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

National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401 

303-275-3000 • www.nrel.gov

 

Department of Homeland 

Security, Science and 

Technology Directorate, Borders 

and Maritime Security Division: 

Renewable Energy Research 

Roadmap

 

Produced under direction of the U.S. Department of Homeland Security,

Science and Technology Directorate, Borders and Maritime Security 

Division by the National Renewable Energy Laboratory (NREL) under 

Interagency Agreement IAG-09-1727 and Task No. WFB9.2000

Technical Report 

NREL/TP-7A40-51491

July 2011
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

National Renewable Energy Laboratory

1617 Cole Boulevard, Golden, Colorado 80401 

303-275-3000 • www.nrel.gov

Department of Homeland 

Security, Science and 

Technology Directorate, 

Borders and Maritime Security 

Division: Renewable Energy 

Research Roadmap

Alicen Kandt and Scott Huffman

Disclaimer: This manuscript has been authored by employees of the Alliance 

for Sustainable Energy, LLC (“Alliance”) under Contract No. DE-AC36-

08GO28308 with the U.S. Department of Energy (“DOE”). The tables and 

figures in this report are limited to use in this report only and are not to be 

further disseminated or used without the permission of the sources cited.

Neither Alliance, DOE, 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 in this 

manuscript, 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 Alliance, 

DOE or the United States Government or any agency thereof. The views and 

opinions of authors expressed herein do not necessarily state or reflect those 

of Alliance, DOE or the United States government or any agency thereof.

Cover photo by Steve Wilcox, NREL PIX/15551

Technical Report 

NREL/TP-7A40-51491

July 2011
iii

Contacts

National Renewable Energy Laboratory 

Alicen Kandt

Senior Engineer 

1617 Cole Boulevard 

Golden, CO 80401 

Phone: 303-384-7518 

E-mail: alicen.kandt@nrel.gov 

Scott Huffman

Senior Engineer 

1617 Cole Boulevard 

Golden, CO 80401 

Phone: 303-275-4384 

E-mail: scott.huffman@nrel.gov

Department of Homeland Security

Jeanne Lin 

Deputy Director, HSARPA/Borders and 

Maritime Security Division, Science and 

Technology Directorate,

Department of Homeland Security

Washington, DC 20528 

Phone: 202-254-5737 

E-mail: jeanne.lin@dhs.gov 
iv

Acknowledgements 

The National Renewable Energy Laboratory (NREL) staff gratefully acknowledges the 

numerous NREL researchers who contributed to this report, including: Robert Thresher (marine 

hydrokinetic); Robi Robichaud (wind); Lin Simpson (batteries); Melanie Caton, Michael Penev, 

Huyen Dinh, Keith Wipke, John Lewis, and Chris Ainscough (fuel cells and hydrogen); Philip 

Pienkos and Jianping Yu (algae biomass); and Phillip Parilla (energy transfer). Andrea Watson 

and Heidi Blakley also contributed to the report review and compilation process.

The NREL staff wishes to acknowledge U.S. Department of Homeland Security (DHS) staff for 

support in coordinating site visits and data gathering, especially John Contreras (U.S. Customs 

and Border Protection [CBP] El Paso Sector), Sudie Hargis (U.S. Coast Guard [USCG] Alaska), 

and Merv Leavitt (CBP headquarters).
v 

List of Acronyms and Abbreviations

A amp

AC alternating current

AMFC alkaline membrane fuel cell

ARPA-E Advanced Research Projects Agency-Energy 

BAU business as usual

BES Basic Energy Science

BMD Borders and Maritime Security Division 

CBP U.S. Customs and Border Protection 

CERDEC Communications-Electronics Research, Development and 

Engineering Center 

CHP combined heat and power 

CIGS copper, indium, gallium, selenide

DARPA Defense Advanced Research Project Agency

DC direct current

DMFC direct methanol fuel cells

DOE U.S. Department of Energy 

DOD U.S. Department of Defense 

DHS U.S. Department of Homeland Security

EE Energy Efficiency 

EERE DOE Office of Energy Efficiency and Renewable Energy

EM electromagnetic

FAD fish aggregating device 

FOB forward operating base 

g/mol grams per mole 

GHG greenhouse gas

GW gigawatt 

HAWT horizontal axis wind turbine 

ICE U.S. Immigration and Customs Enforcement 

IEA-OES International Energy Agency’s Ocean Energy Systems 

Implementing Agreement 

IEC International Electrochemical Commission

kW kilowatt 

kWh kilowatt-hour 

kW/m2 kilowatts per square meter

LCC life cycle cost

LED light-emitting diode

Li lithium

Li-air lithium-air

LiFePO4 lithium iron phosphate

Li-ion lithium-ion 

LiPON lithium phosphorous oxynitride 

Li-S lithium-sulfur

MHK marine hydrokinetic 

MSS mobile surveillance system
vi 

MW megawatt

NASA National Aeronautics and Space Administration

NOx nitrogen oxide 

NREL National Renewable Energy Laboratory 

O&M Operations & Maintenance

ORPC Ocean Renewable Power Company

OTEC thermal energy gradient 

PEMFC proton-exchange membrane fuel cells

POC point of contact 

PV photovoltaic 

R&D research and development

R-21 Rescue-21 

RE Renewable Energy

RFID radio frequency identification 

RFP request for proposal 

rpm rotations per minute 

RVSS remote video surveillance system

S&T Science and Technology Directorate

SBI Secure Border Initiative

SOFC solid oxide fuel cell 

TAG triacylglyceride 

TI turbulence intensity 

TSA Transportation Security Administration

TSR tip speed ratio

TWh/yr terawatt-hours per year 

USABC U.S. Advanced Battery Consortium 

USCG U.S. Coast Guard 

USCIS U.S. Citizenship and Immigration Services

V volt 

VAWT vertical axis wind turbine 

W watt

Wh/kg watt-hour per kilogram 

Wh/L watt-hour per liter
vii 

Executive Summary

Within the U.S. Department of Homeland Security (DHS) Science and Technology (S&T)

Directorate, the Borders and Maritime Security Division (BMD) develops and transitions 

technologies that help enhance the security of our nation’s borders and waterways without 

impeding the flow of commerce and travelers. BMD is identifying next-generation renewableenergy solutions for inclusion in its research portfolio. Recognizing the potential of renewable 

energy to contribute to border security, BMD partnered with the U.S. Department of Energy 

(DOE) National Renewable Energy Laboratory (NREL) to examine border-security energy 

demands and to ensure that advances in renewable energy and energy storage lead to increased 

security in these areas. This research effort is funded by BMD and is a product of a 2-year 

interagency agreement between DHS S&T and DOE. NREL is a national laboratory of the DOE

Office of Energy Efficiency & Renewable Energy (EERE), operated by the Alliance for 

Sustainable Energy, LLC. 

NREL has examined the energy needs along U.S. borders—especially in remote areas—to 

identify opportunities to apply renewable energy solutions today and to define the near- and 

long-term research agendas that will position border components and activities to take advantage 

of renewable energy technologies in the future. This report is a result of those efforts. 

This report provides a summary of the work that BMD and NREL have performed to date. It 

provides an overview of renewable energy technologies that have applicability to DHS security 

operations, and highlights opportunities for future technology pilot projects or research initiatives 

that can supplement current technologies by developing solutions for DHS borders and maritime 

security operational needs. The research roadmap shown in Figure 1 illustrates these renewable 

energy pilot projects on a short-, mid-, and long-term timeline.
viii

Figure 1. DHS renewable energy roadmap outlining potential research opportunities. Illustration by Joshua Bauer, NREL
ix

Table of Contents

1 Introduction ............................................................................................................................................. 1

1.1 Overview: Department of Homeland Security Science and Technology Directorate, 

Borders and Maritime Security Division...................................................................................... 1

1.2 Renewable Energy Research Roadmap: Project Overview....................................................... 1

Workshops............................................................................................................................................ 2

Site Visits.............................................................................................................................................. 5

2 Renewable Energy Research and Technology Opportunities........................................................... 6

2.1 Solar Technology Overview.......................................................................................................... 6

Commercially Available Technologies.................................................................................................. 6

Emerging Photovoltaic Technologies................................................................................................... 7

Department of Homeland Security Relevance: Photovoltaic Applications........................................... 7

2.2 Wind................................................................................................................................................. 9

Technology Overview........................................................................................................................... 9

Commercially Available Technologies—Current/Future Research Trends........................................10

Wind Characteristics ..........................................................................................................................11

Department of Homeland Security Relevance: Options for Powering Remote 

Communication Stations ....................................................................................................................16

2.3 Energy Transfer Overview ..........................................................................................................20

2.3.1 Batteries ................................................................................................................................21

Department of Homeland Security Relevance: Battery Development ...............................................23

2.3.2 Wireless Energy Transfer......................................................................................................28

Rectenna Energy Transfer—Technology Overview...........................................................................28

Department of Homeland Security Relevance: Wireless Energy Transfer ........................................29

Inductive Coupling Energy Transfer—Technology Overview ............................................................30

Department of Homeland Security Relevance: Inductive Coupling Energy Transfer ........................30

Laser Energy Transfer—Technology Overview .................................................................................30

Department of Homeland Security Relevance: Laser Energy Transfer.............................................30

Thermoelectric Technologies—Technology Overview.......................................................................30

Department of Homeland Security Relevance: Thermoelectric Technologies ..................................31

2.3.3 Fuel Cells...............................................................................................................................32

Technology Overview.........................................................................................................................32

Department of Homeland Security Relevance: Fuel Cell Applications ..............................................36

2.4 Marine and Hydrokinetic Energy Technologies........................................................................39

Marine Hydrokinetic Energy Technologies Overview.........................................................................39

Marine Hydrokinetic Energy Resource Availability.............................................................................43

Marine Hydrokinetic Energy Technologies Global Deployment.........................................................45

Roadmap to Address Commercial Pathway and Challenges for Marine 

Hydrokinetic Technologies .................................................................................................................46

Department of Homeland Security Relevance: Marine Hydrokinetic Energy.....................................56

2.5 Biofuels and Algae.......................................................................................................................57

Technology Overview—Biodiesel Production ....................................................................................58
x 

Department of Homeland Security Relevance: Biofuel and Algae Applications ................................61

2.6 Energy Efficiency—Opportunities for Systemic Optimization of Existing and 

Future Systems ............................................................................................................................64

Department of Homeland Security Relevance: Optimize Existing Systems ......................................64

3 Conclusions ..........................................................................................................................................67

4 References.............................................................................................................................................68

Appendix A. Department of Homeland Security Workshops and Site Visits .....................................71

March 19, 2010 (Washington, DC): Introductory Workshop.............................................................71

Attendees ...........................................................................................................................................71

June 21, 2010 (Washington, DC): Data Gathering and Application Prioritization Workshop 

(CBP/NREL) ..................................................................................................................................71

Agenda: Monday, June 21, 2010 .......................................................................................................71

Attendees ...........................................................................................................................................72

June 21, 2010 (Washington, DC): Data Gathering and Application Prioritization Workshop 

(CBP/NREL) ..................................................................................................................................72

July 22–23, 2010 (Bellingham, WA): Northwest Border Low-Flier Workshop................................73

Agenda ...............................................................................................................................................73

Attendees ...........................................................................................................................................74

October 26–29, 2010 (El Paso, TX): El Paso Sector ..........................................................................74

Agenda ...............................................................................................................................................74

Attendees ...........................................................................................................................................76

April 5–9, 2011 (Juneau, AK): AK USCG Operations ........................................................................76

Agenda ...............................................................................................................................................76

Appendix B. Wind .....................................................................................................................................77

Windside ................................................................................................................................................77

Appendix C. Fuel Cells .............................................................................................................................78
xi 

List of Figures

Figure 1. DHS renewable energy roadmap outlining potential research opportunities. Illustration 

by Joshua Bauer, NREL.......................................................................................................... viii

Figure 2. Various types of horizontal and vertical access wind turbines. Illustration by Al Hicks, 

NREL .......................................................................................................................................... 13

Figure 3. Comparison of aerodynamic efficiencies of common types of wind turbines (based on 

Hau 2000). Illustration by NREL .............................................................................................. 15

Figure 4. Proven 11 downwind turbine with spring-loaded blade furling design. Photo from 

Proven Energy........................................................................................................................... 19

Figure 5. Fuel cell types, fuels, and applications. Illustration from DOE............................................ 32

Figure 6. Fuel cell basics. Illustration from DOE................................................................................... 33

Figure 7. Marine hydrokinetic technologies in development worldwide (Khan and Bhuyan 2009) . 40

Figure 8. Five typical wave-energy conversion devices (adapted from Bedard 2006). Illustration by 

NREL .......................................................................................................................................... 42

Figure 9. Four typical kinetic-energy conversion devices for tidal, ocean, and river currents 

(adapted from Bedard 2006). Illustration by NREL................................................................ 43

Figure 10. Total natural tidal-current energy and wave energy resources in United States; A: 

Alaska current, B: California current, C: Florida current, D: Gulf Stream, E: Labrador 

current (adapted from Bedard 2008). Illustration by NREL.................................................. 44

Figure 11. Global installed capacity of ocean energy technologies (IEA-OES 2010) ........................ 46

Figure 12. Development and deployment harmonized with the commercial strategy (Thresher 

2010)........................................................................................................................................... 48

Figure 13. Marine hydrokinetic development and deployment scenario and the overall R&D 

technical strategy (Thresher 2010) ......................................................................................... 50

Figure 14. Ocean Power Technologies PowerBuoy wave generation system uses a "smart", oceangoing buoy to capture and convert wave energy into low-cost clean electricity. Photo 

from Ocean Power Technologies, NREL/PIX 17114.............................................................. 55

Figure 15. ORPC's Beta Turbine Generator Unit generates clean, renewable electricity by 

harnessing the energy of the world's rivers and oceans. Photo from Ocean Renewable 

Power Company, NREL/PIX 17210.......................................................................................... 55

Figure 16. OpenHydro's Open-Center Turbine is designed to be deployed directly on the seabed. 

The first 6-m test unit produces enough energy to supply 150 average European homes 

and save the emission of over 450 tons of CO2 greenhouse gas per year. Photo from 

OpenHydro, NREL/PIX 17243................................................................................................... 56

Figure 17. Biopower production using algal biomass. Illustration by NREL...................................... 59

Figure 18. Biochemical strategies for converting algal feedstock into biofuels. Illustration from 

Sustainable Algal Biofuels Consortium ................................................................................. 60

List of Tables

Table 1. Comparison of Typical Energy-Storage and Delivery Systems ............................................ 22

Table 2. Comparison of Fuel Cell Technologies (DOE 2011)................................................................ 34

Table 3. Summary of Currently Available Estimates for Wave and Current Energy Resources ...... 45

Table 4. Estimated Capital Costs for Marine Hydrokinetic Wave and Tidal Technologies in 2006.. 52

Table 5. Power Output at Various Wind Speeds for Windside Turbine Models ................................. 77

Table 6. Power Curves for Proven 11 Wind Turbine ............................................................................. 77
1 

1 Introduction

1.1 Overview: Department of Homeland Security Science and Technology 

Directorate, Borders and Maritime Security Division

Within the U.S. Department of Homeland Security’s (DHS) Science and Technology (S&T) 

Directorate, the Borders and Maritime Security Division (BMD) develops and transitions 

technologies that help enhance the security of our nation’s borders and waterways without 

impeding the flow of commerce and travelers. This mission is carried out by technical 

professionals responsible for funding, managing, developing, prototyping, testing, and evaluating 

technical solutions for air, land, and maritime borders along with cargo security. BMD’s primary 

end users are operating components within DHS, such as Customs and Border Protection (CBP), 

Immigration and Customs Enforcement (ICE), U.S. Citizenship and Immigration Services 

(USCIS), U.S. Coast Guard (USCG), and Transportation Security Administration (TSA)

(Jennings et al 2010). 

The S&T Directorate works to cooperate and collaborate amongst the divisions within the 

Directorate, including BMD. To ensure that efforts undertaken by BMD are aligned with the 

overarching mission of DHS S&T, BMD is developing a division-level strategic plan (Jennings 

et al 2010). As a part of this plan, BMD is in the process of identifying next-generation 

renewable energy solutions that meet its mission and can be included in its research portfolio. 

Recognizing the potential of renewable energy to contribute to border security, BMD partnered 

with the U.S. Department of Energy (DOE) National Renewable Energy Laboratory (NREL) to 

examine border security energy demands, and to ensure that advances in renewable energy and 

energy storage lead to increased security in these areas. This research effort is funded by BMD, 

and this report is a product of a 2-year interagency agreement between DHS S&T and DOE. 

NREL is a national laboratory of the DOE Office of Energy Efficiency and Renewable Energy

(EERE), operated by the Alliance for Sustainable Energy, LLC. 

1.2 Renewable Energy Research Roadmap: Project Overview

Renewable energy technologies include solar photovoltaics (PV), wind energy, geothermal, 

hydrokinetic energy, and biomass. Fuel cells—another important technology—use hydrogen to 

create energy. Renewable energy technologies have many characteristics that make them 

particularly useful for increased border security, including the following. 

• Continuity of Operations. In the event of grid failure, on-site renewable energy installations 

can continue to operate, maintaining critical loads until grid service can be restored. The 

greater the utilization of renewable energy technologies, the longer operations can run 

without grid power. 

• Remote Operation. A renewable energy technology combined with energy storage can 

operate independent of the electricity grid in remote locations, often requiring very little 

maintenance to provide service. This can enable new capabilities in remote border-security 

operations. 

• Covert Operation. Some renewable energy technologies (such as PV) operate silently and 

require little maintenance. These characteristics make them very useful in locations where 

inconspicuous operations are needed. 
2 

• Reduced Reliance on Infrastructure. In the United States, the aging energy infrastructure 

poses a threat to national security. Electricity that is generated near the load reduces the 

reliance on the electricity infrastructure, thereby reducing risk. 

• Diversification. Employing renewable energy reduces dependence on foreign oil, both 

nationally and locally, at the operational level. This helps hedge against increased oil prices 

and supply interruptions that could negatively affect performance at the local level. Taking 

advantage of renewable energy also reduces dependence on fuels supplied from regions of 

conflict.

• Reduced Greenhouse Gas (GHG) Emissions and Sustainable Sources. By definition 

renewable energy technologies are clean and sustainable. Unlike the fossil fuels that the 

United States relies on for most of its energy—such as coal, natural gas, and oil—renewable 

energy technologies are constantly replenished. Furthermore, many of these technologies are 

emission-free.

Considering the compelling arguments for integrating renewable energy into border security, 

BMD initiated efforts with NREL to examine the energy needs along U.S. borders, especially in 

remote areas; to identify opportunities to apply renewable energy solutions today; and to define 

the near- and long-term research agendas that will position border components and activities to 

take advantage of renewable energy technologies in the future. This report is a result of these

efforts. 

Workshops

The NREL staff hosted workshops for DHS BMD component staff. The purpose of these 

workshops was to introduce component staff to NREL and to renewable energy technologies, 

and to provide an overview of the BMD-NREL project. The workshops also allowed component 

staff to brief NREL staff on the mission and operations of the component as well as existing and 

future energy needs. 

March 19, 2010 (Washington, DC): Introductory Workshop

This workshop was the initial meeting to convene stakeholders and outline the project and 

general project strategy. As a result of this workshop, CBP staff members were informed about 

this work effort, next steps were defined, and project points of contact (POC) were identified.

June 21, 2010 (Washington, DC): Data Gathering and Application Prioritization 

Workshop (CBP/NREL)

At this workshop NREL and CBP personnel presented an overview of each organization’s 

mission and organizational structure. CBP personnel next presented an overview of the types of 

equipment typically used to accomplish their mission and the types of conditions under which 

the equipment typically is used. 

There were approximately 25 pieces of equipment identified by generic name or purpose and 

manufacturer. Some of these pieces of equipment were grouped based on how they typically 

could be connected together to accomplish a specific mission. Workshop attendees then 

categorized the equipment into several subcategories that helped define possible power solutions 

for each piece of equipment. These categories were based on the following. 

• Power consumption range 
3 

• Stealth conditions under which they operate 

• Length of time between refueling 

• Mobility requirements

A number of considerations were made within each of these categories. One of the assumptions 

was that an infinite number of custom power supply sizes probably would be unrealistic as well 

as logistically undesirable for CBP. Workshop attendees decided to limit the number of power 

supply sizes to five: 1 watt (W), 100 W, 1,000 W, 7,000 W, and 10 kilowatt (kW). These sizes 

could accommodate the wattage of the current equipment being operated on the power supplies, 

and could be a contingency for the potential addition of equipment in the future. 

Units also were initially categorized by their mobility. After the first workshop, attendees 

decided that mobility is not the characteristic that most strongly determines a potential solution.

Visibility and the ability to refuel a unit became the more dominant characteristics in the 

consideration of a potential solution. Stationary units, which are not mobile, were defined by 

how easily they are hidden. Due to its dimensions, a large stationary communications tower 

would be difficult to hide visually, and therefore would not require a quiet or hidden power 

supply. A small communications device that could be hidden from visibility, however, could 

benefit from a stealthy and quiet power supply. 

Because it often is difficult to find an off-the-shelf solution that has all the desired features in one 

unit, workshop attendees determined that the features desired in each unit should be prioritized in 

order of importance. CBP prioritized the following solution characteristics by desirability. 

• Stealth (sound, site, dimensional limitations, refueling) 

• Type of communications network utilized 

• Costs (first cost, operations and maintenance [O&M] costs, carbon costs, 

disposal/recycling costs)

• Reliability/robustness of the unit 

• Refueling logistics (transportation of the fuel and the type of fuel) 

• Time between refueling 

• Replacement parts availability

• Preferred procurement methodology (three-bid or sole-source)

Additionally, to formulate an optimum solution, the following information related to the existing 

equipment also was requested from CBP. 

• Are there alternate manufacturers of these units and is it a custom design?

• What is the range of micro-climates, vegetation conditions, and water availability under 

which these units will operate? 

• What is the operational energy-consumption profile of these units in terms of peak power 

consumption, and what is the duration of this consumption (volts (V), amps (A), watts (W), 

phase, alternating current/direct current [AC/DC])?

• Do these units need to operate off-grid? 

• Do these units require emergency backup power? If so, at what level of redundancy? 

