1–10 kW Stationary Combined Heat 

and Power Systems Status and 

Technical Potential

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Independent Review

Published for the U.S. Department of Energy Hydrogen and Fuel Cells Program

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November 2010
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iii

Independent Review Panel Executive Summary

May 28, 2010 

From: Independent Review Panel for 1–10 kW Stationary Combined Heat and Power 

Systems Status and Technical Potential

To: Mr. Mark Ruth, NREL, Alliance for Sustainable Energy, LLC 

Subject: Independent Review Panel Report 

As per the tasks and criteria of the Independent Review Charter of November 13, 2009, this 

document represents the Independent Review Panel’s unanimous technical conclusion, arrived at 

from data collection, document reviews, stakeholder interviews, and deliberations between 

February 2010 and May 2010. 

Conclusions 

The Independent Review Panel was commissioned by the National Renewable Energy 

Laboratory’s Systems Integrator to review the status of 1–10 kW CHP stationary fuel cell 

systems and to comment on the achievability of cost, efficiency, and durability targets. The 

Independent Review Panel evaluated the three independent fuel cell technologies that are being 

developed to address the market needs of 1–10 kW CHP stationary systems: low-temperature 

proton exchange membrane (LT-PEM) fuel cell systems operating, for the most part, in a 

temperature range of 60°–90°C; high temperature PEM (HT-PEM) fuel cell systems operating in 

a temperature range of 130°–180°C; and solid oxide fuel cell (SOFC) systems operating in a 

temperature range of 550°–1,000°C. 

Stakeholder claims regarding the current status for efficiency, cost, and durability varied widely

within each of these three technologies. DOE reports the 2008 status of electrical efficiency, 

CHP efficiency, and durability at 34%, 80%, and 6,000 hours, respectively (see Table 2). Those 

values are representative of or even on the low end of demonstrated results. On the other hand, 

the stakeholders claimed that the reported 2008 status for factory cost ($750/kW) is low, 

especially for the low end of the 1–10 kW range. 

In Table 1, the Panel provides its own perspectives on the cost and performance technical 

potential in 2012, 2015, and 2020 for each fuel cell technology. This information is based on the 

collective fuel cell experience of the panel members and is arrived at independently from the 

inputs of the stakeholders. While there is some correspondence between the Panel’s perspective 

and the inputs from the stakeholders, in some cases the Panel does not agree with the 

stakeholders. For example, an operating lifetime of 60,000 h may be feasible but will likely be at 

cost and efficiency levels that will be unacceptable to end users. 

In analyzing the achievability of the DOE cost, efficiency, and durability targets, the Panel 

concludes the following: 

• The electrical efficiency target of 45% is likely to be achievable with HT-PEM and 

SOFC fuel cells but is unlikely to be achieved by LT-PEM fuel cells. 
iv

• Only SOFC systems are likely to achieve the targeted CHP efficiency of 90% at the 

required electrical efficiency. 

• Based on anticipated technical advances and improvements in manufacturing capability 

of the fuel cell industry, the factory cost target of $450/kW will be extremely challenging 

for all of the technologies. 

The durability target of 40,000 h is deemed achievable but 60,000 h is a significant challenge, 

especially in conjunction with factory costs near the $450/kW target. 
v 

Table 1. Panel Perspective on Cost and Technical Potential for 1–10 kW CHP Stationary Fuel Cell Systems Operating on Natural Gasa

a Standard utility natural gas delivered at typical residential distribution line pressures. b Regulated AC net/lower heating value of fuel.

c Cost defined at 50,000 unit/year production (250 MW in 5-kW modules). The basic unit includes all processing necessary for conversion of natural gas to 

unregulated DC power; i.e., the basic unit does not include power conditioning.

d Time until > 20% net power degradation.

2012 2015 2020

LT PEM HT PEM SOFC LT PEM HT PEM SOFC LT PEM HT PEM SOFC

Electrical efficiency at rated 

power,

b % 38 42 40 40 42 45 40 45 60

CHP energy efficiency,% 85 85 85 87 87 90 87 87 90

Factory cost,

c $/kW

1,000–

1,500

1,000–

2,000

1,300–

4,500

750–

1,200

550–

1,500

1,000–

3,000 450–750 450–750

1,000–

2,000

Transient response (10%– 

90% rated power), min < 1 <1 5 < 1 < 1 3 < 1 < 1 2

Start-up time from 20°C 

ambient temperature, min 30 30 60 20 20 45 15 15 30

Degradation with cycling, 

%/1,000 h <0.3 <0.3 <0.7 <0.3 <0.2 <0.5 <0.2 <0.2 <0.3

Operating lifetime,

d h 30,000 30,000 30,000 40,000 40,000 35,000 40,000 40,000 40,000

System availability, % 97 97 97 98 98 98 99 99 99
vi 

The Panel’s conclusions and R&D priorities for individual fuel cell technologies are summarized

below and discussed further in the recommendations section of this report (see section 10).

LT-PEM Fuel Cell Systems

• The majority of LT-PEM fuel cell systems produced today are at the low end of the 1–10 

kW range. 

• More R&D investment for the fuel processing, air management, and power conditioning 

subsystems is needed to meet the DOE 2015–2020 targets. 

• The 2020 target of 45% electrical efficiency will be a stretch goal unless catalyst systems 

can be improved and operating temperature increased to at least 90°C. 

• At present, the low quality of heat available from LT-PEM fuel cell systems may limit 

their use beyond residential cogeneration. 

HT-PEM Fuel Cell Systems

• HT-PEM fuel cell systems are an emerging 1–10 kW CHP stationary application, but 

their cost of $1000/kW–$2000/kW is greater than the factory cost proposed by the DOE 

status and targets. 

• HT-PEM fuel cell systems have demonstrated the 2012 and 2015 electrical efficiency 

targets at beginning-of-life (BOL), and the 2020 target of 45% electrical efficiency is 

considered feasible. 

• One stakeholder has reported a CHP efficiency of 88%, and CHP efficiencies in the range 

of 85% to 90% are considered reasonable.

• R&D investments in system demonstration, fuel processing cost reduction, and power 

conditioning subsystems are necessary. Additional fuel cell component R&D is needed to 

advance the HT-PEM systems.

SOFC Systems

• SOFC systems either already achieve or are capable of achieving DOE targets for 

electrical and CHP efficiencies, but the start-up time and factory cost targets are 

challenging. 

• An insufficient number of SOFC prototype units have been installed, so information on 

the current status and future investment needs is limited. Further investment in prototype 

units would increase the understanding of durability and costs. 

• R&D investment is needed to lower the cell, interconnect, and power conditioning costs. 

Discussion of Conclusions 

The Panel believes that each of the three technologies is at a different level of maturity and has 

its own pros and cons relative to the cost and technical targets identified by DOE. Depending on 

end-user requirements for product attributes such as life cycle cost, reliability, operational 

characteristics, or quality of heat, one particular technology may possess an inherent advantage 

over its competitors. For example, the low operating temperature of LT-PEM fuel cell systems 

requires that a multi-component gas reforming subsystem be included to ensure the levels of 
vii 

carbon monoxide do not significantly reduce efficiency, whereas an SOFC system can provide in 

situ reforming of natural gas.

The Panel and stakeholders recognize that the cost of a 1 kW unit will not be one-tenth of the 

cost of a 10 kW unit. While the stack subsystem may scale proportionately, the cost of the 

balance-of-plant components will be significantly more per kW for the lower power systems, 

especially at the 1–2 kW range. As such, it may be more representative to split the power range 

into two and define the technical potential of each range. 

It is the Panel’s belief that the lack of stakeholder consensus on cost and technical potential in 

later years is as much a factor of limited information as it is a reflection of the capability of the 

technologies to meet the technical potential. An insufficient number of fuel cells for 1–10 kW 

CHP stationary applications have been manufactured to permit a credible prediction of the cost at 

a production volume of 50,000 units per year; therefore, the panel recommends a rigorous, 

bottom-up, manufactured cost evaluation of each technology. 

Achieving an operating lifetime of 60,000 h (2020 target) with original installed capital was seen 

by the majority of stakeholders as either an enormous challenge or in some cases as an 

unnecessary requirement. The Panel agrees with the majority of stakeholders who recommended 

a 40,000 h technical goal for operating life in 2015 and 2020. Many assumed that such lifetimes 

would be most practically achieved through a replacement and maintenance strategy. Following 

40,000 h of operating lifetime, it seems reasonable to include cell/stack change-out as part of a 

maintenance program to extend the life of the system. 

A common thread from the stakeholder inputs is the need to develop the commercial market. 

