NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Contract No. DE-AC36-08GO28308

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the 

Stringfellow Superfund Site in 

Riverside, California

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Land Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

Otto VanGeet and Gail Mosey

Technical Report

NREL/TP-6A20-48770

December 2010
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

National Renewable Energy Laboratory

1617 Cole Boulevard

Golden, Colorado 80401

303-275-3000 • www.nrel.gov

Contract No. DE-AC36-08GO28308

Feasibility Study of Economics 

and Performance of Solar 

Photovoltaics at the 

Stringfellow Superfund Site in 

Riverside, California

A Study Prepared in Partnership with the 

Environmental Protection Agency for the 

RE-Powering America’s Land Initiative: 

Siting Renewable Energy on Potentially 

Contaminated Land and Mine Sites

Otto VanGeet and Gail Mosey

Prepared under Task No. WFD4.1000

Technical Report

NREL/TP-6A20-48770

December 2010
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of 

any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately 

owned rights. Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors 

expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

Available electronically at http://www.osti.gov/bridge

Available for a processing fee to U.S. Department of Energy

and its contractors, in paper, from:

U.S. Department of Energy

Office of Scientific and Technical Information

P.O. Box 62

Oak Ridge, TN 37831-0062

phone: 865.576.8401

fax: 865.576.5728

email: mailto:reports@adonis.osti.gov

Available for sale to the public, in paper, from:

U.S. Department of Commerce

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

phone: 800.553.6847

fax: 703.605.6900

email: orders@ntis.fedworld.gov

online ordering: http://www.ntis.gov/help/ordermethods.aspx

Cover Photos: (left to right) PIX 16416, PIX 17423, PIX 16560, PIX 17613, PIX 17436, PIX 17721

Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.
iii

Acknowledgments

The National Renewable Energy Laboratory (NREL) thanks the U.S. Environmental Protection 

Agency (EPA) for its interest in securing NREL’s technical expertise. In particular, NREL and 

the assessment team for this project are grateful to the Stringfellow facility managers, engineers, 

and operators for their generous assistance and cooperation. Special thanks go to Mikos 

Fabersunne and Allen Wolfenden from the State of California and to Lura Matthews and 

Charnjit Bhullar from EPA for hosting the site visit. The authors would also like to thank Sean 

Ong of NREL for his assistance.
iv

Executive Summary

The U.S. Environmental Protection Agency (EPA), in accordance with the RE-Powering 

America’s Land initiative, selected the Stringfellow Superfund Site in Riverside, California for a 

study of solar photovoltaic (PV) feasibility. The National Renewable Energy Laboratory (NREL) 

was contacted to provide technical assistance for this project. The purpose of this report is to 

assess the site for possible PV installation and estimate the cost, performance, and site impacts of 

different PV options. In addition, the report recommends financing options that could assist in 

the implementation of a PV system at the site. The economics of the potential systems were 

analyzed using an electric rate of $0.13/kWh, and incentives that are offered by Southern 

California Edison (SCE) under the California Solar Initiative (CSI). NREL recommends the 

installation of ground-mounted PV. Because of the high cost of energy, dropping cost of PV, 

excellent solar resource and excellent SCE incentives a government owned PV system provides a 

reasonable payback, is easy to implement, and is therefore recommended. If funding is not 

available then a third party ownership arrangement Power Purchase Agreement (PPA) is the 

most plausible way for a system to be financed on this site.
v

Table ES-1.Stringfellow Superfund Site Summary

Tie-in Location

Array 

Tilt 

(Deg)

Area (ft2

) 

Required

PV 

System

Size 

(kW)

Annual 

Output 

kWh/yr

Annual 

Cost 

Savings 

after O&M 

($/year)

Total 

System Cost 

with No 

Incentives 

($)

CSI Incentive 

$0.26/kWh for 

5 years, ($)

after 5 years

Cost ($)

after 5 

years of CSI 

incentives

Payback 

Period after 

CSI Incentive 

(years)

Ground-mounted; Treatment Plant only = 430,000 kWh annual

Treatment plant 20 71,192 285 430,000 53,479 1,543,841 559,000 984,841 18

Treatment plant

Single 

axis 73,410 242 430,000 53,429 1,573,521 559,000 1,014,521 19

Stringfellow site with virtual net metering = 648,000 kWh annual

Site 20 107,285 429 648,000 80,592 2,155,695 842,400 1,313,295 16

Site

Single 

axis 110,627 365 648,000 80,516 2,200,423 842,400 1,358,023 17
vi

Table of Contents

List of Figures ........................................................................................................................................... vii

List of Tables ............................................................................................................................................. vii

1 Study Location...................................................................................................................................... 1

2 Photovoltaic (PV) Systems.................................................................................................................. 2

2.1 Types of PV Systems...........................................................................................................3

2.1.1 Ground-Mounted Systems..........................................................................................3

2.1.2 Roof-Mounted Systems ..............................................................................................4

2.2 PV System Components ......................................................................................................4

2.2.1 PV Array .....................................................................................................................4

2.2.2 Inverters ......................................................................................................................4

2.2.3 Operation and Maintenance ........................................................................................5

2.3 PV Size and Performance ....................................................................................................5

3 Photovoltaic (PV) Sites ........................................................................................................................ 6 

3.1 PV Size and Performance ....................................................................................................6 

3.1.1 Energy Use..................................................................................................................8

3.1.2 Net Metering .............................................................................................................11

3.1.3 Virtual Net Metering.................................................................................................12

3.1.4 PV Location ..............................................................................................................15

4 Economics and Performance............................................................................................................ 21

4.1 Assumptions and Input Data for Analysis.........................................................................21

4.2 Other Incentives and Financing Opportunities..................................................................22

5. Conclusions and Recommendations ............................................................................................... 24

Appendix A. Contacts and Assessment Team Members...................................................................... 25

Appendix B. Assessment Assumptions and Assumptions for Calculations ..................................... 26

Appendix C. Solar Access Measurements ............................................................................................. 27

Appendix D. Comparison of SCE CREST to CSI Steps 6 and 7 Using the Solar Advisor Model...... 28

Appendix E. Electrical Single-Line Diagrams ........................................................................................ 29
vii

List of Figures

Figure 1. Major components of grid-connected photovoltaic (PV) system.....................................2

Figure 2. Aerial photograph showing proposed treatment plant and PV location.........................15