• Is energy, power, or fuel storage needed? If so, why and for how long? 
4 

• What is the length of time between refueling?

• How often does the equipment need to communicate its data back to headquarters? 

• What method of communication is preferred?

Another factor that impacts the ability to bring change is the number of devices deployed for 

each purpose. The greater the number of devices the more incentive there is to invest in reengineering an efficient renewable energy solution. 

During the workshop CBP staff listed the following tasks or issues as priorities for their 

organization. 

• Implementing a mobile surveillance system (MSS) to replace diesel genset

• Reducing the weight and size of packable power supplies to support 5-day missions

• Reducing sound at stealth sites

• Reducing the risk of spills at all sites

• Minimizing the need to resupply at stationary/permanent sites 

• Supporting recon 3, implement long-range, hand-held thermal imaging for single-person use 

• Developing power solutions for tactical checkpoints and forward operating bases (FOB) 

• Powering sensor packages for “low-flyer” threats

o Low-power sensor packages, reduced-power satellite communications link

o 20 W to 50 W 

NREL addressed the first seven priorities during a site visit to the southern border stations. The 

last item was covered during the Seattle meeting.

July 22–23, 2010 (Bellingham, WA): Northwest Border Low-Flier Workshop

During the June 21 workshop in Washington, DC, CBP requested that NREL personnel attend a 

meeting in Bellingham, Washington, that focused on the “low-flying” drug smugglers coming in 

through the northern border near Seattle, WA. The NREL staff members also were asked to 

present a range of possible power solutions for technologies that could detect low-flying vehicles 

in remote sites.

The focus of the workshop was two pronged. The first objective was to decide the technology on 

which to spend currently available funding so that a technology solution could be put into place 

immediately. The second objective was to strategize a solution for the future and develop 

language that could be placed in a request for proposal (RFP) to solicit sensing-technology 

solutions from industry professionals. There was some difficulty in developing language that was 

sufficiently broad enough to allow the industry maximum leeway to develop creative solutions, 

but at the same time to constrain solutions to functional requirements. 

There was general agreement by CBP workshop participants that the short-term solution was to 

purchase two mobile radar units for immediate deployment. The consensus was that, although 

these units likely would be detected and seen by the “low-fliers,” the units also would enable the 

channeling of the low-fliers into specific flight paths so CBP could more easily target them. 
5 

Several months later, the scope of the RFP language was approved by the group and turned over 

to CBP procurement personnel. 

Site Visits

October 26–29, 2010 (El Paso, TX): El Paso Sector

In October 2010, NREL staff visited the El Paso sector. The objective of this site visit was to 

gain an understanding of CBP operations along the southern border, and specifically in the El 

Paso sector. The visit began with an in-brief to CBP staff. The NREL staff provided an overview 

of NREL, renewable energy technologies, and the present project.

The NREL staff outlined site-visit expectations, which primarily encompassed gathering 

firsthand knowledge from users of power-consuming systems. The equipment identified as 

priorities in the June 21 workshop included: 

• MSS

• Powering sensor packages for low-flying threats 

• Reducing weight/size of packable power supplies 

• Reducing sound, risk of spill, and/or resupply at stationary/permanent sites 

• Recon 3 

• Tactical checkpoints and FOBs. 

During this site visit NREL staff worked to understand everyday operations, applications, and 

constraints of these technologies by speaking with operators in the field. The characteristics 

associated with energy-using and energy-producing equipment was collected. The staff members 

also worked with CBP staff to identify problems, issues, and constraints to future operations. The 

site visit included assessments at sector facilities, border patrol stations, border patrol permanent 

checkpoints, remote video surveillance system (RVSS) sites, Bridge of the Americas port of 

entry, border patrol special operations division, border patrol emergency planning office, border 

patrol tactical checkpoint, border patrol FOB, and SBInet (Secure Border Initiative) towers.

April 5–9, 2011 (Juneau, Alaska): Alaska U.S. Coast Guard Operations

In April 2011, NREL staff visited the USCG operations in Juneau, Alaska. The objective of this 

site visit was to gain an understanding of USCG operations in Alaska, specifically in the Juneau 

area. The visit began with an in-brief to USCG staff. The NREL staff members provided an 

overview of NREL, renewable energy technologies, and this project. They next outlined 

expectations for the site visit, which primarily encompassed gathering firsthand knowledge from 

users of power-consuming systems. 

During the site visit NREL staff heard presentations from Rescue-21 (R-21) staff members and 

gathered extensive data regarding R-21 power needs. NREL wind turbine researchers 

participated remotely (via phone) and learned of the challenges of installing wind turbines on 

mountaintops in Alaska, and discussed potential next steps for identifying or creating a 

mountaintop-viable wind turbine. The NREL staff members also participated in a meeting with 

Alaska Marine Exchange System staff.
6 

2 Renewable Energy Research and Technology Opportunities

Renewable energy technologies can provide sustainable, reliable power for a variety of 

applications. Off-the-shelf technologies can be used in the near term to increase border security. 

Mid- and long-term research opportunities exist to develop additional technologies that better 

improve the operations of DHS components in supporting border security. An overview of a 

variety of renewable energy technologies is presented below, along with near-, mid-, and longterm research opportunities relevant to DHS security operations. 

2.1 Solar Technology Overview

PV technologies convert sunlight directly into electricity. There are many different types and 

classes of PVs. Commercialized PVs are generally broken down into two categories: thin film 

and wafer technologies. 

Commercially Available Technologies

Thin-Film Photovoltaics

Thin-film PV technologies generally are deposited on a rigid or flexible substrate. They can be 

manufactured in continuous processes, resulting in a lower cost per unit of power produced. 

Because they can be deposited on flexible substrates, they also can be rolled up for easy 

transport. A number of different types of thin-film technologies exist, including: 

• Amorphous silicon, which offers 7% efficiency in available commercial products

• Cadmium telluride, which offers 11% efficiency in available commercial products and is the 

current market leader

• CIGS (copper, indium, gallium, selenide), which offers 11% efficiency in available 

commercial products. 

Wafer Photovoltaics

Wafer PV technologies generally are made of solid silicon wafers, either mono- or polycrystalline. Silicon is cast as a single ingot and then sliced into very thin wafers; this wastes 

much of the material. Wafer PVs as a rule have greater efficiencies than those of thin-film 

technologies. Commercial products with efficiency in the range of 14% to 20% are available. 

Multi-Junction Photovoltaics

Other variations of wafer and thin-films include multi-junction PV technologies. These cells 

layer different types of PV to capture different spectrums of light, thus increasing the overall 

efficiency of the composite PV system. In the past, these have been used in applications 

requiring the greatest efficiency for a given area or weight, such as in aerospace applications. 

Increasingly, these high-efficiency multi-junction devices (30% efficiency in production) are 

being used in systems that concentrate sunlight by up to 500 times using either reflectors or 

lenses. Essentially, this allows a very small area of a more expensive and more efficient PV cell 

to be used with a larger area of less-expensive reflectors or lens, resulting in a system with a 

lesser overall cost per peak watt of power.
7 

Potential Pilot Project

The areas around the Port of Valdez in Alaska 

are off limits to private boaters due to the 

possibility of interference with oil tankers 

leaving the port. Twenty percent of all U.S. oil 

currently is shipped out of this location, making 

it vital to national security. At present, the only 

way to mark these areas is with buoys, which 

attract seals, which in turn attract pleasure 

boaters even more. 

A pilot project utilizing a PV/battery system to 

provide power for a laser marking tool could be 

used to mark the boundary on the water 

surface, replacing the buoys. It also might be 

possible to power specialized “voice-throwing” 

technology speakers mounted on buoys that

could notify boaters that they are in a restricted

area.

Reported Efficiencies of Photovoltaics

All PV technologies can achieve higher efficiencies when produced in perfect in laboratory 

settings, but when these products are produced in factories these lab-based efficiencies drop.

Some of this effect is due to the variability of conditions in the factory setting versus near-perfect 

laboratory conditions. Some is also due to manufacturers making cost-benefit decisions as to 

how high an efficiency to implement based on how much incremental manufacturing costs will 

rise to accomplish that increase in cell efficiency. This manufacturing price (in dollars per peak 

watt of electricity produced by the final cell) is generally what manufacturers will use to 

determine how high an efficiency to implement in manufacturing. Cells will compete in the 

marketplace on price based on the particular features and needs required by different 

applications. Where area and weight are important, then customers will generally be willing to 

pay higher prices per peak watt for higher efficiencies which will lower the area and weight. 

All PV efficiencies quoted in this report are for factory-produced products. 

Emerging Photovoltaic Technologies 

Emerging PV technologies include dye-sensitized cells (11% efficiency), organic cells (8%

efficiency), and quantum-dot cells, none of which are currently produced commercially. The 

main difference of these products is that they can be produced without using silicon; therefore, in 

the future, they could be produced at lower costs. 

Additionally, in the future quantum-dot technology 

could enable PV to be produced at higher efficiencies by 

targeting specific wavelengths of light. 

A fourth category of emerging PV technology is based 

on nano-antenna (a technology-relative of the rectenna) 

and would consist of arrays of nano-sized antenna 

designed to pick up the radio frequency of the sun’s 

rays. Only very preliminary steps have been taken to 

determine the feasibility of this concept.

Department of Homeland Security Relevance: 

Photovoltaic Applications

PV panels do not have moving parts, and when 

combined with batteries they are very reliable—

assuming there is sufficient solar resource in the area in 

which they are being used. Additionally, they operate 

silently which affords them a measure of stealth.

Following this line of thought, more efficient cells result in reduced exposed area; therefore the 

likelihood that they would be seen is minimized. 

Batteries currently comprise approximately 80% of the gear weight that military personnel 

typically carry. During site visits to the U.S. southern border, discussions with CBP field 

personnel revealed that batteries also comprised a significant load for these CBP covertoperations field personnel, although this can vary by mission. Border Patrol personnel who are 

on remote or clandestine missions could use PV chargers to provide power and thus reduce 

battery weight. 
8 

Because DHS operates along the southern border, which experiences some of the country’s best 

solar resources; this could potentially reduce the area of PV required to power and recharge the 

batteries used by personnel out in the field as well as for covert monitoring and sensing devices. 

However PV units used in Alaska would likely require some sort of additional backup power 

source besides PV recharged batteries during the winter months when the hours of sunlight are 

drastically reduced. 

Today’s Opportunities—Off-the-Shelf Applications

Foldable and flexible PV battery chargers can be used to recharge batteries in the field, lessening 

the need to carry weighty replacement batteries. Navigational buoys can use PV to charge 

batteries during the daytime to power lights, audible signals, or communications signals 

operating at night. 

Tomorrow’s Potential

NREL currently is working on a pilot project to integrate PV with a portable light-emitting diode 

(LED) light tower for use along the southern border of the United States that could dramatically 

reduce the need for U.S. Border Patrol personnel to refill the fuel tank on the backup diesel 

generator. 

NREL also proposed a pilot project utilizing a PV–battery system to provide power for a laser 

marking tool used to show the boundary on the water surface around the Port of Valdez in 

Alaska. These areas are off-limits to private boaters due to the possibility of interference with 

tankers leaving the port. Currently, the only way to mark these areas is with buoys. Buoys attract 

seals which, in turn, attract pleasure boaters all the more. Because 20% of all U.S. oil currently is 

shipped from this location, the area is vital to national security. It also might be possible to 

integrate off-the shelf “voice-throwing” speakers with PV mounted on buoys that could notify 

boaters that they are in a restricted area. Both of these applications would save USCG personnel 

time and resources by allowing them to easily determine which boats present real threats versus 

those which are simply pleasure boats.

It could be possible to utilize high-efficiency, triple-junction PV along with specialized 

application-specific batteries to power small distributed-sensor units used to detect low-flying 

aircraft transporting drugs over the northern border. Staff members from NREL attended a 

workshop in the summer of 2010 aimed at planning future response to this problem. It was 

proposed that future units might communicate via satellite. There also are opportunities to utilize 

PV to power water-based sensor systems (current—possibly unknown—units, or future units 

used to detect vessels). It might be possible to use PV to charge micro-drones used for 

surveillance of fishing-vessel intruders. These hovering micro-drones could land in the water and 

float until they recharge. Soaring drones might stay aloft indefinitely, riding thermal currents and 

charging batteries during the day which then would power motors and keep them aloft at night. 

Currently, CBP on the southern borders is experiencing repeated failures of standard PV panels 

installed at mountaintop communications sites, due to structural failure caused by high winds. 

NREL currently is part of the international committee to establish standards for PV based on 

climate-specific regions around the world. Although heat-related failures have not been reported 

by CBP personnel, the extreme temperatures in the southwest United States doubtlessly will 

require specialized PV technologies to withstand the heat exposure over time. Until an 
9 

international standard has been established, NREL can assist DHS by writing a specification for 

purchasing climate-specific PV panels.

Long-Term Applications and Research

It might be possible to create camouflaged solar panels by perfecting a new class of solar panels 

based on nano-antenna-based solar-electric devices. This concept is in its infancy and would 

require additional research into nano-materials science as well as manufacturing techniques. Due 

to the high quantity of direct beam sunlight occurring in the areas along the southern U.S. 

borders, DHS may consider establishing concentrating PV arrays at sites along the border to 

provide power to border patrol stations, or possibly to power drones that are recharged wirelessly 

while hovering near the units. 

2.2 Wind

Wind is air that has high kinetic energy, and can be transformed into useful energy via windturbine blades and generators. Uneven heating of the earth’s surface creates wind energy. 

Warmed surfaces warm the air. The warm air rises and cooler air rushes in to take its place; the 

result is wind. The earth’s rotation—which causes day and night—is responsible for one aspect 

of the heating and cooling cycle. Other factors, such as orientation or slope of a surface, or 

surfaces that have different rates of reflectivity, absorptivity, and transmissivity also contribute to 

uneven heating. Wind also can be affected (accelerated, decelerated, increased turbulence) by 

other factors, such as terrain, proximity of bodies of water, buildings, and vegetative cover.

Overall, wind is a diffuse resource that can generate electricity cost effectively and competitively 

in many regions. 

The economic viability of a wind project is dependent upon the interplay between the wind 

resource and the competing cost of electricity. A strong wind resource (Class 5 and Class 6) can 

compete against electricity in most areas of the continental United States. A modest wind 

resource (Class 2 and Class 3) can compete against high-priced electricity (i.e., New England, 

Alaska, Hawaii). Strong wind and the high cost of electricity make wind a compelling option 

with a short payback. Low wind and low cost of electricity might not be economically viable for 

wind energy. 

Technology Overview

During the past decade, wind energy has been the fastest-growing energy technology in the 

world, with an annual growth rate in installed capacity of more than 30%. The U.S. wind 

industry broke all previous records by installing nearly 10,000 megawatts (MW) of new 

generating capacity in 2009. In the first quarter of 2011, the United States had 1,100 MW of new 

wind capacity installed, down substantially from the pace of 2007–2009 as the effects of the 

recession, reduced access to capital, reduced demand for electricity, and other factors impacted 

wind development activities. Current U.S. wind capacity is more than 40,100 MW (AWEA 

2011). In the “small wind” market—those less than 100 kW in size—the market grew by 15% in 

2009, resulting in 20.3 MW of new installed capacity bringing the total installed capacity to 100 

MW (AWEA 2009). 
10 

The wind industry has several distinct sectors, each with its own technology characteristics and 

development/deployment strategies that apply. 

• Commercial or Utility-Scale Wind: 1-MW to 3-MW wind turbines installed in groups of 

30 to 600 at sites with a very good wind resource, to form wind farms that inject clean green 

energy onto the utility grid via transmission lines. Much of the wind industry growth is due 

to this sector.

• Community-Scale Wind: 20-kW to 1,500-kW wind turbines installed in groups of one to 

three on the customer side of the utility meter to reduce the amount of electricity the entity 

(community/school/company/etc.) purchases from the utility.

• Residential-Scale Wind: 0.1 kW to 20 kW wind turbines installed at a home or small 

business on the customer side of the utility meter to reduce the amount of electricity the 

customer purchases from the utility.

Each of these sectors of the wind industry essentially includes different technologies (they all 

could be called “wind turbines,” but there are profound fundamental differences), assessment 

methods, economics, environmental considerations, and factors that serve as the drivers for those 

sectors.

There is a wide range of commercially available wind turbines with very different intended 

applications, sizes, orientations, efficiencies, and cost structures. There is no one design or size 

that is “the best in all applications”; rather, there are applications that favor certain sizes and 

designs, as they provide the better relative economics and performance within the applicationdriven constraints. 

Installed cost ranges similarly are quite broad, as both the turbines and the construction factors 

can vary widely. Over the past 3 to 4 years, the typical installed costs of utility-scale turbines 

range from approximately $1,500/kW to $2,500/kW. The cost of electricity generated has been 

in the $0.04/kWh to $0.08/kWh range over this period (Wiser and Bolinger 2009). Well-sited 

small wind turbines can cost in the $3,000/kW to $6,000/kW range installed, with variations due 

to installation and construction cost variations, availability and quality of state or utility 

incentives, and wind resource. The resultant cost of electricity produced could be in the 

$0.15/kWh to 0.20/kWh range (Windustry 2011). Poorly sited small turbines can produce 

electricity in the $0.20/kWh to 0.50/kWh range. 

For the USCG, the need to supply reliable, less-costly power for the communications systems on 

remote mountaintops makes residential-scale wind turbines most applicable, although the wind 

turbines to consider typically would not be considered to be within the residential market. The 

turbines recommended for these remote locations are the most stalwart models produced by 

companies that specialize in robust wind turbines. 

Commercially Available Technologies—Current/Future Research Trends

The primary thrust of current research efforts is toward utility-scale wind turbines focused on the 

following. 

• Reducing installed costs of large land-based wind turbines 

• Increasing turbine efficiency in wind energy conversion and electricity production 
11 

Multi-Agency Collaboration 

DOE created the Federal Wind Siting Information 

Center to provide wind developers and wind 

project managers with current information 

regarding wind turbine impacts on airport and 

military radar systems, NEXRAD (weather) radar 

systems, and military operations. 

This multi-agency collaborative effort provides 

valuable initial siting information and feedback 

for all levels of wind development from 

community wind through large scale wind farms. 

(www.eere.energy.gov/windandhydro/federalwin

dsiting/radar.html) 

• Reducing the cost of electricity produced by large offshore wind turbines 

• Addressing renewable systems integration rules, impacts, operating strategies, and system 

planning to promote wind competing without disadvantage against other energy-generation 

technologies 

• Expanding and promoting deployment of distributed wind turbines across the United States

to achieve fivefold increase in unit deployment from 2007 through 2015 

• Facilitating technology acceptance of utility-scale wind such that at least 30 states achieve 

100 MW of installed wind capacity with at least 15 states achieving at least 1,000 MW 

In the smaller turbine market, the market drivers are: 

• Improving efficiencies in blades, alternators, and inverters 

• Reducing number of components and overall amount of materials to reduce installed costs 

• Establishing certification facilities and protocols for small wind turbine certification; 

• Improving reliability and decreasing O&M costs

• Enabling cost-effective wind resource assessment for small turbines and projects. 

Wind Characteristics

Wind resources are very site specific. Different sites in close proximity to each other, but with 

varying topographical features (e.g., ridges versus valleys, canyons versus mountains), 

vegetation (i.e., tall trees versus grassland or cropland), and surface roughness (i.e., city 

skyscrapers versus flat or rolling farmland), can have entirely different wind regimes. One could 

prove to be economic and another might not. 

Wind Power

The amount of wind varies with the season, time of 

day, and weather events. The wind speed at any given 

time determines the amount of power available in the 

wind and subsequently the power that can be captured 

using a wind turbine generator. The power available in 

the wind is given by the following equation. 

P = A ρV3/2 

Where 

P = power of the wind (watts) 

A = windswept area of the rotor (blades) = π 

D2

/4 = π r2 [m2] (π r2 [10.76 ft2])

ρ = density of the air [kg/m3

] (2.2 lb/3.28 ft3) (at sea level at 15°C)

V = velocity of the wind [m/s] (3.28 ft/sec)
12 

Wind power (P) is proportional to velocity cubed (V3). Therefore, if wind velocity is doubled 

then wind power increases by a factor of eight (23

 = 8). Consequently, small differences (e.g., 

increases) in average speed cause significant differences (e.g., increases) in energy production. 

To understand the wind resource at a particular site, a wind assessment typically is undertaken 

using a tall met tower equipped with anemometers to measure wind speed at multiple heights, 

wind vanes to measure wind direction, and temperature and atmospheric pressure sensors. These 

sensors and the data collected help to inform a number of important turbine and siting 

parameters. One factor of great interest to turbine manufacturers is turbulence.

Turbulence

The turbulence intensity (TI) is defined as the standard deviation of the wind speed within a time 

step divided by the mean wind speed over that time step; TI is a measure of wind gustiness. High 

turbulence can lead to increased turbine wear and potentially increased O&M costs. At reduced

wind speeds, the calculated turbulence intensity often is high but the impact of the turbulence is 

of little consequence to the wind turbine itself due to the low wind speeds. Turbulence at greater 

winds speeds is of more interest and concern to wind turbine manufacturers, as it increases wear 

and tear on many turbine components and can lead to premature failure. 

Wind Turbine Technologies

There are a variety of commercially available wind turbine technologies for using wind energy to 

make electricity. Wind turbines should be designed to be robust yet efficient, and lightweight but 

sturdy. Turbines have rotors—also known as airfoils—that capture the kinetic energy of the wind 

and translate it into a rotational force that turns the rotor mechanically. The rotor is attached to a 

drive shaft that typically is attached to a gearbox or other electricity conversion mechanism. The 

design of the airfoil determines whether the rotor (and turbine) is classified as a “lift” or a “drag” 

wind turbine. 

Air flowing over a stationary airfoil produces two forces—lift and drag. A lift force is 

perpendicular to the air flow and drag force is in the same direction of the air flow. A primary 

difference between the two as it relates to electricity production and efficiency is that the rotor of 

a drag wind turbine can spin no faster than the wind acting on the blade. However, a lift turbine, 

due to the pressure differential as the flowing air moves to an area of low pressure to get around 

the airfoil, can produce rotational speeds at the tip of the rotor that are much greater than the 

speed of the wind. The term "tip speed ratio" is defined by the angular velocity of the rotor tip 

compared to the velocity of the wind. 