Identifying and taking advantage of early market opportunities is one way to build commercial 

momentum for 1–10 kW CHP stationary fuel cells. These opportunities can be found in specific 

geographic regions where the cost of grid electricity is high and there is a use for the produced 

heat or where operations are in remote locations. Early adopters who are less cost sensitive

provide another market opportunity. Federal and state governments can play a pivotal role in 

many ways such as directed R&D funding, manufacturing process optimization and quality 

controls development, demonstration programs, manufacturer and end-user incentives, 

component specification, and codes and standards development. 
viii 

___________________________________________________ 

Dr. Hans Maru 

___________________________________________________ 

Dr. Subhash C. Singhal 

___________________________________________________ 

Dr. Charles Stone 

____________________________________________________ 

Mr. Douglas Wheeler 
ix

Table of Contents

Independent Review Panel Executive Summary .................................................................................... iii

Conclusions .............................................................................................................................. iii

LT-PEM Fuel Cell Systems ............................................................................................... vi

HT-PEM Fuel Cell Systems............................................................................................... vi

SOFC Systems ................................................................................................................... vi

Discussion of Conclusions ....................................................................................................... vi

Table of Contents....................................................................................................................................... ix

List of Tables ............................................................................................................................................... x

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

1.1 Technical and Cost Targets ..................................................................................................1

2 Panel Mandate and Objective.............................................................................................................. 2

3 Methodology ......................................................................................................................................... 3

4 Constraints and Assumptions ............................................................................................................ 4

4.1 Independent Review Panel Assumption ..............................................................................4

5 Evaluation of Cost and Technical Potential based on LT-PEM Technology.................................. 5

5.1 Electrical and CHP Efficiency .............................................................................................6

5.2 Factory Cost .........................................................................................................................6

5.3 Transient Response Characteristics .....................................................................................7

5.4 Start-up Time .......................................................................................................................7

5.5 Operating Lifetime ...............................................................................................................7

5.5.1 Degradation with Cycling ...........................................................................................8

5.6 System Availability ..............................................................................................................8

5.7 Capital Cost Reduction Through Manufacturing Capability ...............................................8

6 Evaluation of Cost and Technical Potential based on HT-PEM Technology ................................. 9

6.1 Electrical and CHP Efficiency .............................................................................................9

6.2 Factory Cost .......................................................................................................................10

6.3 Transient Response Characteristics ...................................................................................10

6.4 Start-up Time .....................................................................................................................11

6.5 Operating Lifetime .............................................................................................................11

6.5.1 Degradation with Cycling .........................................................................................11

6.6 System Availability ............................................................................................................12

6.7 Capital Cost Reduction Through Manufacturing Capability .............................................12

7 Evaluation of Cost and Technical Potential based on SOFC Technology ................................... 12

7.1 Electrical and CHP Efficiency ...........................................................................................13

7.2 Factory Cost .......................................................................................................................13

7.3 Transient Response Characteristics ...................................................................................14

7.4 Start-up Time .....................................................................................................................14

7.5 Operating Lifetime .............................................................................................................14

7.5.1 Degradation with Cycling .........................................................................................14

7.6 System Availability ............................................................................................................14

7.7 Capital Cost Reduction Through Manufacturing Capability .............................................14

8 Comparative Analysis of Key Fuel Cell Technologies.................................................................... 15

8.1 Key Component Breakdown ..............................................................................................15

8.2 Major Differences ..............................................................................................................17

8.2.1 Electrolyte and Operating Temperature ....................................................................17

8.2.2 Cell Design ................................................................................................................17
x 

8.2.3 Fuel Cell Stack ..........................................................................................................17

8.2.4 Fuel Processor ...........................................................................................................18

8.2.5 Air Handling .............................................................................................................18

8.2.6 Power Conditioning System (PCS) ...........................................................................19

8.3 Meeting End-User Requirements .......................................................................................19

8.3.1 Cost ...........................................................................................................................19

8.3.2 Technical Targets ......................................................................................................20

8.3.3 Manufacturing Status ................................................................................................20

8.3.4 External Factors ........................................................................................................20

9 Supplier Network ................................................................................................................................ 20

9.1 Status of Supplier Network ................................................................................................21

9.2 Establishing a Mature Supplier Network ...........................................................................22

10 Recommendations ............................................................................................................................. 22

11 References .......................................................................................................................................... 24

12 Acknowledgements............................................................................................................................ 25

Appendix A. Independent Review Team................................................................................................. 26

Appendix B. List of Stakeholders Contacted......................................................................................... 28

Companies................................................................................................................................28

Organizations ...........................................................................................................................29

National Laboratories...............................................................................................................29

List of Tables 

Table 1. Panel Perspective on Cost and Technical Potential for 1–10 kW CHP Stationary Fuel 

Cell Systems Operating on Natural Gasa

 .................................................................................. v

Table 2. Preliminary Cost and Technical Targets: 1–10 kWe Residential Combined Heat and 

Power Fuel Cells Operating on Natural Gasa [1] ...................................................................... 1

Table 3. Comparison of Various Components, Subsystems, and Other Parameters for Three 

Candidate Fuel Cell Types [5] ................................................................................................ 16
1 

1 Introduction

The U.S. Department of Energy (DOE) Fuel Cell Technologies (FCT) Program Manager 

requested the DOE Fuel Cell Technologies Program’s Systems Integrator at the National 

Renewable Energy Laboratory (NREL) to commission an independent review of combined heat 

and power (CHP) stationary systems status and potential, with specific reference to the 2010 

published preliminary cost and technical targets for 1–10 kW CHP fuel cell systems (see Table 

2).

1.1 Technical and Cost Targets

Preliminary technical and cost targets for fuel cells used in CHP and auxiliary power applications 

were released by DOE in 2009. These targets are based on Request for Information responses 

from fuel cell developers and the broader R&D community working in technology areas related 

to the intended applications. Table 2 summarizes these preliminary targets and lists the 2008 

status. Final targets will be published in the next revision of the Fuel Cell Technologies Program 

Multi-Year Research, Development and Demonstration Plan, to be released in 2011. 

Table 2. Preliminary Cost and Technical Targets: 1–10 kWe Residential Combined Heat and Power

Fuel Cells Operating on Natural Gasa [1]

2008 Status 2012 2015 2020

Electrical efficiency at rated powerb 34% 40% 42.5% 45%

CHP energy efficiencyc 80% 85% 87.5% 90%

Factory costd $750/kW $650/kW $550/kW $450/kW 

Transient response 

(10%–90% rated power) 5 min 4 min 3 min 2 min

Start-up time from 20°C ambient 

temperature 60 min 45 min 30 min 20 min

Degradation with cyclinge < 2%/1,000 h 0.7%/1,000 h 0.5%/1,000 h 0.3%/1,000 h

Operating lifetimef 6,000 h 30,000 h 40,000 h 60,000 h

System availability 97% 97.5% 98% 99%

a Standard utility natural gas delivered at typical residential distribution line pressures.

b Regulated AC net/lower heating value of fuel.

c Only heat available at 80°C or higher is included in CHP energy efficiency calculation.

d Cost includes materials and labor costs to produce stack, plus any balance of plant necessary for stack operation. 

Cost defined at 50,000 unit/year production (250 MW in 5-kW modules). e Based on operating cycle to be released in 2010.

f Time until > 20% net power degradation.

Following the publication of these targets, NREL commissioned an Independent Review Panel 

of industry experts (see Appendix A) to evaluate the reasonableness of the preliminary cost and 

technical targets in relation to 2008 fuel cell status estimates and projections out to 2020. 

The Independent Review Panel posed a common series of specific questions (see section 3) to a 

collection of industry experts, fuel cell system developers, and fuel cell component developers.
2 

The responses from stakeholders were then collated and analyzed. These data were 

supplemented by primary and secondary reference sources in combination with more than 110 

years of collective expertise of the Panel in all areas of fuel cell technology.

Defining a single set of representative cost and technical targets for 1–10 kW CHP stationary 

fuel cell systems is complicated because there are at least three independent fuel cell 

technologies that can be used to address the market needs. There are two proton exchange 

membrane (PEM) fuel cell technologies, low temperature PEM (LT-PEM) and high temperature 

PEM (HT-PEM), which operate at around 60°–90°C and 130°–180°C, respectively. Efforts to 

increase the LT-PEM fuel cell system’s operating temperature above 90°C are underway. In 

addition, solid oxide fuel cell (SOFC) technology, operating at 550°–1,000°C, is being 

developed for this market. While liquid phosphoric acid fuel cells (PAFC), direct methanol fuel 

cells (DMFC), and theoretically molten carbonate fuel cells (MCFC) could address 1–10 kW 

CHP stationary fuel cell systems, the Panel is not aware of any significant efforts in these areas, 

and as such, the Panel has focused its analysis on LT-PEM, HT-PEM, and SOFC systems.

Section 4 outlines the constraints and assumptions used to analyze the data and structure

recommendations.

Using data derived predominantly from stakeholders, the current status of each of the three key 

technologies relative to the existing DOE status and future potential for the CHP stationary 

application is outlined in sections 5–7. Section 8 includes a comparison of each technology, 

indicating the various pros and cons associated with the technology and relative to product 

requirements. Section 9 includes a discussion of the supplier network. 

Based on its analyses, the Panel has proposed a series of recommendations, which are described 

in section 10. These recommendations may provide the process by which the next iterations of 

cost and technical potential are compiled and reported. In addition, the Panel has highlighted 

potential areas where the development toward meeting 2015 and 2020 targets might be 

facilitated. 

The report ends with acknowledgments to various key contributors and to the many stakeholders 

who gave their valuable time and inputs, without which this report could not have been written. 

2 Panel Mandate and Objective

The NREL Systems Integrator is responsible for conducting independent reviews of progress 

toward meeting the FCT Program’s technical targets. An important technical target of the FCT

Program is a distributed generation fuel cell system operating on natural gas, propane, or similar 

fuel that achieves the following 2020 targets for 1–10 kW CHP applications: 45% electrical 

efficiency and 60,000 h durability at $450/kW (assuming a production rate that meets 

commercialization requirements and does not include integrated auxiliaries, battery, and power 

regulation necessary for unassisted start). At this time, no manufacturer is producing fuel cell

systems in the quantities needed for market introduction of small scale CHP products; as such,

these estimates are necessary for DOE to gauge progress toward meeting its targets. 

