatilis LLC 488 Ridgefield Road,

Shelburne, VT 05482-6311 

150,000 George A. Powch Recovery Act—Electret Field 

Enhanced Organic Solar Cells 

Physical 

Sciences Inc.

20 New England Business 

Center, Andover, MA 01810-

1077

149,816 Juan Montoya Recovery Act—SolarFlex 

(Surface Plasmon Energy 

Trapping on Organic Solar 

Cell) 

Physical Optics

Corporation

20600 Gramercy Place, 

Bldg. 100. Torrance, CA 

90501-1821 

149,987 Xiaowei Xia Recovery Act— Hybrid 

Electrical And Thermal Energy 

System 

Luna Innovations 

Incorporated

1 Riverside Circle, Suite 

400. Roanoke, VA 24016-

4962 

150,000 Steve Joslin Recovery Act—Advancement 

of Nano-Material Production 

for OPV Acceptors 

Nano-C, Inc. 33 Southwest Park, 

Westwood, MA 02090-1524 

148,771 Henning Richter Recovery Act—

Nanocomposite Structures for 

OPV Devices 

Structured 

Materials 

Industries, Inc.

201 Circle Drive North, Unit 

102, Piscataway, NJ 08854-

3723

150,000 Gary S. Tompa Recovery Act—

ZnO/ZnS/P3HT Core-Shell 

Heterostructure Organic 

Hybrid Solar Cells 

Luminit, LLC 1850 W. 205 Street, 

Torrance, CA 90501-1526 

149,999 Kevin Yu Recovery Act—Solar 

Photovoltaic Holographic 

Cogeneration System 

Giner 

Electrochemical 

Systems, LLC

89 Rumford Avenue, 

Newton, MA 02466-1311 

149,684 Simon G. Stone Recovery Act—Advanced 

Membrane Technology for the 

Hybrid Sulfur Process 

Electrolyzer 

D R A F T
Company Name Company Address Amount PI Title

Asylum 

Research 

Corporation

6310 Hollister Ave., Santa 

Barbara, CA 93117-3115 

146,777 Roger Proksch Recovery Act—Nanoscale 

Probe System for Organic 

Photovoltaics 

Covalent Solar, 

Inc.

1 Broadway, 14th Floor,

Cambridge, MA 02142-1187 

149,813 Jon Mapel Recovery Act—Organic Solar 

Concentrators for Low-Cost 

Solar Power Generation 

InnoSense LLC 2531 W. 237th Street, Suite 

127, Torrance, CA 90505-

5245 

150,000 Uma Sampathkumaran Recovery Act—Nanostructured 

Photovoltaic Device 

Solarno Inc. 153 Hollywood Dr., Coppell, 

TX 75019-7306 

149,000 Anvar Zakhidov Recovery Act—Parallel 

Tandem Organic Solar Cells 

with Carbon Nanotube Sheet 

Interlayers 

Physical Optics 

Corporation

20600 Gramercy Place, 

Bldg. 100. Torrance, CA 

90501-1821 

149,989 Juan Hodelin Recovery Act—Thermally 

Assisted Photoelectrochemical 

Hydrogen Generation using a 

Holographic Concentrator

Phasiks, Inc. 10842 Noel St., Suite 106. 

Los Alamitos, CA 90720 

150,000 Richard Welle Recovery Act—Segmented 

Fresnel CSP for Community 

and Business Applications 

D R A F T
Solar Congressional Earmarks

Performing Organizations: CEC Stuyvesant Cove, Inc. (CEC); CENTRIA, Inc.; Crowder College; 

Eikos, Inc.; Greenfield Community College; Nevada Institute for 

Renewable Energy Commercialization (NIREC); North Dakota State 

University (NDSU); Nye County, NV; Regents of New Mexico State 

University (NMSU); Rural Development, Inc.; San Francisco Public 

Utilities Commission (SFPUC); The Solar Energy Consortium (TSEC): 

University of Arizona; University of Arkansas at Little Rock (UALR); 

University of Hartford; University of Louisville Research Foundation, Inc.; 

University of Nebraska at Kearney; University of Nevada, Las Vegas

(UNLV) Research Foundation; Bexar County; Utah State University

USU); Omega Optical, Inc.; City of Beacon, NY; St. Clair Community 

College; Vermont Department of Education; Salt Lake County.

 

Key Technical Contacts: Carolyn Elam (DOE/GO, Primary Contact), 303-275-4953, 

carolyn.elam@go.doe.gov 

Stephanie Sung (DOE/GO), 303-275-4899, stephanie.sung@go.doe.gov 

Joe Lucas (DOE/GO), 303-275-4849, joe.lucas@go.doe.gov 

Steve Palmeri (DOE/GO), 303-275-4832, steve.palmeri@go.doe.gov 

Jim Payne (DOE/GO), 303-275-4756, jim.payne@go.doe.gov 

Brad Ring (DOE/GO), 303-275-4930, brad.ring@go.doe.gov 

Holly Thomas (DOE/GO), 303-275-4818, holly.thomas@go.doe.gov 

Brian Hunter (DOE/GO), 303-275-4934, brian.hunter@go.doe.gov 

 

DOE HQ Technology Manager: Thomas Rueckert, 202-586-0942, Thomas.rueckert@ee.doe.gov 

FY 2009 Budget: $7,247K (DOE/GO) awarded; $23,291 (DOE/GO) in negotiation

____________________________________________________________________________________

Objectives

• Manage 28 congressional earmarks and 10 new awards through the Consolidated Appropriations 

Act, 2009 

• Conduct research related to DOE Solar Energy Technologies Program objectives.