Wind turbines are designed to be well-balanced, symmetrical machines that minimize friction to 

maximize the mechanical energy transformed into electrical energy. Turbulent winds can cause 

imbalanced thrust loads into the rotor, leading to increased wear and tear on shafts, gear boxes, 

and bearings and resulting in premature failure. Ice loading on rotors, as expected to be experienced on mountaintop locations in Alaska, can rapidly create extreme imbalance conditions that 

can lead to catastrophic premature failure. Routine O&M is a necessary aspect of the long-term 

viability of any turbine. Occasionally, repair and replacement of worn parts (e.g., gears, blades, 

shafts) are needed for a turbine to achieve its normal operating parameters.
13 

Utility-scale wind turbines are typically designed for particular wind conditions and turbulence 

factors, so a given turbine may have several models available. After an analysis of the wind 

resource data, if the wind conditions call for a more robust design (International Electrochemical 

Commission [IEC] Class I versus Class II or Class III), then that is what is specified. At sites 

with less wind and low turbulence, longer blades can increase wind capture. Small wind turbines 

have fewer, if any, optional design features. 

The orientation of the shaft that transforms wind energy to mechanical to electrical energy is the 

defining characteristic classifying two major types of wind turbines: the vertical axis wind 

turbine (VAWT) and the horizontal axis wind turbine (HAWT). The HAWTs are the turbines 

seen most commonly in wind applications worldwide. The orientation of the shaft that 

transforms wind energy to mechanical to electrical energy is the defining characteristic.

Figure 2 shows various turbine configurations that have been considered for wind energy 

conversion machines, grouped by axis orientation.

Figure 2. Various types of horizontal and vertical access wind turbines. 

Illustration by Al Hicks, NREL

Vertical Axis Wind Turbines

VAWTs have been in use for many years with many different design variations. All the different 

designs can be categorized into two basic design types or principles: Savonius rotor and Darrieus 

blade, described in more detail below. 

Savonius Rotor 

The Savonius rotor is an impulse-type rotor, with a maximum theoretical efficiency of 

approximately 19%; it essentially is pushed by the wind. The push principle is demonstrated in 

turbines originally consisting of two or more vertical sails or paddles that are blown around their 

vertical axis by the wind. The simplest type of wind generator is the Savonius turbine, which 

utilizes the push principle. In 1922, Finnish engineer S.J. Savonius substantially updated this 

basic concept when he replaced the sails with airfoils (essentially cups or half oil drums) with 

their open sides opposing each other and fixed to a central vertical shaft. The cup in line with the 

wind flow catches the wind and so turns the shaft 180°, bringing the opposing cup into the flow. 
14 

The next cup then repeats the process, causing the shaft to rotate a further 180° and complete a 

full rotation. There are numerous variations to this design theme, some with additional airfoils on 

the same shaft and some with their airfoils set at different angles or positions on the shaft.

Darrieus Blade

The other VAWT option, using the pull principle, evolved in 1931 when a French engineer, 

George J.M. Darrieus, invented a new type of vertical-axis wind turbine. The Darrieus-type 

machine consists of two or more flexible airfoil blades which are attached to both the top and 

bottom of a rotating vertical shaft, giving the machine the appearance of a giant egg beater. The 

Darrieus rotor is a thrust- or lift-type rotor, with a maximum theoretical efficiency of 

approximately 59%; it essentially is pulled by the wind. The wind blowing over the airfoil 

contours of the blades create aerodynamic lift, which actually pulls the blades along. Over time, 

researchers have begun working to improve the Darrieus machine by rationalizing the geometry 

of the blades. Many different shapes and sizes have been developed. 

Horizontal Axis Wind Turbines

HAWTs are most commonly seen in applications across the United States. They can range in 

size from as small as 400 W to as large as 5 MW. There are thousands of the smaller turbines 

used in applications to provide ranchers, farmers, homeowners, and small-business owners with 

the ability to generate their own electricity to partially or wholly replace electricity from the grid. 

Significant research and development have been undertaken in the past decade to improve the 

performance and reduce the cost of these smaller turbines.

The HAWTs often use a furling mechanism to orient the turbine out of the wind in extremely 

windy conditions and prevent turbine damage. The mechanism itself is designed for typical 

horizontal airflow. The mechanism can rotate the rotor out of the wind in the vertical or 

horizontal plane. Utility-scale turbines have controls to adjust a blade’s pitch to minimize the 

effects of wind speeds that are too great. 

Upwind versus Downwind

Wind turbines can be designed with the rotor either in front of the tower relative to the incoming 

wind (“upwind” turbine), or behind the tower (“downwind” turbine). There are advantages and 

disadvantages to each configuration. An upwind turbine requires a yaw mechanism (similar to 

the tail of a wind vane) that helps point the rotor in the direction of the wind. In this 

configuration, the rotor sees less impact of the tower on the wind although there is some 

interference by tower on the wind flow. The primary disadvantage of this system is that the rotor, 

which is attached to the nacelle, must extend far enough in front of the tower that the blades 

cannot bend into the tower even in extreme wind conditions. Tilt angle of the nacelle, blade 

flexibility versus stiffness, and the balance point of the nacelle attachment all must be integrated 

into the design parameters to ensure successful operation in extreme gusts or high-wind events. 

The rotor also can be designed to be downwind of the tower. The nacelle itself is designed to 

serve as the “tail” so that the rotor will align to the wind automatically without the need for a 

separate yaw mechanism. The rotor blades can be more flexible, as there is much less chance of 

a blade hitting the tower. The more flexible blades can be a disadvantage due the potential for 

blade fatigue. The tower also has a greater impact on the wind flow, causing greater turbulence 

on the rotor and potentially greater wear and tear on blades, shafts, and gears.
15 

Tip-Speed Ratio 

Figure 3 compares the rotor power coefficients (CPR) for different types of wind turbines with the 

tip speed ratio (TSR). The TSR is the ratio of the speed at the tip of the blade to the speed of the 

wind, and is a function of the design and type of turbine. A high TSR can generate a lot of noise 

and also can block the wind from moving through the rotor. A low TSR allows too much wind 

energy to pass through the rotor. 

Figure 3. Comparison of aerodynamic efficiencies of common types of wind turbines (based on 

Hau 2000). Illustration by NREL

Typical rotor CPR values range from 0.2 to 0.45. The lower end of the range is associated with 

drag-type devices such as the Savonius machines. Three-bladed HAWTs are at the highest end of 

the range. The wider the curve, the more efficient the design is across different wind speeds. The 

optimum CPR is found at TSR values ranging from 5.0 to 6.0. 

One important performance consideration not easily gleaned from Figure 3 is that, although the 

TSR varies within a small band for each type of rotor configuration, the rotations per minute 

(rpm) vary widely and inversely from small to large turbines. That is, small turbines have very 

high rotations per minute (500 rpm to 1,500 rpm for 1-W to 400-W turbines) and large turbines 

have very low rotations per minute (12 rpm to 28 rpm for 1-MW to 3-MW wind turbines).
16 

Department of Homeland Security Relevance: Options for Powering Remote 

Communication Stations

The “Wind Power Rescue 21 Alaska” report,

1

A wind system would operate in a manner similar to PV by serving to provide float charge or 

trickle charge to the batteries whenever the wind is blowing. It is conceivable that during periods 

of high wind and low battery state of charge a wind system even could provide bulk charging, 

although it might be better to keep the operational algorithms simple and consistent. 

completed by the USCG and provided to NREL, 

was very useful in understanding the realm of the challenging environment the mountaintop 

communications system operate in, particularly during the fall-winter-spring months. The 

“Alaska NDS Support” systems are designed to operate from one of two battery banks 

(combined 2,000 A/hr capacity). Power generation is supplied to the battery banks with either a 

propane generator (redundant 7.5-kW generators) or using PV modules (2.88 kW peak power). A 

PV system provides charge to the batteries, if needed, whenever the sun is shining. Most of this 

charging is expected to be in either the float- or trickle-charge phase of battery charging, when 

the battery bank is partially discharged. The propane generator provides bulk charging whenever 

the battery system voltage falls below a preset state of charge. This cycling approach is intended 

to minimize the runtime of the generator, as it only turns on when bulk charging is needed. 

If a wind turbine is added to the existing system it is conceivable that it would be necessary to 

add a load bank into the hybrid system configuration to provide load, particularly when the wind 

system is producing at half or more of its rated power and the battery system is in float- or 

trickle-charge phase.

Today’s Opportunities: Best Current Wind Options for the Department of 

Homeland Security

The “Wind Power Rescue 21 Alaska” report provided useful information regarding rapid 

catastrophic failure of two “robust” HAWT turbines. 

• HR3 (3 kW) by Northern Power Systems; no longer in production 

• Bergey BWC 1500 (1.5 kW) by Bergey WindPower; no longer in production although the 

nominal equivalent is the XL.1 (1.0 kW) turbine 

The HR3 turbine has been known to perform consistently in the harsh environment and extreme 

winds on Black Island in Antarctica at a National Science Foundation communication station. 

Five of six deployed HR3’s in Alaska, however, did not survive the first winter. There is not 

enough information available to have confidence in speculating on the reasons for this vast 

difference in performance. The sole “survivor” was on Naked Island, which has milder weather 

than the other locations. More details on the precise failure modes would be insightful, although 

it is understood that the failure mode might not have been obtainable due to the remoteness of 

the sites, the extreme conditions that cause failure, or the time lapse between failure and the 

arrival of project personnel. 

According to the “Wind Power Rescue 21 Alaska” report, twelve Bergey BWC-1500 (1.5 kW) 

wind generators were installed at six sites in southeast Alaska, but all failed. Initially the BWC1500 failures were suspected to be caused by a blade flexing and striking the tower, therefore 

 

1 Provided to NREL's A. Kandt and S. Huffman by DHS.
17 

several failed units were replaced with stiffer blades and a smaller tower-mount pipe. None of 

the BWC-1500 wind generators survived a full year even with these changes. 

As stated in the report, there is no “true” or verified cause of the failure of these wind turbines. It 

is speculated that the failure could have been due to a combination of ice loading and turbulent 

wind. Ice loading can cause static loads in excess of design parameters, and rotational loads that 

are imbalanced and exceed design loads. These appear to be among the potential causes for 

premature failure. There also could be other root or contributing causes. 

There is no easy, fail-safe, off-the-shelf wind energy solution for this application, given the costs 

of providing propane annually per site (approximately $25,000/yr to $26,000/yr) and in 

aggregate (approximately $400,000/yr to $420,000/yr), as well as the great risks associated with 

airlifting fuel to the high sites. However, there could be several options worth pursuing on a pilot 

project or field-test basis. The goal of the field test would be to determine wind turbine viability 

and expected life in these environments, thus enabling the determination of an approximate 

overall life cycle cost (LCC) for the system as compared to business as usual (BAU).

The goal of the field test and subsequent analysis would be to achieve a reasonable cost savings 

over the life cycle of a wind turbine (and the entire hybrid power system). A conceivable 

scenario (not usually considered “successful”) could include wind turbine failure within 5 years 

(this is an arbitrary number), rather than its design life of 20 years, if there were substantive 

savings accrued over those 5 years as compared to business as usual. If, over a 5-year period, 

fewer helicopter trips are needed per year or generator run-time is reduced enough that overhaul 

or replacement is delayed by 1 to 3 years, for example, then a 5-year wind turbine life might be 

more economically advantageous than business as usual. The overall net result would be an 

improved, but not perfect, system. 

Pilot Opportunities for Wind Turbines 

From discussions with various turbine manufacturers and direct experience with a variety of 

wind turbines in extreme environments, two types of rugged wind turbines designed for extreme 

conditions appear to merit the field test: a VAWT with narrow Savonius rotor, and a HAWT 

with spring-loaded furling blades. 

Savonius Option 

A variation of the Savonius turbine can be seen in the Windside2

 

2 Refer to the Windside website for sample photos: 

 turbine design, in which the 

drums of the Savonius rotor have evolved into fluted, spiral-formed vanes. The Finnish 

company, Oy Windside Production, produces this machine. It consists of two vertical curved 

airfoils mounted between two disks. Whenever wind blows horizontally through this device, the 

disk turns and drives a generator. These machines are suited for use on buoys, offshore 

platforms, buildings, signs, and posts, which require only small amounts of power. They often 

also are used to charge battery backup systems or to supplement low-voltage PV solar panels, 

and to power signs, public telephones, low-voltage transmitters, and other small systems. They 

are well-suited for isolated areas with severe weather. The turbines are simple, rugged, and 

reliable, and come in sizes with output of up to 3 kW. 

www.windside.com/gallery 
18 

Other benefits include the following. 

• Turbine can accept wind from any horizontal direction (omnidirectional) so is does not use 

slip rings or a yaw mechanism

• Very rugged design suitable for harsh climates

• Generator is on the ground, so it is easier to service than most HAWTs

• Direct-drive permanent-magnet generator with no gearbox 

• Slower rotor movement can make the turbine more visually pleasing than that with a rapidly 

spinning blade 

• Wind tolerance limits are 60 m/s (134 mph) 

• Multiple size options 

Disadvantages of the Savonius turbine include the following. 

• Very low efficiency

• Cannot reduce wind profile in extreme wind events 

• High weight-to-energy production ratio—the added cost of transportation and a foundation 

should be considered as part of the cost of energy—not recommended for building-top 

applications 

• High cost-to-energy production ratio

• The 50-Hz model could be the only frequency option (this might not be an issue for batterycharging-only system) 

This turbine is designed for extreme weather conditions—such as the arctic and the desert—

where a small amount of power is needed and other alternatives do not work well. Consequently, 

its high cost of energy is not a limiting factor for these applications. 

HAWT Option

Proven Energy manufactures a series of downwind wind turbines designed for a range of 

extreme conditions.3

Proven Energy products include a patented blade assembly, which allows the wind turbines to 

regulate speed, thus maximizing output. As the wind gets stronger, the blades pitch and cone to 

reduce their aerodynamic efficiency. This lets the Proven Energy wind turbine maintain a high 

output even in the fiercest storms—unlike many turbines which require braking to protect 

themselves at high wind speeds. 

 One unique design feature of the downwind turbine is its spring-loaded 

blade furling design. In strong winds, the hinges allow the blades to hinge back out of the wind, 

dissipating wind energy by reducing the effective size of the swept-area plane perpendicular to 

the wind and helping to control rotor speed.

The Proven 11 (5.2-kW) or 35-2 (12.1 kW) turbines might be appropriate sizes to consider. 

Benefits of this technology include the following. 

• Hinged blade-furling system reduces turbine overspeed events

• Direct-drive permanent-magnet generator does not require a gearbox 

 

3 Visit Proven Energy at www.provenenergy.co.uk/our-products/ or Alaskan Wind Industries at 

www.akwindindustries.com/allproven.php for more information.
19 

• Very rugged design suitable for high-wind or gusty regimes 

• Wind survivability limits are 70 m/s (134 mph) for the Proven 11, and 54 m/s (121 mph) for 

the Proven 35-2 

• Multiple size options 

Disadvantages of the HAWT turbine include the following.

• High cost-to-energy ratio

• Blade length can lend itself to rotor imbalance during icing events

• Must yaw into the wind—in swirling winds this can lead to excessive wear chasing the wind

The Proven 11 turbine shown in Figure 4 is designed for extreme weather conditions in remote 

places.

Figure 4. Proven 11 downwind turbine with spring-loaded blade furling design. 

Photo from Proven Energy

Tomorrow’s Potential: Wind Turbine Field Test Plan Outline

It is worthwhile to proceed with a multiyear field test aimed at building on incremental success 

and learning from potential failures, versus expecting the perfect solution to emerge from the 

first test. Over time, improved system designs, equipment selection, and siting guidelines are 

expected to emerge and to result in better-performing systems at a lower cost than existing 

systems. Although the selected turbines might fail to survive in the short term, both provide 

promising opportunities to develop more-robust turbines for comparable applications worldwide. 
20 

Potential Research Project

Both of the selected manufacturers have been 

working to improve wind-turbine design and 

performance over time. Being able to provide 

them with test sites that are able to support 

additional data collection might be of interest 

to these companies.

Although these turbines represent a narrow 

segment of small markets with limited 

applicability, they also represent very highvalue projects with a significant need for 

improved performance.

NREL recommendations to DHS include the following. 

• Have DHS field service personnel inquire with 

multiple manufacturers about taking a wind 

installation and O&M workshop 

• Select midrange sites in terms of extreme weather 

for each turbine 

• Have DHS field personnel take wind turbine siting 

training

• Purchase, install, and field test two of the most 

ruggedized manufacturers' turbines at the same time 

and location in Year 1 

• Collect as much useful practical data from each 

installation each year (i.e., wind-speed data from multiple heights on a tower, wind vanes at 

multiple heights) for analysis

• Analyze the collected data at each site and complete a “Lessons Learned” report

• Develop improved turbine selection, siting, and configuration guidelines based on “Lessons 

Learned” report 

• Repeat this process through several iterations over a 4- to 6-year period, to evolve better 

wind turbine options and solutions for remote DHS communication sites in Alaska. 

Long-Term Applications and Research

DHS and NREL could work with wind turbine manufacturers on several design-parameter 

improvements targeting the weather extremes of mountaintops and Alaska in particular. No 

contact yet has been established with these manufacturers, but NREL is interested in leading this 

discussion should DHS likewise be interested in this pursuit. Potential areas of design alteration 

might include the following. 

• Windside—Enlarge shaft or bearings to enhance durability 

• Proven—Reduce blade length to reduce impact of rapid gusts 

The manufacturers could have their own ideas of the design parameters they are interested in 

refining or altering for these types of extreme sites.

Also, a defrosting unit could be developed to utilize the heat from backup power generators to 

de-ice ruggedized horizontal wind turbines used to power communications equipment on 

mountaintop sites. This technology would ensure that fossil fuels generally only would be used 

when a wind turbine has been stopped due to ice buildup. This also is precisely the conditions 

under which waste heat would be available to defrost the turbine blades, thus minimizing the 

need to use and transport backup fuel to these dangerous sites. 

 

2.3 Energy Transfer Overview

Energy transfer technologies are an important component of energy-using systems. They enable 

the transfer of energy from a power producing source, such as PV panels or a wind turbine, and 

they transfer it to the energy consuming device, such as a communications or light tower system. 
21 

2.3.1 Batteries

Based on the CBP and USCG applications identified during NREL site visits, there is need for 

batteries with the following characteristics.

• Improved energy density for portable power applications associated with hand-held devices

and remote field operations. 

• Improved cycle life for integration with renewable energy storage involving 

communications, sensors, lighting, tracking, and boundary markers. In some cases, the main 

emphasis is to increase the times between change-outs and maintenance to decrease life-cycle 

costs and any hazards to people.

• A broader operational temperature range for use in extreme conditions such as cold 

mountaintops or hot deserts. 

Specific needs and research and development (R&D) gaps will depend explicitly on the 

performance requirements of each electronic system. This data has not yet been procured from 

DHS, but these three areas outline the general development needed for batteries. 

Batteries Technology Overview—Current Status

United States energy security and viable, large-scale, renewable-energy options to a great extent 

depend on revolutionary developments in battery and fuel-cell technology for transportation, 

portable power, and stationary energy-storage applications. Batteries and fuel cells are being 

developed because they offer the potential for greater efficiency energy utilization and perhaps 

energy storage. Existing batteries and fuel cells currently have substantial cost, durability, 

temperature, and energy-storage density problems. 

In general, due to their relatively low costs, deep-cycle lead acid batteries are widely deployed 

and are the most common renewable-energy storage system in use. Depending upon the specific 

application, however, commercially available lithium-ion (Li-ion) and other batteries might 

compete very well on a full life-cycle cost basis and could provide superior performance. As 

shown in Table 1, present secondary (rechargeable) batteries typically are limited to gravimetric 

energy densities below 200 Wh/kg and have cycle lives of fewer than 500 cycles. Metal hydride 

batteries typically have lower energy densities than Li-ion-based batteries because the metals are 

substantially heavier, even though hydrogen (the lightest element) is used as the principal energy 

carrier. Even other metal-air batteries, such as zinc-air, have relatively low energy densities 

because the elements are heavier (i.e., the molecular weight of zinc is 65.39 g/mol). Again, 

depending on the specific application, greater cycle lives can be achieved with commercially 

available lithium iron phosphate (LiFePO4)–based batteries, which also offer very good 

discharge and recharge rates.
22 

Table 1. Comparison of Typical Energy-Storage and Delivery Systems

System Anode Cathode

Voltage 

(nominal) Energy Density Cycle Life Cost

V Wh/kg Wh/l Cycles $

60% Efficient Fuel Cell 

with Tank Pt Pt 1.3 <600 <500 ~4000 (hours) $$$

Supercapacitors NA NA NA 10 NA >106 $$$

Gas with ~35% Efficient 

Engine NA NA NA <5001 <4001 ~2,000 hours $

Lithium-Air (Li-air) Li O2 (air) ~3 ~3602 ~400 ~60 $$

Lithium-Sulfur Li S 2.2 ~10002 ~1100 ~50 $$

Planar Lithium Li Oxides ~4 ~400 ~600 >1000 $$$

Thin-Film Li/Lithium 

Phosphorous Oxynitride

(LiPON) Electrolyte Li LiCoO2 4.2 200* 450 100,000 $$$$

LiFePO4 C LiFePO4 3 90 183

>2000 

(@80%) $$

Lead-Acid Pb PbO2 2 35 70 200–250 $

Nickel-Cadmium Cd Ni oxide 1.2 35 80 400–500 $$

Nickel-M-Hydride (MH) Ni oxide 1.2 50 175 400–500 $$

Lithium Ion C LixCoO2 4 170 300 >500 $$$

Lithium-Organic Li MnO2 3 120 265 500 $$$

Edison Fe Ni Oxide 1.2 30 55 $

Silver-Zinc Zn AgO 1.5 90 180 $$

Nickel-Zinc Zn Ni oxide 1.6 60 120 $

Nickel-Hydrogen H2 Ni oxide 1.2 55 60 $

Silver-Cadmium Cd AgO 1.1 55 100 $$$

Zinc-Air Zn O2 (air) 1.5 150 160 $

Note: Technologies shaded in light blue are in development or are not commercially available and are compiled from many 

different sources. The remainder can be found in the Handbook of Batteries, Third Edition (Linden and Reddy 2002).