An Independent Review Panel (see Appendix A) was formed to review the status and probability 

of achieving the preliminary cost and technical potential related to the 2008 fuel cell status 
3 

estimates and the projected targets out to 2020. The Panel members were selected for their 

expertise in each of the three technologies that have the potential to meet the DOE targets for the 

stated applications: LT-PEM fuel cell systems; HT-PEM fuel cell systems; and SOFC systems. 

3 Methodology

The primary sources of information for the Panel’s independent review were technical- and 

business-related interviews of key stakeholders in the identified technology areas. These

stakeholders are listed in Appendix B. The stakeholders were asked about their businesses and 

their fuel cell technology type(s) and were asked the following introductory questions to obtain 

information on technology and commercialization status, potential improvements, and R&D 

needs for the technologies: 

Question 1. The U.S. Department of Energy (DOE) has published technical and cost targets for 

1–10 kW CHP systems and is seeking confirmation that these targets represent the acceptable 

industry targets. Your thoughtful comments on the validity of these targets or recommended 

changes will help DOE in their planning for future R&D programs. As part of your 

recommendations, would you prefer the emphasis of the DOE effort be on cell stack 

development, system component and balance-of-plant development, or all of the above? For the 

three areas, what are the main technology barriers to achieving the performance targets you have 

established and how do these targets compare to the DOE targets? Keeping in mind that all 

budgets would be limited, where do you recommend the DOE emphasize their R&D programs? 

Question 2. The objective of the market transformation programs operated by DOE and 

the Defense Logistics Agency is to accelerate market development. Examples are the 

PEM forklift truck and PEM backup power programs. Please suggest market transformation 

programs for stationary 1–10 kW CHP systems that would accelerate product development. 

Question 3. The high initial capital cost for stationary fuel cell systems is often cited as a barrier 

to commercialization. What are the stationary applications for which the initial cost will not be a 

major hindrance? Which R&D programs or market transformation programs would accelerate 

cost reduction for 1–10 kW CHP applications?

Question 4. The establishment of a mature supplier network can be a pathway to cost reduction. 

At the present stage of development, what aspects of a supplier network should become a high 

priority?

Question 5

The information obtained from the interviews was summarized by the Panel and, in most cases, 

edited and approved by the respective stakeholder. The Panel conducted its interviews and 

evaluation between February and April 2010. In producing this final report, the Panel used these 

discussions with stakeholders, some information from stakeholder websites, and its own 

collective fuel cell experience and expertise.

. Durability is a significant barrier for commercial viability of fuel cell-based CHP 

systems. Beyond the development of robust materials and designs, what other strategies are you 

considering to achieve and provide customer satisfaction in this area?
4 

Informative presentations were also provided by the Acting DOE-Fossil Energy Solid State 

Energy Conversion Alliance (SECA) Program Manager, DOE-FCT Program, NREL, and 

Battelle. Information from these presentations was considered by the Panel in writing this final 

report.

4 Constraints and Assumptions

The DOE stationary fuel cell system preliminary targets given in Table 2 were to be used as a 

reference for the industry stakeholders, who were asked questions about their system status and 

future design characteristics in relation to the 2008 status and future target data. The targets in 

Table 2 are constrained by the following:

• Stationary power systems should be rated in the range of 1–10 kW, operating on natural 

gas at typical residential pressures.

• Stationary power efficiency is based on AC net power / "lower heating value of fuel.” 

• Only heat available at 80°C or higher is considered for CHP.

o This constraint could eliminate consideration of many of the LT-PEM fuel cell 

systems and possibly some HT-PEM fuel cell systems. For the purpose of this 

report, the Independent Review Panel collected and reports CHP information for 

all LT-PEM and HT-PEM fuel cell systems.

• The cost target should consider only the cell stack and the balance-of-plant (BOP) 

components necessary for the operation of the cell stack.

o Industry practice breaks out the cost of the fuel cell system into three categories: 

1) fuel processing system, 2) cell stack, and 3) power conditioning with balanceof-plant components associated with each of the respective categories. For the 

LT-PEM fuel cell systems, HT-PEM fuel cell systems, and low temperature 

SOFC systems, the overall fuel cell system cost would include the fuel processor 

as an additional cost component. The high temperature SOFC system does not 

have a fuel processor cost component; hence, the high temperature SOFC system 

cost should be lower relative to the other fuel cell systems reviewed here. All of 

the fuel cell systems require a desulfurization process to pre-treat the natural gas.

The differences in system designs based on operating temperature should 

influence overall fuel cell system cost. Cost should be estimated based on 

production of 50,000 units per year.

• DOE reports the factory cost status for 2008 based on performance and on low volume 

production extrapolated to a 50,000-unit annual production cost.

• The DOE factory cost targets for 2012, 2015, and 2020 are guided by the perceived cost 

the market will accept and not by actual fuel cell system costs. 

4.1 Independent Review Panel Assumption

The Independent Review Panel, along with DOE and the Fuel Cell Technologies Program’s 

Systems Integrator, reviewed this group of assumptions and constraints, which formed the 

framework for the Independent Review Panel’s analysis and interviews with the fuel cell 

industry. 
5 

The Independent Review Panel defined a high level fuel cell system block diagram, shown in 

Figure 1, which is generic and represents LT-PEM and HT-PEM fuel cell systems as well as

SOFC systems. 

Figure 1. Block diagram of generic fuel cell system

The analysis and data collection focused on evaluating the major components and not on the subcomponent detail; i.e., the focus would not be on catalysts, membranes, interconnects, the steam 

generator, or other stack and BOP components. The hardware requirements related to CHP 

thermal management and power conditioning subsystems were not addressed. 

5 Evaluation of Cost and Technical Potential based on LT-PEM 

Technology

LT-PEM fuel cell systems have been used in applications in the low end of the 1–10 kW power 

range for more than 10 years. The majority of the development and product demonstration has 

been in Japan, with significant activities in South Korea and in Europe over the last 5–7 years. In 

all cases, the advances in technology and deployment have been assisted by government 

incentives to component suppliers, fuel cell development companies, and end users. To date, 

more than 11,000 LT-PEM fuel cell systems have been deployed in Japan [2], with electrical 

efficiencies as high as 38% based on LHV of natural gas and CHP efficiencies of up to 85%. 
6 

Most of the LT-PEM fuel cell systems deployed in stationary power applications operate at 

around 60°–65°C and at up to 3 psig, but some developers are using systems that operate at 

higher temperatures. These systems are fueled using reformate from natural gas, liquefied 

petroleum gas (LPG), and even kerosene in some demonstrations being conducted in Japan. 

LT-PEM fuel cell systems represent the most mature technology today in the low end of the 1–

10 kW power range. This technology has benefited from the greatest level of sustained 

development and broad-based demonstration in residential CHP stationary applications.

However, there are some concerns that the low quality of heat produced could limit its 

application in areas beyond residential cogeneration where high heat quality is a requirement. 

An additional operational issue related to LT-PEM fuel cell systems is the relative complexity of 

the reformer gas clean-up subsystem. At temperatures below 120°C, the stack’s platinum-based 

catalysts are susceptible to performance losses at carbon monoxide (CO) levels in excess of 100 

ppm. In general, these LT-PEM fuel cells require less than 10 ppm CO during regular operation, 

thereby increasing the cost and complexity of the gas reforming process. 

5.1 Electrical and CHP Efficiency

The LT-PEM stakeholders confirmed that DOE’s 2008 electrical efficiency status was well 

within the demonstrated capability of their systems. There was a consensus among stakeholders 

that achieving 40% to 45% electrical efficiency will be a stretch for LT-PEM fuel cell systems 

operating on reformed fuels, including natural gas. The CHP efficiency was reported to be as 

high as 85% with current product designs. However, the ability to achieve 90% efficiency, the 

2020 DOE target, is a significant stretch unless the operating temperature can be increased 

beyond 60°–65°C, the operating temperature stated by most stakeholders, to offer the end user a 

higher quality of heat. 

5.2 Factory Cost

The majority of LT-PEM fuel cell systems produced today are at a power level of 1 kW or less.

While these systems were initially developed to meet the needs of the Japanese market, they 

have now been adopted in other countries in Asia and in Europe. The majority of stakeholders 

believe that the DOE cost targets are unnecessarily aggressive for this power level and that the 

technology is capable of reaching an end product (including water tank) selling price to the 

utilities of $5,000–7,000/kW by 2012–2015. As expected, system costs are very sensitive to 

production volume. Most stakeholders agree that while the DOE targets may be achievable at 

50,000 units, at volumes closer to 5,000 units per year, costs could be double those cited in 

DOE’s preliminary targets (Table 2). 

As with all fuel cell applications, stack materials and BOP components are candidates for cost 

reduction, and improvements in manufacturing processes, such as the deployment of roll-to-roll 

processing and equipment, and quality control measures can increase yields and reduce costs. 

Leveraging the use of costly components developed for non-fuel cell applications, such as air 

management subsystems and power conditioning devices, is desirable.

When questioned about validation of factory costs, most stakeholders indicated that 

manufacturers have not yet completed sufficiently detailed analyses to a high level of confidence 

in their cost results. For the stack subsystem, one manufacturer identified cost potential for the 
7 

2012–2015 timeframe to be within the $1,000–$1,200/kW range, with an emphasis on producing 

products within the lower power levels of the 1–10 kW range in volumes in the low 10,000s. 