Figure 3. Site plan showing proposed treatment plant location.....................................................16

Figure 4. Existing site plan showing topographic contours and proposed PV location in center 

and east portion of truck parking area............................................................................17

Figure 5. Photographs of proposed PV in center and east portion of truck parking area ..............19

Figure 6. Photographs of SCE meter and electrical distribution panels serving existing plant.....20

Figure 7. PV Costs.........................................................................................................................21

Figure 8. SAM input used to evaluate the economics of CREST versus CSI Steps 6 and 7.........23

Figure B-1. Solar access measurements for proposed PV site.......................................................27

Figure E-1. The 1200-amp main distribution and metering panel “MDP” at the existing treatment 

plant—with spaces for possible PV tie-in ..................................................................29

Figure E-2. The 800-amp panel “PP” at the existing treatment plant—with spaces for possible 

PV tie-in......................................................................................................................30

List of Tables

Table ES-1.Stringfellow Superfund Site Summary.........................................................................v

Table 1. Energy Density by Panel and System................................................................................3

Table 2. Site Identification Information and Specifications............................................................6

Table 3. Performance Results for 20-degree fixed-tilt PV ..............................................................7

Table 4. Performance Results for 0-degree single-axis PV.............................................................7

Table 5. Meters and Rates Schedules ..............................................................................................8

Table 6. Summer Rate Schedule TOU PA: Off-Peak, Mid-Peak and On-Peak Energy Rates......10

Table 7. Winter Rate Schedule TOU PA: Off-Peak, Mid-Peak and On-Peak Energy Rates........10

Table 8. Comparison Rate Schedule TOU PA-2, PA-A and PA-B...............................................10

Table 9. Stringfellow Superfund Site Summary............................................................................14

Table B-1. Cost, System, and other Assessment Assumptions......................................................26
1

1 Study Location

Industrial wastes were disposed of on the Stringfellow Superfund Site1

In 1983, the site was listed as a Superfund site on the National Priorities List as 

California's highest priority hazardous waste site. The California Department of Toxic 

Substances Control is responsible for monitoring and operating remediation systems at 

the site. These systems include three groundwater extraction and treatment systems 

extending from the waste disposal site into Glen Avon, California.

(the site) from 

1956 to 1972. During this period, up to 20 unlined surface impoundments for liquid 

wastes were located in the 17-acre disposal area. Approximately 34 million gallons of 

liquid wastes containing spent acids, solvents, pesticide-manufacturing byproducts, heavy 

metals, and various organic and inorganic compounds were discharged into the surface 

impoundments during the operational period.

Assessment team members from NREL, the State of California and the U.S. 

Environmental Protection Agency (EPA) conducted a site assessment visit on December 

17, 2009 to determine whether PV is feasible for the site. Team members and their 

contact information are included in Appendix A.

 1 For more information about the site, see http://yosemite.epa.gov/r9/sfund/r9sfdocw.nsf/

3dec8ba3252368428825742600743733/0c1b8f989b2c080288257007005e9440!opendocument.
2

2 Photovoltaic (PV) Systems

Photovoltaics (PV) are semiconductor devices that convert sunlight directly into 

electricity. They do so without any moving parts and without generating any noise or 

pollution. They must be mounted in unshaded locations: rooftops, carports and groundmounted arrays are common mounting locations. PV systems are well suited to the sunny

Riverside, California area, where the average global horizontal annual solar resource—

the total solar radiation for a given location, including direct, diffuse, and groundreflected radiation—is 5 kWh/m2

/day, which is excellent.

This number, however, is not the amount of energy that can be produced by a PV panel in 

this location. The amount of energy produced by a panel depends on the several factors, 

including the type of collector, the tilt and azimuth of the collector, the module 

temperature, the level of sunlight and the weather conditions. An inverter is required to 

convert the direct current (DC) to alternating current (AC) of the desired voltage 

compatible with building and utility power systems. The balance of the system consists of 

conductors/conduit, switches, disconnects and fuses. Grid-connected PV systems feed 

power into the facility’s electrical system and do not include batteries. Figure 1 shows the 

major components of a grid-connected PV system and illustrates how these components 

are interconnected.

Figure 1. Major components of grid-connected photovoltaic (PV) system

PV panels are very sensitive to shading. When shade falls on a panel, that portion of the 

panel is unable to collect the high-energy beam radiation from the sun. PV panels are 

made up of many individual cells that all produce a small amount of current and voltage. 

These individual cells are connected in series to produce a larger current. If an individual 

cell is shaded, it acts as resistance to the whole series circuit, impeding current flow and 

dissipating power rather than producing it. The NREL solar assessment team uses a 

SolmetricTM solar path calculator to assess shading at particular locations by analyzing 
3

the sky view where solar panels will be located. By finding the solar access, the NREL 

team can determine if the area is appropriate for solar panels.

If a site is found to have much potential for a PV system, the next step is to determine the 

size of the system. System size depends highly on the average energy use of the facilities 

on the site. It is generally not advisable to provide more energy than the site will use due 

to the economics of most net metering agreements.

2.1 Types of PV Systems

2.1.1 Ground-Mounted Systems

Ground-mounted PV systems are usually the lowest cost option to install on a $/DC-Watt 

basis. There are several mounting options available, each having different benefits for 

different ground conditions. Table 1 outlines the energy density values that can be 

expected from each of the different system types. Due to the lack of hybrid HE panels as 

a significant portion of the commercial market, they were not included in the financial

analysis. Installing panel types that do not hold a significant portion of the commercial 

market would not be feasible for a large-scale solar generation plant.