* Depends upon substrate type and thickness. 

1. Note energy densities are reduced because tank and engine weights are included. 

2. Best demonstrated; Li-Air and Li-S batteries have the potential to be greater than 2,500 Wh/kg

DOE and the U.S. Advanced Battery Consortium (USABC) have been developing Li-ion 

batteries for hybrid and plug-in hybrid electric vehicles with the near-term goals of 140 Wh/kg 

and $20/kW ($250/kWh) at large-scale production. There are significant doubts in the battery 

community as to whether the energy density of li-ion batteries will be able to be pushed to the 

200+ watt-hour per kilogram (Wh/kg) system (300 watt-hour per liter [Wh/L]) level energy 

densities and the more than 1,000 cycle lives required for widespread deployment of all-electric 

vehicles. Development efforts to try and meet these goals, however, are focusing on improved 

materials, architectures, and manufacturing processes.

Developmental Batteries Overview

Lithium-air batteries offer relatively high energy densities, but the required transport and 

permeation of oxygen often limits rates to charge and to discharge, and have substantial overpotentials that reduce recharge efficiencies. Overpotential is the added electrical or ionic 

resistance in the battery due to different competing mechanisms. Substantial development is 

needed to improve membranes and electrolytes to create highly durable secondary Li-air 

batteries with long lives. Similarly, lithium-sulfur (Li-S) batteries that use very inexpensive 
23 

earth-abundant materials have the potential for high energy densities but have relatively poor 

cycle life and require substantial development.

In general, typical commercially available Li-ion and other batteries last a few hundred cycles 

when discharged to ~80% of their full capacity. This means that, to maximize cycle life, 

additional capacity must be included, ultimately increasing weight and costs. Furthermore, for 

renewable-energy storage applications that typically cycle daily, most batteries will require

replacement within a year or two unless additional capacity is added to decrease the depth of 

discharge. Basically, by decreasing the depth of discharge to approximately 50%, more than 

1,000 cycles can be achieved and, in some cases, 5 to 10 years between replacements can be 

designed for a specific power system. 

A few high–cycle life batteries are being developed, but capacities and rates are major issues. In 

addition to cycle life and energy density, battery performance typically decreases substantially at 

colder temperatures, also requiring extra capacity to be included to provide the required power 

and energy storage. In general, a few rechargeable batteries can operate to approximately -20°C; 

thus, battery heating systems must be included for operation where temperatures are lower. This 

requires increased capacity to adequately address the heating system’s power requirements. 

Depending upon pulsed power, change-out time, and system-life requirements, a complete 

energy-storage system could require primary and secondary batteries with supercapacitors, and 

potentially even reversible fuel cells. These types of evaluations are performed routinely, but are 

very dependent upon the application and the operating conditions. 

Department of Homeland Security Relevance: Battery Development

Depending on the specific application, DHS will require different levels of battery research, 

development, and integration to provide cost-effective and enabling solutions. Technology 

foraging will enable DHS able to leverage past and present work performed by industry, NASA, 

the U.S. Department of Defense (DOD), In-Q-Tel, and DOE to provide energy-storage systems 

optimized for specific DHS missions. For example, DHS requirements for batteries with higher 

energy densities, greater power, faster rates, longer cycle life, and wider operational temperature 

range are very similar to requirements by industry, DOE, NASA, DOD, and other agencies that 

need transportation, portable, and stationary energy storage. 

Today's Opportunities—Near-Term Integration with Commercially Available Batteries

Battery technology is advancing and new performance capabilities are becoming available, 

therefore it is prudent to reevaluate energy storage solutions for several DHS missions. DHS can 

consult with national laboratories, DOD, NASA, and industry to identify potential advanced 

energy-storage solutions for present DHS missions. DHS could then work with In-Q-Tel or 

similar entities to bring these innovations into fruition. These evaluations can include appropriate 

batteries, supercapacitors, and other integrated components, as well as any system testing 

necessary to demonstrate safe operation that meets the performance requirements.

Life-Cycle Cost and Durability Evaluations 

Many handheld and remote field–operation devices can use a wide range of relatively new dropin batteries and supercapacitors that can increase operating times, decrease weight, and decrease 

overall life-cycle costs. Rechargeable Li-ion batteries, for example, are available commercially 
24 

in a vast array of energy-storage packages that can directly replace battery packs in existing 

electronic devices.

The primary effort requires identifying appropriate replacement batteries and performing a quick 

life-cycle cost analysis to determine the cost savings. Additionally, some effort could be required 

to ensure that the replacement batteries are safe and meet performance requirements. This can be 

accomplished by working with manufacturers and other agencies, and performing durability and 

failure testing.

Replacement-Battery Evaluations

Similarly, DHS can work with manufacturers, national laboratories, other agencies to identify 

and design near-drop-in ready energy-storage solutions for renewable energy storage 

applications where longer cycle lives are needed to increase the times between change-out and 

maintenance. In the near-term this can be done by identifying commercially available advancedbattery solutions and designing the appropriate depth of discharge needed to meet the cycle-life 

performance requirements. 

These evaluations require a tradeoff of lesser overall battery costs for increased performance 

requirements. For example, Li-ion batteries probably can be used for remote, cold, mountaintop 

communication and tracking applications. The greater costs of the Li-ion batteries, however, will 

be increased further by the need for enhanced capacity. The greater capacity is needed to adjust 

depth of discharge for the desired change-out times, the cold temperatures, and the additional 

heating required to keep the battery temperatures above -20°C. These design issues will be 

balanced against the elimination of maintenance costs and the reduced costs of transporting and 

changing-out batteries, especially where physical safety is a major problem.

Similar battery evaluations and initial testing can be performed for any of the other DHS 

applications associated with lighting, tracking, sensors, and boundary markers. As compared to 

lead-acid batteries, Li-ion batteries require three times less weight and volume to provide the 

same power and energy storage. This leaves substantial weight and area for developing a drop-in 

replacement that has the extra capacity—and temperature-control capabilities—needed to meet 

mission goals, including more than doubling the time between change-outs and maintenance.

Another potential application for DHS would be to optimally combine primary batteries with 

supercapacitors or advanced secondary batteries (depending on the mission specifications) for 

remote sensing and monitoring equipment. For equipment such as seismic monitors that only 

sends out signals when specific events activate the system, perhaps a long-life primary battery 

such as Li-thionyl chloride battery—which has energy densities of approximately 750 Wh/kg—

can be integrated with rechargeable batteries and supercapacitors for communications

equipment. In this case, the primary battery provides a low level of power for the sensor to 

continually perform its monitoring function, and then charges a secondary battery or 

supercapacitor for the much greater power required to send communications. 

Li-thionyl chloride batteries are relatively inexpensive and have very low self-discharge, which 

enables 10 to 20 years of continuous operation (as compared to the approximately 1-year 

operation of many rechargeable batteries). This makes these batteries ideal for some 
25 

applications—such as the remote detection of seismic events caused by people walking, for 

which hundreds of thousands of sensors are needed and cost will be a primary driving factor.

Tomorrow’s Potential—Battery Development and Prototype Demonstration

Addressing some DHS mission specifications will require development and demonstration 

efforts during the next 3 to 5 years. Although this is not sufficient time to perform the research 

required to develop batteries with fundamentally new performance capabilities, it is sufficient to 

redesign and reconfigure energy-storage systems for specific applications and to perform longerterm demonstrations and testing. The greater power demands of remote lighting, tracking, and 

boundary markers, for example, requires substantial amounts of design, integration, and testing 

work. Most of these applications presently rely on grid electricity or diesel generators.

In general, the integration of battery energy storage with renewable-energy generation from wind 

and PV installations is a commercially available set of technologies. The integration of largecapacity batteries for some of these applications with renewable energy generation and perhaps 

fuel cells, however, requires significant design and prototype demonstration efforts. Sandia 

National Laboratory, for example, is developing prototype portable-lighting demonstration 

systems using hydrogen fuel cells. Additionally, NREL is developing technology to optimize the 

conversion of wind electricity to hydrogen generation. In both cases, the significant high power 

demands have required several years for the engineering and testing to demonstrate high-quality 

performance. Similar efforts are required to adequately resolve battery-based or batteryintegrated renewable energy storage for high-power applications such as remote or portable 

lighting, tracking systems, communications, and boundary markers. 

Mountaintop Communications and Tracking Systems

As discussed, existing Li-ion batteries with heaters and limited depth of discharge can be 

designed and evaluated in a relatively short time to determine whether they are full life cycle 

cost-effective replacements for these applications. If appropriate solutions are identified, then a 

longer-term prototype engineering demonstration effort is required to optimize performance and 

demonstrate that the performance criteria can be met. This will include scaled or full-scale 

testing under appropriate cold-temperature conditions to show that the battery systems can meet 

the mission goals. 

Remote Seismic Sensors

The redesign of the energy-storage system for seismic sensors also can be performed relatively 

quickly to determine the appropriate commercially available solutions. Given the harsh 

conditions and long on-station lifetime requirements of these systems, however, appropriate 

accelerated durability and performance tests will be needed to ensure that the performance goals 

are fully met. Additional prototype field-testing and long term health monitoring also is required 

to help identify areas that need to be improved. 

Remote/Portable Lighting

Due to the very high power and high renewable energy storage requirements of lighting 

applications, substantial design and evaluations with scaled (and then full-scale) prototypes is 

needed to demonstrate that such large systems can be integrated in relatively small spaces and 

can meet the performance objectives in harsh environments. This especially is an issue if Li-ion 
26 

batteries are used in applications in which thermal runaway is a major concern that requires 

engineered solutions to ensure safe operation. 

Boundary Markers

Similar to the lighting application, most boundary marker renewable energy storage systems will 

require high power and high capacities. In the case of the USCG Seward Harbor Laser and 

warning annunciator boundary markers, however, the power requirements probably are well 

beyond what batteries alone can provide cost effectively. In this case, batteries, fuel cells, and 

hydrogen generation and storage, all must be optimally integrated directly with wind, PV, tidal, 

and wave renewable-energy generation. 

DHS, with NREL’s support, could work with the Naval Research Laboratory to integrate 

commercially produced fuel cells from Ford or General Motors with novel underwater hydrogenstorage expandable tanks to provide the primary power for the boundary markers when 

renewable energy is not available. This effort would leverage NREL’s work on optimized wind 

to hydrogen. Additionally, integrating secondary batteries and supercapacitors could meet the 

peak- and rapid-power requirements of the application, such as when the fuel cell is starting up 

and for providing continuous high-quality power from fluctuating renewable energy sources.

Solid-State Secondary Lithium-Battery Development

NREL is actively working with Planar Technologies to develop a solid-state Li-battery that has 

up to 400 Wh/kg energy densities and well beyond a 1,000-cycle life. Unlike present solid-state 

batteries, Planar is integrating cathodes with high capacities and working with DOE’s Advanced 

Research Projects Agency-Energy (ARPA-E) and DOD to optimize these batteries for the high 

power requirements of transportation applications. 

Based on present development efforts, NREL can work with Planar, DOE, and DOD to develop 

integration strategies for these new batteries with applications that could be suitable for DHS. 

These batteries potentially will have approximately four times the energy density and two to ten 

times the cycle life of commercially available Li-ion batteries, therefore many DHS applications 

could be directly improved with the Planar battery. Additionally, although specific coldtemperature performance has not been measured, the solid-state nature of the battery should be 

more appropriate with cold temperatures—even well below -20°C—thus affecting cold 

mountaintop communications and tracking applications as well. As this technology is developed 

and moved to commercial manufacturing, NREL will continue to work with all participants to 

identify DHS applications where the Planar battery is an effective replacement based on full lifecycle costs.

Durability and Performance Testing of Batteries for Specific Missions

With all these mission-specific efforts, DOE can leverage its battery-testing expertise and work 

with other agencies and with industry to provide appropriate durability and safety testing of the 

prototype energy-storage systems developed. This would involve determination of failure 

mechanisms and catastrophic failure analyses. Additionally, long-term cycle testing and 

accelerated testing (where possible) can be performed to fully demonstrate that mission 

objectives can be met. Lastly, DOE can monitor installed systems in the field to provide realworld performance tracking that can be used to improve the systems. 
27 

Long-Term Battery Research and Development

Advanced High Energy-Density and Cycle-Life Batteries

In general, low-cost batteries with higher energy densities, high cycle lives, and a wider range of 

operating temperature are needed to meet or enhance many DHS missions. As noted, Li-air and 

Li-S batteries offer tremendous potential to meet these requirements, but require focused R&D to 

overcome fundamental challenges. Both Li-air and Li-S use earth-abundant, inexpensive 

materials that have very high theoretical energy densities—well in excess of even presently 

available fuel cells when the hydrogen storage system is included.

DHS can work with other agencies and institutions to leverage existing development efforts at 

NREL that can provide improved sulfur stabilization with conducting nanomaterials and 

improved architectures, designs, and materials for oxygen integration with lithium. As is the case 

for hydrogen-air technology associated with fuel cells, lithium-air technology has the potential 

for very high energy densities because the inherent weight of the cathode material (i.e., oxygen 

in the air) is not carried with the battery. However, some weight associated with oxygen 

dissociation and separation decreases overall Li-air battery energy densities.

Similarly, the sulfur in an Li-S battery is very light and the extra weight of the sulfur cathode is 

somewhat offset by the higher voltages attained with the sulfur as compared with the Li-air 

system. Lastly, the ultimate element for batteries is the lightest (i.e., hydrogen). NREL is 

developing hydrogen-based batteries with potential energy densities in excess of 3,000 Wh/kg. It 

also is developing organic radical batteries with more than 1,000 Wh/kg. The key here is the use 

of lightweight materials to store the hydrogen. In all these cases, substantial R&D is needed.

International Boundary Aerial Drone Patrols 

The Defense Advanced Research Project Agency (DARPA) and DOD have developed a number 

of drones for specialized missions. Integration with renewable energy recharging is very 

difficult, however, and represents the forefront of technology development today. On-station 

airships represent the ultimate goal of these efforts. Using this technology, an observation 

platform remains above the specified zone for up to one year using renewable energy provided 

by PV and sufficient energy storage provided by fuel cells and batteries. Unfortunately, the 

required energy densities for storage and generation do not yet exist; thus more fundamental 

development efforts are needed. As discussed, it might be possible to use rectenna technology to 

transmit power to the airship, thus decreasing the weight required for power generation and 

energy storage sufficiently to enable this type of surveillance platform. Similarly, a drone that 

lands on the water for recharging is a very advanced system that might or might not be possible 

to create using the technology presently available. 

In general, existing batteries can provide a first step in design and testing, and can be only a 

small part of subsequent energy storage options that utilize the higher energy densities 

achievable with fuel cells. Reversible fuel cells that produce hydrogen and also provide power 

still are developmental. That said, the integration of electrolyzers and fuel cells for this 

application will not work due to the extra weight. 

As discussed above, DHS can work with researchers and industry to develop batteries with

potentially higher energy densities than that of fuel cells with the hydrogen storage systems. 

Additionally, as discussed in the fuel cell section, NREL is working with industrial partners to 
28 

develop reversible solid-oxide based fuel cells that generate hydrogen or methane and also 

provide electricity from hydrogen or methane. This work could be leveraged for DHS goals. This 

type of reversible-fuel-cell system can produce and use hydrocarbon fuels that have much higher 

storage system energy densities than can be achieved with hydrogen, and also provide highquality heat that when combined with a microturbine can produce energy efficiencies of more

than 80%. Both technologies substantially increase the overall power-system energy density, 

thus enabling longer flight times between recharging. DHS can work with partners to develop 

new revolutionary batteries and reversible–fuel-cell systems with the goal of attaining energy 

densities of more than 1,000 Wh/kg, as needed to enable continuous or long-time monitoring of 

international boundaries via aerial drones. 

2.3.2 Wireless Energy Transfer

Wireless energy transfer enables the powering of devices or the recharging of batteries without 

the power supply having to physically contact the devices consuming the power. One advantage 

this type of transfer such is that it keeps the device’s location covert. Other advantages include 

potentially reducing the labor involved in retrieving or digging-up devices to change-out 

batteries or replenish liquid fuel. Another is reducing the need for oxygen to burn liquid fuels, 

thus minimizing the accompanying heat signatures.

Technology Overview

For any type of wireless energy-transfer technology, important factors that must be considered 

include the quantity of energy to be transferred, how fast the transfer must be, and how far away 

from the receivers the transmitter is located. Also important is the types and quantities of media 

that the energy must travel through (i.e., air, water, clouds, dry soil, wet soil). To obtain a good, 

integrated solution additional questions should be considered, such as the following. 

• Is there opportunity to improve the efficiency of the operating device’s power consumption? 

• What is the capacity of the receiving device’s battery storage?

• What time interval between recharging is desirable to maintain the stealth and the 

effectiveness of the receiving devices? 

• How small must the device be?

• How small must the associated energy receiving component be? 

A number of different technologies have been proposed to wirelessly transfer energy. Presently, 

the most viable include rectennas, inductive coupling, and laser transfer. Each of these 

technologies is at a different stage of development and commercialization.

Rectenna Energy Transfer—Technology Overview

Rectenna is the abbreviated name given to rectifying antennas. A rectenna is an antenna which 

can receive electromagnetic (EM) radiation of various different types (i.e., signals from 

commercial radio stations, microwaves, and radar) and convert it to DC electricity. Rectennas 

generally are tuned to one specific type of radiation. Because EM radiation occurs as a wave 

form it can be rectified or restructured into DC current using an electronic device called a 

rectifier. This is accomplished in the same way that alternating current—which also occurs as a 

wave form—can be rectified and restructured into direct current.
29 

A rectenna is a receiver only and requires a transmitter to produce the original EM radiation 

(energy) that is received by the rectenna. That transmitter can be powered by a nonrenewable 

power source, such as the utility grid or a diesel generator, or by clean power source such as a 

PV panel, wind turbine, or fuel cell.

An advantage of rectenna technology is that, depending on the type, size, and power of the 

transmitters and receivers, power can be sent from a transmitter to a rectenna over a long or short 

distance without having any physical contact with the rectenna—possibly even without being in 

the direct line of sight of the rectenna. This would allow covert sensors to be powered or 

batteries recharged without revealing the device’s exact location. Disadvantages include creating 

radio-frequency interference, and the potential for energy loss in the transfer process. 

State of Rectenna Technology

There is a long history of rectenna research and prototype devices. NASA has investigated the 

use of rectenna technology for many years, hoping to one day use it to transmit energy generated 

by solar PV panels in low earth orbit down to the earth’s surface. Although they do not transmit 

energy, several technologies nonetheless utilize principles similar to rectenna. One of the bestknown examples of commercialized rectenna technology is the radio frequency identification 

(RFID) chip. These chips increasingly are being substituted for bar codes as a wireless way of 

transferring information about items being transported and sold. Ground-penetrating radar also is 

worth mentioning because it transmits information via EM radiation through soil media.

Currently, there are very few (if any) commercial products using rectenna technology to transmit 

energy. 

Department of Homeland Security Relevance: Wireless Energy Transfer

These technologies are significant because they allow the repowering of hidden detection sensors 

(e.g., buried seismic sensors) while keeping the locations of these sensors relatively covert 

during the recharging process. 

Today's Opportunities

No off-the-shelf technologies currently are available for wireless energy transfer. 

Tomorrow's Potential

Transmitters could be integrated into a vehicle—such as a Humvee—and driven near buried 

sensors to recharge the sensor battery without needing to dig it up, thus keeping buried-sensor 

locations covert. Areas of research include the following. 

• Work with manufacturers to develop a prototype transmitter and rectenna receiver that could 

receive power for ground-buried sensors.

• Work with manufacturers to develop a prototype transmitter that could be transported and 

effectively integrated covertly into a vehicle. 

• Investigate the dampening effects that various soils might have on the efficiency of 

transmitting power from an aboveground transmitter to a buried receiver connected to a 

sensing device.

Long-Term Applications and Research

Drones could be equipped with repeaters that could relay power transmitted from far away 

locations to the sites of the sensors. Alternatively, it also might be possible—depending on the 
30 

power needed—to incorporate a power source and transmitter directly into a drone. Research is 

needed in the areas of micro–EM transmitters, receivers, and relays that could be utilized on 

drones to transmit or relay power to buried devices. These devices possibly could double as 

communications signal relays to extend the range of communications equipment for DHS 

personnel working covertly in the field. 

Inductive Coupling Energy Transfer—Technology Overview

Inductive coupling works using the same principle as a transformer. Electrical current flowing 

through a coil of wire creates a magnetic field. If that magnetic field is placed close to another 

coil of wire, then the magnetic field in the first coil of wire creates a magnetic field in the second 

coil of wire, which also “induces” electrical current flow in the second coil of wire. Current 

applications include the wireless charging of batteries for cell phones and laptops by laying them 

on top of special charging mats, as well as the wireless charging of batteries for medical implants 

and electric vehicles. Advantages of this technology are that it is relatively mature, relatively 

efficient, and inexpensive as compared to other wireless energy-transfer technologies. A 

disadvantage of this technology is that the power source coil must be in very close proximity 

(possibly directly on the soil above a buried unit). 

Department of Homeland Security Relevance: Inductive Coupling Energy Transfer

Today's Opportunities

Transmitters could be integrated into a vehicle and driven over buried sensors to recharge the 

sensor battery without digging up the sensor. This method, however, would require the 

transmitter to be precisely on top of the sensor, thus compromising its location to some degree. 

Laser Energy Transfer—Technology Overview

Laser energy transfer is a concept very similar to the rectenna, except that it uses a laser beam 

instead of EM radiation to transmit the energy. This concept has been proposed for transmitting 

electricity from PV arrays orbiting the earth directly to a receiver on earth. Advantages of this 

technology include the ability to transmit power over long distances in a very narrow beam cross 

section accurately, and the lack of any radio-frequency noise. Disadvantages of this technology 

include the need for a direct line of sight to transmit the power, the energy inefficiency of the 

process, the absorption of light by the atmosphere, and the relative lack of commercial products. 