Catalyst cost remains an issue, given the requirements for high efficiency and greater than 

40,000 h of durability. Gas diffusion media, bipolar plates, and sealing materials are cell 

components for which incremental cost reduction, without detriment to durability or efficiency, 

is desirable. 

The cost of the reformer and its related components, including reformate clean-up, was not 

specifically addressed by the majority of stakeholders as a cost issue per se, but challenges 

associated with sulfur as a fuel contaminant and the development of a cost effective desulfurizer 

were noted by many to be worthy of further investment. 

As with all fuel cell technologies being developed for stationary power applications, cost 

reductions related to air management subsystems and power conditioning devices were noted as 

areas for additional investment.

5.3 Transient Response Characteristics

The DOE targets for transient response are well within the performance levels already 

demonstrated for the LT-PEM fuel cell systems. While the reformer is the slowest responding 

subsystem on the order of 100s of seconds, it is assumed for transient response that the reformer 

is already at operating temperature. The response times for the rest of the LT-PEM systems are 

very fast, on the order of < 10 seconds. 

For LT-PEM fuel cell systems operating in the grid-parallel mode, the grid would deliver 

supplementary power during the transient operation and effectively provide backup to the fuel 

cell. For systems functioning in a grid-independent mode, batteries or supercapacitors could be 

used to provide the power required during the transient. 

5.4 Start-up Time

The start-up time for LT-PEM fuel cell systems depends on the reforming process used, e.g., 

steam reforming, partial oxidation, or autothermal reforming. For steam reforming, the start-up 

times from ambient temperature can be less than 30 minutes; this is projected to decrease to less 

than 10 minutes by 2015. For the lower power units in the 1–10 kWrange, the smaller thermal 

mass of the reformer will ensure that start-up from ambient conditions, as defined by the DOE 

targets, is not a commercialization issue for LT-PEM systems.

5.5 Operating Lifetime 

The majority of stakeholders responded that the DOE durability targets of up to 30,000 h are not 

a significant commercialization issue, while some stakeholders believe that a durability of 40,000 

h is already achievable with today’s technology, at least for the stack components. To go beyond 

this level of durability, a number of different strategies could be employed, depending on the 

cost of components. Stakeholders noted that existing residential heat and electrical systems 

require regular maintenance and replacement of parts due to failure and wear out. A similar 

approach could be employed for fuel cell systems, depending on the replacement cost of 

components, the ease of serviceability, and the frequency of repair. Most stakeholders said that a 

minimum of 10,000–20,000 h of operating lifetime would be required for commercial viability. 
8 

A majority of stakeholders noted that the components that suffered from the most frequent 

failures and required replacement most often were actually related to the balance-of-plant. 

However, the systems under evaluation today do not contain the components that meet the 

ultimate commercial cost targets, and there may be some tradeoffs between durability and cost as 

lower cost materials and components are utilized in system designs.

Almost all of the stakeholders challenged the target beyond 40,000 h, suggesting that this is not 

required to achieve commercial success. If such lifetimes were to be required beyond 2020, the 

objective would be best addressed through servicing and component replacement, rather than 

incurring the huge cost and timeline associated with developing the materials and designs to 

meet a 60,000 h operating life. 

Some stakeholders suggested that operating lifetime alone is not the best indicator of value to the 

end users; using a metric of cost per kWh, while taking the complete cost of ownership into 

account, would be more useful. This metric would also have to take into account the variances 

between grid-connected and grid-independent systems. Some countries are providing incentive 

tariffs to end users for energy feedback to the grid, and in some cases for avoidance of use of 

grid energy, thereby freeing capacity for other uses. 

5.5.1 Degradation with Cycling

The operational characteristics and design of LT-PEM fuel cell systems allow for rapid and 

frequent response to load cycling without significant detriment to performance and durability. 

One stakeholder noted that existing demonstration units have shown more than 2,000 ON/OFF

real time cycles in an ongoing test with negligible loss in performance and an overall system 

operating life in excess of 30,000 h. 

Through experience in developing automotive stacks, many stakeholders have gained 

fundamental understanding of the degradation process resulting from ON/OFF cycling as well as 

rapid load following behavior. This has led to improvements in materials and designs that have 

significantly reduced performance degradation during cycling for LT-PEM fuel cell systems in 

CHP applications. 

Overall, most stakeholders were not able or willing to address this technical target in significant 

detail. 

5.6 System Availability

A majority of stakeholders consider 97% availability to be a reasonable value for the current 

status of technology. Future systems will be optimized to meet the DOE availability targets for 

2015 and 2020. 

5.7 Capital Cost Reduction Through Manufacturing Capability

Existing LT-PEM fuel cell systems have demonstrated sufficient capability that they are ready 

for use in applications where the grid electricity price is high and in remote areas where the grid 

is either not available or is less reliable than in large urban areas. This capability will facilitate

larger demonstration programs and early commercial growth, allowing for investment in 

manufacturing process optimization and deployment of higher levels of automation, which will 

in turn reduce capital cost. Increased confidence in the technology will generate the necessary in-
9 

field data to accelerate design improvements, drive down cost, and create the necessary sales 

volume to enhance the capability of the supplier network while building manufacturing 

understanding and efficiencies. While LT-PEM fuel cell systems are the most advanced and 

commercially viable in the low end of the 1–10 kW power range, these systems still require 

further cost reduction and enhancements in stack design and BOP components to become 

competitive with the cost and reliability of grid electricity. The low quality of heat currently 

produced from these systems will likely limit their adoption in certain applications. 

Opportunities to increase operating temperature without detriment to cost and reliability are 

being pursued. 

6 Evaluation of Cost and Technical Potential based on HT-PEM 

Technology

HT-PEM fuel cell system development is ongoing in the United States, Europe, and Asia, with 

several product demonstrations, mostly in the United States, initiated in the last several years.

HT-PEM fuel cell systems operate in the temperature range of 130°–180°C and are commonly 

reported to operate at 160°C. The operating pressure is atmospheric to ~2 atmospheres, 

depending on the manufacturer’s cell stack and system design. HT-PEM fuel cell systems 

operating on reformed natural gas have electrical efficiencies of 40% to 45% at BOL. At 

operating temperature, the HT-PEM fuel cell system is tolerant to relatively high carbon 

monoxide concentrations of 1% to 2%, and as such does not require the more complex and 

expensive reformate clean-up systems seen in LT-PEM fuel cell systems.

The CHP efficiency of HT-PEM fuel cell systems benefits from the moderate fuel cell operating 

temperature and the quality waste heat from the fuel cell anode and cathode exhaust. The waste 

heat can be used to generate steam for the fuel processing system. The integration of the waste 

heat from the fuel cell exhaust is an important contributor to reaching 40% to 45% BOL 

electrical efficiency.

HT-PEM fuel cell systems perform similarly to liquid electrolyte PAFC systems and, for the HTPEM fuel cell systems reported here, the membrane contains phosphoric acid as a component of 

the electrolyte. The HT-PEM fuel cell system fabricators report that the vapor pressure of 

phosphoric acid is reduced when the acid is bound in the membrane and acid loss degradation is 

reduced or possibly eliminated, dependent on the mole ratio of acid used to produce the final 

membrane. In the PAFC system, the design of the cell components significantly reduces the 

phosphoric acid loss.

6.1 Electrical and CHP Efficiency

The HT-PEM fuel cell system stakeholders stated that the 2012 and 2015 electrical efficiency 

targets are well within their capability, with some stakeholders reporting 2010 electrical 

efficiencies at 43%. There is a consensus among stakeholders that 45% electrical efficiency 

would be a difficult but feasible target to achieve in 2020. 

All of the HT-PEM fuel cell system stakeholders agree that CHP efficiency of 85% is possible 

and in some cases has already been demonstrated. One stakeholder has demonstrated (in 2010) 

88% CHP efficiency under laboratory conditions. The 2020 CHP efficiency target of 90% is a 
10 

reachable goal based on stakeholder feedback. For these CHP efficiencies, the HT-PEM fuel cell 

system will deliver hot water at 60°C to 80°C. 

One stakeholder, UTC Power, addressed the heat quality issue with a “high-grade heat option” 

for their commercial PAFC. This option uses some of the thermal energy (almost 50%) to 

increase the quality of the heat and deliver 125°C steam; however, the overall CHP energy 

efficiency for the high quality heat option is 60%–70%. 

6.2 Factory Cost

Some of the stakeholders believe that factory costs higher than the DOE 2008 status by a factor 

of 2 or more are acceptable to some end users today. In some cases, present factory costs are 3

times the DOE 2008 status. Future cost potential identified by some of the stakeholders was

greater than the DOE cost targets for 2015 and 2020. 

One stakeholder suggested that the DOE targets are perhaps too stack-centric. Other subsystems, 

such as the inverter, will drive up the fuel cell system cost. Several HT-PEM fuel cell system 

stakeholders identified the high cost of power conditioning for fuel cell systems as a potential 

problem. 

The validity of the potential factory costs responses may be questioned, because some of the 

respondents indicated that their answers were not based on a detailed analysis, but rather on 

estimates of where a fuel cell cost could be in 2012, 2015, and 2020. 