Accomplishments

• Awarded 10 new congressional earmarks.

____________________________________________________________________________________

1. Introduction

We negotiated and funded 10 of 29 

congressionally directed projects. These funds 

were directed by the Consolidated Appropriations 

Act, 2009. The projects were fully funded this year, 

although several are multiyear.

2. Technical Approach

In addition to the 10 projects funded in 2009, all 

projects from prior years were active during FY 

2009. The awards are summarized in the tables. 

Agreement Title FY 2008

Budget ($K)

CEC; Christopher Collins 492

Agreement Title FY 2008

Budget ($K) 

(Solar 2 Green Energy, Arts & 

Education Center)

CENTRIA, Inc.; Richard A. Mowrey 

(Building-Integrated Photovoltaic 

Solar Energy System ) 295

Crowder College; Dan Eberle 

(Crowder College Missouri 

Alternative & Renewable Energy 

Technology (MARET) Center) 0*

Eikos, Inc.; Paul J. Glatkowski 

(Transparent Coatings for Solar Cell 

Research Project ) 1,818

Greenfield Community College; Glen 

Haywood (Sustainable Energy Model 

Greenhouse) 394

NIREC; Jim Croce 1,476

D R A F T
Agreement Title FY 2008

Budget ($K) 

(Renewable Energy Research and 

Development)

NDSU ; Philip Boudjouk 

(Center for Nanoscale Energy) 5,904

Nye County; Pam Webster 

(Nye County Renewable Energy 

Feasibility Study) 492

NMSU: Shuguang Deng 

(High Efficiency Cascade Solar Cells) 984

Rural Development, Inc.; Anne 

Perkins 

(Wisdom Way Solar Village ) 394

SFPUC; John F. Doyle 

(MUNI Ways and Structures Building 

Integrated Solar Membrane Project) 610

TSEC; Vincent Cozzolino 

(Solar Consortium of New York 

Photovoltaic Research and 

Development Center ) 1,476

University of Arizona; Roger Angel 

(Development of Concentrator PV 

Systems for Solar Electricity) 984

UALR; Alexandru Biris 

(Novel Photovoltaic Devices Based 

on Polymeric and Carbon 

Nanostructured Materials) 1,181**

University of Hartford; Barry T. Lubin

(Evaluation of Economic Benefits of 

Distributed Photovoltaic Systems) 492

University of Louisville Research 

Foundation, Inc.; M. Keith Sharp 

(Sustainable Buildings: Using Active 

Solar Power) 394**

University of Nebraska at Kearney; 

Christopher L. Exstrom 

(CIBS Solar Cell Development ) 935

University of Nevada–Las Vegas 

Research Foundation; Wilber 

Pittinger 

(Photonics Research and 

Development) 0*

UNLV; Biswajit Das 

(Solar Cell Nanotechnology) 738

* Funded with prior year funds

** Continuation of existing (prior year) Congressional 

Earmark 

Agreement Title (Awarded)

FY 2009 

Budget ($K)

Bexar County; Golda Weir (Bexar 

County Parking Garage Photovoltaic 

Panels)

475

TSEC; Petra Klein (Comparative 

Analysis of Turnkey Silicon Solar Cell 

Processes and Equipment) 594

USU; Jeff Muhs (Multi-functional 

Solar Energy Research Systems 

Research) 1,665

Omega Optical, Inc; Gary Carver 

(Solar Power Generation 

Development) 1,427

City of Beacon; Mayor Steve Gold 

(Solar Electric Power System) 66

St. Clair County Community College; 

Denise McNeil (Solar Electric and 

Wind Power Systems) 190

Vermont Department of Education; 

Cathy Hilgendorf (Sustainable 

Energy for Vermont Schools) 500

TSEC; Petra Klein (Photovoltaic 

Innovation) 1,903

Salt Lake County; Teresa Young 

(Energy Efficient Buildings) 618

Nevada Institute for Renewable 

Energy Commercialization; Jim 

Croce

(Renewable Energy Research and 

Development) 475

Agreement Title (In Negotiation)

FY 2009 

Budget ($K)

Creighton University 1,141

NDSU 4,757

Oregon Department of Energy 380

Xunlight Corporation 1,189

Rochester Institute of Technology 951

Isles, Inc. 237

Sandia National Laboratories 1,903

Lehigh Valley Hospital and Health 

Network 951

Crowder College 951

ULAR 1,189

Oregon Department of 

Transportation 951

Islip Town Hall 475

City of Trenton 475

Orange County Florida Government 237

Essex County 951

Township, Cherry Hill, NJ 285

Clark County School District 1,189

City of St. Petersburg 1,427

Vermont Department of Public 

Service 713

UNLV 951

Rural Development, Inc. 570

Andre Agassi Charitable Foundation 1,189

3. Accomplishments and Future Directions

3.1 Solar 2 Green Energy, Arts & Education 

Center (CEC—Collins)

Objective

• Complete preliminary design work on a netzero energy consumption, Leadership in 

Energy and Environmental Design (LEED) 

platinum-rated center in New York. 

D R A F T
Accomplishments

• Completed Acoustic Site Survey, investigation 

and sizing of battery backup system, and 

study of potential “pre-fab” options. Received 

report on power consumption for Building 

Exhibit and developed new energy analysis 

Report

• Completed schematic design, design 

development and preconstruction documents 

phases (including new renderings) and 

achieved 86% completion on construction 

documents, including a new design and 

drawing Set at 75% completion

• Completed 100% of engineering and

foundation documents. 