Department of Homeland Security Relevance: Laser Energy Transfer

No DHS applications have been determined for this wireless technology at present. 

Thermoelectric Technologies—Technology Overview 

Thermoelectric devices typically are solid-state devices with no moving parts, which create an 

electric current when exposed to a temperature difference on opposite sides of the device.

Typically, this means that one side of the device must be cold and the other side hot. There are 

three separately identified effects that produce this result, the Pelier, the Seebeck, and the 

Thompson effects. Additionally, changing the sides of the device that are heated and cooled 

changes the direction of current flow. Alternatively, heat can be moved from one side of the 

device to the other side by actively running current through the device, thus producing a cooling 

effect. An advantage is the ability to use low-level heat to generate power. A disadvantage is the

potential for the energy source to create a heat signature that could be detected by infrared 

goggles. 
31 

State of Heat-Driven Technologies

Heat-driven devices have been in use for years. They initially were utilized by NASA, which 

used small nuclear reactors on satellites to create heat which then used a thermoelectric device to 

create electricity. More recently these devices have been used to cool electronics and to create 

miniature solid-state refrigerators and heaters for use in cars. Recently, there has been a 

resurgence of research on these devices in an attempt to improve the net energy efficiency of 

automobiles by converting some of their waste heat into electricity. 

Department of Homeland Security Relevance: Thermoelectric Technologies

These devices could be used to power buried sensors using only the temperature difference 

between the sun-heated surface soil and the consistent ~50°F (10°C) lower ground temperature. 

Additionally, during the winter nighttime temperatures can reverse and dip to less than 50°F 

creating a temperature difference in the opposite direction, and creating a current flow. By 

adding a power converter, this opposite-direction current flow could be used to continue to 

generate power to charge a battery at night. During times of the day when there is no difference 

between the temperature at the surface and the temperature in the deep soil no charging would 

take place. 

Today's Opportunities

A manufacturer currently is producing units which utilize the difference between the surface 

temperature and deep ground temperature to generate power. This unit should be compared with 

the power requirements of existing ground sensors to determine whether they could provide 

enough power to operate the heat-driven device. 

Tomorrow's Potential

It might be possible to work with manufacturers to develop custom versions of the off-the-shelf 

products presently available. These would operate more efficiently and improve off-the-shelf 

opportunities. Areas of research include the following. 

• Determine whether there is a discernable heat signature associated with these units that could 

be picked up with infrared technology and, if so, whether there is a way to disguise the heat 

signature. 

• Work with sensor manufacturers to develop an integrated design to reduce the power 

required by the sensors so that it could be powered by the ambient-temperature differences.

• Create a hybrid unit that can be powered by ambient-temperature differences most of the 

time and then recharged via a rectenna intermittently or more often if the sensor failure 

started to occur more frequently in a particular area.

• Determine whether different types of soils (indistinguishable from normal indigenous soils) 

which could harvest, store, and conduct sunlight and heat more efficiently could be found or 

developed to improve the power-generating capacity of thermoelectric devices.

• Determine how seasonal temperature and moisture differences would affect the power 

generation. 
32 

Fuel Cell Benefits

• Efficiencies can be 60% (electrical) and

85% (with CHP)

• More than 90% reduction in criteria 

pollutants

2.3.3 Fuel Cells

A fuel cell is a device that creates uses hydrogen or hydrogen-rich fuel and oxygen to create 

electricity. Fuel cells are more energy efficient than combustion engines, and the hydrogen used 

to power them can come from a variety of sources. If pure hydrogen is used as a fuel, then fuel 

cells emit only heat and water, thus eliminating concerns about air pollutants or GHGs. Figure 5

shows many types of fuel cells and their diverse applications. 

Figure 5. Fuel cell types, fuels, and applications. Illustration from DOE

Technology Overview

A fuel-cell system is made up of several key components 

that can include: 

• Fuel delivery module (from a fuel processor or a 

hydrogen storage tank) 

• Fuel cell stack

• Balance of plant 

• Power electronics module 

• Control system. 

The fuel-delivery module governs the delivery of hydrogen to the fuel-cell stack and is needed in 

most fuel-cell installations. Hydrogen is produced and purified on demand for the fuel-cell 

system by a fuel processor. The fuel processor converts the fuel supply (e.g., natural gas, biogas) 

into a hydrogen-rich stream, which is purified to an acceptable level for the fuel-cell stack. 

Maintaining the required hydrogen purity is critical in these systems. Certain contaminants in the 

fuel supply act as poisons to the fuel-cell stack and drastically shorten the lifetime of the fuel-cell 

system. As discussed below, there are several types of fuel-cell designs. The hydrogen purity 

specification varies for different designs. Hydrogen also can be delivered and stored on-site in a 

tank to power the fuel-cell system.

The electrochemical process of converting hydrogen into electricity and heat occurs in the fuelcell stack. The stack is surrounded by various other plant components (e.g., valves, air blowers, 

sensors), and monitors and regulates system operation. Hydrogen is fed into the anode side of the 
33 

fuel-cell stack and air is fed to the cathode side of the stack to sustain the electrochemical 

reaction. An illustration of this reaction can be seen in Figure 6.

4

 

Figure 6. Fuel cell basics. Illustration from DOE

DC electricity is produced by the fuel cell. A power electronics module typically is incorporated 

into the fuel-cell system design to manage the power output and quality from the fuel-cell 

system. If the end user requires AC output, then the conversion from DC to AC power is 

accomplished in the power electronics module. DC to DC power conversion also is employed in 

some applications (e.g., telecom backup material handling equipment). A control system is used 

to operate the entire fuel-cell system and typically interfaces with the electrical system at the 

customer site and provides remote telemetry of the fuel cell operation.

Fuel Cell Types, Efficiencies, Costs, Status of Deployment (Megawatts Installed)

The installed cost of a fuel cell system depends on the type of fuel-cell system selected, its 

configuration, and its size. Cost information is obtained by contacting a fuel-cell manufacturer. 

The Fuel Cell Power Model5

 

4 In addition, an animation of this reaction is available at 

 can be used to perform a preliminary evaluation of using fuel cells 

at the site location. Installed costs for a fuel-cell system can range from $5,000/kW to 

$10,000/kW, and include purchase, warrantee, transportation, installation, connection, and 

commissioning. A fuel cell operates like a battery, except that it can provide continuous power. 

Instead of requiring charging, this electrochemical device uses oxygen and a readily replenished 

fuel such as hydrogen to produce electricity. Individual fuel cells are stacked in a module to 

produce the desired energy output, much like commercial batteries use an array of individual 

cells. Heat and water are the primary byproducts, therefore fuel cells are virtually pollution free 

and have more than twice the efficiency of traditional combustion technologies; typically ranging 

from 40% to 65%. When fuel cells are deployed in an automobile, fuel economy of 36 to 52 

www.eere.energy.gov/hydrogenandfuelcells/fuelcell_animation.html

5 Available at www.hydrogen.energy.gov/ fc_power_analysis.html
34 

miles per gallon of gasoline equivalent is typical (NREL 2010). Energy in the form of heat and 

electricity is produced as long as fuel is supplied to the fuel cell.

Fuel cells can provide power for a range of applications, from laptop computers to utility power 

plants. A power converter can convert the DC power produced by the fuel cell into AC power 

that is compatible for use by both consumer and industrial customers. When the heat from the 

fuel cell is captured and used in combination with the electrical power (combined heat and 

power, CHP), fuel cells have efficiency rates of between 70% and 85%. Table 2 provides a 

comparison of the various fuel cell technologies.6

Table 2. Comparison of Fuel Cell Technologies. Table from DOE

 

Fuel Cell 

Type

Common 

Electrolyte

Common 

Fuels

Operating 

Temperature

Typical 

Stack 

Size Efficiency Applications Advantages Disadvantages

Polymer 

Electrolyte 

Membrane 

(PEM)

Perfluoro 

sulfonic 

acid 

Hydrogen, 

Methanol, 

Biomethanol 

50-100°C 

122-212° 

typically 80°C 

< 1 kW100 kW 60% transportation 

35% 

stationary 

• Backup 

power 

• Portable 

power 

• Distributed 

generation 

• Transportation 

• Specialty 

vehicles

• Solid electrolyte 

reduces corrosion 

and electrolyte 

management 

problems 

• Low temperature 

• Quick start-up 

• Expensive 

catalysts 

• Sensitive to fuel 

impurities 

• Low temperature 

waste heat 

Alkaline 

(AFC)

Aqueous 

solution of 

potassium 

hydroxide 

soaked in a 

matrix 

Hydrogen 90-100°C 

194-212°F 

10-100 

kW

60% • Military

• Space 

• Cathode reaction 

faster in alkaline 

electrolyte, leads 

to high 

performance 

• Low-cost 

components

• Sensitive to CO2

in fuel and air 

• Electrolyte 

management 

Phosphoric 

Acid 

(PAFC)

Phosphoric 

acid 

soaked in a 

matrix 

Hydrogen, 

Natural Gas,

Biogas 

150-200°C 

302-392°F 

400 kW 

100 kW 

module 

40% • Distributed 

generation 

• Higher 

temperature 

enables CHP 

• Increased 

tolerance to fuel 

impurities 

• Pt catalyst 

• Long start-up time 

• Low current and 

power 

Molten 

Carbonate 

(MCFC)

Solution of 

lithium, 

sodium, 

and/or 

potassium 

carbonates, 

soaked in a 

matrix 

Natural Gas,

Biogas 

600-700°C 

1112-1292°F 

300 kW3 MW 

300 kW 

module 

45-50% • Electric 

utility 

• Distributed 

generation 

• High efficiency 

• Fuel flexibility 

• Can use a variety 

of catalysts 

• Suitable for CHP 

• High temperature 

corrosion and 

breakdown of cell 

components 

• Long start-up time 

• Low power 

density 

Solid Oxide 

(SOFC)

Yttria 

stabilized 

zirconia 

Natural Gas, 

Biogas 

700-1000°C 

1202-1832°F 

1 kW-2 

MW

60% • Auxiliary 

power 

• Electric 

utility 

• Distributed 

generation 

• High efficiency 

• Fuel flexibility 

• Can use a variety 

of catalysts 

• Solid electrolyte 

• Suitable for CHP 

and CHHP 

• Hybrid/GT cycle

• High temperature 

corrosion and 

breakdown of cell 

components 

• High temperature 

operation requires 

long start-up time 

and limits 

One advantage of fuel cells is that hydrogen fuel can be derived using a variety of domestic 

resources such as biomass, water, natural gas, propane, and methanol. Hydrogen generated by 

 

6 For a list of commercially available fuel cell technologies, see www.fuelcells.org/usfccproductlist.pdf
35 

water electrolysis—the splitting of water molecules into hydrogen and oxygen using 

electricity—can be beneficial when used in combination with variable renewable-energy 

technologies such as solar and wind. When the electricity used for water electrolysis is produced 

by a variable renewable-energy source, the hydrogen stores the unused energy for later use and is 

classified as a renewable fuel and energy resource. 

The largest markets for fuel cells today are stationary power, portable power, auxiliary power 

units, and forklifts. Fuel-cell deployment statistics are as follows.

• Approximately 75,000 fuel cells have been shipped worldwide 

• Approximately 24,000 fuel cells were shipped in 2009 (a more than 40% increase from 2008 

numbers) 

• Approximately 50 new large (>10 kW) fuel cells were installed in 2009, and a 4.8-MW fuel 

cell will be installed in the new World Trade Center in New York City

• More than 1,500 fuel cell systems have been sold into the North American material-handling 

market to power forklifts

• More than 1,000 fuel cells providing combined heat and power for residences are being 

demonstrated in Japan (the program plans to demonstrate more than 3,000 units) 

• Some stationary fuel cells are available with 80,000-hour warranties on the stack, and some 

manufacturers report about 40,000 hours between major overhauls. 

Fuel cells offer the following benefits. 

• High efficiencies for energy conversion 

o Approximately 40% to 50% electrical efficiency (lower heating value [LHV] of 

hydrogen) 

o 80% or greater overall efficiency, including utilization of waste heat 

• Indefinite operating time as long as fuel is provided 

• Scalable from milliwatts to megawatts

• Emission-free operation with direct hydrogen fuel cells 

• Quiet operation 

• Reliability

Drawbacks of fuel-cell use include cost and lack of fuel infrastructure (i.e., production, storage, 

distribution).

Fuel Cell Research Objectives

The DOE Fuel Cell Technology Program addresses the key challenges facing the widespread 

commercialization of fuel cells. The program outlines fuel cell cost and durability targets of $750 

per kW and 40,000-hr durability for stationary systems and $30 per kW and 5,000-hr durability 

for vehicles. There is a proposed hydrogen cost target of approximately $6 per gallon gas 

equivalent (dispensed and untaxed). The target for fuel cell range is over 300 miles for vehicles 

without compromising interior space or performance. DOE is also working on safety, codes and 

standards development, creation of a domestic manufacturing and supplier base, public 

awareness and acceptance of fuel cells, and the development hydrogen supply and delivery 

infrastructure.
36 

Research is also ongoing in currently non-commercially available fuel cell technologies, 

including microbial fuel cells and tri-generation fuel cell concept.7

Department of Homeland Security Relevance: Fuel Cell Applications

 

Today’s Opportunities

Fuel cells and hydrogen can play an important role in U.S. energy strategy, with the potential for 

use in a broad range of applications. This section highlights the commercially available 

applications as identified during the site visits, and is divided into the categories of backup power 

systems, remote power stations, and portable power. 

Backup Power Systems

Fuel-cell systems can be price-comparable with traditional technologies such as coal and oil 

when the fuel-cell systems provide added value through quiet operation, increased efficiency, 

and reduced GHG emissions. Companies currently offering commercial backup power fuel cell 

systems include, but are not limited to, the following. 

• IdaTech, LLC (www.idatech.com) 

• Altergy Systems (www.altergy.com) 

• Relion (www.relion-inc.com) 

• Hydrogenics (www.hydrogenics.com/fuel/ups) 

• Intelligent Energy (www.intelligent-energy.com/products_and_services/fuel_cells/

power_systems/) 

• Dantherm-Power (www.dantherm-power.com/Products/Backup_power.aspx) 

• ClearEdge Power (www.clearedgepower.com/) 

These commercial fuel cell backup power systems are applicable to the following applications. 

• Communications systems on mountaintops 

• Power quality at facilities with grid power

Remote Power Stations

Fuel-cell systems are a good option for providing power in remote locations because they have 

fuel flexibility and can be configured to provide heat and power-supply needs. They are currently 

used for telecommunication towers, homes, mobile lighting, and emergency communications. 

Remote power stations are applicable to the following applications. 

• Stadium lighting 

• Portable light towers

• Portable remote operating stations 

• Communications systems on mountaintops 

Commercially available remote power systems include, but are not limited to, the following. 

 

7 More information is available at www.eere.energy.gov/hydrogenandfuelcells/pdfs/program_plan2010.pdf 
37 

• Multiquip (www.multiquip.com) 

• Trenergi (www.trenergi.com/aboutus.htm) 

• Dantherm-Power (www.dantherm-power.com/Products/Backup_power.aspx) 

• ClearEdge Power (www.clearedgepower.com/) 

Portable Power Systems

Portable fuel-cell power systems are available for military, emergency, and recreational 

applications. The operational advantages offered by these systems relative to traditional 

generator systems include reduced weight, low acoustic signatures, extended run times, increased 

energy density, increased efficiency, and reduced emissions. Companies currently offering 

portable fuel-cell power systems include, but are not limited to, the following. 

• Protonex (www.protonex.com) 

• Ultracell (www.ultracellpower.com) 

• Adaptive Materials, Inc. (www.adaptivematerials.com) 

• SFC Energy (www.sfc.com/en/) 

• Oorja Protonics (www.oorjaprotonics.com) 

• IRD Fuel Cell Technology (www.ird.dk/index.php) 

• MTI MicroFuel Cells (www.mtimicrofuelcells.com/) 

• Lilliputian (www.lilliputiansystemsinc.com/) 

• Angstrom Power (www.angstrompower.com/) 

• Jadoo Power (www.jadoopower.com/) 

These portable fuel-cell power systems would be applicable to following applications identified 

by DHS. 

• Recharging and powering handheld devices

• Recharging and powering equipment at remote locations

• Seismic sensors 

Renewable Energy Storage Solutions 

NREL is working with different companies to efficiently convert renewable energy from wind 

and solar to hydrogen. NREL is also developing reversible fuel cell technologies that could be 

integrated with renewable energy to provide the direct energy storage needed with wind and 

solar, while with the same unit providing the power when the renewable energy is no longer 

available. This potentially decreases cost and weight, but substantial development is required to 

provide durable fuel cells that can provide both hydrogen generation and electricity for 

thousands of cycles. Furthermore, while PEM fuel cells may be developed for this application, 

the higher potential efficiencies of SOFCs may also be leveraged. 

Tomorrow’s Potential

Handheld Devices (1 W to 100 W) 

A leading area for DOE-funded hydrogen storage research is performing catalyst research for 

direct methanol fuel cells (DMFC) and proton-exchange membrane fuel cells (PEMFC) to 

improve their performance and durability. DHS can leverage NREL’s fuel-cell program with 
38 

DOE to power the DHS security mission. Most DMFCs are designed for consumer applications 

such as laptops, cell phones, and sensors. There also are DMFC systems that have been 

developed specifically to power portable devices of U.S. soldiers. These are funded by DOD (the 

U.S. Army Research Office, DARPA, and the Army’s Communications-Electronics Research, 

Development and Engineering Center [CERDEC]), thus there is a potential for collaboration 

with DOD and the companies that developed DMFCs as power sources and battery chargers for 

these applications. NREL has collaborated and continues to collaborate with portable-power 

companies such as MTI MicroFuel Cells and Ultracell. 

Direct methanol fuel cells are very well suited for powering or charging batteries that power 

handheld devices such as night-vision devices. The DMFCs are small, light, and have high 

energy capacity. They are especially suited for long-term operations that batteries cannot fulfill. 

The liquid-methanol fuel is easy to handle, light, and safe to use as a fuel cartridge. The highenergy fuel provides high energy density in a small package. The DMFC technology presently is 

available as both commercial and demonstration products. A pilot project using this technology 

to power or charge hand-held devices for DHS needs now is possible. 

Alkaline membrane fuel cells (AMFCs) also are being developed by DOD for soldier power 

needs. This technology is not as developed as that of DMFCs, but it has great cost benefits 

because relatively inexpensive non-precious metals can be used as catalysts. NREL also is 

conducting research in this field for DOE Basic Energy Science (BES) and recently put together

a workshop on AMFCs for DOE EERE. DHS again can leverage the research and development

funded by DOE for homeland security applications. 

Catalyst Research and Development (3 to 5 Years)

Wide commercialization of DMFCs currently is limited by the performance and durability of the 

anode catalyst. DOE is developing a fuel-cell catalyst that potentially can produce ten times the 

performance of other state-of-the art DMFCs—at a lower catalyst loading and greater catalyst

durability. This can translate to lower cost and lighter, smaller DMFC systems that can provide 

long operating times. Depending on the specific DHS power needs and size, weight, and capacity 

requirements, a DMFC system can be produced that will meet DHS security mission needs.

Remote Operations (Less than 5 kW) 

The DMFCs and AMFCs producing power have been demonstrated. Oorja Protonics has a 

commercial 1-kW DMFC system that charges the lead-acid batteries in forklifts. CellEra has a 

2-kW hydrogen-air AMFC system that uses non-precious metals as catalysts and is targeted for 

backup power applications. Systems such as these can be used to remotely charge batteries and 

equipment. 

Long-Term Applications and Research

Handheld Devices (1 W to 100 W) 

Another key area for research and development assistance is on more durable, high-temperature 

membranes and non-precious catalysis for AMFCs. These are the two major barriers to 

commercialization of this technology. Currently, AMFCs use hydrogen as a fuel; however, other 

fuels—such methanol, ethanol, hydrazine, and dimethyl ether—can be used. The problem with 

carbonaceous fuel is that carbon dioxide is formed and can react with the hydroxide and harm the 
39 

MHK Technology Status

Today the development status of MHK 

technology is comparable to the wind 

industry in the 1980s.

fuel cell. High-temperature membrane and catalysis research can alleviate this problem and make 

AMFC more viable.

To identify and remedy areas of vulnerability in U.S. border security, DHS can tap into NREL’s 

wide collaborative network of other national laboratories, industry, and academia that are 

conducting research, development, testing, and evaluation of fuel-cell and hydrogen 

technologies. As an example, NREL is working with different companies to efficiently convert 

renewable energy from wind and solar to hydrogen. NREL also is developing reversible fuel-cell 

technologies that could be integrated with renewable energy to provide the direct energy storage 

needed with wind and solar, with the same unit providing the power when the renewable energy 

no longer is available. This potentially decreases cost and weight, but substantial development is 

required to provide durable fuel cells that can provide both hydrogen generation and electricity 

for thousands of cycles. Furthermore, although PEM fuel cells might be developed for this 

application, the greater potential efficiencies of solid oxide fuel cells (SOFCs) also can be 

leveraged.

2.4 Marine and Hydrokinetic Energy Technologies

Marine and hydrokinetic energy can be broadly categorized as wave energy, tidal current, openocean current, river current, and ocean thermal gradient. Salinity gradient energy often is 

included as a form of marine energy. The technologies used to convert these forms of energy to 

electricity often are referred to collectively as marine hydrokinetic (MHK) energy technologies.

A brief introduction to MHK technologies and their current status is provided in this section. 

Also included is a more in-depth exploration of the scientific, technical, and nontechnical 

challenges and barriers to their wide-spread use. This second section, called "Roadmap to 

Address Commercial Pathway and Challenges for Marine Hydrokinetic Technologies" (page 47), 

will inform DHS in terms of how fast mainstream MHK technologies are moving, and how this

might impact DHS applications. The reader may choose to bypass this discussion and skip to the 

"Department of Homeland Security Relevance: Marine Hydrokinetic Energy" section starting on 

page 56. 

Marine hydrokinetic–energy generation technologies have been under development since the 

1976 oil embargo, but this development has been sporadic and inconsistent. Only prototypes and 

early production models have been deployed as 

demonstration projects. The current state of the industry can 

be compared to the early stages of the wind energy industry 

in the 1980s. Many concepts have been proposed with a wide 

variety of methods for energy capture and conversion but 

there has been little technology convergence. Dozens of 

companies are trying to deploy these technologies around the 

world. 