Cost reductions based on manufacturing improvements such as high roll-to-roll processing for 

the cell components and improvements in material stability are important advancements 

necessary to approach the DOE factory costs, according to the stakeholders.

One manufacturer believes it can maintain high quality and achieve the target factory cost by 

keeping all production capability in-house; i.e., vertical integration of the manufacturing process.

On the opposite extreme, another manufacturer proposes to outsource all of the stack component 

production to limit capital investment in manufacturing equipment and thereby achieve the 

factory cost targets.

6.3 Transient Response Characteristics

Stakeholders did not consider the transient response targets to be important for the 1 kW HTPEM fuel cell systems in residential applications. These stakeholders consider the grid to provide 

backup power to the 1 kW HT-PEM fuel cell system; i.e., the system operates in a grid-parallel 

mode. 

Rapid transient response times are < 10 seconds with battery or supercapacitor assist. The ratelimiting component for the rapid transient response is the reformer response. To achieve rapid 

response, the system needs to be designed with a surplus of hydrogen available to operate the 

fuel cell and compensate for the slow reformer response, in addition to the battery and 

supercapacitor assist. Without battery buffering, and once the stack/reformer is hot, a 5 minute 

transient response time is achievable with a 2 minute transient time possible in the future. 
11 

6.4 Start-up Time

A start-up time of 30 minutes in 2010 is presently feasible for one stakeholder. This stakeholder 

also stated that an improvement in start-up time was not needed. While asked, other stakeholders 

did not address start-up time for the HT-PEM fuel cell system. One stakeholder suggested that 

regular maintenance could be done "on the fly" without turning off the HT-PEM fuel cell system

and that the only time the system would be turned off is for change-out of the cell stack, or every 

40,000 h. 

6.5 Operating Lifetime

The operating lifetime status for 2008 (6,000 h) and targets for 2012 (30,000 h), 2015 (40,000 h), 

and 2020 (60,000 h) are valid according to the HT-PEM fuel cell system stakeholders. The 

stakeholders’ 2020 (60,000 h) operating life target is greater than the Panel’s perspective in 

Table 1. Change-out of the cell stack at less than 40,000 h (5 years) was considered restrictive 

and too expensive by more than one stakeholder. The acceptance of these operating lifetimes by 

the HT-PEM fuel cell system stakeholders is strongly influenced by the similarities in the 

operating conditions of the HT-PEM fuel cell systems to the PAFC systems and the success of 

UTC Power in meeting the 60,000 h life for a commercial phosphoric acid fuel cell.

Some stakeholders expressed concern over acid loss, because this limits operational life. The 

acid loss problem was resolved by UTC Power for their larger (200 kW and 400 kW) models 

through continuous recycling of the acid within each individual cell. Similar technology could 

resolve acid loss issues for HT-PEM fuel cell systems. Other approaches include development of 

improved membrane materials that bind the acid within the membrane and significantly reduce 

its vapor pressure; advances in this area have been claimed by at least one stakeholder.

A critical issue for several stakeholders is the operating life of the BOP components, such as

blowers and valves. For stationary applications, the lifetime of the furnace or boiler is a 

suggested measure of durability. However, thermal systems are not operated continuously, while 

power demand for a residential or commercial facility in many cases is continuous at some load 

level. The stakeholders recommended a minimum operating life of 40,000 h. 

Stakeholders proposed that operating life should be qualified to mean operating life at rated 

power. Lowering the operating point of the fuel cell system to less than rated power can increase 

the operating life of the system; however, this effectively increases the purchase price per kW of 

the fuel cell system and increases the energy production costs. For commercial applications, 

stakeholders suggested that operating life be expressed in kWh. Operating life alone is not a 

good indicator of performance because commercial and residential users are concerned with 

$/kWh. This view is consistent with the LT-PEM fuel cell system stakeholder inputs on 

operating life. 

6.5.1 Degradation with Cycling

One stakeholder reported degradation at 0.3%/1,000 h for 2008, which is considerably less than 

the < 2%/1,000 h status reported by DOE for 2008. The same stakeholder has set their 2015 

degradation goal at 0.25%/1,000 h for 2015, which is less than half of the 2015 DOE target. It is 

unclear whether such low degradation rates are obtainable over 40,000 h, because these are early

results. Other stakeholders did not directly address degradation but rather discussed durability of 

the cell stack as a critical issue. 
12 

Given the close association of HT-PEM fuel cell systems with PAFC systems through the 

phosphoric acid in the electrolyte, HT-PEM fuel cell system stakeholders anticipate similar 

degradation rates as the technology matures.

6.6 System Availability

The target for one stakeholder is 100% availability, but most stakeholders did not discuss system 

availability. HT-PEM fuel cell systems operating in the grid-parallel mode use the grid as backup 

and the availability target is readily met. The grid-independent mode is a more difficult problem 

to address. One stakeholder suggested Mean Time Between Forced Outages (MTBFO) as an 

additional target that may more appropriately define system availability. 

6.7 Capital Cost Reduction Through Manufacturing Capability

Driving down stack cost components will be governed by manufacturing advances and increased 

yields. The big issue is how to bridge the gap between pilot scale and full scale continuous 

production. For many organizations, the present manufacturing approach is the “pick-and-place” 

manufacturing technology. Research and development on manufacturing automation and 

adaptation of appliance manufacturing technologies, e.g., manufacture of air conditioners, would 

drive down the cost of HT-PEM fuel cell systems.

High-cost components for the HT-PEM fuel cell system are the MEA catalysts and the bipolar 

plates. R&D efforts can drive down the material cost and result in capital cost reductions. The 

introduction of continuous, roll-to-roll processing for MEA manufacturing is an important step 

that needs to be completed to increase manufacturing rates with a concomitant reduction in cost.

Many stakeholders identified power conditioning as a prime area for cost reduction. Some

stakeholders recommended that the cost of the fuel processor be addressed by manufacturing 

R&D. Mass production of reformers would greatly assist in the reduction of first cost for the HTPEM fuel cell system. Another potential route to cost reduction is standardization of these BOP 

subsystems; commonality of BOP components would increase market volume and drive down 

costs.

7 Evaluation of Cost and Technical Potential based on SOFC 

Technology

Solid oxide fuel cells (SOFC) operate in three temperature ranges and use different electrolytes 

for each: low temperature from about 550°C to 600°C, usually consisting of ceria-based 

electrolyte; intermediate temperature from 700°C to 850°C, consisting of a thin zirconia- or 

lanthanum gallate-based electrolyte; and high temperature from 900°C to 1,000°C, consisting of 

a thicker zirconia-based electrolyte. 

All of these SOFC systems are capable of generating power using hydrogen or carbon monoxide 

as the fuel. The lower temperature systems require an external fuel processing system to convert 

natural gas to reformate (hydrogen, carbon monoxide, carbon dioxide, and steam); however, the 

external fuel processor does not require a shift reactor to convert carbon monoxide and steam to 

hydrogen because the SOFC can use the carbon monoxide as fuel. The higher temperature units 

process the natural gas fuel to hydrogen and carbon monoxide internally in the stack or in the 

anode chamber of the fuel cell. Strict control of the carbon-to-steam ratio of the anode fuel feed 
13 

gas prevents the formation of carbon deposits (coking) in the anode chamber during internal 

reforming. 

SOFC systems operating on natural gas have a wide range of electrical efficiencies, from 35% to 

60%, depending upon the operating conditions. The CHP efficiency of SOFC systems benefits 

from the high fuel cell operating temperature, and waste heat from the fuel cell can be used for 

thermal applications. The heat from the fuel and air exhaust is used to pre-heat the incoming 

reactants.

7.1 Electrical and CHP Efficiency

The SOFC stakeholders identified the 2012, 2015, and 2020 electrical efficiency targets to be

well within their capability, with one stakeholder reporting 2010 electrical efficiency at 60%. 

These electrical efficiencies represent BOL values. The SOFC stakeholders report that 

performance degradation of the SOFC systems (discussed below) will reduce the electrical 

efficiency to 35%–40% at end-of-life (EOL). 

One stakeholder suggested that operating at 60% electrical efficiency does not provide the 

optimum ratio of electrical efficiency and thermal efficiency and that lower electrical efficiency 

in the range of 35%, achieved by operating at higher current density, may better fulfill customer 

requirements for CHP. 

Present CHP efficiency is 85%, and all of the SOFC stakeholders agree that the CHP efficiency 

target of 90% is possible and in some cases already demonstrated. The high quality of the SOFC 

heat readily satisfies the CHP targets. 

7.2 Factory Cost

The SOFC stakeholders stated that the DOE factory cost targets were very aggressive. Some of 

the stakeholders report 2008 and current factory costs for the systems to be ~ $9,000/kW at low 

production volume. Some stakeholders suggested a factory cost of ~$4,500/kW at a production 

rate of 50,000 units per year. These system costs may reflect the high cost for SOFC balance-ofplant subsystems, such as heat exchangers for pre-heating the reactants, which are more exotic 

and costly at higher temperatures. 

The SOFC stakeholders stated that the $/kW cost for a 10 kW system would be less than the 

$/kW cost of a 1 kW system. While the number, size, and cost of the cell stack repeat parts 

(anode-ceramic membrane-cathode, interconnects, and seals) would scale with the kW rating, the 

reduction in cost of the fuel processor, power conditioning unit, and other BOP components 

would not be proportional to the kW rating of a fuel cell system. The SOFC stakeholders’ higher 

$/kW cost for 1 kW systems than for 10 kW systems is consistent with the stakeholder inputs for 

the LT-PEM and the HT-PEM fuel cell systems. 