3.2 Building-Integrated Photovoltaic (BIPV) Solar 

Energy System (CENTRIA—Mowrey) 

Objectives

• Increase adoption of solar energy by 

developing standard BIPV designs 

• Develop standard PV system designs, 

specifications, and support for standing-seam 

roof manufacturers, including electrical 

component design, roof wire management, 

testing, commercialization, and complete 

standards development

• Work with BIPV metal roofing companies to 

promote products and adoption into building 

designs to grow market.

3.3 Crowder College Missouri Alternative & 

Renewable Energy Technology (MARET) Center 

(Crowder College—Eberle) 

Objective

• Develop 27,500-ft2 facility as a living 

laboratory to support solar and other 

renewable energy development through 

professional degrees, new product 

commercialization, renewable business 

incubation, and consumer education. 

Accomplishment

• Completed work on prototype roof section, 

modular bays, and site and structural plans for 

first phase of construction.

Future Directions

• Finish environmental assessment to comply 

with National Environmental Policy Act

(NEPA) standards. 

• Complete design work on the integrated 

mechanical and electrical energy collection, 

recovery and exchange systems.

3.4 Transparent Coatings for Solar Cell Research 

Project (Eikos—Glatkowski) 

Objectives

• Synthesize and characterize novel 

nanomaterials for transparent conductive 

coatings (TCCs) for use in thin-film PV and 

other energy applications

• Formulate inks for printing high-conductivity 

nanomaterial-based coatings

• Demonstrate environmental stability of 

coatings

• Evaluate cost-performance-processing 

tradeoffs.

Accomplishments

• Determined gravure/roll coating is a suitable 

method for CNT/binder deposition for PV 

applications 

• Developed reliable method to purify goodquality metallic NW 

• Synthesized nanomaterials for TCCs. Eikos 

has developed CNT ink with excellent RT

performance from two new suppliers, enabling 

us to meet current and future orders. One of 

these new companies is U.S.-based, ensuring 

material supply for sensitive government 

applications

• Utilized Eikos CNT coatings as a back contact 

in a cadmium telluride (CdTe) multi-junction 

device. Work presented at the 34th IEEE PV

Specialists Conference

• Successfully developed a CNT/triple binder 

coating capable of meeting RT specifications 

and weathering environmental conditions 

• Adapted ink formulations and developed new 

printing protocols to enable a more reliable 

deposition of complex and conductive CNT 

patterns of variable sizes by ink-jet printing 

• Developed a new AR binder system that 

enables CNT-based TCC to meet all PV 

specifications. This new formulation also 

simplifies processing and reduces costs 

• Conducted heat treatment experiments to 

purify and characterize CNT from multiple 

suppliers.

Future Directions

• Work with prescreened SWCNT suppliers to 

improve the quality of as-produced CNT 

material

• Integrate coatings into thin-film organic and 

polycrystalline PV 

• Integrate binder top coats into CNT TCC for 

use in PV cells 

• Improve CNT ink RT performance and 

stability.

3.5 Sustainable Energy Model Greenhouse 

(Greenfield Community College—Haywood) 

D R A F T
Objective

• Build a zero-net energy impact solar 

greenhouse that incorporates passive solar 

design, thermal storage, energy conservation 

features, PV, and an active geothermal 

heating system. 

Accomplishment

• Completed contracting process with consultant 

to develop design feasibility study for 

greenhouse. 

Future Directions

• Complete design plans with bid documents; 

scheduled for late spring/summer 2010 

construction

• Create teaching and learning environment to 

support biology and renewable energy 

curricula with carbon-neutral greenhouse 

equipped with passive solar, PV, solar thermal 

systems, and interface with geothermal 

system. 

3.6 Renewable Energy Research and 

Development (NIREC—Croce) 

Objective

• Select and fund clean energy research and 

development, and support the transformation 

of these ideas into sustainable enterprises.

Accomplishments

• Successfully launched two competitive 

Requests for Proposals (RFPs). 

• Selected and began process of awarding 

approximately $300,000 in research and 

technology development projects

• Successfully completed two R&D projects 

(awarded in 2008) on time and on target 

• Presented and participated in numerous 

outreach activities to educate the clean energy 

innovation community on the challenges, 

potential solutions, and significant economic 

benefits to clean energy technology 

development and deployment. 

Future Directions

• Search for, assess, and award funds to 

deserving projects: 

• Fund at least six new R&D projects and 

support the development of their 

commercialization road map

• Continue to nurture a robust network of

innovation ecosystem partners

• Conduct education and outreach activities to 

facilitate interest in the need for clean energy 

technologies. 

3.7 Center for Nanoscale Energy (NDSU—

Boudjouk) 

Objectives

• Evaluate efficacy of NDSU liquid silanes and 

atmospheric-pressure deposition technologies 

in PV device manufacturing

• Develop routes for effective catalytic 

conversion of plant-derived olefins and other 

renewables into high-value chemicals and 

materials

• Evaluate new catalyst compositions in carbonnanotube-based membrane electrode 

assemblies (MEAs) in polymer electrolyte fuel 

cells (PEMFCs) to improve the performance 

and reduce the costs of the catalysts for 

oxygen reduction. 

Accomplishments

• Achieved a breakthrough in the synthesis of 

cyclohexasilane (Si6H12), where yields have 

been improved to >90% 

• Achieved ultrahigh-rate silicon deposition rates 

(8Å/s) by using PECVD using Si6H12 as the 

silicon source, potentially enabling higher 

production rates for Si thin-film PV cells

• Achieved aerosol printing of an Ag currentcollecting grid on c-Si cells, where fine 

resolution (less than 5 μm) minimizes 

shadowing losses

• Achieved high selectivity in the oxidative 

cleavage of monounsaturated carboxylic acids 

derived from oil seeds, yielding high-value 

polymer precursors.