Marine Hydrokinetic Energy Technologies Overview

Many MHK concepts have been proposed with a variety of methods for energy capture and 

conversion. There are more than 100 concepts in various stages of development in 24 countries 

around the world (Khan and Bhuyan 2009). In the United States alone, there are at least 40 MHK 
40 

concepts currently being developed; however, there is little convergence of the technology, 

indicating that no particular technology or configuration has yet been shown to be superior. 

Figure 7 illustrates general types and numbers of technology concepts under development 

worldwide and their current development status. 

Figure 7. Marine hydrokinetic technologies in development worldwide (Khan and Bhuyan 2009)

Figure 7 includes the tidal-barrage concept, which usually is not considered to be a marine 

hydrokinetic technology. Tidal barrages are dam structures built across the mouth of an estuary 

that has a high tidal range. The barrage is conceptually identical to a conventional hydroelectric 

dam on a river except that the barrage or dam can generate power during incoming and outgoing 

tides. Barrage systems are not be considered further here because they already are commercial, 

and therefore they are not included in the family of MHK technologies. Figure 7 groups tidalcurrent devices and ocean-current devices into one category for convenience. Many tidal devices 

also are being proposed for ocean-current applications; they would use modified supporting 

structures, foundations, or mooring arrangements. Figure 7 clearly indicates that most of the 

development is in the area of ocean wave and tidal- and ocean-current technologies—which is 

why this report focuses on these technologies. There is growing interest, however, in ocean 

gradient energy, often called ocean thermal energy gradient (OTEC), and salinity gradient energy 

conversion. These technologies are not considered in this report because they have not yet been 

tested at a practical commercial-prototype scale. The International Energy Agency’s Ocean 

Energy Systems Implementing Agreement (IEA-OES) Annual Report 2010 presents a 

comprehensive report of global activities for all of the marine energy technologies.8

The following sections describe the configurations for the major device types of conversion 

technologies for wave- and water-current energy converters. A comprehensive listing of marine 

 

8 Also available at www.iea-oceans.org/_fich/6/2010_Annual_Report.pdf 
41 

and hydrokinetic device configurations, current projects, and development companies is provided 

in the Marine and Hydrokinetic Technology Database on the DOE website (DOE 2011).9

Wave-Energy Conversion Technologies

 

The wave-energy converters currently deployed or under development can be described as 

absorbers, attenuators, oscillating water columns, overtopping devices, and inverted pendulums. 

These all are defined below. 

• Absorbers extract energy from the movement of a buoy—relative to the ocean floor—with 

the rise and fall of waves. This movement is converted to electrical energy via either a linear 

or a rotary generator.

• Attenuators capture wave-energy using a principal axis that is oriented parallel to the 

direction of the incoming wave. These devices convert the energy created by the relative 

motion of the articulated bodies of the devices as waves pass along them. 

• Oscillating water columns are partially submerged enclosed structures. Air fills a chamber 

in the upper part of the structure which is above the water level. Incoming waves are 

funneled into the structure from below the waterline, causing the water column within the 

structure to rise and fall with the wave motion. This alternately pressurizes and depressurizes 

the air in the chamber, pushing and pulling it through an air turbine mounted in a portal in the 

top of the chamber structure.

• Overtopping devices allow waves to lift water over a barrier to fill a reservoir that is drained 

through a hydro turbine. These often are described as low-head hydro facilities because they 

convert the potential energy of the elevated water in the upper reservoir to generate power—

much like a conventional hydropower dam. 

• Inverted-pendulum devices use the surge motion of waves to rotate a large, hinged paddle 

back and forth. The flapping motion drives hydraulic pumps that, in turn, drive electrical 

generators. Alternatively, linear generators are used to directly convert the wave energy into 

electrical energy.

Schematics of several of these (generic) devices are presented in Figure 8. The technology status 

of wave energy converters is thoroughly reviewed in Bedard (2006), Falcao (2010), and Khan 

and Bhuyan (2009). More-detailed information also is provided in these sources. 

 

9 Also available at www.eere.energy.gov/windandhydro/hydrokinetic/default.asp 
42 

Figure 8. Five typical wave-energy conversion devices (adapted from Bedard 2006). 

Illustration by NREL

Tidal, Open-Ocean, and River-Current Hydrokinetic Technologies

Tidal energy potentially can be converted to electrical energy through water height differences or 

through the kinetic energy created when alternating tides and geography induce water flows. A 

tidal barrage converts potential energy to electrical energy by allowing large reservoirs to fill 

during high tide, and then releasing the water through conventional hydropower turbines during 

low tide. Tidal, ocean-current, and river-current turbines convert the kinetic energy in flowing 

water into electricity in exactly the same manner that a wind turbine converts the kinetic energy 

in wind into electricity. The status of tidal energy technology is reviewed in Bedard (2006) and 

Khan and Bhuyan (2009). 

Figure 9 illustrates four common tidal-energy devices, an axial-flow horizontal-axis turbine; a 

cross-flow vertical-axis turbine; an articulated oscillating hydrofoil generator; and a Venturi 

augmented axial-flow, horizontal-axis turbine. In general, these devices can be shrouded or 

unshrouded, and the rotation axis can be either horizontal or vertical.
43 

Figure 9. Four typical kinetic-energy conversion devices for tidal, ocean, and river currents 

(adapted from Bedard 2006). Illustration by NREL

Marine Hydrokinetic Energy Resource Availability

Assessing the available resources for MHK technologies is a difficult and complex task. Each of 

the different technologies involves a distinctly different technical discipline and requires 

estimating different physical variables in the natural environment. For devices that extract energy 

from tidal, ocean currents, and river flows, the quantity of interest is the velocity field and its 

time history. For wave devices, the time history of the wave height is of primary interest. For 

ocean thermal-energy converters, interest lies in the temperature difference between the surface 

waters and waters at depth; this temperature difference is used to run a heat engine to generate 

electricity. Salinity gradient energy devices make use of the energy released from the mixing of 

saltwater and freshwater. This depends on the concentration of salt and the availability of a 

freshwater source, and most of these quantities are not well documented historically. For 

example, tidal flows always have been of great interest to seafarers, but generally it is the range 

of tidal heights that is of interest and not the velocity field; there is little historical data on tidal 

velocities to support kinetic energy estimates.

Resource estimates often are separated into two distinct quantities. The first quantity of interest is 

the kinetic energy in the natural flow at a particular location, such as at a river cross section, a tidal 

estuary cross section, or the wave energy along a length of coastline at some distance from shore. 

The kinetic energy contained in the natural flow (kWh/year) is the energy moving through a 
44 

particular cross section of an estuary or channel. Alternatively, often the kinetic power density 

(kW/m2

) of the flow at a location is assessed, and then integration of the kinetic power density over 

time and the cross-sectional area will give the total energy at the cross section for the year. The 

kinetic energy and the kinetic power density are quantities that provide an estimate of the amount 

of energy that is present in the natural environment, and sometimes are referred to as theoretical 

potential, gross potential, or natural resource potential. This type of estimate for the natural kinetic 

energy resource gives insight into the geographic locations of high levels of natural resources, and 

an estimate of the spatial extent and quality of those resources. Figure 10 illustrates the location 

and approximate level of wave, tidal, and current resources in the United States.

Figure 10. Total natural tidal-current energy and wave energy resources in United States; 

A: Alaska current, B: California current, C: Florida current, D: Gulf Stream, E: Labrador current 

(adapted from Bedard 2008). Illustration by NREL

The second resource quantity of interest is the amount of the specific natural resource that can be 

extracted practically. Estimating the natural resource is difficult, but estimating the practically 

extractable resource is even more difficult. In most cases, the practically extractable resource 

cannot be directly derived from an estimate of the natural resource alone. This occurs because 

the amount of extractable resource can be changed by the introduction of the energy-extraction 

device into the flow. Generally, it is expected that introducing the device consequently reduces 

the amount of energy that can be extracted from the flow, but this is not always the case. The 

interaction of a device with the natural physical flow at a site changes the physics of the flow 

and—depending on the flow constraints—this can either increase or decrease the extractable 

energy. Additionally, environmental policies and laws that require no significant environmental 

impacts, plus any other usage restrictions (such as fishing and shipping lanes), almost always 

reduce the possible level of extraction at a particular site.
45 

Minimal Resource Required

Marine hydrokinetic devices can 

generate small quantities of energy to 

power instrumentation and sensors at 

remote locations from a minimal natural 

resource.

Table 3 summarizes the potential extractable U.S. ocean 

renewable resources that, at present, only have been crudely 

assessed. There is considerable uncertainty in these estimates, 

and the extractable limits are based on rough engineering 

assumptions that have not been verified with real-world test 

data. In fact, the methodology for estimating the tidal 

resources is not fully developed at this time. For that reason, 

the estimates in Table 3 probably represent a lower boundary

for the actual tidal resources. They are reported here simply to provide an understanding of the 

current status of MHK resource assessment, and to demonstrate that additional research is 

needed. It also should be noted that Table 3 was developed with commercial bulk power 

generation in mind, and small energy demands (several watt-hours to a few kilowatt-hours) can 

be generated with only minimal resources and using relatively small devices, but the cost will be 

quite high as compared to conventional electric utility sources.

Table 3. Summary of Currently Available Estimates for Wave and Current Energy Resources

Energy 

Source Natural Resource

Extractable Resource

(Existing Estimates) Comments and Notes

Wave 

Energy

Total United States = 

2,100 terawatt-hours 

per year (TWh/yr) 

Total United States = 260 TWh/yr

(67 TWh/yr excluding Alaska 

and Hawaii)

Based on Bedard (2007) data and 

rough engineering assumptions 

for extraction potential

Tidal 

Current

Unknown

(115 TWh/yr for 3 sites

including Alaska)

U.S. estimate incomplete

(6 TWh/yr for 3 sites, 

excluding Alaska)

Based on few sites from Bedard 

(2007) and engineering 

assumptions for extraction 

potential

Ocean

Current

175 TWh/yr

(Florida current only) 21 TWh/yr (Florida current only)

Based on Hanson (2010) for 

Florida current, and Bedard 

(2007) engineering assumptions 

for extraction potential

Marine Hydrokinetic Energy Technologies Global Deployment

The global installed capacity of ocean energy systems is illustrated in Figure 11. The information 

was compiled from data provided by delegate members of the IEA-OES Implementing 

Agreement as listed in the 2010 Annual Report (IEA-OES 2010). Note that much of the global 

installed tidal-energy capacity is in the form of tidal-barrage technology which, as noted, really is 

conventional hydropower technology using an impoundment in a tidal estuary. 
46 

Figure 11. Global installed capacity of ocean energy technologies (IEA-OES 2010)

Roadmap to Address Commercial Pathway and Challenges for

Marine Hydrokinetic Technologies

The marine hydrokinetic renewable energy stakeholders in the United States have developed a 

draft technology roadmap that lays out a pathway for commercialization and addresses the 

challenges faced by this new form of renewable energy technology. The stakeholders for this 

new industry include technology developers, project developers, policy makers, government 

regulators, investors, parts and component suppliers, consultants, environmental organizations, 

government and university researchers, and ocean users. These stakeholders include the groups 

that will be most affected by the development of this new technology. These groups will supply 

the skilled workforce needed to manufacture and install the facilities, and their communities will 

host the facilities in nearby public waters. This roadmap is a working document, which means 

that it will evolve over time and will be updated as knowledge of these technologies and the 

environment in which they are deployed increases. Changes in policies, public perceptions, and 

energy economics also are likely to modify the roadmap's pathways and time frames. The classes 

of energy-conversion technologies included in the industry MHK roadmap are wave, tidal and 

river current, ocean thermal energy, and osmotic energy. 
47 

The Marine Hydrokinetic Industry 

Roadmap 

The MHK industry has developed a 

shared vision and technical strategy to 

address the development needs of this 

new renewable energy source.

The Elements of the United States Roadmap

The U.S. roadmap is based on the following four main elements.

• Vision Statement: The vision statement provides a destination for the roadmap—a picture of 

the desired future outcome. In this case, the vision is a picture of the MHK industry and its 

accomplishments by 2030. 

• Deployment Scenario: The deployment scenario provides one possible pathway by which 

the MHK industry could evolve to fulfill the vision.

• Commercial Strategy: The commercial strategy provides pathways to achieve the 

deployment scenario and to overcome barriers to commercialization of the technologies.

• Technical Strategy: The technical strategy provides pathways to address the research and 

development issues that must be solved to achieve the commercial strategy, mobilize the 

deployment, and reach the envisioned goal by 2030. 

The Roadmap Vision

The stakeholders developed the following vision statement as 

a challenging target for the MHK industry to achieve by 

2030. 

• To establish a commercially viable marine renewable 

energy industry that is supplied by a robust U.S. 

manufacturing chain, generates domestic jobs, and 

competes on a level playing field with other energy 

sources to serve both domestic and international marketplaces in 2030. 

• To deploy at least 20 gigawatts (GW) of combined marine renewable energy capacity in an 

economically, environmentally, and socially responsible manner by 2030. 

The Development and Deployment Scenario

The upper portion of Figure 12 illustrates the MHK technology development and deployment 

scenario envisioned in the U.S. Marine Hydrokinetic Roadmap. It shows a measured, sequential 

development process driving the technology evolution that will lead to commercial viability and 

the vision of 20 GW of installed capacity by 2030. Domestic benefits include research and 

development knowledge, manufacturing and supply chain development, harbor and port 

infrastructure development, and the creation of jobs across the nation and in coastal 

communities. The global environment will benefit from a new carbon-free energy source.
48 

Figure 12. Development and deployment harmonized with the commercial strategy 

(Thresher 2010)
49 

The Commercial Strategy

Figure 12 shows the harmonization between the MHK development and deployment scenario 

and the commercialization strategy. The upper portion of the figure shows the technology 

development and deployment time line. The bottom portion of the figure lists eight major 

barriers to development and deployment and outlines strategies that address those barriers. 

Figure 12 also illustrates the complex challenges that must be addressed between 2010 and 2020 

for the industry to be ready to transition to full-scale commercial production and installation of 

large projects by 2020. The technology must be mature enough to be installed in large quantities 

without major problems, and it must be priced competitively. The siting and permitting 

requirements must be well-established and routine; therefore, environmental-study requirements 

must be understood and also must be timely and affordable. Most importantly, appropriate 

policies and incentives must be in place to support the transition of this technology to 

commercial-scale production, and to facilitate the development of the market and the related 

supply chain, including job training and public education. 

The Technical Strategy

Figure 13 illustrates the MHK development and deployment scenario together with the overall 

R&D technical strategy. The lower portion of Figure 13 provides a brief description of the scope 

of research and development for each major category of work. The arrow timelines show the 

types of activities that are expected to take place during each time interval. It should be 

understood, however, that many activities will take place simultaneously, and a number of the 

activities will overlap. The intent of the roadmap is to provide a logical and coordinated 

sequence for the primary activities that are expected to achieve the desired vision. 

For the MHK device developers, the development and deployment scenario in Figure 13 shows 

that—from 2010 to 2015—the primary activities are prototype testing and demonstration 

projects. These activities involve permitting and environmental studies, testing of machines as 

single units, and deploying small arrays. In the period from 2015 to 2020, efforts shift to the 

commercial scaling of projects and gaining operation experience in the water. Although there 

still will be a significant investment from 2020 to 2030—both in developing new technology and 

improving existing designs—the greater investment is anticipated in scaling-up to the production 

and manufacture of larger projects in the 100-MW capacity range. 

One of the critical activities slated for 2010 to 2015 is the development of support capabilities at 

U.S. test centers. For MHK devices to evolve it is critical to prove and validate performance for 

the machines in a real-world operating environment. Timely access to—and tailored support 

from—the National Marine Test Centers will enable developers to ensure that their devices have 

good energy capture and high reliability. After 2015, these testing capabilities must evolve with 

the industry—both in terms of device scale and the supporting infrastructure systems. After 

2020, the test centers might need to develop a campaign for ad hoc remote testing programs at 

industry sites to address device-specific or site-specific issues that can occur during operation. 

For other engineering and scientific contributors in the MHK industry, the major activities from 

2010 to 2015 and beyond are to develop capabilities to support the initial start-up of the industry. 

Beyond 2030, the focus is anticipated to be driven by industry-specific technical needs based on 
50 

Special-Purpose Power 

Generators

Over the next 5 years, the Industry will 

be researching and perfecting wave and 

tidal devices at a small to medium scale, 

so it is an opportune time to perform 

R&D for special purpose power plants 

that are tailored for high reliability and 

operation in hostile remote 

environments.

the evolution of the technology. Figure 13 provides only high-level categories for anticipated 

R&D activities. These are explored in more detail in the full roadmap (Thresher 2010). 

Figure 13. Marine hydrokinetic development and deployment scenario and the overall R&D 

technical strategy (Thresher 2010)

Research and development of ocean energy devices can take 

5 years or more from concept to ocean prototype testing, 

depending on complexity. A new concept always is simulated 

with a numerical model to gain understanding of its 

performance and dynamic behavior at low cost. Next, 

subscale tank tests are run (at one or two scales) to validate 

and improve the modeling. Open-ocean prototype tests are 

run at full scale, or near full scale, after the concept is well 

vetted by the models and tank testing. Lastly, a full-scale 
51 

National Marine Test Centers

National marine energy testing centers 

have been established by DOE, and can 

be used to operationally test and prove 

prototype power-generation systems. 

These centers have cooperative 

research agreements with NREL for 

technical support and advice.

prototype is built and tested. Development of a full-scale prototype and its related testing 

programs only is warranted if there is a great probability of producing a superior device that can 

be commercialized successfully. The key research issues for ocean-energy devices focus on a 

single device’s performance and loads and its performance in large arrays. 

For wave energy to become commercial and generate significant amounts of energy, the devices 

must perform well in large arrays. This means that the array layout and spacing and control 

strategies are of paramount importance. Additionally, the overall control of the wave-device 

array is of great importance. Optimizing the individual performance of a device probably will not 

be as important as optimizing the entire array’s energy capture. System models are crucial to 

accurately estimate system costs and to understand the influence of device scale and array size. 

Reliability and survival during operation and extreme events also are important factors for the 

success for these technologies.

Figure 13 shows the expected timeline to develop the testing facilities and capabilities needed to 

support the development of all of the MHK technologies. DOE has named three new national 

marine test centers to support development of ocean energy technologies, listed below.

• Northwest National Marine Renewable Energy Center. Oregon State University in 

Corvallis and the University of Washington in Seattle are jointly running the Northwest 

National Marine Renewable Energy Center. The Northwest Center provides a full range of 

capabilities to support wave and tidal energy development for the United States. 

• National Marine Renewable Energy Center of Hawaii. The University of Hawaii in 

Honolulu established a center to facilitate the development and implementation of 

commercial wave-energy systems in Hawaii and to assist the private sector in moving 

ocean thermal-energy conversion systems beyond proof-of-concept to precommercialization, long-term testing.

• Southeastern National Marine Renewable Energy Center. Florida Atlantic University has 

established a center to facilitate the development and implementation of ocean current 

systems and to assist in moving ocean thermal-energy conversion systems and ocean watercooling systems research through testing and commercialization. 

The early emphasis is on developing test-center capabilities 

and infrastructure, along with associated testing protocols, 

sensors, and data collection methodologies. It is anticipated 

that the United States will need test centers that can perform 

open-water testing of wave, tidal, ocean current, river, and 

ocean thermal technologies to support all of the MHK 

technology development pathways. The early priority is to 

develop the capability to test devices in realistic open-water 

conditions. 
52 

Marine Hydrokinetic Cost 

Reduction Potential

Marine hydrokinetic technologies are 

high-torque low-speed energy 

generators similar to wind turbines and 

have a great potential for cost reduction 

with experience over time.

The full roadmap contains detailed figures that illustrate the research strategy for wave, tidal, and 

river current devices; enabling technologies; testing facilities; resource characterization; and 

environmental research. It also provides a complete picture of the technical challenges in each 

technology area (Thresher 2010). 

Cost of Marine Hydrokinetic Technologies

A public-domain analysis of wave and tidal energy-generation technology costs for existing 

prototype devices was performed and then described in the 2006 Carbon Trust Report

(Callaghan and Boud 2006). This report provides a cost range for the 2006 prototypes and firstproduction wave and tidal-stream energy devices. This report gave the costs in 2006 British 

pounds sterling which were converted to U.S. dollars at the conversion rate of 1.78$/British 

pounds sterling. These device costs are shown in Table 4 below, and illustrate the economic 

challenge for this new technology to become cost competitive in global energy markets. 

Table 4. Estimated Capital Costs for Marine Hydrokinetic Wave and Tidal Technologies in 2006

Description

Low Cost

($/kW)

Mid Cost

($/kW)

High Cost

($/kW)

Wave Energy Device 7,700 11,900 16,100

Tidal/Current Energy Device 8,600 11,450 14,300

These costs are quite high as compared to conventional fossil-based generation, and even are 

high as compared to other renewable technologies. Note, however, that MHK technology is a 

new renewable energy technology, and all of the competing renewable energy technology costs 

initially were just as high—or higher—when research was first initiated in the 1970s and 1980s. 

Land-based wind plant capital costs, for example, in the early 1980s were about $4,500/kW. This 

cost was reduced to $1,200/kW in 2004 (Wiser and Bolinger 2010). This represents a cost

reduction by a factor of about 3.75. Since 2004, however, all power-plant costs have increased 

significantly, for both wind plants and conventional technologies. In 2009, land-based wind-plant 

costs on average increased to about $2,000/kW. Currently, the cost of offshore wind technology 

is estimated to be approximately $4,000/kW (Musial and 

Ram 2010), and offshore wind is considered to be nearly 

competitive at good wind sites. Therefore, if the cost of MHK 

technologies could be reduced by a similar factor then it 

would be in this competitive price range. Further costanalysis work currently is being performed by DOE and 

European entities such as the Carbon Trust in the United 

Kingdom, but results have not yet been released publicly. 