Table 1. Energy Density by Panel and System

System Type Fixed Tilt Energy Density 

(DC-Watts/Sq. Ft)

Single Axis Tracking 

Energy Density

(DC-Watts/Sq. Ft)

Crystalline Silicon 4 3.3

Thin Film 3.3 2.7

Hybrid HE 4.8 3.9

For the purposes of this analysis, it was assumed that crystalline silicon PV panels are 

used. In order to get the most out of the ground area available, it is important to consider 

whether the site layout can be improved to better incorporate a solar system. If there are 

unused structures, fences, or electrical poles that can be removed, the un-shaded area can 

be increased to incorporate more PV panels. When considering a ground-mounted 

system, an electrical tie in location should be identified to determine how the energy 

would be fed back into the grid. For this report, only fixed axis ground-mounted systems 

and single axis tracking systems will be considered. Fixed tilt systems are installed at a 

specified tilt, and are fixed at that tilt for the life of the system. Single axis tracking 

systems have a fixed tilt (horizontal in this case) on one axis and a variable tilt on the 

other axis. The system is designed to follow that sun in its path through the sky. This 

allows the solar radiation to strike the panel at an optimum angle for a larger part of the 

day than can be achieved with a fixed axis system. A zero tilt (horizontal) single axis 

tracking system will collect about 18% more electricity per capacity (kW) than a fixedtilt (non-tracking) system at Stringfellow. The drawbacks include increased operation and 

maintenance (O&M) costs, less capacity per unit area to avoid self-shading (DCWatt/ft2), and greater installed cost ($/DC-Watt). The annual energy production per unit 

area (kWh/ft2) is slightly less with single axis tracking, but adequate land should be 

available at Stringfellow, so this is not an issue. The performance specifications will 
4

allow either fixed tilt or single axis tracking at any tilt; the evaluation criteria will include 

O&M costs.

2.1.2 Roof-Mounted Systems

In many cases, the roof is the best location for a PV system. On this site, no roof area is 

available, so roof-mounted analysis will not be conducted.

2.2 PV System Components

The PV system considered here has these components:

• PV arrays, which convert light energy to DC electricity

• Inverters, which convert DC to alternating current and provide important 

safety, monitoring and control functions

• Various wiring, mounting hardware, and combiner boxes

• Monitoring equipment

2.2.1 PV Array

The primary component of a PV system, the PV array, converts sunlight to electrical 

energy; all other components simply condition or control energy use. Most PV arrays 

consist of interconnected PV modules that range in size from 50 peak DC-Watts to 300 

peak DC-Watts. Peak watts are the rated output of PV modules at standard operating 

conditions of 25°C (77F) and insolation of 1,000 Watts/m2. Because these standard 

operating conditions are nearly ideal, the actual output would be less under typical 

environmental conditions. PV modules are the most reliable components in any PV 

system. They have been engineered to withstand extreme temperatures, severe winds and 

impacts. ASTM E1038-052 subjects modules to impacts from one-inch hail balls at 

terminal velocity (55 mph) at various parts of the module. PV modules have a life 

expectancy of 20–30 years, and manufacturers warranty them against power degradation 

for 25 years. The array is usually the most expensive component of a PV system; it 

accounts for approximately two-thirds the cost of a grid-connected system. A large 

choice of PV manufacturers is available.3

2.2.2 Inverters

PV arrays provide direct current power at a voltage that depends on the configuration of 

the array. This power is converted to alternating current at the required voltage and number 

of phases by the inverter. Inverters enable the operation of commonly used equipment such 

as appliances, computers, office equipment and motors. Existing inverter technology 

provides true sine wave power at a quality often better than that of the serving utility. The 

locations of both the inverter and the balance of the system equipment are important.

Inverters are available that include most or all of the control systems required for 

 2 ASTM Standard E1038, 2005, "Standard Test Method for Determining Resistance of Photovoltaic 

Modules to Hail by Impact with Propelled Ice Balls," ASTM International, West Conshohocken, PA, 2005, 

DOI: 10.1520/E1038-05. http://www.astm.org/Standards/E1038.htm 3 Go Solar California, a joint effort of the California Energy Commission and the California Public Utilities 

Commission, provides consumer information for solar energy systems. See http://www.gosolarcalifornia

.org/equipment/pvmodule.php.
5 

operation, including some metering and data-logging capability. Inverters must provide 

several operational and safety functions for interconnection with the utility system. The 

Institute of Electrical and Electronic Engineers, Inc (IEEE) maintains standard “P929 

Recommended Practice for Utility Interface of Photovoltaic (PV) Systems,”4 which allows 

manufacturers to write “Utility-Interactive” on the listing label if an inverter meets the 

requirements of frequency and voltage limits, power quality, and non-islanding inverter 

testing. Underwriters Laboratory maintains “UL Standard 1741, Standard for Static 

Inverters and Charge Controllers for Use in Photovoltaic Power Systems,”5 which 

incorporates the testing required by IEEE P929 and includes design (type) testing and 

production testing. A large choice of inverter manufacturers is available.6

2.2.3 Operation and Maintenance

The PV panels come with a 25-year performance warranty. The inverters, which come 

standard with a five-year or ten-year warranty (extended warranties available), would be 

expected to last 10-15 years. System performance should be verified on a vendor 

provided web site. Wire and rack connections should be checked annually. This 

economic analysis uses an annual O&M cost computed as 0.17% of the total installed 

cost, which is based on the historical operation and maintenance (O&M) costs of installed 

fixed-axis grid tied PV systems. For the case of single-axis tracking, the analysis uses an 

annual O&M cost of 0.35% of total installed cost based on the historical costs existing 

single-axis tracking systems.

2.3 PV Size and Performance

The PV arrays must be installed in unshaded locations on the ground or on building roofs 

that have an expected life of at least 25 years. For this assessment, the predicted array 

performance was determined using PVWatts, TM a performance calculator for gridconnected PV systems created by NREL’s Renewable Resource Data Center.7 The 

performance data was used to calculate the amount of revenue that could be expected 

each year. The project economics were based on this analysis; the calculations can be 

found in Appendix B. 

 

4 ANSI/IEEE Std 929-1988 IEEE Recommended Practice for Utility Interface of Residential and 

Intermediate Photovoltaic (PV) Systems, http://standards.ieee.org/reading/ieee/std_public/

description/powergen/929-1988_desc.html. 5 Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed 

Energy Resources: UL 1741 (http://ulstandardsinfonet.ul.com/scopes/1741.html) 6 Go Solar California approves inverters.

7 http://www.nrel.gov/rredc/pvwatts/
6 

3 Photovoltaic (PV) Sites 

3.1 PV Size and Performance 

PV arrays must be installed in un-shaded locations on the ground or on building roofs 

that have an expected life of at least 25 years. The site has excellent annual solar access 

of 96% based on solar access measurements taken during the site visit; see Appendix C 

for details. The predicted array performance was found using PVWatts Version 2 for 

Riverside, California.8 Table 2 shows the station identification information, PV system 

specifications, and energy specifications for the site. 