Future Directions

• Conduct a technoeconomic analysis of Si6H12-

based processes for producing Si-based thin 

films needed in PV devices

• Probe the mechanism of transformation of 

Si6H12-based inks into thin-film Si

• Utilize high-throughput combinatorial (HTC) 

methodologies to investigate high-value 

polymer materials that can be synthesized 

from plant-derived chemicals

• Evaluate the activity and stability of carbonnanotube-supported platinum alloy catalysts 

for electrochemical oxygen reduction.

3.8 Nye County Renewable Energy Feasibility 

Study (Nye County—Webster) 

Objectives

• Develop land use and community 

preparedness plans that support responsible 

and sustainable renewable energy 

development in areas targeted by project 

developers

• Measure and report solar and wind 

characterization data to assess generation 

potential

D R A F T
• Provide comprehensive liaison, environmental 

regulation, and support services to energy 

developers and government agencies involved 

in Nye County. 

Accomplishments

• Completed an Amargosa Valley Area Plan to 

guide the design and permitting of solar 

thermal power plants in the valley. The plan 

has been approved, and two 500-MW projects 

have progressed to the EIS phase

• Evaluated the former Barrick Mine site for 

suitability for a 20- to 30-MW PV power 

generation facility

• Installed Internet-monitored solar intensity and 

weather monitoring instrumentation on county 

building rooftop sites in Pahrump (2,693 ft 

elevation) and Tonopah (5,863 ft elevation). 

The UNLV Center for Energy Research 

carried out this work.

• Set in motion three lease-option agreements 

for PV solar projects on the Tonopah Airport 

site

Brought a 100-MW solar thermal power-tower 

project using molten salt technology to the EIS 

phase. The site is northwest of Tonopah Future 

Directions

• Assist developers with the BLM permitting and 

agency approval processes to move projects 

toward construction

• Redirect landfill study earmark funds toward a 

new transmission for export study that will 

propose transmission corridor upgrades and 

expansions to support the delivery of Nye 

County renewable energy generation capacity 

to the California market. 

3.9 High Efficiency Cascade Solar Cells (NMSU—

Deng)

Objectives

• Develop new organic semiconducting PV

• Develop band-enhancing layers

• Study mechanisms of percolation for charge 

transfer in new organic semiconductors

• Use cascade solar cell architecture to develop 

semiconductors. 

Accomplishments

• Synthesized high-purity SWNT, DWNT, 

MWNT, N-SWNT and Nanolance chains

• Built first generation of vertical cells and 

generated IP associated with it 

• Produced new all-organic optical limiting 

composites 

• Produced new hybrid optical limiters with the 

highest nonlinear limiting values in the visible 

and near-IR region. 

• Developed new thin-film sensors from 

nanocomposites that have broadband 

responses in the GHz region (for wind turbine 

blade sensor coating) 

• Completed theoretical studies of functionalized 

and doped carbon nanotubes in selfassembled complexes

• Initiated studies of core-shell semiconductor 

nanoparticles embedded in electroactive 

polymers

Future Directions

• Complete first stage of vertical cells by 

developing a 1-cm2 cell composed of multiple 

devices 

• Demonstrate new vertical cells operating in air 

• Deliver new nanocomposites for potential use 

as new n-type semiconductors 

• Calculate the electronic and optical properties 

of nanoparticles embedded in polymers

• Study the absorption characteristics and the 

efficiency of charge transport of 

nanocomposite materials

• Develop suitable nanocomposites for all 

aspects of new architecture

• Obtain spectroscopic and morphological 

control of nanocomposites through materials 

characterization

• Optimize nanocomposites for use in a flat 

panel cell and develop new cells.

3.10 Wisdom Way Solar Village (Rural 

Development, Inc.—Perkins) 

Objectives 

• Enhance Wisdom Way Solar Village, a 

development of 20 prototypical near zero net 

energy affordable homes by adding solar hot 

water systems and high efficiency windows. 

Researchers with the DOE Building America 

Program will monitor the homes for 

performance

• Enable residents to reduce their energy 

budgets for electricity, heat, and hot water to 

as low as $300 per year (in 2007 dollars).

Accomplishments

• Completed and sold eight near zero net 

energy homes,

• Installed high efficiency windows for 16 units

• Installed 16 solar hot water systems

• Began monitoring 4 homes for performance.

Future Directions

• Complete remaining 12 units

• Rent 2 units to households with disabled 

members

• Sell final 10 units by December 2010.

D R A F T
3.11 MUNI Ways and Structures Building 

Integrated Solar Membrane Project (SFPUC— 

Doyle) 

Objectives

• Install BIPV system using best available, 

highest efficiency technology to meet about 

25% of the building’s total facility load, which 

averages 52,560 kWh per month.

Accomplishments

• Completed preliminary roof structural and 

electrical evaluation, taking California 

Environmental Quality Act (CEQA)

requirements into account

• Completed preliminary designs for a BIPV 

installation on the facility roof and specified 

monitoring of BIPV system

• Revised and streamlined city RFP contract 

documents to make bidding process easier for 

solar contractors

• Selected eight qualified firms to receive RFP.

Future Directions

• Issue and advertise RFP 02/10

• Start construction in late summer 2010 with 

completion estimated for December 2010.

3.12 Solar Consortium of NY PV R&D Center 

(TSEC—Cozzolino) 

TSEC is an industry-led nonprofit dedicated to 

eliminating the technical and economic barriers to 

the widespread use of solar energy in New York 

State. 