Environmental Impact Concerns

Marine hydrokinetic technologies are new and emerging, and the significance of possible 

environmental effects is not well understood. Boehlert et al. (2007) reviewed the possible 

environmental effects of wave development. Additionally, the potential effect of wave 

development on marine birds has been reviewed independently (Grecian 2010), as have the 

potential environmental effects due to tidal development (Polagye et al. 2010). Multidisciplinary 

scientific research is required to develop a better understanding of the environmental 

implications of MHK technologies before they are widely deployed (Gill 2005; Inger et al. 

2009). At this time, there is a comprehensive understanding of the range of possible 
53 

environmental effects and interactions that could take place as MHK technologies are deployed.

There also seems to be a reasonable understanding of which of these effects could potentially 

have high ecological significance, but there is little or no understanding of the actual impacts. 

This is because, globally, there are so few devices in the water to observe and measure the real 

impacts—which many agree is a logical next step. It generally is agreed that the potential for 

significant impacts is almost negligible, provided that early deployments are small and the 

installations are monitored appropriately. 

There are concerns that it might be difficult to measure any actual impacts for single prototype 

and small installations due to the highly variable environment in the ocean. Currently there also 

are no standard monitoring protocols for MHK projects in the United States. In Europe, however, 

a project called EquiMar has been established to develop harmonized monitoring protocols for 

MHK prototype deployments. These protocols and related recommendations could serve as a 

starting point for study and field data collection efforts in the United States, as well as the 

development of U.S. protocols. Lastly, the IEA-OES recently established a new task to share 

environmental information among the member countries in an effort to accelerate the 

development of a global understanding of environmental impacts. 

Studies to better understand and estimate the significance of any impacts on marine life, marine 

geography, recreation, cultural resources, and public safety are needed before MHK technologies 

can be widely deployed. The following list of environmental stressors and potential impacts is 

summarized from the workshops and papers described herein. 

• Effects of energy-removing structures on wave height, tidal current flow patterns, and the 

resulting sediment transport

• Effects of electromagnetic fields on fish and marine mammals

• Interactions of MHK devices with fish and marine mammals

• Impacts of chemical emissions into the atmosphere and ocean

• Effects of introduced hard structures, including effects of fish aggregating devices (FADs) or 

artificial reefs

• Acoustic effects of many devices on fish and marine mammals

• Visual impacts

• Conflicts with other uses of sea space (e.g., fishing, boating, shipping, clamming, crabbing) 

• Effects of installation and decommissioning 

• Cumulative impacts of all these issues over time

Current U.S. Department of Energy Research and Development for Marine Hydrokinetic

Technologies

The DOE Wind and Water Power Program sponsors research and development of advanced 

MHK technologies, with the objective of understanding their generation potential and identifying 

and addressing the technical and nontechnical barriers to their use. The MHK technologies 

supported generally include devices that capture energy from waves, tides, ocean currents, the 

natural flow of water in rivers, and marine thermal gradients without building new dams or 

diversions. In 2005, Congress passed the Energy Policy Act of 2005 and the Energy 

Independence and Security Act, which authorized substantial new funding to conduct research 

and development on marine and hydrokinetic technologies. In 2008, Congress began 

appropriating funding that allowed the program to fund research on MHK technologies. 
54 

The mission of the DOE Water Power Program is to assess the potential energy extractable from 

domestic rivers, estuaries, and marine waters, and to assist the U.S. industry to harness MHK

renewable energy resources in an environmentally sustainable and cost-effective manner. The 

DOE program has two major thrusts for MHK technologies. The first is technology 

development, and it seeks to:

• Prove device functionality and generate cost, performance, and reliability data 

• Develop design codes and models necessary for system development and testing

• Ensure the necessary facilities exist to generate and collect system data

• Develop standards and models to analyze and evaluate test data. 

The second thrust is to accelerate market development by: 

• Quantifying the resource available, and—using technology performance and cost data—

projecting economic viability of MHK technologies 

• Evaluating and minimizing key environmental risks associated with deployment of MHK

projects

• Disseminating data on the technology and resource, and integrating this information into 

energy benefit and deployment models. 

Open-Water Prototype System Testing, Demonstration, and Operation

The DOE Wind and Water Power Program supports a significant number of R&D projects 

including concept studies, wave-tank testing, component development, proof-of-concept 

research, system-integration projects, and open-water full-scale prototype system testing. The 

open-water prototype system projects aim to test the newest and most advanced technology 

currently available in the world. Pictures of the device configurations are provided in Figure 14, 

Figure 15, and Figure 16. The prototype tests to be performed over the next 2 to 3 years are 

designed to assess the readiness of MHK technology for use in demonstration projects. Three 

prototype projects will be deployed in the next 1 to 2 years. 

• Ocean Power Technologies, Inc. (Pennington, NJ) will deploy a full-scale 150-kW 

PowerBuoy system in the Oregon Territorial Sea and collect 2 years of detailed operating 

data. This project will obtain critical technical and cost performance data for one of the most 

advanced wave-energy converters in the United States. 

• Ocean Renewable Power Company (ORPC) (Portland, ME) will build, install, operate, and 

monitor a commercial-scale array of five grid-connected TidGen Project devices on the sea 

floor in Cobscook Bay off Eastport, Maine, in two phases over 3 years. The project will 

advance ORPC’s cross-flow turbine tidal-energy technology by producing a full-scale, gridconnected energy system, and will gather critical technical and cost performance data for one 

of the most advanced tidal-energy systems in the United States. The completed project will 

comprise an array of interconnected TidGen hydrokinetic energy-conversion devices, 

associated power electronics, and interconnection equipment into a system fully capable of 

commercial operation in moderate- to high-velocity tidal currents in water depths of up to 

150 feet. 

• Public Utility District No.1 of Snohomish County (Everett, WA) will deploy, operate, 

monitor, and evaluate two 10-meter diameter Open-Centre Turbines (developed and 
55 

manufactured by OpenHydro Group Ltd.) in Admiralty Inlet of Puget Sound. The project is 

expected to generate 1 MW of electrical energy during periods of peak tidal currents with an 

average energy output of approximately 100 kW. This full-scale, grid-connected tidal turbine 

system will gather critical technical and cost performance data for one of the most advanced 

tidal turbine projects in the United States. 

Figure 14. Ocean Power Technologies PowerBuoy wave generation system uses a "smart", oceangoing buoy to capture and convert wave energy into low-cost clean electricity. 

Photo from Ocean Power Technologies, NREL/PIX 17114

Figure 15. ORPC's Beta Turbine Generator Unit generates clean, renewable electricity by 

harnessing the energy of the world's rivers and oceans. 

Photo from Ocean Renewable Power Company, NREL/PIX 17210
56 

Marine Hydrokinetic Vision for 

Department of Homeland Security 

Applications 

The vision is to provide power 

generators for DHS offshore and river 

applications that would generate 

electrical energy with high reliability from 

renewable energy sources that do not 

require fuel or frequent maintenance.

Figure 16. OpenHydro's Open-Center Turbine is designed to be deployed directly on the seabed. 

The first 6-m test unit produces enough energy to supply 150 average European homes and save 

the emission of over 450 tons of CO2 greenhouse gas per year. 

Photo from OpenHydro, NREL/PIX 17243

The DOE website provides additional information on the MHK technologies and a description of 

the R&D projects that currently are being funded (DOE 2011).

Department of Homeland Security Relevance: Marine Hydrokinetic Energy

The DHS application of MHK renewable-energy generators would be in the area of supplying 

power for observational equipment and facilities located on coastal sites, on remote rivers, and 

for sites where other power sources are not readily accessible or are prohibitively expensive. The 

plan would be to provide power generators for DHS applications that would deliver electrical 

energy with high reliability from renewable energy sources that do not require fuel or frequent 

maintenance. The systems could operate unattended for long periods and could generate power 

for facilities, observational equipment, sensors, and transmitters employed in securing U.S. 

borders. These renewable-energy generation units would be tailored for specific applications and 

have redundant systems to assure reliable operation for lengthy periods without maintenance. 

Today's Opportunities and Tomorrow's Potential

It is clear from this overview of MHK technologies that there 

currently are no off-the-shelf commercial products that can 

be applied directly to DHS applications. In the 3-to-5 year 

time frame, however, there is time to design, develop, and 

manufacture a custom product for DHS applications and to 

fully test it at one or more demonstration projects. As 

discussed, the R&D time line for a new ocean energy 

generator easily can take 5 years from concept to ocean 

prototype testing and demonstration. To develop a new 

custom product it is best to first perform simulations with 

numerical models to gain knowledge of the expected 

performance and dynamic behavior and to estimate the cost. This relatively inexpensive first 

phase is needed to show the viability of a particular concept and to perform design trade-off 

studies to optimize the design prior to investing in wave-tank or water-tunnel experiments. Next, 

with a well-understood concept, subscale tank tests should be run at one or two different scales 

to verify the design concept and the numerical simulations. After the concept is well vetted by 
57 

the modeling and tank testing, open-ocean prototype tests then would be performed at or near 

full scale. Proceeding to build and test a full-scale prototype only is warranted if there is a great

probability that the product can successfully perform the envisioned mission role. The final step 

is to manufacture a small number of units for pilot-scale deployment and then track their 

performance and reliability over 1 to 2 years to prove the product in variety of real-world

applications and in different operating environments. 

NREL has managed a development program of this type for the DOE Wind Program several 

times over the past two decades. The GE 1.5-MW wind turbine was developed under such a 

program, for example, and the Clipper 2.5-MW turbine also was a product of a similar 

development program. Both of these turbines were developed as public-private partnerships in 

collaboration with a wind-industry partner to ensure that the resulting commercial product would 

be economically viable in the electricity marketplace. These turbines both currently are being 

installed in large numbers in the United States. In fact, the GE 1.5 has captured a majority share 

of the U.S. wind-turbine market and has garnered a significant share of the global market. This 

type of development process to produce a power generator for DHS applications could result in 

the creation of a commercial supplier of these power generators that could meet the remote 

generation needs of DHS and other agencies with similar needs, such as DOD. 

Long-Term Applications and Research

In the longer term, it would be possible to develop more-complex high-performance systems for 

special applications that would have more demanding or unusual requirements for performance, 

cost, and reliability. Bottom-mounted ocean platforms, for example, that employ a multitude of 

sensors could be used to track ocean traffic both acoustically and by other means. Alternatively, 

an unmanned vehicle powered only by ocean waves could be developed to patrol a region of the 

ocean autonomously for long periods. Depending on the power needs and the application, hybrid 

power systems that make use of more than one renewable energy resource could be explored. For 

example, solar and wind generators could be used to augment the level of energy available. 

There has been little recent development of hybrid power systems for special applications 

requiring high reliability and that run on locally available renewable energy resources. Perhaps 

now is the time to invest in the development of self-sustaining power systems that can operate 

unattended for long periods in harsh remote environments. 

2.5 Biofuels and Algae

All algae are nonvascular plants (i.e., lacking a specialized nutrient-distribution system) and 

include macroalgae (seaweeds) and microalgae. Microalgae generally refer to all algae too small 

to be seen clearly without aid. They include the prokaryotic cyanobacteria and the eukaryotes 

green algae and diatoms, among other types. This report also includes aquatic plants such as 

duckweed in the general category of “algae,” as they could be cultivated and harvested similarly. 

Although algae perform oxygenic photosynthesis (i.e., split water to produce oxygen and fix 

carbon dioxide into biomass using sunlight), many also can use organic substrates (e.g., glucose, 

acetic acid) in the light or dark (mixotrophic growth and heterotrophic growth, respectively). 

This report discusses the multiple uses of algae, and proposes ideas that might be of interest to 
58 

DHS. Most ideas described are longer-term research projects, with short-term research

exceptions noted. 

Technology Overview—Biodiesel Production

Although both microalgae and macroalgae for centuries have been used as foods, the potential of 

algae as feedstocks for fuel production is a relatively recent concept. In the 1950s, researchers

began to evaluate algal biomass as an energy source using anaerobic digestion for producing 

methane. During the oil embargo in the 1970s, DOE began to fund the Aquatic Species Program 

which evaluated micro- and macroalgae along with aquatic plants and wetland emergents as 

feedstocks for energy production, eventually focusing on microalgae because their potential for 

high lipid production made them a potential feedstock for biodiesel production (lipid content as 

high as 60% of total biomass has been observed at NREL). 

The lipids produced by microalgae primarily are composed of triacylglycerides (TAGs) which 

have a composition very similar to vegetable oils, although they can be enriched for 

polyunsaturated fatty acids such as omega-3 and omega-6 fatty acids which have healthpromoting properties, but they actually are poor starting materials for fuels. More recently, 

vegetable oils and algae lipids have been converted to hydrocarbon biofuels by using 

conventional catalytic properties. The biofuels are used as substitutes for gasoline, diesel, jet 

fuel, and marine distillate. Solazyme, the company which produces algal lipids by a 

heterotrophic process (i.e., by growing algae in dark fermentors with sugar growth substrates), 

has contracts with the U.S. Navy to provide thousands of gallons of both jet fuel and marine 

distillate to assist in meeting the U.S. Navy goals for replacement of 50% of its fossil-fuel use 

(336 million gallons per year) by 2020. 

Biodiesel Co-Products

Although it is the high lipid content of algae that have placed them in the spotlight for advanced 

biofuel production, that is only one part of the overall opportunity for energy generation. After 

lipids have been removed from the algal biomass, the remaining material contains approximately 

equal amounts of protein and carbohydrate. As such, this material remains a potential feedstock 

for anaerobic digestion to produce methane (Figure 17)—though the nitrogen-to-carbon ratio is a 

slightly high and could require supplementation with a low-nitrogen material such as municipal 

solid waste or forestry or agricultural residues. Wastewater treatment facilities often use algae 

ponds as part of tertiary wastewater cleanup and the biomass from that has been shown to be a 

suitable feedstock for anaerobic digestion.
59 

Figure 17. Biopower production using algal biomass. Illustration by NREL

The carbohydrate fraction of algal biomass also can be used as a feedstock for fermentation to 

ethanol or other advanced biofuels. Many algal strains can accumulate starch, thus providing a 

ready supply of glucose for fermentation. The oleaginous algae, however, do not make much 

starch, at least not under conditions of high lipid productivity. In these cases, once the lipids have 

been extracted the remaining carbohydrate mainly is in the form of cell-wall polymers. Just as 

plant cell walls (composed of cellulose, hemicellulose, and lignin) are more difficult to break 

down to monomeric sugars, algal cell walls have been shown to be resistant to degradation. 

Additionally, they can be composed of sugars rarely seen in plant cell walls, including 

glucosamine, uronic acids, and glycolipids. The decades of experience breaking down terrestrial 

plant biomass to monomeric sugars using both chemical and enzymatic treatments will not 

necessarily lead to rapid progress for the deconstruction of algal biomass, nor will the resulting 

sugars necessarily provide accessible substrates for fermentative organisms (Figure 18). 
60 

Figure 18. Biochemical strategies for converting algal feedstock into biofuels. Illustration from 

Sustainable Algal Biofuels Consortium

The most straightforward means of conversion of algal biomass to energy is through combustion 

in conventional engines, power plants, and boilers. Microalgal biomass has approximately the 

same energy content as coal, and proposals have been made to mix microalgae with diesel to 

reduce fossil-fuel use. Processes that involve spraying coal with microalgae slurries for use in 

power plants also have been described, but both of these approaches require significant 

dewatering of the algae biomass which reduces the energy returns and the value. The high 

nitrogen content of microalgal biomass relative to coal could result in high nitrogen-oxide (NOx) 

emissions or necessitate special scrubbing processes.

Food and Feed Production

Conversely, the high nitrogen content of algal biomass can make it a useful food source. As 

noted, microalgae and macroalgae have been used for foods for centuries. Algae strains such as 

Spirulina and Chlorella can be found in health food stores. These and other strains of algae have 

been used in aquaculture for fish and shellfish production. Algae proteins also are being 

considered as a replacement for animal or fish protein for animal and pet food, as the cost and 

availability of proteins becomes increasingly problematic. The same cost and availability 

pressure is causing human food producers to consider algae as a potential raw material.

In addition to the proteins in algae other components, such as carotenoids and omega-3 fatty 

acids, also are in demand for nutraceuticals. These components often are produced in algae for 

use for food supplements. The omega-3 fatty acids found in abundance in fish is due to the 

accumulation in their tissues as algae are passed up the food chain. Algal biofuels are a highvolume, low-value product, therefore the production processes and raw materials to be used are 

by necessity low cost and low quality. There typically is a slight a disconnect in the discussions 

of high-value co-product (i.e., animal feed, human food) coupled with biofuel production. 

Water Remediation, Carbon Dioxide Capture, Oxygen Production, 

Hydrogen Production, and Mineral Recovery

As noted, algae often are used for tertiary wastewater treatment, where they have the potential to 

remove inorganic nutrients such as nitrogen, phosphorous, and potassium from the water for 
61 

Wild Algae Harvest

A decommissioned USCG ship could be 

retrofitted for a pilot project to determine 

whether it would be possible to harvest 

wild algae. Macroalgae and aquatic 

plants should be the initial targets 

because they are more readily harvested 

than microalgae. The algae biomass 

could be converted to fuels and fertilizer 

at onshore anaerobic digesters. 

Alternatively the biomass could be used 

to generate fuel (methane) on board to 

power the ship’s systems. An onboard 

anaerobic digester also could treat 

human waste for enhanced fuel 

production.

incorporation into biomass. Algae have been shown to grow with earlier-stage wastewater, where 

they can metabolize the carbon compounds present. Under such conditions they grow 

mixotrophically; that is, with a mixture of carbon dioxide and organic carbon. Under these 

conditions, the algal growth has the added benefit of remediation of wastewater to advance its 

purification for disposal.

An economic value from algal growth can come from the capture of carbon dioxide (typically 

expected to come from fixed carbon-dioxide sources such as power plants and cement kilns), 

although the lack of federal policy regarding carbon dioxide emissions does not provide any 

immediate financial benefit. Part of the process of photosynthesis involves the splitting of water 

to yield oxygen. Under some conditions, the oxygen could be captured, providing some coproduct credit. Some algae also are able to reduce hydrogen ions in water to hydrogen gas, 

another potential product. Biological hydrogen production has been explored at NREL for a 

number of years, and although a production process can be complicated (oxygen inhibits 

hydrogen production, and producing oxygen and hydrogen simultaneously could lead to an 

explosion), much progress has been made regarding both the biology and the process options. 

As noted, algae biomass can accumulate inorganic nutrients such as nitrogen, phosphorous, 

potassium, and sulfur, which can make the algae suitable for green fertilizer. This is true for both 

microalgae and macroalgae. It also is possible to recover the sludge from anaerobic digesters fed 

with algae biomass for recycling as a growth nutrient or for use as a fertilizer. Not only are algae 

capable of accumulating inorganic nutrients, they also have been shown to capture mercury and 

other heavy metals often present in flue gas from a coal-fired power plant or in the water used for 

cultivation. Although this can present a toxicity or environmental problem, it also can be considered a positive aspect of water remediation, and the ability to concentrate compounds present 

at low levels in the water phase might provide an opportunity for recovery of strategic materials. 

Strategic materials could include precious or rare earth metals that could be present at 

concentrations in water too low to recover economically. In the future, a strategic material might 

be phosphorous, which rapidly is being depleted for fertilizer, solubilized, and lost to water 

runoff. Concentration and capture of these materials by algae could provide a competitive edge 

for the United States—which currently depends on foreign 

sources for procuring phosphorus. 

Department of Homeland Security Relevance: 

Biofuel and Algae Applications

Today’s Opportunities and Tomorrow’s Potential

No off-the-shelf opportunities are currently available for 

algae. The only immediate opportunity for use of algal 

biomass is as a food supplement and nutraceutical source. 

Algae currently are grown for this purpose in large ponds or 

photobioreactors. If there is a use for these products in 

strategic areas for maritime and border security, production 

facilities could be established quickly, provided that the 

climate and necessary inputs (sunlight, carbon dioxide, 

nutrients, water) are available.
62 

Airport Algae Cultivation

A project that might be of interest to 

DHS would be to establish algal 

cultivation facilities in the unused land 

surrounding airports. NREL is currently 

in discussions with a group including a 

municipal airport, an electrical utility, a 

commercial algal biofuels company, and 

a number of academic scientists to 

establish a demo facility at an airport. 

The facility would make use of carbon 

dioxide generated on site by incineration 

of municipal solid waste and would use 

brackish water from underground 

aquifers.

Wild Algae Harvest

There might be water areas in which DHS operates that are rich in wild algae and other aquatic 

plants. Some water bodies are rich in nutrients from agricultural runoff and show periodic algae 

blooms. The decay of algae biomass is known to consume dissolved oxygen to levels unable to 

support animal survival, causing large areas of “dead zone.” Wild algae harvesting thus could 

serve multiple functions, including waterway clearing to enhance patrol ship access; energy 

production from the algae biomass; nutrient removal for fertilizer production; and reducing dead 

zones to support fishery, recreation, and tourism. 

Initially a decommissioned USCG ship could be retrofitted for a pilot project to determine 

whether it would be possible to harvest wild algae. Macroalgae and aquatic plants should be the 

initial targets because they are more readily harvested than microalgae. The algae biomass can be 

converted to fuels and fertilizer at onshore anaerobic digesters. Alternatively, the biomass can be 

used to generate fuel (methane) on board to power the ship’s systems. An on-board anaerobic 

digester also could treat human waste for enhanced fuel production. 

For large-scale nutrient removal from areas like the dead zone in the Gulf of Mexico around the 

mouth of the Mississippi River, macroalgae could be seeded and periodically harvested in a 

large-scale aquaculture. It’s important to note that the dead zones are not formed by the algae 

themselves, but rather by the die-off that occurs after the algae bloom. The algal biomass

becomes a nutrient for aerobic microorganisms which rapidly consume all of the available 

oxygen in the water, consequently killing fish and other aquatic animals. Deliberately harvesting 

the algae before the die-off would eliminate the dead zones and would allow for recovery of 

nutrients that otherwise would be lost at sea.

Research on the conversion of macroalgae to transportation fuels is ongoing. For example, the 

DOE ARPA-E program supports a Bio Architecture Laboratory and assists DuPont on 

macroalgae conversion to butanol (a gasoline replacement). 