Table 2. Site Identification Information and Specifications 

Station Identification 

Cell ID 176362 

State California 

Latitude 34.0° N 

Longitude 117.3° W 

PV System Specifications 

DC Rating 1.00 kW 

DC to AC Derate Factor 0.77 

AC Rating 0.77 kW 

Array Type Fixed Tilt 

Array Tilt 20.0° 

Array Azimuth 180.0° 

Energy Specifications 

Cost of Electricity 13.0 ¢/kWh

 

 

8

PV Watts is a performance calculator for grid-connected PV systems. It was created by NREL’s 

Renewable Resources Data Center. For more information, see http://rredc.nrel.gov/solar/calculators/

PVWATTS/version2/
7

Table 3 shows the performance results in kWh/kW for 20-degree fixed-tilt PV from 

PVWatts for Riverside.

Table 3. Performance Results for 20-degree fixed-tilt PV

Month Solar Radiation

(kWh/m2

/day)

AC Energy

(kWh)

Energy Value

($)

1 4.22 94 12.22

2 4.80 98 12.74

3 5.64 126 16.38

4 6.40 135 17.55

5 7.02 152 19.76

6 7.70 157 20.41

7 7.59 158 20.54

8 7.45 154 20.02

9 6.55 132 17.16

10 5.39 116 15.08

11 4.61 99 12.87

12 4.00 89 11.57

Year 5.95 1510 196.30

Table 4 shows the performance results for 0-tilt single-axis tracking PV from PVWatts 

for Riverside.

Table 4. Performance Results for 0-degree single-axis PV

Month Solar Radiation

(kWh/m2

/day)

AC Energy

(kWh)

Energy Value

($)

1 4.14 95 12.35

2 5.16 107 13.91

3 6.43 146 18.98

4 7.86 170 22.10

5 8.80 193 25.09

6 9.54 196 25.48

7 9.72 204 26.52

8 9.15 192 24.96

9 7.61 157 20.41

10 5.80 128 16.64

11 4.63 101 13.13

12 3.87 88 11.44

Year 6.90 1775 230.75
8

3.1.1 Energy Use

The site has nine different Southern California Edison (SCE) meters. The majority of the 

energy use, 430,512 kWh annually from May 2007 through April 2008, is for the 

treatment plant, meter ID 3-029-1238-11, the last meter listed in Table 5. Table 6 and 

Table 7 describe seasonal and time-of-use energy rates during the summer season.

9

Table 5. Meters and Rates Schedules

Meter ID

Rate

Schedule

Peak (kW)

Apr' 08

Total Annual Energy 

Consumption

(kWh)

Mean Monthly Energy 

Consumption

(kWh)

3-029-1236-34 PA-2 12 46,296 3,858 

3-029-1236-54 PA-2 5 22,785 1,899 

3-029-1236-63 GS-2 16 15,313 1,276 

3-029-1237-60 PA-2 9 56,798 4,733 

3-029-1237-80 PA-2 2 17,670 1,473 

3-029-1237-89 PA-2 4 34,290 2,858 

3-029-1237-97 PA-2 3 23,129 1,927 

3-029-1238-05 PA-2 1 1,826 152 

3-029-1238-11 PA-2 165 430,512 35,876 

Annual Site Total (kWh) 648,619

 9 Detailed rate schedule is available at http://www.sce.com/NR/sc3/tm2/pdf/ce43-12.pdf. This detailed rate 

schedule does not contain information on different on and off-peak rates as described above. The electric 

bills were annualized, and it was determined that the rates are higher in the summer season, but on- and offpeak rates are not currently being charged. Rate schedule PA-2, an “agricultural and pumping” rate, is used 

for most of the site. For more information, see http://www.sce.com/NR/rdonlyres/

7E7A46DB-7DDD-468F-A3C8-8F187C68F06C/0/081212_Power_Agriculture_2.pdf.
9

Tables 6, 7, and 8 show the time-of-use (TOU) PA- rate PA-2 and TOU-PA rate 

schedules. The PA-2 schedule is a seasonal rate (winter and summer) that includes a 

periodic demand charge based upon the peak electrical load realized in any 15-minute 

interval during the billing period. The current demand charge is approximately one-third 

of cost billed to the pump and treat plant (PTP) account. An analysis of the 15-minute 

interval data by DTSC indicates that the peak demand during the last 12 months was 192 

kW. If the PTP demand increases to 200 kW, the utility would require that DTSC switch 

the PTP to the time-of-use rate schedule, TOU-PA. Schedule TOU-PA has energy rates 

for off-peak, mid-peak, and on-peak periods during summer and winter months. In 

addition, schedule TOU-PA includes a service charge or demand charge, depending upon 

which of two options, “Rate A” or “Rate B,” is elected under the schedule. According to 

a SCE rate analyst10, Rate A likely would be the better option for the PTP.11 NREL 

recommends consideration of TOU PA Rate B because most motors at the treatment 

plant are on variable speed drives which limit demand kW as compared to Rate A based 

on motor name plate HP. Rate B has lower On-Peak and Mid-Peak Rates. NREL did not 

conducted detailed rate analysis for the Stringfellow site but has analyzed similar TOU 

rates in San Diego and determined that the combination of low demand charges, low offpeak rates and low energy use during peak hours (due to the PV system’s contribution) 

results in the lowest cost.

12

 10 Telephone conversation between Judy Zimmerman of SCE and Mikos Fabersunne of DTSC, November 

19, 2010. Zimmerman recommended that DTSC switch from PA-2 to TOU-PA as soon as possible and

estimated that the annual savings for operating the PTP, without the PV system, would be approximately 

$5000.

11 Tables 6 and 7 come from http://www.sce.com/NR/rdonlyres/7E7A46DB-7DDD-468F-A3C8-

8F187C68F06C/0/081212_Power_Agriculture_2.pdf. 12 See Doris, Ong, and Van Geet (July 2009). “Rate Analysis of Two Photovoltaic Systems in San Diego.” 