Objectives

• Enable TSEC’s Solar Innovation and Solar 

Solutions teams to work with public and 

private entities, industry, and universities to 

overcome technical and technology barriers to 

solar energy use

• Facilitate TSEC’s Enable Manufacturing 

Teams as they work with industry partners to 

grow and retain jobs in renewable energy in 

New York State and to bring new products to 

market.

Accomplishments

• Worked with the Federal Prison system and 

the U.S. Department of Justice, along with two 

industry partners, to establish a manufacturing 

capability within the prison system

• Assisted EarthKind Energy, a solar hot water 

collector company with R&D and 

manufacturing capability, during its relocation

to New York State.

• Initiated and coordinated the work of four NYS 

county workforce agencies and the State 

University of New York (SUNY). Thirteen 

companies with about 50 job openings 

attended the session, along with 400 job 

seekers

• Coordinated SUNY New Paltz Solar usage 

projects (three hospital in Ulster County, NY, 

and an off-grid PV Air National Guard 

installation in Newburgh, NY) 

• Provided technical support to SUNY New 

Paltz solar car team for the Formula Sun 

Grand Prix Race in Cresson, Texas 

• Received NYSERDA grant for Advance 

Energy System Mass Transit

• Assisted Prism Solar Technology to 

manufacture its proprietary solar concentration 

film

• Established a daily renewable energy ebulletin reaching a diverse and growing 

number of readers. 

Future Directions

• Expand use of off-grid applications of solar 

energy products 

• Increase focus on solar farming in NYS

• Increase focus on solar thermal applications

• Continue collaborations between industry and 

academia for technology transfer and new 

product commercialization

• Conduct solar education and outreach

activities. 

3.13 Development of Concentrator PV Systems for 

Solar Electricity (University of Arizona—Angel) 

Objectives

• Cost-competitive generation of solar electricity

• Demonstrate a new approach to concentrating 

PV generation in a working prototype

• Develop new manufacturing methods aimed at 

mass production at low cost.

Accomplishments

• Constructed prototype with multijunction PV 

cell at 1,000 x concentration; end-to-end test 

shows 27% conversion efficiency. 

• Developed a new manufacturing method for 

back-silvered solar reflectors demonstrated in 

segmented unit 3 m in diameter

• Constructed a low-cost, low-mass 2-axis 

tracker to carry 70 m2

 of glass reflectors

Future Directions

• Build and demonstrate a 20-kW prototype unit 

• Develop and demonstrate production at 1 

MW/year rate

• Facilitate transition to industrial production. 

3.14 Novel PV Devices Based on Polymeric and 

Carbon Nanostructured Materials (UALR—Biris) 

Objectives

D R A F T
• Develop highly efficient and cost-effective 

solar devices using the unique optical and 

electronic properties of carbon nanostructured materials and photosensitive 

polymers. 

Accomplishments

• Harvested light using high-density, p-type, 

single-wall carbon nanotube/n-type silicon 

heterojunctions. 

• Developed polymer Functionalized n-Type 

Single Wall Carbon Nanotube PV Devices

• Investigated the electrical, optical, and 

morphological properties of P3HT-MWNT 

nanocomposite prepared using in situ 

polymerization

• Characterized pristine G-PANI films for 

electrodes to replace Ca and Al 

• Fabricated and tested carbon nanotube 

(SWNT-P3HT) composite cell structures

• Characterized SSDP-PANI thin films for HTMs

• Synthesized boron-doped SWNTs and

fabricated and tested a B-SWNT/n-Si 

structure.

Future Directions 

• Develop PANI/n-Si-based solar cell

• Fabricate p-SWNT/n-SWNT cell with 3D 

networked junction

• Direct the self assembly of functional 

nanoparticles using polymer tethers

• Use enhanced lifetime of triplet exciton to 

create bulk heterojunction PV

• Continue to work on hybrid thin-film PV cells

• Modify graphene and fabricate graphenecarbon nanotube-based solar cell.

3.15 Evaluation of Economic Benefits of 

Distributed PV Systems (University of Hartford—

Lubin) 

Objectives

• Concentrate on economic benefits of 

distributed PV systems and adding support of

investigations into the effect on faults that 

could affect meeting load requirements.

• Use existing research to develop economic 

and engineering models and existing PV 

installations to obtain data on both generation 

and load

• Use simulation models to determine the 

influence of distributed PV systems on 

operational faults on the inverters and load

• Determine net loss or gain in economic values 

based on effect of PV systems on reliability of 

meeting load requirements.

Accomplishments

• Acquired advanced dynamic simulation code 

to model both the solar generation and the 

loads of operating systems

• Used the university’s PV system to verify the 

simulations and effects of the system

• Initiated an agreement with Connecticut

companies to gather operating information 

from installed systems to compare with the 

model. 

Future Directions

• Complete work to develop and validate 

simulation model of the PV installation at the 

university

• Initiate planning for data acquisition with 

owner-operated PV installations

• Evaluate data for indications of fault 

generation. 

3.16 Sustainable Buildings: Using Active Solar 

Power (University of Louisville—Sharp) 

Objectives

• Demonstrate to public officials, developers, 

commercial establishments, industries, and 

citizens the benefits of using solar 

technologies, including PV streetlights, 

daylighting, and solar water heating. 

• 

• Conduct simulations, bench-scale testing, and 

full-scale prototype testing on heat pipeaugmented passive solar heating system

• Explore thermochemical energy storage for 

concentrating solar systems through 

simulations. 

• Develop training for installers of solar PV and 

water heating systems; design and construct a 

heliodon.