The high cost of SOFC systems is somewhat unexpected because they do not use a platinum 

catalyst. Instead, the high cost is due to expensive high temperature materials for interconnects, 

heat exchangers, manifolding, and power conditioning system. The minimum requirements for 

SOFC system cost [3] set by the Solid State Energy Conversion Alliance (SECA) are lower than 

the DOE 1–10 kW targets considered by the stakeholders. The discrepancy is due to differences 
14 

in power rating; the SECA program considers multi-megawatt SOFC systems, while 1–10 kW 

SOFC systems are considered in this independent review.

7.3 Transient Response Characteristics

The transient response targets for 2015 and 2020 were reasonable according to most of the 

stakeholders for the 1 kW SOFC stationary residential applications. One stakeholder reported a 

present transient response time of 15 minutes; however, this was not considered an issue because 

the system operates in a grid-parallel mode and the electrical grid supplies backup power. 

SOFC system stakeholders reported that rapid transient response (< 2 sec) is not possible when 

operating in the grid-independent mode, even with battery or supercapacitor assist.

7.4 Start-up Time

Start-up times for the SOFC stakeholders varied from 2.5 h to 20 h, well beyond the DOE 2008 

status of 60 min. The SOFC stakeholders operate their systems continuously. Shut-down (with 

thermal cycling) degrades the performance of the SOFC systems. The longer start-up times 

represent SOFC systems designed for continuous operation, and modification of the system 

design to facilitate faster start-up times is considered an unwarranted cost by some stakeholders.

7.5 Operating Lifetime

The operating lifetime status for 2008 (6,000 h) is reasonable and has been demonstrated by 

more than one SOFC system stakeholder. A couple of stakeholders report operating lifetime at 

10,000 h under well-defined conditions and control. Longer operating lifetimes in the range of 

30,000 h (2012), 40,000 h (2015), and 60,000 h (2020) will be challenging, according to SOFC 

system stakeholders. 

Some stakeholders consider change-out of the cell stack to be a solution to the operating lifetime

issue. Other stakeholders consider stack change-out to be an unacceptable, expensive process. 

No stakeholders claimed that BOP life is an issue.

7.5.1 Degradation with Cycling

The degradation targets set by DOE are reasonable for SOFC systems, although there is a large 

variance in the degradation data. Some stakeholders report present degradation rates at 1%–2% 

per 1,000 h, while other stakeholders report degradation rates at 0.1%–0.3% per 1,000 h.

Thermal cycles impact degradation considerably more than load cycles do. One manufacturer 

expects 200 thermal cycles to be achievable over the life of the stack with degradation at 2% per 

1,000 h within a few years. 

7.6 System Availability

The 97% availability status is reasonable for systems using today’s technology. Future systems 

will meet the DOE availability targets of 98% and 99% by 2015 and 2020, respectively. One 

stakeholder considered reliability a more important issue than availability.

7.7 Capital Cost Reduction Through Manufacturing Capability

To date, fewer than 200 SOFC CHP systems have been deployed globally based on the 

Independent Review Panel's knowledge and as indicated by Fuel Cell Today [4]. These systems 

have been used to demonstrate different cell and BOP materials and designs. Very few 

companies have been able to gain significant manufacturing experience with these systems. As 
15 

materials and designs for the SOFC CHP systems that meet the early commercialization targets 

and volumes for cost, lifetime, reliability, and overall functionality emerge, it appears 

appropriate that more efforts be directed toward manufacturing to reach the final cost target. 

Significant cost reduction and increased reliability can be achieved with investments in 

manufacturing process development, equipment design, on-line quality control procedures, and 

factory acceptance testing methodologies.

High-cost components for the SOFC CHP system are the cells and the interconnects. R&D 

efforts can drive down the material costs and result in capital cost reductions. Many stakeholders 

identified power conditioning as a prime area for cost reduction. Another potential route to cost 

reduction is standardization of BOP subsystems; commonality of BOP components would 

increase market volume and drive down costs. 

8 Comparative Analysis of Key Fuel Cell Technologies

The three candidate fuel cell systems, LT-PEM, HT-PEM, and SOFC, have been discussed 

individually in sections 5–7. This section provides a comparative analysis of these three fuel cell 

systems. 

8.1 Key Component Breakdown

A fuel cell system can be described in terms of cells (electrolyte membrane, anode, cathode, 

diffusion layers, bipolar plates) stacked in series to generate practical DC voltage. Sealing and 

thermal management are two critical aspects of a stack design. Proper sealing of cell edges and 

gas manifolds throughout different operating conditions is required for efficient operation over 

the life of the stack. Proper thermal management design is essential to maintain uniform 

temperatures in planar as well as in stacking directions. Steam required for reformer reaction is 

also generated in the thermal management subsystem. 

A fuel cell system can be complicated. A fuel such as natural gas has to be converted to a H2-rich 

feed with minimal sulfur; ambient air has to be cleaned up to remove any particulate and 

chemical impurities; and DC power generated by the fuel cell has to be converted to AC using a 

power conditioning system (PCS). Detailed evaluations of the individual systems were given in 

sections 5–7. An R&D effort is required to simplify the overall system, thereby reducing the cost 

while increasing reliability. Each of the fuel cell systems discussed here operates in different 

ways, depending on the technology, application, and end-user requirements. 

Table 3 compares various components, subsystems, and other parameters for the three fuel cell 

technologies discussed in this report [5]. In sections 8.2 and 8.3, the major end-user requirements 

are examined from the perspective of typical characteristics of a given system.
16 

Table 3. Comparison of Various Components, Subsystems, and Other Parameters for Three Candidate Fuel Cell Types [5] 

Fuel Cell 

Type 

Electrolyte Operating 

Temperature 

Electrodes Bipolar Plate Fuel 

Processor

Cooling System 

Output 

Advantages Disadvantages

Low

Temperature 

Proton 

Exchange 

Membrane 

(LT-PEM) 

Solid organic 

polymer polyperfluorosulfonic 

acid 

60°–90°C Noble 

metal

Graphite/carbon

composite or 

metallic

External 

reformer, 

shift 

reactor, 

and 

selective 

oxidizer

Water 

cooling

< 1–250 

kW 

-Solid 

electrolyte 

with no

electrolyte 

loss issues

-Low 

temperature

-Quick startup

-Low 

temperature 

waste heat

 

High 

Temperature 

PEM 

(HT-PEM) 

PBI or alternate 

polymer system, 

both with 

phosphoric acid

130°–180°C Noble 

metal 

Graphite 

composite or 

metallic

External 

reformer 

and shift 

reactors

Water/steam 

cooling

< 1–250 

kW 

-Higher overall 

efficiency with 

CHP 

-Increased 

tolerance to 

impurities in 

hydrogen

-Poor cathode 

performance 

due to anion 

adsorption

Solid Oxide 

(SOFC) 

Stabilized 

zirconia or ceria

550°–1,000°C Ceramic or 

cermet 

Ceramic or 

metallic 

Internal or 

external 

reformer

Air cooling 

and internal 

reforming 

< 1 kW 

– multiMW 

-High 

efficiency 

-Fuel flexibility 

 -Solid 

electrolyte 

reduces 

electrolyte 

management 

problems 

-May not 

tolerate thermal 

cycling 
17 

8.2 Major Differences

 

8.2.1 Electrolyte and Operating Temperature

Solid polymer electrolyte membranes with high proton conductivity are utilized in LT-PEM and 

HT-PEM fuel cell systems. The LT-PEM fuel cell system uses perfluorosulfonic acid ionomers 

with a Teflon-like structure, in which all ion-exchange functionalities are chemically bound into 

the polymer. HT-PEM fuel cell systems use a different chemistry that is based on a 

polybenzimidazole (PBI) containing phosphoric acid. PBI is commercially available and used in 

many non-fuel cell applications. Because of a strong bond between phosphoric acid and PBI, 

phosphoric acid loss is minimized when the two compounds are used at equivalent molar ratios. 

However, acid loss remains a concern for performance and durability when excess phosphoric 

acid is used. Researchers are evaluating chemistries other than PBI to try to address the acid loss 

issue, as are the developers of the PBI-based membranes. A PBI-free electrolyte has been 

developed that incorporates phosphoric acid. This membrane is specifically synthesized for fuel 

cell applications and is claimed to be less susceptible to acid loss than PBI membranes are. 

The fuel cell operating temperature dictates the quality of byproduct heat available for CHP 

applications. The LT-PEM fuel cell systems can operate at 60°–90°C, but most of the systems 

providing long life (30,000 h) were operated at 65°C. HT-PEM fuel cells operate at 130°–180°C 

and are therefore tolerant to higher levels of CO, on the order of 2%, in the fuel. At certain 

temperatures, SOFC systems can actually use CO as a fuel and therefore are tolerant to all CO 

levels, obviating the need for a shift converter and, in the case of LT-PEM fuel cell systems, a 

selective oxidizer.

Operating temperatures of 550°–1,000°C for SOFC systems imply longer start-up time, which 

has a strong influence on cyclic degradation rates. Byproduct heat from SOFC systems can 

produce high pressure steam and high quality hot water. Many SOFC system developers propose 

that because the system is capable of delivering high electrical efficiencies, it can be designed to 

operate continuously, thereby reducing the cyclic degradation rate.