NREL/TP-6A2-43537 Golden, CO: National Renewable Energy Laboratory. http://www.nrel.gov/docs/

fy09osti/43537.pdf.
10

Table 6. Summer Rate Schedule TOU PA: Off-Peak, Mid-Peak and On-Peak Energy Ratesa

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Mid-Peak Energy Rateb

On-Peak Energy Ratec

Mid-Peak Energy Rated

Off-Peak Energy Ratee

a Summer season begins 12:00 a.m., June 1 and continues until 12:00 a.m.,

October 1.

b 8:00 a.m. - 12:00 a.m. weekdays except holidays c 12:00 a.m. - 6:00 p.m. weekdays except holidays d 6:00 p.m. - 11:00 p.m. weekdays except holidays e all other hours

Table 7. Winter Rate Schedule TOU PA: Off-Peak, Mid-Peak and On-Peak Energy Ratesa

Monday Tuesday Wednesday Thursday Friday Saturday Sunday

Mid-Peak Energy Rateb

Off-Peak Energy Ratec

a Winter season begins 12:00 a.m., October 1 and continues until 12:00 a.m., June 1.

b 8:00 a.m. - 9:00 p.m. weekdays except holidays c 9:00 p.m. - 8:00 a.m. weekdays and all day on weekends including holidays

Table 8. Comparison Rate Schedule TOU PA, PA-A and PA-B

Rate $/kW $/HP

Summer 

($/kWh on 

peak)

Summer 

($/kWh mid

peak)

Summer 

($/kWh off 

peak)

Winter 

($/kWh mid

peak)

Winter 

($/kWh off 

peak)

PA-2 8.06 -- 0.11582 0.11582 0.11582 0.05944 0.05944

PA- A -- 4.89 0.229858 0.0925 0.03646 0.07782 0.03444

PA-B 7.83 -- 0.10745 0.0615 0.03648 0.06096 0.03446
11

3.1.2 Net Metering

Net metering is an electricity policy for consumers who own renewable energy facilities. 

"Net", in this context, is used to mean, "what remains after deductions"—in this case, the 

deduction of any energy outflows from metered energy inflows. Under net metering, a 

system owner receives retail credit for at least a portion of the electricity it generates. As 

part of the Energy Policy Act of 2005,

13

[2]

under Sec. 1251, all public electric utilities are 

required upon request to make net metering available to their customers. :

(11) NET METERING.—Each electric utility shall make available upon 

request net metering service to any electric consumer that the electric 

utility serves. For purposes of this paragraph, the term ‘net metering 

service’ means service to an electric consumer under which electric energy 

generated by that electric consumer from an eligible on-site generating 

facility and delivered to the local distribution facilities may be used to 

offset electric energy provided by the electric utility to the electric 

consumer during the applicable billing period.

California's net-metering law,14

Net excess generation (NEG) is carried forward to a customer's next bill. Under prior 

law, any NEG remaining at the end of each 12-month period was granted to the 

customer's utility. In 2009, California Assembly Bill 920 (AB920)

which took effect in 1996, requires utilities to offer net 

metering to all customers with solar and wind-energy systems up to 1 megawatt (MW).

15

Renewable energy certificates (RECs)

gave net metering 

customers two additional options for the NEG remaining after a 12-month period. They 

can roll over any remaining NEG from month-to-month indefinitely, or they can receive 

financial compensation from their utility for the remaining NEG. By January 1, 2011, the 

California Public Utilities Commission (CPUC) must develop a compensation valuation 

for the remaining NEG if customers choose the financial compensation option. The ratemaking authorities of publicly-owned utilities must develop their own compensation 

methods for the remaining NEG through public proceedings. By January 31, 2010, 

utilities must notify all of their net metering customers of these new options. If the 

customer makes no affirmative election for either option, the utility will be granted their 

NEG at the end of the 12-month period with no compensation to the customer. 

16

 13 For a summary of this bill and its full text, see 

, also known as green certificates, green tags, or 

tradable renewable certificates, are tradable commodities in the United States that 

represent proof of electric energy generation from eligible renewable energy resources

(renewable electricity). The RECs that are associated with the electricity produced and 

are used on-site remain with the customer-generator. If, however, the customer chooses 

to receive financial compensation for the NEG remaining after a 12-month period, the 

utility will be granted the RECs associated with only that surplus they purchase.

http://frwebgate.access.gpo.gov/cgi-in/getdoc.cgi?dbname

=109_cong_bills&docid=f:h6enr.txt.pdf. 14 For more information about California's net metering law, see http://www.dsireusa.org/incentives/

incentive.cfm?Incentive_Code=CA02R&re=1&ee=1. 15 http://www.leginfo.ca.gov/pub/09-10/bill/asm/ab_0901-0950/ab_920_bill_20091011_chaptered.pdf 16 For a description of RECs, see http://apps3.eere.energy.gov/greenpower/markets/

certificates.shtml.
12

California does not allow any new or additional demand charges, standby charges, 

customer charges, minimum monthly charges, interconnection charges, or other charges 

that would increase an eligible customer-generator's costs beyond those of other 

customers in the rate class to which the eligible customer-generator would otherwise be 

assigned. The CPUC has explicitly ruled that technologies eligible for net metering (up to 

1 MW) are exempt from interconnection application fees, as well as from initial and 

supplemental interconnection review fees.

Publicly owned utilities may elect to provide co-energy metering, which is the same as 

net metering, except that it incorporates a time-of-use (TOU) rate schedule. Customergenerators with systems sized between 10 kW and 1 MW, who are subject to time-of-use 

rates, are entitled to return electricity to the system for the same TOU (including realtime) price that they pay for power purchases. However, TOU customers who choose to 

co-energy meter must pay for the metering equipment capable of making such 

measurements. Customer-generators retain ownership of all RECs associated with the 

generation of electricity they use on site.

3.1.3 Virtual Net Metering

California Assembly Bill 2466 (AB 2466),

17 codified as Section 2830 of the Public 

Utilities Code, was signed into law by Governor Schwarzenegger in September 2008 and 

became effective on January 1, 2009. The law allows a local government to install 

renewable generation of up to 1 MW at one location within its geographic boundary and 

to generate credits that can be used to offset charges at one or more other locations within 

the same geographic boundary. This billing arrangement is called virtual net metering 

(VNM). 18

The California State Legislature defined local government to include cities, counties, 

school districts, special districts, political subdivisions or other local public agencies that 

are authorized to generate electricity. The legislature decided that the tariff would not be 

available for the state, any agency or department of the state, or any joint powers 

authority. Because the site is a state site, it probably does not qualify under AB2466 for 

VNM. However, SCE could allow VNM if they choose to. The SCE customer 

representative for the site customer should be asked if VNM whether an option.