Airport Algae Cultivation 

The requirements for large-scale cultivation of microalgae under photosynthetic conditions 

include land for ponds and photobioreactors (an acre of ponds can produce between 1,000 and 

5,000 gallons of biodiesel or renewable jet fuel per year), 

water, carbon dioxide, inorganic nutrients, and sunlight. A 

project that might be of interest to DHS would be to establish 

algal-cultivation facilities in the unused land surrounding 

airports. NREL currently is in discussions with a group 

including a municipal airport, an electrical utility, a 

commercial algal-biofuels company, and a number of 

academic scientists to establish a demo facility at an airport.

The facility would make use of carbon dioxide generated on 

site by incineration of municipal solid waste and would use 

brackish water from underground aquifers. 

This sort of demonstration project could serve as a model for 

a number of similar facilities situated at USCG airports or at 

other municipal airports at which DHS operates. For airports 
63 

Border Algae Cultivation

Algal cultivation facilities could be used 

to valorize underutilized land located 

near borders, especially the United 

States–Mexico border. The warm 

climate, availability of saline aquifers, 

and availability of sunlight throughout the 

desert southwest provide key ingredients 

for large-scale algae cultivation. As with 

remote airports, many areas around the 

United States–Mexico border are reliant 

on supplies that are brought in from 

remote locations. The algae ponds could 

provide energy and food products for 

more self-sufficient operation.

located in remote locations, the algal products such as biofuels, methane, oxygen, and protein 

could help make the airport more self-sufficient and less dependent upon supplies brought in 

from other places. It also might be possible to determine additional uses of the cultivation 

facility. For example, the algal ponds could allow for improved instrumentation for navigation or 

emergency landings. The abundance of water used for cultivation also could be used for 

firefighting efforts. 

The lowest capital-cost approach to production of algal biomass will make use of open-pond 

production systems (Davis et al. 2011). Much work is being done to reduce the cost for 

fabrication of photobioreactors to take advantage of the 

potential process superiority (e.g., greater biomass 

concentrations, enhanced carbon-dioxide transfer, reduced 

water evaporation) without incurring greater production 

costs. If costs are not an issue, and border or maritime 

security advantages are factored in, then material science 

research can be performed to fabricate photobioreactors from 

materials that have electropolymeric properties. This could 

enable the photobioreactor array to serve as sensors or large 

antennae for communications or security monitoring. 

Although it is unlikely that remote airports need be concerned 

with carbon-dioxide emissions, algal-cultivation facilities 

could be used to reduce GHG emissions from electrical 

generators. 

Border Algae Cultivation 

Similarly, algal cultivation facilities could be used to valorize underutilized land located near 

borders, especially the U.S.-Mexico border. The warm climate, availability of saline aquifers, 

and availability of sunlight throughout the desert southwest provide key ingredients for largescale algae cultivation. As with remote airports, many areas around the U.S.-Mexico border are 

reliant on supplies that are brought in from remote locations. The algae ponds could provide 

energy and food products to allow for a more self-sufficient operation. Ponds or photobioreactors 

could be used to discourage or hinder border crossing and ponds could be fitted with sensors to 

monitor the sort of agitation that occurs when someone tries wading across. Additionally, algae 

culture and processing operation could transform some of the uninhabited border areas into 

inhabited areas, expanding the numbers and value of border guards and therefore enhancing 

border security. 

Algae also could be grown next to other strategic sites where a significant quantity of carbon 

dioxide is generated, for example, on a DHS remote installation that uses a power generator 

continuously. The algae biomass then can be digested anaerobically for biogas production. This 

could be a short-term research project. Initial test and demonstration could involve cultivation of 

duckweed with carbon-dioxide feeding, because duckweed is easy to harvest.
64 

Macroalgae Cultivation

Macroalgae can be grown in waters 

sheltered from waves. Macroalgae can 

be used for food, as industrial feedstock 

for extraction of high value chemicals, 

and for fuel production. For DHS remote 

installations, food and fuel from 

macroalgae culturing could enhance 

self-sufficiency. Initial fuel production 

could be via anaerobic digester.

Cultivation in Bay and Tidal Zones 

Another short-term research project could be to grow algae in 

waters sheltered from waves. Macroalgae culture and 

harvesting techniques are well established in Asia, with 

China being the largest macroalgae producer in the world. 

Macroalgae can be used for food, as industrial feedstock for 

extraction of high-value chemicals, and for fuel production. 

For DHS remote installations, food and fuel from macroalgae 

culturing could enhance self-sufficiency. Initial fuel 

production could be via anaerobic digester.

Microalgae could be grown in tidal zone using either seawater or freshwater entering the sea; 

tidal zones are underutilized surface areas. A challenge for algae cultivation in the area is that the 

facility must be built to withstand periodic flooding by seawater. 

2.6 Energy Efficiency—Opportunities for Systemic Optimization of Existing 

and Future Systems

In general, energy efficiency opportunities fall into two categories.

• New materials or breakthroughs which create new classes of products or categories of 

products that operate more energy efficiently than current products or system components. 

• Systemic rightsizing of components or subassemblies which are a part of a system. These 

components originally were used to reduce the first-cost of the system at the expense of 

higher operational energy consumption. Power supplies are notorious for being designed for 

reduced price and not for low power consumption, and are contained in almost every 

electronic device. Desktop computer power supplies, for example, use half of their power just 

for the fan used to remove waste heat from the power supply. 

Advantages to optimizing existing systems include reducing the need to refuel devices, as well as 

reducing the size and potentially the first cost of the unit which supplies the source-power for the 

unit. Disadvantages to optimizing existing systems include the need to design custom units or 

retrofit off-the-shelf units, and potentially voiding their warranties. This can be avoided by 

developing solutions in cooperation with the equipment manufacturers. There also is the 

potential for higher first costs.

Department of Homeland Security Relevance: Optimize Existing Systems

Improving the efficiency of equipment can lengthen the operating time between recharging or 

refueling of covert equipment, which could lengthen the lifetime of the equipment and reduce or 

help eliminate the amount of time DHS personnel are required to be in hazardous circumstances 

under which refueling in remote sites often occurs. For example, improving the efficiency of the 

power supplies used in mountaintop radio broadcasting equipment would reduce their energy 

consumption and would therefore also reduce the need to sling propane tanks down from 

helicopters to the mountaintop to refuel storage tanks located there. This benefit therefore 

potentially could reduce the manpower needed to refuel devices.
65 

Today’s Opportunities

Improving the Efficiency of Electronic Devices 

Virtually all of the existing electronic devices used by DHS can be analyzed to determine how 

efficiently they utilize power and also how they potentially can be retrofitted. This eventually 

could lead manufacturers to incorporate efficiency improvements identified by NREL into nextgeneration products. 

Developing Rapidly Deployable, Self-Sufficient Arctic Housing Units

There is a need for the USCG to expand their operations into the upper arctic regions of Alaska. 

This was confirmed in a recent speech on June 20, 2011, by the Coast Guard Commandant, in 

which he described the huge increase in commercial oil and shipping activity in the arctic areas 

since the warming of the arctic passageways. He described the USCG’s need to rapidly deploy 

bases to cover these areas in case of oil spills or other significant incidents. In addition, cruise 

lines are beginning to venture as far north as the Bearing Strait. All of these ships are unprotected 

and vulnerable to terrorism, piracy, and environmental disaster. If something were to happen, the 

distance from current USCG facilities to these newly opening areas is equivalent to flying halfway across the lower continental United States. 

This situation has caused the USCG to begin planning for several small FOBs which, for 

deployment speed, may consist of a rented hangar at an existing airport. By deploying

containerized ultra-efficient, self-contained, 100% renewably powered portable housing units, 

the USCG will be able to rapidly roll out these FOBs without the usual 5-year construction 

process by just placing several of these units at a rented hangar. In addition, as new issues 

emerge, these units could be rapidly moved to new locations to cover new threats without the 

need to deal with the complications of expanding utilities. 

Reducing the Frictional Drag of Ships Utilizing Low Drag Coatings

There is a new generation of Low-Drag Ship Hull Coatings which can reduce the frictional drag 

on ship’s hulls. These new coating, based on biologically and chemically inert Teflon-type 

compounds, are a new generation of coatings which not only prevent the build-up of biological 

organisms, but also reduce the frictional drag of the ship hull surfaces. These compounds 

improve on past coatings which were primarily designed to kill biological organisms and thus 

prevent the build-up of biologically induced surface roughness, which increases frictional losses 

for ships. The new coatings not only save energy by reducing frictional drag, they also reduce the 

frequency with which ships need to be dry-docked for hull cleaning, which is a very expensive 

and time consuming process. 

Tomorrow’s Potential

We anticipate that additional opportunities will emerge as NREL staff dialog with and visit 

additional DHS sites. 

Long-Term Applications and Research

Reducing the Frictional Drag on Ships Utilizing Micro-Bubble Technology

Emerging research indicates that ships may be able to be retrofitted to utilize micro bubbles 

injected at the bottom of the hull of ships to further reduce the frictional drag on these ships. 

Based on other friction reduction technologies’ effects, this type of system should also increase 
66 

distance range and increase the top speed of existing ships, and possibly allow the reduction in 

engine size of future generations of ships. 

It may be possible to combine this micro-bubble technology with low frictional ship hull 

coatings and utilize the carbon dioxide from the exhaust of ship engines to provide the source gas 

for this effect. In addition, the resulting carbon dioxide–enriched water after it has provided its 

friction reducing effect would further speed the growth of algae and the scavenging of lost 

nutrients in nutrient-overburdened areas such as the dead zone in the Gulf of Mexico at the 

mouth of the Mississippi. Even if the system could not be utilized in an on-board algae 

harvesting system, it may be possible that introducing ship engine carbon dioxide into sea waters 

(depending on the waters) could provide some form of partial carbon dioxide sequestration or 

short-cycling, thus reducing the Coast Guard’s effect on climate change due to fuel consumption. 
67 

3 Conclusions

Renewable energy technologies present a number of near-term applications and longer-term 

research opportunities that can enhance DHS component operations. These technologies—PV, 

wind turbines, batteries, fuel cells, biofuels, MHK, wireless energy transfer, and energy 

efficiency—exist now or can be developed, and can enable the mission to be more stealthy, 

secure, safe, effective, or efficient. The technologies and opportunities outlined in this report can 

form a solid foundation for BMD’s renewable energy research portfolio. 

Next steps in identifying the most appropriate technologies for near-term deployment include 

further data collection and analysis of on-the-ground operations, prioritization of existing or 

anticipated needs by equipment users and other stakeholders, and identification of solutions. 

Research opportunities exist to pilot solutions that have previously been identified during site 

visits, such as stadium lighting systems that incorporate PV panels, LED lighting, and smart 

controls. Additional, multi-year research strategies can be devised to create application-specific 

solutions for existing and anticipated operational needs. 
68 

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71 

Appendix A. Department of Homeland Security Workshops and 

Site Visits

March 19, 2010 (Washington, DC): Introductory Workshop

Attendees

• NREL: Andrea Watson

• SBInet

o Allen Gamble, Executive Director

o Merv Leavitt, SBI technical director

o Sarah Schroerluke, Northern Border Director 

o Jim Rierdon, Program Manager SBInet

o Brian Willoughby 

June 21, 2010 (Washington, DC): Data Gathering and Application Prioritization 

Workshop (CBP/NREL)

Agenda: Monday, June 21, 2010

12:30 – 1:00 pm Introductions, Workshop Overview and General Background 

• Around the room introductions 

1:00 – 1:15 pm Overview (NREL)

• Brief overview of NREL and team capabilities, project scope, and project timeline 

1:15 – 1:30 pm Overview (CBP) 

1:30 – 2:30 pm Energy Needs Brainstorm 

• Outline CBP energy needs 

o Energy-using equipment 

o Locations 

o Grid connected vs. off-grid

o Quantity

• Priorities and vulnerabilities

o Noise

o Visibility

o Cost

o Other

2:30 – 2:45 pm Break

2:45 – 3:30 pm Energy Needs Brainstorm (continued) 

• Future operations and energy needs 

• Partnerships 

o DOD

o Manufacturers

o Other
72 

3:30 – 4:00 pm Data Collection Methodology 

• Sensitive data

• Site visit(s)

• O&M contacts

4:00 – 4:30 pm Next steps

Attendees

June 21, 2010 (Washington, DC): Data Gathering and Application Prioritization 

Workshop (CBP/NREL)

CBP personnel next presented an overview of the types of equipment typically used to 

accomplish their mission and the types of conditions under which the equipment is typically

used. There were approximately 25 different pieces of equipment identified by generic name or 

purpose as well as manufacturer.
73 

Mission Equipment Manufacturer

MSS/MSC Telephonics Corp.

Re-deployable radar Telephonics/IAI

Re-deployable camera Flur, Axsys, more

Game camera varied

Microwave relay tower Boeing Corp.

SBInet radar camera tower Boeing Corp.

Clandestine comms L3, Motorola, more

Remote deployment Base TBD

RVSS tower Boeing Corp.

LETC WIN-Radio, L3

TRIPwire TBD

UGS Varied

SAT Ku band receiver ... Huges Huges

LOS downlink (BMS) BMS

802.11/16 varied

Lighting varied

5KW generator equivalent varied

July 22–23, 2010 (Bellingham, WA): Northwest Border Low-Flier Workshop

The purpose of this workshop was to bring together technologists with the major stakeholders 

within the Coast Guard who are responsible for apprehending low flying aircraft bringing 

contraband into the US primarily over the Northwest border with Canada near Seattle and 

Spokane. The goal of the meeting was to decide the best use of funding for a short term 

technology solution and brainstorm and write an RFP for a longer term solution which might be 

procured. NREL Attendees: Scott Huffman, and John Leahey 

Agenda

July 22, 2010—Chrysalis Inn Conference Center

0830-0845 Background and Introductions 

0845-0930 Meeting Purpose and Scope 

0930-1050 Threat Assessment and Current CONOPS

• 0930-1000 Havre Sector/Air Branch

• 1000-1030 Spokane Sector/Air Branch 

• 1030-1050 Blaine Sector/Bellingham Air Branch

1050-1200 Potential Technologies and Other Agency Briefs 

1200-1330 Lunch

1300-1700 System CONOPS

July 23, 2010—Washington State Patrol Conference Room

0830-1020 DOTMLPF Analysis
74 

1020-1030 Break

1030-1200 Capture Operational Requirements 

1200- 1300 Lunch

1300-1530 Wrap Up and Way Ahead 

Attendees

Name Organization Phone Number Email Address

Harley McCray CBP/SBI 571 468 7496 harley.l.mccray@cbp.dhs.gov

John Leahey NREL 303 275 4241 john.leahey@nrel.gov

Scott Huffman NREL 303 275 4384 scott.huffman@nrel.gov

Bob Dorsey DHS S&T 703 877 7159 dorseyr@msd.nro.mil

Swami Iyer USAF Test Pilot School 661 227 8882 swami.iyer@edwards.af.mil

Sean Monroe CBP/OBP 360 332 9213 sean.monroe@dhs.gov

Terry Jenner CBP/AMO(MT) 406 750 4675 terry.jenner@dhs.gov

Todd Liebrand CBP/Border Patrol 406 945 2300 todd.liebrand@dhs.gov

Chuck Lair CBP/AMOC 951 570 9676 chuck.lair@dhs.gov

Lance R. Lyons CBO/OBP/SPW 509 353 2397 lance.lyons@dhs.gov

Todd Birdsong CBO/OBP/SPW 509 353 2747 todd.l.birdsong@dhs.gov

Mike Amato CBP/SBI 571 468 7066 michael.amato@cbp.dhs.gov

Andrea Coffey CBP/SFO 360 332 2695 andrea.coffey@dhs.gov

Mike Bumberger SBP/AMOC 951 656 0965 michael.bumberger@dhs.gov

Merv Levitt CBP/SBI 571 468 7568 merv.levitt@dhs.gov

John Abe NRO/GED 408 978 7520 johnabe@rightmagic.com

Raul Rios NRO 206 697 2225 raul.a.rios@us.army.mil

Debbie Engels CBP/OFO 360 332 4656 deborah.engels@dhs.gov

Cesar Moreno CBP/OBP/SIU/AMO 360 927 0259 cesar.moreno@cbp.dhs.gov

Darrell Feller CBP/OAM 202 255 5944 darrell.feller@dhs.gov

Christopher Rosen CBP/OAM 360 410 8359 christopher.rosen@dhs.gov

Luis Bencosmo CBP/OAM 586 612 8391 luis.bencosmo@dhs.gov

Keith Powell CBP/OAM 360 734 5939 keith.powell@dhs.gov

Rob Smith CBP/OAM 509 535 9416 rob.smith@dhs.gov

Maria Ireland CBP/OAM 571 468 7286 maria.g.ireland@cbp.dhs.gov

Chris Higgins CBP/SBI 703 401 6929 higgins_chris@bah.com

Leo Morris CBP/SBI 571 468 7569 leo.a.morris@cbp.dhs.gov

October 26–29, 2010 (El Paso, TX): El Paso Sector

The purpose of this meeting was to kick off the site-visit of the NREL staff members Scott 

Huffman, Alicen Kandt, and Travis Simpkins to the El Paso Sector and introduce them to the 

various sites and challenges faced by CBP personnel in the region. The rest of the week was 

spent visiting the CBP sites in the El Paso Sector to see sites firsthand and interview field 

personnel about technology needs and challenges that might be able to be solved with RE and 

EE. 

Agenda

October 25, 2010—Travel Day

October 26, 2010—Day 1 

0900 Kick-Off Meeting at El Paso Border Patrol Sector Headquarters
75 

0930 Sector Facilities (MSS Garage/Garage/Tower/Fueling Area)

1100 Ysleta, TX Border Patrol Station (Communications Tower/Fueling Area)

1200 Lunch

1300 Ysleta, TX Border Patrol Permanent Checkpoint 

1430 El Paso, TX Border Patrol Station (RVSS Sites) (Maybe PDT)

• Levee Stadium Lighting (International Boundary at YST and/or EPS) 

• Portable Light Plants (Levee/International Boundary at YST/EPS)

• Skybox Towers (International Boundary at YST and/or EPS) 

October 27, 2010—Day 2 

0800 Bridge of The Americas OFO Facility (Port of Entry Cargo Operations)

1000 Santa Teresa, New Mexico Border Patrol Station

• Mobile Surveillance System, Recon III, FLIR 

1200 Lunch

1300 Border Patrol Special Operations Division (Mobile Command Center) 

1430 Border Patrol Emergency Planning Office (Generators, Batteries)

October 28, 2010—Day 3 

0900 Deming, New Mexico Border Patrol Station 

1000 Deming, New Mexico Border Patrol Tactical Checkpoint (Highway 11) 

1200 Lunch

1300 Border Patrol Forward Operating Base (Deming, NM Border Patrol Station)

1400 Boeing SBInet Tower in Playas, NM (Deming, NM Border Patrol Station)

October 29, 2010—Day 4 

0800 Catch-Up Day

• Question and Answer (Data Collection, Action Items)

1200 Lunch

1400 Close-Out Meeting at El Paso Sector Headquarters

October 30, 2010—Travel Day 

*ITEMS TO DISCUSS: Fuel & Power Issues, Personnel Interviews, Battery Issues, Fuel 

Procedure/Policy, Fuel Usage Data, Packable Power
76 

Attendees

April 5–9, 2011 (Juneau, AK): AK USCG Operations

The purpose of this site visit was to meet with USCG personnel regarding mission challenges 

they face related to border security and ways in which RE and EE could be used to solve these 

challenges.

Agenda

Date Scott Huffman Alicen Kandt

Monday, April 4 Travel to Juneau, AK

Tuesday, April 5 Meet with Kodiak 

biomass project 

stakeholders

Travel to Juneau, AK

Wednesday, April 6 Meet with USCG R21 

at Mayflower Island to 

discuss wind and fuel 

cell opportunities

Meet with USCG R21 

at Mayflower Island to 

discuss wind and fuel 

cell opportunities

Thursday, April 7 TBD: Site visits? TBD: Site visits?

Friday, April 8 TBD: Site visits?

Travel home

TBD: Site visits?

Travel home
77 

Appendix B. Wind

Windside

The table below lists the expected power output at various wind speeds for several models of the 

Windside turbines. Without an effective wind resource history, it is recommended to consider 

either the WS-12 or WS-30 Model (shown in italics). Though not shown explicitly in this table, 

“Model A” turbines are designed for the most extreme winds—60 m/s (134 mph)—are the 

recommended version of these turbines to consider for the communication sites. 

Table 5. Power Output at Various Wind Speeds for Windside Turbine Models

Table 6. Power Curves for Proven 11 Wind Turbine

Model Model Model Model Model Model

WS-0.15 WS-0.30B WS-2 WS-4 WS-12 WS-30

Wind Wind Power (W) Power (W) Power (W) Power (W) Power (W) Power (W)

Velocity Velocity

3 m/s 7 mph 1 2 10 20 60 150

4 m/s 9 mph 2 4 20 40 120 300

5 m/s 11 mph 3 7 35 70 211 527

6 m/s 13 mph 5 10 50 100 300 750

7 m/s 16 mph 7 15 75 150 450 1,125

8 m/s 18 mph 10 21 105 210 630 1,575

9 m/s 20 mph 15 30 150 300 900 2,250

10 m/s 22 mph 20 40 200 400 1,200 3,000
78 

Appendix C. Fuel Cells

Evaluation of technologies for topic areas: 

In the following tables, we display the concensus of four NREL staff in regards to the 

applicability of fuel cell technologies to individual DHS applications. The NREL staff who 

participated in the analysis each have industrial background in fuel cell design before joining 

NREL. We incorporated expertise from stationary prime-power fuel cells, backup power fuel 

cells, and portable direct methanol fuel cells. We used a decision matrix for this analysis. Each 

staff member was provided a table. The tables were used to record the wellness of technological 

fit between each DHS energy application and each fuel cell type. Additionally, we solicited our 

experts to provide a list of potential system suppliers and developers. Suppliers were provided 

for each category of fuel cell application. Once all tables were complete, we aggregated the 

tables. Below we display the results of our findings. High scores reflect better fit between fuel 

cell technologies and DHS applications. For example, a score of 9 means that all experts agree 

that this can be a very good technological fit, while a score of 1 means the fit is marginal. Areas 

where no score is assigned, we believe there isn’t a good fit at all. 
79