Future Direction

• Collaborate with Kentucky Solar Partnership to 

conduct educational outreach and support the

installation of solar water heating systems and 

construction of zero energy homes.

3.17 CIBS Solar Cell Development (University of 

Nebraska at Kearney—Exstrom) 

Objectives

• Fabricate and study new PV material, copper 

indium boron diselenide, CuInxB1-xSe2 (CIBS)

• Exceed CuIn1-xGaxSe2 (CIGS) PV efficiencies 

with CIBS goals of 25% (single-film) and 15% 

(module) through chemical composition 

changes. 

Accomplishments

• Deposited Cu.45In.55-xBx precursor films of 

varying boron concentrations (22% to 63%) on 

molybdenum-coated quartz. These films 

D R A F T
remained adherent and appear to have a wide 

bandgap because they are transparent 

• Demonstrated that in solvothermal CIBS 

preparations from oleylamine solvents, boron 

reagent amounts do not have an effect on 

nanocrystalline product material properties. 

Raman spectra and XRD patterns are 

consistent with CuInSe2 regardless of boron 

amount. Boron ions may be occupying 

interstitial sites in the crystal lattice 

• Developed a new room-temperature aqueous 

solution-based preparation method for 

nanocrystalline CuInSe2. In this method, all 

reagent species are solubilized. This may 

facilitate boron incorporation into the 

chalcopyrite lattice structure if this method 

proves viable for CIBS synthesis.

Future Directions

• Determine primary reaction and annealing 

factors that determine boron composition 

control in CIBS

• Develop CIBS nanocrystalline-to-thin-film 

processing via rapid thermal annealing, inkjet 

spray techniques, or related technology

• Generalize the room-temperature aqueous 

solution-based preparation of CIBS. 

3.18 Solar Cell Nanotechnology (UNLV—Das) 

Objectives

• Develop low-cost nonlithographic

nanofabrication technology to fabricate thinfilm porous templates as well as uniform 

arrays of semiconductor nanostructures to 

make high- efficiency solar cells. 

Accomplishments

• Optimized thin-film structure for creation of 

uniform arrays of nanostructures

• Optimized aluminum deposition process by 

investigating sputtering and e-beam deposition 

techniques

• Investigated buffer materials for ITO-coated 

glass substrates

• Investigated and optimized aluminum layer 

thickness

• Designed and implemented a new anodization 

apparatus

• Investigated anodization process to optimize 

process parameters. 

Future Directions

• Optimize process parameters for desired 

template parameters

• Develop the two-step anodization process for 

improved structural control

• Design and implement electrochemical 

synthesis apparatus

• Investigate and optimize electrochemical 

synthesis process

• Develop and optimize the electrophoretic 

synthesis process

• Implement and characterize nanostructurebased solar cells. 

3.19 County Parking Garage Photovoltaic Panels

(Bexar County—Weir)

Objectives

• Promote the use of renewable energy while 

minimizing the impact of vehicle emissions 

• Help sustain Bexar County’s ongoing goal of 

energy efficiency

Accomplishment

• Complete design development. 

Future Directions

• Develop construction documents for PV 

systems

• Install PV system. 

3.20 Comparative Analysis of Turnkey Silicon 

Solar Cell Processes and Equipment (TSEC—

Cozzolino)

Objectives

• Assist IBM with preparing a comprehensive 

report showing the advantages and 

disadvantages of currently available Si PV 

technology and developing a technology road 

map

• Carry out a full cost and technology 

comparison of currently available crystalline 

(mono, multi, poly) Si PV technology and 

create a technology road map to set forth 

ways to compete (on a cost basis) with 

traditional methods for generating electricity. 

Accomplishments

• Completed an initial evaluation of road maps

and prepared a preliminary report for use in 

driving remaining work.

Future Directions

• Complete engineering analysis of the most 

promising turnkey crystalline Si lines 

available from commercial providersEvaluate 

and compare the total “cost of ownership” 

among various turnkey providers

• Generate turnkey producers from a common 

set of characterized Si based substrates 

which to be analyzed and measured using 

many techniques.

• Evaluate each turnkey line for applicability of 

thin Si as a starting material

• Gain a thorough understanding of the 

technology, allowing a qualified, multientity 

team (national labs, academia, and industry) 

D R A F T
to move forward on reducing costs and 

heightening efficiency to compete with 

traditional power generation techniques. 

3.21 Multi-functional Solar Energy Research 

Systems Research (USU—Muhs)

Objectives

• Strengthen and diversify USU energy R&D 

capabilities by exploring pathways to combine 

novel solar and biofuels production 

technologies with innovative co-located energy 

systems capable of simultaneously producing 

electricity or process heat. 

3.22 Solar Power Generation Development

(Omega Optical, Inc—Carver)

Objectives

• Create a solar cell prototype with low cost and 

high efficiency while avoiding both scarce and 

toxic materials

• Optimize the electronic properties of organic 

thin films

• Deposit organic-based Schottky cells

• Implement spectral splitting 

• Integrate PV and photothermal (PT) collection 

mechanisms. 

Accomplishments

• Assembled team and established lab space 

(late August 2009) 

• Installed and dedicated two thin-film 

deposition systems to this program

• Deposited and evaluated several organic 

materials Installed test equipment

• Collected preliminary data including SEM

images, x-ray diffraction, optical transmittance, 

resistivity, and mobility. 

Future Directions

• Optimize PV and PT cell collection efficiency

• Fabricate PV and PT modules

• Optimize module reliability

• Integrate PV and PT collection into residential 

building materials. 