IF SCE were to allow VNM, energy use for the entire site could be offset by a larger 

system. This would also allow a lower installation cost because all PV could be fed into 

the closest SCE connection point rather than having to tie into the treatment plant 

distribution panel, which is about 400 feet away. The connection point could also be used 

for the future plant. A new transformer may be required. A “feed in” meter would be 

installed and would credit the other meters on site. The cost of a new meter and tie-in is 

assumed to be $10,000 for this economic analysis.

Because it is unknown whether SCE will allow VNM, these options were analyzed:

 17 http://www.leginfo.ca.gov/pub/09-10/bill/asm/ab_2451-2500/ab_2466_bill_20100428_amended_asm_

v98.pdf

18 For more information about VNM, see http://www.pge.com/b2b/newgenerator/ab2466/.
13

• Size the installed PV system to offset the annual load of the existing treatment 

plant, which is about 430,000 kWh. Tie the PV system into the existing plant 

after the meter, which would require about 400 feet of new overhead 

transmission line at 480V. Recent case studies have quoted the costs of new 

transmission lines at $1.5 Million per mile installed.

19

• Size the installed PV system to offset the annual load of the existing treatment 

plant, which is about 648,000 kWh. Tie the PV system into the existing SCE 

distribution at the closest available location and feed a new meter for VNM. 

The cost of the SCE tie-in was assumed to be $10,000.

Therefore, the new 

transmission will add an estimated $120,000.

 19 http://news.cnet.com/Shrinking-the-cost-for-solar-power/2100-11392_3-6182947.html
14

Table 9. Stringfellow Superfund Site Summary

Tie-in

Location

Array 

Tilt 

(Deg)

Area (ft2

) 

Required

PV 

Syst. 

Size 

(kW)

Annual 

Output 

(kWh/yr)

Annual 

Cost 

Savings 

after 

O&M 

($/year)

Electrical 

Tie-in

Cost ($)

Total 

System 

Cost with 

No 

Incentives 

($)

Payback 

Period 

with No 

Incentive 

(years)

CSI 

Incentive 

$0.26/kWh 

for 5 

Years, $ 

after 5 

Years

Cost $ 

after 5 

years of 

CSI 

incentives

Payback 

Period 

after CSI 

Incentive 

(years)

Ground-mounted; Treatment Plant only = 430,000 kWh annual

Treatment 

plant

20 71,192 285 430,000 53,479 120,000 1,543,841 29 559,000 984,841 18

Treatment 

plant

Single 

axis

73,410 242 430,000 53,429 120,000 1,573,521 29 559,000 1,014,521 19

Stringfellow Superfund Site with virtual net metering = 648,000 kWh annual

Site 20 107,285 429 648,000 80,592 10,000 2,155,695 27 842,400 1,313,295 16

Site Single 

axis

110,627 365 648,000 80,516 10,000 2,200,423 27 842,400 1,358,023 17
15

3.1.4 PV Location

The proposed PV system would be located in the existing truck parking area, which is 

visible in the bottom center of Figure 2. The center of parking lot NE of PTP is:

Latitude: 34.026850 (34° 1' 36.660" N)

Longitude: -117.455430 (118° 32' 40.452" W)

Figure 2. Aerial photograph showing proposed treatment plant and PV location

The existing plant is located in the bottom center of the image.

Credit: California Department of Toxic Substances Control

Figures 3 and 4 show the proposed treatment plant location and the existing site plan, 

respectively. Figure 5 depicts the proposed PV location, and Figure 6 depicts an SCE 

meter and electrical distribution panels serving the existing plant.
16

Figure 3. Site plan showing proposed treatment plant location

Credit: California Department of Toxic Substances Control and Tetra Tech Inc.
17

Figure 4. Existing site plan showing topographic contours and proposed PV location in center and east portion of truck parking area

Credit: California Department of Toxic Substances Control and Tetra Tech Inc.
18

a) Truck parking area looking south, PV 

proposed in center and east portion of area, new 

treatment plant on west (right side of picture). 

Arrow shows existing SCE overhead electrical 

distribution on west edge of parking area. Credit: 

Otto Van Geet, NREL

b) Closer view of flat truck parking area that is 

well suited for PV. Credit: Otto Van Geet, 

NREL

c) West side of truck parking area looking 

southwest, new treatment plant on west (right 

side of picture); arrow shows existing SCE 

overhead electrical distribution on west edge of 

parking area. Credit: Otto Van Geet, NREL

d) Closer view of SCE overhead electrical 

distribution and possible PV tie-in location if 

virtual net metering were allowed by SCE.

Credit: Otto Van Geet, NREL
19

e) Existing treatment plant looking east. Credit: 

Otto Van Geet, NREL

f) SCE overhead electrical distribution serving 

existing plant. Credit: Otto Van Geet, NREL

Figure 5. Photographs of proposed PV in center and east portion of truck parking area
20

a) SCE main meter 3-029-1238-11 in main 

distribution & metering panel “MDP” at existing 

treatment plant located in center of plant.

b) Electrical distribution panels serving existing 

plant.

c) Electrical distribution panels serving existing plant.

Figure 6. Photographs of SCE meter and electrical distribution panels serving

existing plant
21

4 Economics and Performance

4.1 Assumptions and Input Data for Analysis

For this analysis, the following input data were used. The installed cost of fixed tilt 

ground-mounted systems was assumed to be $5/W, and the installed cost of a single-axis

was assumed to be $6/W. These prices include the PV array and the balance-of-system 

(BOS) components for each system, including the inverter and electrical equipment, as 

well as the installation cost. The economics of grid-tied PV depend on incentives, the cost 

of electricity, the solar resource, and panel tilt and orientation. For this analysis, the cost 

of electricity was assumed to be $0.13 as reported by the State of California based on 

electric bills for the site.

Figure 7. PV Costs20

A system DC to AC conversion of 77% was assumed. This included losses in the 

inverter, wire losses, PV module losses, and losses due to temperature effects, and other 

losses. Figure 7 summarizes average system installation costs for grid-tied U.S. PV 

systems in 2008; however, the costs have dropped significantly since 2008. PVWATTS

Version 2 was used to calculate energy performance.

It was assumed for this analysis that federal incentives are received. It is important to find 

incentives or grants to make PV cost effective. If the PV system is owned by a private 

tax-paying entity, this entity may qualify for a 30% federal tax credit and accelerated 

depreciation on the PV system, which is worth about 15%. The total potential tax benefits 

to the tax-paying entity are about 45% of the system cost. Because the state and federal 

governments do not pay taxes, private ownership of the PV system would be required to 

capture tax incentives.