8.2.2 Cell Design

The membrane electrode assembly (MEA) is the heart of power production in PEM fuel cell 

systems. Heat released in the fuel cell reaction has to be removed for steady state operation. An 

effective cooling approach is critical for a simple, cost effective cell/stack design and therefore is 

a subject of many patents. Loading of a noble metal catalyst (mg/cm2

) is a major cost 

contributor. The loading also influences degradation rate and operating lifetime. 

Electrochemically, SOFC systems operate differently from PEM fuel cell systems. In SOFC 

systems, oxygen ions are produced at a cathode and travel through a ceramic electrolyte to the 

anode. The cell construction for SOFC may be planar or tubular. The electrolyte layer is very 

thin to minimize resistive losses across the electrolyte. SOFC uses non-noble metal catalysts and 

therefore offers a cost saving in this regard. 

8.2.3 Fuel Cell Stack

Two types of stacking approaches are used in candidate fuel cell systems: axial in-series and tube 

bundles. All PEM stacks use planar cell construction. SOFC stacks use planar or tubular designs. 

MEAs are placed on a bipolar plate in a planar cell construction. The cell temperature profile and 
18 

bipolar plate material strongly influence the stability and cost of the bipolar plate. An MEA may 

provide sealing at the edges; otherwise a separate gasket is used. A gas diffusion layer (GDL) is 

used to maximize utilization of electrode surface area and assist in heat and water management 

for the stack. To assist in water management, the PEM GDL is made hydrophobic using Teflon. 

Some developers propose as many as seven layers and claim a negligible cost differential 

between five-layer and seven-layer MEA construction. The design of optimum cell size and 

number of cells in a stack is dependent on the operating voltage and current, cost of materials, 

stack components, and PCS as a function of DC input voltage. 

The reactant gases have to be delivered uniformly for optimum utilization of cell area, especially 

in larger stacks. Strict quality control in manufactured parts is essential. External manifolding, 

internal manifolding, and hybrid manifolding approaches have been reported to provide adequate 

sealing and separation of fuel, oxidant, and coolant. 

For SOFC systems, tubular cell and stack construction is expected to yield better gas sealing and 

thermal cycling capability, but it may be more expensive than planar construction, especially for 

stacks in the 1–10 kW power range. 

8.2.4 Fuel Processor 

Natural gas is assumed to be the fuel of choice for baseline residential or stationary CHP 

applications. Hydrogen is extracted from natural gas via steam reforming at 700°–800°C in an 

“external” reformer for PEM systems; autothermal reforming provides for a faster start-up, but it 

is more expensive. Waste heat from PEM is not available at reforming temperatures, so 

supplemental heat is provided by burning fuel, which penalizes electrical efficiency. For high 

temperature fuel cells such as MCFC and SOFC systems, waste heat is available at the reforming 

temperatures, so there is no electrical efficiency penalty. It is also advantageous to perform at 

least a part of the reaction in an “internal” reformer within the stack, which helps provide stack 

cooling and cell temperature uniformity. 

A common comment by stakeholders was the need to develop a desulfurization subsystem.

Odorants are added by pipeline gas companies for leak detection, but they are poisonous for 

PEM fuel cell and SOFC systems. Removal of these odorants requires expensive equipment and 

sorbents. Stakeholders suggested that these odorants should be standardized so that the same 

equipment can be utilized by different fuel cell systems and in different countries in Europe and 

North America. Some research into non-sulfur based odorants is being conducted in Japan. The 

results from the study may be used to recommend preferred odorants from a fuel cell viewpoint. 

Different strategies are employed for exhaust fuel recycling and for operating pressure, resulting 

in different impacts on cost and durability. 

8.2.5 Air Handling

Large quantities of air are required for reactant air and for cooling. An industrial blower is 

generally inefficient and can consume significant amounts of power, taxing the system’s

electrical efficiency. A more efficient, cost-effective blower is desirable for all fuel cell 

technologies. Low-cost heat exchangers are desirable for heating or cooling various gas streams. 
19 

8.2.6 Power Conditioning System (PCS)

As mentioned before, DC power produced by the fuel cell is converted to AC power in a PCS

The efficiency of this equipment is inversely proportional to the cost. The input operating 

voltage range also affects the cost of PCS. If the design can be standardized, order volume can be 

high, leading to cost reduction. The control system for fuel cell, fuel processing, and PCS can be 

integrated, reducing the total system cost.

8.3 Meeting End-User Requirements

The end user in residential applications is an individual home-owner, a multiple housing 

management company, a utility company, or an independent power producer. Power 

requirements may range from 3–5 kW for a single family home in the United States. Multiple 

fuel cell units may be sited to match the customer demand. The end user desires the following 

important characteristics from the on-site fuel cell unit:

• High electrical efficiency

• High thermal (CHP) efficiency

• 3–4 year return on investment (ROI) 

• High reliability and durability.

These requirements were translated into quantitative technology and cost targets by DOE (see 

Table 2). Each of the three fuel cell systems meets some of the requirements; however, some 

trade-offs are needed for selecting one particular type. 

8.3.1 Cost 

A 2020 target of $450/kW is provided as a “factory cost” objective by DOE. The Independent 

Review Panel’s interviewees indicated that this target is challenging for all three fuel cell types. 

Rather than a single value, the Panel estimated an experience based range of “achievable” cost 

values for each technology given in Table 1. 

Net end-user installed cost will be higher than the factory cost target. If any site engineering and 

site preparation is required, these costs should be accounted for in the overall economic analysis. 

For 1 kW units, both internal and external installations have been used; external installations 

were used in Japan to minimize regulatory issues. Larger fuel cell units, say 10 kW, could be 

skid-mounted, requiring minimal work at the site. Some assembly cost should be assumed for 

skid mounting at the manufacturing plant. Installation costs in the United States have been very 

high for small numbers of units; however, this is believed to be an infancy issue that will be 

resolved as regulatory bodies become more familiar with fuel cell technology and as volume 

grows. 

The return on investment (ROI) for the end user will depend on fuel cell usage, spark-spread, 

electric versus thermal control, over- or under-sizing of the unit with respect to site demand, 

grid-connect versus grid-independence, thermal cycling profile and frequency, stack replacement 

frequency and cost, frequency of repair, and down time. A separate study is needed to quantify 

the cost related to fuel cell product capabilities. The 1–3 kW systems will be more expensive 

($/kW) than 10 kW systems. 
20 

8.3.2 Technical Targets

Technical targets for the three fuel cell systems were deemed feasible by the interviewees, 

although some targets were characterized as “aggressive.” Several interviewees stated that SOFC 

systems can easily exceed the DOE 2020 electrical efficiency target of 45%, but this may be at a 

small sacrifice to CHP efficiency. The SOFC system may require longer start-up time than the 

HT-PEM or LT-PEM fuel cell systems. One interviewee stated that start-up time was irrelevant 

for residential applications, especially where grid connection was included. 

8.3.3 Manufacturing Status 

Manufacturing capacity and experience reflect the level of technology and reliability of the fuel 

cell power plant. Significant global manufacturing capacity exists for LT-PEM fuel cell systems.

The existing capacity for HT-PEM and SOFC power plants is not so mature. 

Factory cost of a fuel cell system is governed by capacity factor and production volume. The 

manufacturer designs its manufacturing plant based on anticipated demand and demand growth. 

Manufacturing efficiencies that come with greater levels of automation cannot be effectively 

used at low production rates. When the sales volume is initially ramping up, the manufacturer’s

unit cost is higher than the projected cost. 

8.3.4 External Factors

Sometimes external factors such as utility support and interest, national and state government 

policies, and strength of industry players influence the technical progress and future 

implementation of a fuel cell system. If the utility companies are willing to accommodate new 

technology on their grid and are willing to back up the power interruptions, infancy-related fuel 

cell failures will become less significant. A utility company may also own the stationary fuel cell

unit and simply charge the end user for electricity and heat usage. The latter approach would 

make the financing and maintenance of the unit an easier task. National and state government 

policies have helped fuel cell development in Japan. Environmental-related initiatives have 

helped the growth of installed fuel cell capacity in Europe and California. All three fuel cell 

systems have benefitted from the support of the U.S. Department of Energy and Department of 

Defense. 

Stakeholders commented that the technology, as well as developers and suppliers, will benefit if 

a strong industry player participates in the development process. On the other hand, the 

technology development decelerates if a large industrial player drops out.

9 Supplier Network

Fuel cell stack components as well as BOP components can be procured from suppliers outside 

the fuel cell company to minimize a developer’s investment in working capital and 

manufacturing infrastructure. The manufacturer can then focus attention on the development and 

commercialization of proprietary fuel cell technology. For the LT-PEM and HT-PEM fuel cell 

systems, cell component supplier networks were encouraged by the fuel cell system 

manufacturers and integrators. As a result, several companies have established themselves as 

suppliers of catalysts, membranes, MEAs, and bipolar plates. On the other hand, the SOFC and 

MCFC system manufacturers have vertically integrated the manufacture of cell components for 

the assembly of these high temperature fuel cell systems. 
21 

Based on fuel cell system type, the cell stack generally includes the following components: 

• Electrolyte layer (SOFC systems) or membrane layer (LT-PEM and HT-PEM fuel cell 

systems)

• Anode and cathode layers 

• Gas diffusion layers (GDL) for some systems including a microporous layer (LT-PEM 

and HT-PEM fuel cell systems)

• Gas flow and current collection layers with specific geometry: bipolar plates (LT-PEM 

and HT-PEM fuel cell systems) or interconnects (SOFC systems) 

• Gas seals, gas manifolds, and stacking hardware. 