3.23 Solar Electric Power System (City of Beacon, 

NY—Gold)

Objectives

• Purchase PV system for the City of Beacon’s 

Municipal Building’s southwest-facing roof, as 

large as 14 kW

• Install a public real-time monitoring system 

display and an educational display to 

demonstrate how the system works, present 

the cost savings, and outline the 

environmental benefits.

3.24 Solar Thermal, Solar Electric and Wind 

Power Systems (St. Clair Community College—

McNeil)

Objectives

• Purchase equipment to advance student and 

community studies in alternative energy and 

energy management. This will be partnered 

with existing and proposed curricula to create

a “living lab,” along with fixed and mobile 

simulated hands-on experimentation units. 

Students will be able to attain an associate’s 

degree in alternative energy. 

3.25 Sustainable Energy for Vermont Schools 

(Vermont Dept. of Education—Hilgendorf)

Objectives

• Work with 10 Vermont public schools to 

develop solar power educational programs. 

This will fund the site feasibility and initial 

design, and the installation of PV systems on 

schools. PV installations (5 kW) at schools will 

be used to promote K-12 cross-discipline 

curriculum modules, teacher professional 

development, and workforce development 

initiatives.

3.26 TSEC Photovoltaic Innovation NY (TSEC—

Klein)

Objectives

• Advance solar innovation and R&D by 

advancing solar technology in partnership with 

industry and academia

• Develop solar solutions to overcome barriers 

to solar implementation in various unique solar 

applications 

• Enable manufacturing in partnership with 

state/local economic development agencies, 

industry, and academia to yield technical and 

economic resources that renewable energy 

companies need to grow; in addition, support 

job growth in the renewable energy field

• Assist IBM with preparing a comprehensive 

report showing the advantages and 

disadvantages of currently available Si PV 

technology and developing a technology road 

map

• Assist Prism Solar Technology in the 

maximum conversion of plasma display 

manufacturing equipment for PV cells and

modules and Prism’s patented Holographic 

Optical Elements (HOE).

Accomplishments

• Assisted subrecipients in project management 

and collaboration 

D R A F T
• Used the SEMILAB mapping tool to obtain 

lifetime maps on selected upgraded 

metallurgical grade (UMG) solar cells from

Schmid, a German turnkey cell manufacturer 

• Compared lifetime maps and diffusion length 

maps to UMG solar cell efficiencies. Results 

indicate weak correlation of cell performance 

with lifetime and with UMG alloy blend

• Took preliminary quantum efficiency 

measurements, which also indicate weak 

dependence on lifetime/diffusion length

• Set up and calibrated a PV characterization 

workstation equipped with a solar simulator for 

studying cells with areas of 2”×2”Obtained 

initial results for AC and DC PV parameters for 

a reference Si solar cell to standardize 

measurement procedures and to benchmark 

UMG-Si cell performance 

• Presented initial findings at a CAMP 

symposium in October 2009. Submitted a

paper on this work for presentation at the 

Semicon China 2010 Conference in 

Shanghai, China, March 16–18, 2010.

Future Directions

• Continue to advance solar innovation for solar 

solutions and to enable manufacturing

• Fabricate and characterize composites of 

UMG Si with PV solar grade Si to allow for a 

full cost and technology comparison of 

available crystalline (mono, multi, poly) Si PV 

production to result in a technology road map

(work to be done by IBM & Clarkson) 

• Maximize Prism Solar Technologies’ 

conversion of plasma display manufacturing 

equipment line and area to manufacture PV 

cells and modules, along with Prism’s HOE.

3.27 Energy Efficient Buildings (Salt Lake 

County—Young)

Objectives

• Install solar PV (approximately 300 kW) on 

selected county facilities using a Power 

Purchase Agreement (PPA) model. This will 

allow for increased energy efficiency with each 

facility. These installations will also 

demonstrate renewable technologies to 

communities in the county. 

4. FY 2009 Special Recognitions and Patents

NMSU 

• “Versatile Unfolding Solar Deployment 

System,” S. Curran et al., U.S. patent 

application filed. 

• “Organic Photovoltaic Pixel Tandem Wrap 

Cell,” S. Curran et al., U.S. patent application 

filed. 

• Filed patent application for “Vertically Stacked 

PV and Thermal Solar Cell,” S. Curran et al., 

U.S. patent application filed.

UALR 

• Z. Li and A.S. Biris, “Light‐Harvesting with 

Single Wall Carbon Nanotubes/n‐Silicon 

Heterojunctions.” UALR ID #: 09-14; U.S. 

patent application 61/211,825, pending. 

NIREC

• University of Nevada Reno, U.S. patent 

application 61169496. 

• University of California, Davis, U.S. patent 

application # 12/404. 

University of Arizona

• “Solar Concentrator Apparatus with Large, 

Multiple, Co-Axial Dish Reflectors,” U.S. 

patent application 12/463,001, pending.

• “PV Generator with a Spherical Imaging 

Lens for use with a Paraboloidal Solar 

Reflector," U.S. patent application 12/463,016, 

pending 

• “Method of Manufacturing Large Dish 

Reflectors for a Solar Concentrator 

Apparatus,” U.S. patent application 

12/463,026, pending. 

5. Major FY 2009 Publications

NMSU (nine published or submitted, including the 

following): 

• M. Vasiliev, M. Lopez del Puerto, A. Jain, 

Lugo-Solis, and J. R. Chelikowsky, 

“Application of Time-Dependent DensityFunctional Theory to Molecules and 

Nanostructures,” J. Mol. Struct.: THEOCHEM, 

914,115-129 (2009).