 20 Wiser, R.; Barbose, G.; Peterman, C.; Darghouth, N. (2009). “Tracking the Sun II: The Installed Cost of 

Photovoltaics in the U.S. from 1998-2008.” LBNL-2674E. Berkeley, CA: Lawrence Berkeley National 

Laboratory.
22

4.2 Other Incentives and Financing Opportunities

The Database of State Incentives for Renewable Energy (DSIRE) provides a summary of 

net metering, interconnection and incentives available to customers. The utility for the 

site is SCE.

Net Metering Agreement—California's net-metering law, which took effect in 1996, 

requires all utilities, to offer net metering to all customers for solar and wind-energy 

systems up to 1 megawatt (MW).

Interconnection—Net metering in California applies to renewable-energy systems up to 

1 MW in capacity and includes provisions for TOU net metering. Net-metered systems 

up to 1 MW are exempt from paying costs associated with the interconnection studies, 

distribution system modifications or application review fees discussed below.

21

Performance-based incentives (PBI) for systems that are 30 kW and larger began in 2007 

at $0.39/kWh for the first five years for taxable entities and at $0.50/kWh for the first five 

years for government entities and nonprofits. The incentive levels decline as the 

aggregate capacity of PV installations increases. PBI will be paid monthly based on the 

actual amount of energy produced over five years. Residential and small commercial 

projects under the 30-kW threshold can also choose to opt in to the PBI rather than the 

upfront Expected Performance-Based Buydown approach. However, all installations of 

30 kW or larger must take the PBI.22 The program is managed by Southern California 

Edison (SCE).

23

Current incentives are $0.15/kWh for commercial customer-generators and $0.26/kWh 

for government and non-profit customer-generators. Locking in at the existing incentive 

level—when Step 7 is reached for SCE the incentives drop to $0.09/kWh for commercial 

customer-generators and to $0.19/kWh for government and non-profit customergenerators— is strongly recommended.

NREL also evaluated the SCE CREST program.

24 CREST is a PPA, not a net metering 

agreement like CSI. A Net Generation Output Meter ("NGOM") where SCE pays the 

owner for the energy generated. Stringfellow would still buy energy from SCE under the 

current rate. The CREST program uses a Season Period Energy Adjustment Factor (EAF)

multiplied by the base rate for 25 years:

 21 For details, see http://www.dsireusa.org/incentives/index.cfm?re=1&ee=1&spv=0&st=0&srp=1

&state=CA. 22 For current incentive levels (Step) for each utility, see http://www.csi-trigger.com/. 23 For more information, see http://www.csi-trigger.com/details.aspx?Administrator.

=SCE

24 For more information, see http://www.sce.com/EnergyProcurement/renewables/crest.htm
23

• On-Peak weekday summer, noon-6 pm, 3.13 x $0.10442 = $0.326/kWh

• Mid-Peak weekday summer, 8-noon, 6 - 11 pm, 1.35 x $0.10442 = $0.14/kWh

• Summer: June-September Off-Peak

• All other times 0.75 x $0.10442 = $0.078/kWh

Figure 8. SAM input used to evaluate the economics of CREST versus CSI Steps 6 and 7

The NREL Solar Advisor Model (SAM) was used to evaluate the economics of CREST 

versus CSI Steps 6 and 7, and the SAM input is shown above. The result is that CSI Steps 

6 and 7 has far better economics that CREST, and most future Step in CSI will still have 

better economics. This is because the CREST program provides so little high revenue. On 

Peak and Mid Peak times, and the cost paid during off peak are poor. Participation in the 

current CREST program is not recommended. For detailed results, see Appendix D.

Several options are available for getting solar PV systems financed. One potentially 

feasible financing option is third-party ownership under a power purchase agreement 

(PPA). The PPA works by having a solar contractor install, finance, and operate the 

system while there is a contract in place for a utility company to purchase the electricity 

generated by the system. The system is financed by the solar contractor, and the 

payments are paid by the electricity that is sold to the utility. In this arrangement, the land 

that the solar system occupies must be leased to the owner of the system for the duration 

of the contract. 
24

5. Conclusions and Recommendations 

The site locations considered for a solar PV system in this report are excellent areas in 

which to implement solar PV systems. Using land that cannot be used for other purposes 

would minimize the environmental impact of a solar generation plant. Installing a PV 

system on the compromised land at the site would reduce the amount of energy used to 

run the Stringfellow treatment plant.

It is recommended that the site facilitator, the state of California, contact SCE and 

attempt to set up a VNM agreement for the site. When the system goes out to bid, a 

design-build contract should be issued that requests the best annual output (kWh/yr) at 

the best price and which lets the vendors optimize system configuration, including slope

and the option for single-axis tracking. For multiple reasons—the high cost of energy, the 

dropping cost of PV, the existence of an excellent solar resource and excellent SCE 

incentives—a government-owned PV system provides a reasonable payback, is easy to 

implement, and is therefore recommended. If funding is not available, a third- party 

ownership PPA arrangement is the most feasible way for a system to be financed on this 

site.
25

Appendix A. Contacts and Assessment Team Members

Environmental Protection Agency (EPA) 

Lura Matthews

Center for Program Analysis

Office of Solid Waste and Emergency Response

U.S. Environmental Protection Agency

matthews.lura@epamail.epa.gov

202-566-2539

Charnjit Bhullar,

Remedial Project Manager

Region 9

U.S. Environmental Protection 

Agency

Bhullar.Charnjit@epamail.epa.gov

707-315-5532

State of California

Mikos Fabersunne, P.E.

Legacy Landfill and RCRA Corrective Action Office

Brownfields and Environmental Restoration Program

Department of Toxic Substances Control

8810 Cal Center Drive

Sacramento, California 95826

mfabersu@dtsc.ca.gov

916-255-6543

Allen Wolfenden, Performance 

Manager

San Joaquin and Legacy Landfill 

Office

Department of Toxic Substances 

Control

AWolfend@dtsc.ca.gov

916-255-6540

Tej Pahwa, P.E., Supervising 

Hazardous Substances Engineer I

Legacy Landfill and RCRA Corrective 

Action Office

Department of Toxic Substances 

Control

TPahwa@dtsc.ca.gov

916-255-6548

National Renewable Energy Laboratory (NREL)

Otto VanGeet, P.E.

Senior Mechanical Engineer

303-384-7369

otto.vangeet@nrel.gov

Gail Mosey, Project Manager

303-384-7356

Gail.Mosey@nrel.gov
26

Appendix B. Assessment Assumptions and Assumptions for 

Calculations

Table B-1. Cost, System, and other Assessment Assumptions

Cost Assumptions

Variable Quantity of 

Variable

Unit of Variable

Cost of Site Electricity 0.13 $/kWh

Annual O&M (fixed) 0.17% % of installed cost

Annual O&M (tracking) 0.35% % of installed cost

System Assumptions

System Type Annual energy 

kWh/kW

Installed Cost 

($/W)

Energy Density 

(W/sq. ft.)

Ground fixed 5 acre/MW 20 degrees 1510 $5.00 4.0

Ground single-axis tracking 6 acre/MW 1775 $6.00 3.3

Other Assumptions

1 acre 43,560 sq ft.

1 MW 1,000,000 W

Ground 

Utilization

90% of available 

area
27

Appendix C. Solar Access Measurements

Figure B-1. Solar access measurements for proposed PV site
28

Appendix D. Comparison of SCE CREST to CSI Steps 6 and 

7 Using the Solar Advisor Model

Annual Revenue ($) NPV ($)

Year Case1

(CREST)

Case2

(CSI6)

Case2

(CSI7) Case1 Case2 Case3

1 81,531 259,215 212,689 77,649 246,872 202,561

2 81,531 259,215 212,689 73,951 235,116 192,916

3 81,531 259,215 212,689 70,430 223,920 183,729

4 81,531 259,215 212,689 67,076 213,257 174,980

5 81,531 259,215 212,689 63,882 203,102 166,648

6 81,531 86,405 86,405 60,840 64,477 64,477

7 81,531 86,405 86,405 57,943 61,406 61,406

8 81,531 86,405 86,405 55,184 58,482 58,482

9 81,531 86,405 86,405 52,556 55,697 55,697

10 81,531 86,405 86,405 50,053 53,045 53,045

11 81,531 86,405 86,405 47,670 50,519 50,519

12 81,531 86,405 86,405 45,400 48,114 48,114

13 81,531 86,405 86,405 43,238 45,822 45,822

14 81,531 86,405 86,405 41,179 43,640 43,640

15 81,531 86,405 86,405 39,218 41,562 41,562

16 81,531 86,405 86,405 37,351 39,583 39,583

17 81,531 86,405 86,405 35,572 37,698 37,698

18 81,531 86,405 86,405 33,878 35,903 35,903

19 81,531 86,405 86,405 32,265 34,193 34,193

20 81,531 86,405 86,405 30,728 32,565 32,565

21 81,531 86,405 86,405 29,265 31,014 31,014

22 81,531 86,405 86,405 27,872 29,538 29,538

23 81,531 86,405 86,405 26,544 28,131 28,131

24 81,531 86,405 86,405 25,280 26,791 26,791

25 81,531 86,405 86,405 24,076 25,516 25,516

Total 2,038,287 3,024,177 2,791,548 1,149,100 1,965,965 1,764,533
29

Appendix E. Electrical Single-Line Diagrams

Figure E-1 and E-2 show electrical single-line diagrams for the site and possible PV tie in 

locations.

Figure E-1. The 1200-amp main distribution and metering panel “MDP” at the existing 

treatment plant—with spaces for possible PV tie-in

Credit: State of California
30

Figure E-2. The 800-amp panel “PP” at the existing treatment plant—with spaces for 

possible PV tie-in

Credit: State of California
F1147-E(10/2008)

REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, 

gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this 

collection of information, including suggestions for reducing the burden, to Department of Defense, Executive Services and Communications Directorate (0704-0188). Respondents 

should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a 

currently valid OMB control number.

PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ORGANIZATION.

1. REPORT DATE (DD-MM-YYYY)

December 2010

2. REPORT TYPE

Technical Report

3. DATES COVERED (From - To)

4. TITLE AND SUBTITLE

Feasibility Study of Economics and Performance of Solar 

Photovoltaics at the Stringfellow Superfund Site in Riverside, 

California: A Study Prepared in Partnership with the Environmental 

Protection Agency for the RE-Powering America’s Land Initiative: 

Siting Renewable Energy on Potentially Contaminated Land and 

Mine Sites

5a. CONTRACT NUMBER

DE-AC36-08-GO28308

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

6. AUTHOR(S)

O. VanGeet and G. Mosey

5d. PROJECT NUMBER

NREL/TP-6A20-48770

5e. TASK NUMBER

WFD4.1000

5f. WORK UNIT NUMBER

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

National Renewable Energy Laboratory

1617 Cole Blvd.

Golden, CO 80401-3393

8. PERFORMING ORGANIZATION

REPORT NUMBER

NREL/TP-6A20-48770

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S)

NREL

11. SPONSORING/MONITORING

AGENCY REPORT NUMBER

12. DISTRIBUTION AVAILABILITY STATEMENT

National Technical Information Service

U.S. Department of Commerce

5285 Port Royal Road

Springfield, VA 22161

13. SUPPLEMENTARY NOTES

14. ABSTRACT (Maximum 200 Words)

This report presents the results of an assessment of the technical and economic feasibility of deploying a 

photovoltaics (PV) system on the Stringfellow Superfund Site in Riverside, California. The site was assessed for 

possible PV installations. The cost, performance, and site impacts of different PV options were estimated. The 

economics of the potential systems were analyzed using an electric rate of $0.13/kWh and incentives offered by 

Southern California Edison under the California Solar Initiative. According to the assessment, a government-owned, 

ground-mounted PV system represents a technically and economically feasible option. The report recommends 

financing options that could assist in the implementation of such a system.

15. SUBJECT TERMS

feasibility study; solar photovoltaics; PV system; ground-mounted PV; Stringfellow Superfund Site; brownfields; cost; 

performance; site impacts; financial incentives; financing options; Southern California Edison; California Solar 

Initiative

16. SECURITY CLASSIFICATION OF: 17. LIMITATION 

OF ABSTRACT

UL

18. NUMBER 

OF PAGES

19a. NAME OF RESPONSIBLE PERSON

a. REPORT

Unclassified

b. ABSTRACT

Unclassified

c. THIS PAGE

Unclassified 19b. TELEPHONE NUMBER (Include area code)

Standard Form 298 (Rev. 8/98)

Prescribed by ANSI Std. Z39.18