• N. Al-Aqtash and I. Vasiliev, “Ab Initio Study of 

Carboxylated Graphene,” J. Phys. Chem. C, 

113, 12970-12975 (2009).

• K-S. Liao et al., “Use of Microbiologically 

Formed Nanorods Composed of Elemental 

Tellurium in Polymer Composites for Strong 

Optical Limiting Responses,” Chem. Phys. 

Lett., (12/09). 

University of Arkansas (15 published or submitted, 

including the following):

• Z. Li, E. Dervishi, V. Saini, V.P. Kunets, Y. Xu, 

A.R. Biris, G.J. Salamo, and A.S. Biris, 

"Polymer Functionalized n-Type Single Wall 

D R A F T
Carbon Nanotube Photovoltaic Devices," Appl. 

Phys. Lett. (2010, in press). 

• Z. Li, V.P. Kunets, V. Saini, Y. Xu, E. Dervishi, 

G.J. Salamo, A.R. Biris, and A.S. Biris, “LightHarvesting Using High Density p-Type Single 

Wall Carbon Nanotube/n-Type Silicon 

Heterojunctions,” ACS Nano 3, 1407-1414

(2009). 

• Z. Li, E. Dervishi, Y. Xu, V. Saini, M. 

Mahmood, O.D. Oshin, A.R. Biris, and A.S. 

Biris, “Carbon Nanotube Growth on Calcium 

Carbonate Supported Molybdenum-Transition 

Bimetal Catalysts,” Catalysis Lett. 131(3), 356-

363 (2009). 

NIREC

• M. Mascal and E.B. Nikitin (University of 

California Davis), “Towards the Efficient, Total 

Glycan Utilization of Biomass,” 

ChemSusChem 2(5), 423 (2009).

• M. Mascal and E.B. Nikitin (University of 

California Davis), “Dramatic Advancements in 

the Saccharide to 5-(Chloromethyl)furfural 

Conversion Reaction,” ChemSusChem 9, 859 

(2009).

NDSU

• J. Hoey, D. Thompson, M. Robinson, Z. 

Mahmud, O.F. Swenson, I.S. Akhatov, and 

D.L. Schulz. “CAB-DW for 5 μm Trace-Width 

Deposition of Solar Cell Metallization TopContacts,” Proc. 34th IEEE Photovoltaics 

Specialist Conference, June 8-12, 2009, 1857-

1861.

• K. Pokhodnya, J. Sandstrom, X. Dai, P.

Boudjouk, and D.L. Schulz. “Comparative 

Study of Low-Temperature PECVD of 

Amorphous Silicon using Mono-, Di-, Trisilane 

and Cyclohexasilane.” Proc. 34th IEEE 

Photovoltaics Specialist Conference, June 8-

12, 2009, 1758-1760.

TSEC

• J.E. Garland, D.J. Crain and D. Roy, 

“Examination of Resistive Power Losses in a 

Single Crystal Silicon Solar Cell,” poster 

presented at the Center for Advanced 

Materials Processing Fall 2009 Symposium, 

Oct. 15, 2009.

• J.E. Garland, “Measurement and Analysis of 

Solar Cell Parameters,” talk presented at the 

Physics Department Colloquium, Clarkson 

University, Jan. 15, 2010. 

University of Nebraska at Kearney

• A. Kamler, et al. “Thin Films Formed by 

Selenization of CuInxB1-x Precursors in 

Selenium Vapor,” Sol. Energy Mater. Sol. 

Cells, 93(1), 45-50 (2009). 

• J. Olejníček, et al. “Problems with Synthesis of 

Chalcopyrite CuIn1-xBxSe2,” Mater. Sci. Forum, 

609, 33-36 (2009). 

• C.L. Exstrom, et al. “Solvothermal Preparation, 

Processing and Characterization of 

Nanocrystalline CuIn1-xAlxSe2 Materials,” Proc. 

Mater. Res. Soc. Symp., 1165, M05-03

(2009). 

• J. Olejníček, et al. “A Non-Vacuum Process for 

Preparing Nanocrystalline CuIn1-xGaxSe 

Materials Involving an Open-air Solvothermal 

Reaction,” Sol. Energy Mater. Sol. Cells, 

accepted for publication. 

6. University and Industry Partners

Organization/

Principal Investigator Location Description/Title of Research Activity FY 2008($K)

Eikos, Inc., NREL Golden, CO Expertise, device fabrication, characterization, 

and materials 492

NIREC:

Desert Research Institute

H. Kuhns

University of Nevada, Reno 

A.M.Trzynadlowski

UC Davis, M. Mascal

University of Nevada, Reno

D. K. Kim

Reno, NV

Reno, NV

Davis, CA

Reno, NV

Developing Utility Accountant, a tool to help 

manage utility costs 

Power electronic converter-controller for off-grid

wind turbine systems

Direct conversion of sugars, cellulose, and 

cellulosic biomass into fuels

Condenser for geothermal applications 

90

97

60

70

NDSU

UC-Riverside Riverside, CA

Evaluate novel electrocatalytic materials for fuel 

cells 533

D R A F T
Organization/

Principal Investigator Location Description/Title of Research Activity FY 2008($K)

R. Haddon

University of Toledo

Dr. Marsillac

Toledo, OH Liquid silane-derived films 200

RPI/Harvard

CVM

D. Schneider Sr.

Syracuse University

J. Zhang

Island Bay Window and 

Curtain Wall

Cambridge, 

NY

Syracuse, NY

Long Island, 

NY

Value engineering/optimization of system 

components

System testing

Curtain wall panel fabrication

50

0 

0 

 

D R A F T
D R A F T