The supplier network is the source of BOP components, or subsystems other than the stack itself, 

and includes: 

• Fuel clean-up and fuel processing to extract H2 from pipeline natural gas 

• Water treatment and water/steam management

• Air supply subsystem, air blower, and heat exchangers 

• Power conditioning system (PCS). 

Other subsystems and components manufactured by the supplier network include: 

• Controls, sensors, electric grid interface, and heat recovery system. 

 

BOP components can easily make up 50% or more of the fuel cell system cost. Sometimes their 

availability is unreliable. As such, a mature supplier network is important for overall cost 

reduction. 

9.1 Status of Supplier Network 

The principal fuel cell manufacturers often keep their fuel cell design proprietary and tend to 

keep the manufacturing of fuel cell and stack components under their direct control. This 

approach is often slow and too costly. On the other hand, the fuel cell manufacturers are not 

experts in BOP components, and therefore they need industrial vendors to design, develop, and 

manufacture these components to their specifications. The cost to do this depends on such factors 

as total volume of the order and commonality of components. Using commercial suppliers is 

therefore a pathway to overall system cost reduction. 

Cell components for SOFC and HT-PEM systems are presently available only in small 

quantities. The supply network for cell components is more developed for LT-PEM. Bipolar 

plate design and stack hardware are generally considered proprietary and are procured on a 

special order basis. In many cases, a completely assembled stack is available for system 

integrators. BOP subsystem components that are made to provide specified output are produced a 

few systems at a time and are being further developed. PCS’ are considered by most 
22 

stakeholders as “very expensive,” even though similar systems are available in the wind and 

solar industries. Therefore, further work on PCS would be welcome. The development effort on 

other subsystems and components has been limited. Section 9.2 summarizes specific feedback 

from stakeholders in regard to the priority aspects of supplier network development. 

9.2 Establishing a Mature Supplier Network

Stakeholders suggested the following strategies and actions as high priority: 

• Involve suppliers from the design phase through the development and manufacturing 

stages. Form an academia, industry, and supplier collaboration for cost-effective 

development and commercialization of specific components.

• For sustained involvement of the supplier and for low-cost components, DOE should 

consider facilitating orders with large volume and density. (For example, 1–10 kW units 

may require volume orders of 1,000 to 10,000 systems per year.) It should be noted that 

suppliers need to earn profits across all scales of manufacture if they are to survive 

financially. This comment was made by many of the stakeholders. 

• To create large-volume orders for an individual component, standards and specifications 

should be established. Key components are the power conditioning system, fuel 

processor, high efficiency blower, and air handling systems. Stakeholders recommended 

that DOE should participate proactively in establishing standards and specifications. The 

Japanese government example was often mentioned as a model of successful 

development of suppliers. The Japanese government actively engaged the suppliers, 

helped develop standards and specifications, and supported installations of a large 

number of 1 kW systems. DOE should formulate a long term (5-year) plan for research 

and development, scale-up, and field testing. To initially generate large order volume, the 

fuel cell units could be installed at national laboratories and government buildings. 

• The selected supplier should have adequate quality control systems and resources for 

large-volume manufacturing. If these requirements are not met, the supplier may not be 

successful or reliability may suffer.

• Additional strategies may include the use of commercially available parts for existing 

product lines. Manufacturers may find similar components in the automobile, aerospace, 

solar, and wind industries. Components from other power generation technologies may 

also be more cost effective. Offshore procurement of materials and parts as well as 

offshore manufacturing should be considered. 

 

10 Recommendations

The following recommendations were arrived at using a combination of feedback and 

interactions with DOE and NREL staff, interviews with key stakeholders and experts in each of 

the three key technology areas, as listed in Appendix B, and the Independent Review Panel’s

significant industry experience. 

Cost and Technical Targets
23 

• The factory cost definition should be revisited to provide a clearer position on which 

components are included and which are excluded. This definition should take into 

account the fact that some technologies require different components, especially those 

related to natural gas reforming. Key technical criteria should be specified separately for 

each fuel cell technology to reflect the inherent differences in maturity, design, and 

operational strategy. 

• Mean Time Between Forced Outages (MTBFO) should be adopted as a more accurate 

and meaningful measure of system availability. For example, a MTBFO of 2,920 h 

represents a 99% availability based on a yearly scale and would clearly state the time 

period between interruptions.

• Factory cost and certain technical requirements (e.g., start-up time) do not scale linearly 

with power level. As such, it may be useful to split the targets into two power ranges, to 

be defined with the assistance of a more detailed market study. 

Areas for Further Development

• A rigorous, bottom-up, manufactured cost evaluation for each technology is critical to 

ascertain investment focus in areas that will provide the earliest and highest returns.

• Technology and supplier development support directed toward power conditioning, air 

management, and desulfurization subsystems will bring value to all fuel cell 

technologies. 

• There is a direct link between electrical efficiency and thermal efficiency. Given this

linkage, we recommend a market study be done to clarify the optimum balance between 

electrical and thermal efficiency from an end-user perspective.

• A more detailed analysis of the required operational lifetime, including how it can be 

most cost-effectively achieved, would be beneficial, especially for the 2020 target of 

60,000 h. 

• Early investments in manufacturing process optimization, quality control, codes and 

standards development, and service and maintenance strategies will help drive cost 

reduction and customer acceptance.

Path to Commercialization

• Government support programs, such as direct rebates that reduce the high cost of capital, 

feed-in tariffs and credits for off-grid electricity generation, or market transformation 

programs that purchase stationary fuel cell systems, should be considered as positive 

methods to accelerate volume production, reduce cost, and increase commercialization of 

stationary CHP fuel cell systems.

• Partnerships should be fostered between utility companies and fuel cell developers to

encourage the development and deployment of grid-connected products. Coupled with 
24 

incentives for end-user sale of surplus electricity back to the grid, these efforts will 

provide a greater value proposition for fuel cell adoption.

• To reflect the differing levels of maturity and to facilitate further development in meeting 

commercialization targets, a different approach will have to be pursued for each fuel cell 

technology, especially for the stack components. Technology and components from other 

applications can be leveraged; e.g., PAFC materials are likely viable for use in HT-PEM 

fuel cell systems.

General Recommendations

• Broadening the focus beyond residential cogeneration, the most cost-sensitive 

application, will provide opportunities for early markets that are less cost sensitive while 

assisting in the transition to this higher-volume application.

• Supporting activities that help grow effective supplier networks from raw materials to 

final systems and encouraging supplier involvement and cooperation in the early design 

phase of a new system can reduce product development cost and cycle times.

• Defining a “cost-of-use metric,” such as $/kWh, that would take into account incentives 

like feed-in tariffs associated with grid connection and avoidance of grid electricity use 

could help offset end-user concerns regarding initial high capital cost and payback.

11 References 

1. U.S. Department of Energy. “DOE Releases Preliminary Fuel Cell Cost and Technical 

Targets for Combined Heat and Power and Auxiliary Power.” Washington, DC: U.S. 

Department of Energy; November 17, 2009. 

http://www1.eere.energy.gov/hydrogenandfuelcells/news_detail.html?news_id=15626. 

2. Hisao, W. “Commercialization of Residential Fuel Cell Systems at Tokyo Gas.” 

Presented at the 20th World Energy Congress, Rome, Italy, 2007. 

http://www.worldenergy.org/documents/p001503.pdf. 

3. 2009 SECA/Fuel Cells Accomplishments Summary. Pittsburgh, PA: U.S. Department of 

Energy National Energy Technology Laboratory.

http://www.netl.doe.gov/technologies/coalpower/fuelcells/publications/SECA_FC_Acco

mp_Summary_2009.pdf. 

4. Fuel Cell Today. “Semi-Annual Legislation Review: April 2010.” Fuel Cell Today Web 

site; July 22, 2010. Available at http://www.fuelcelltoday.com/media/pdf/surveys/2010-

April-Half-Yearly-Legislation-Review.pdf. 

5. Adapted from DOE/EERE fuel cell comparison chart: U.S. Department of Energy, DOE 

Hydrogen Program, “Comparison of Fuel Cell Technologies.” Washington, DC: U.S. 

Department of Energy; December 2008.

http://www1.eere.energy.gov/hydrogenandfuelcells/fuelcells/pdfs/fc_comparison_chart.p

df. 
25 

12 Acknowledgements

The authors would like to acknowledge the following individuals for providing useful 

information related to this independent review: 

• Mark Ruth, NREL, and Dimitrios Papageorgopoulos, DOE/EERE, for providing useful 

contractual and technical information.

• Travis Shultz, acting SECA Technology Manager, National Energy Technology 

Laboratory, DOE-Fossil Energy, for providing status of the SOFC research and 

development programs funded by DOE. 

• Jennifer Kurtz, NREL, for overview of stationary fuel cell durability. 

• Darlene M. Steward, NREL, for fuel cell power model for CHP and CHHP economics 

and performance analysis.

• Kathyayani Mahadevan, Battelle, for evaluation of the market opportunity and technoeconomic potential of fuel cell micro-CHP products. 
26 

Appendix A. Independent Review Team

The National Renewable Energy Laboratory identified and contracted with the following four 

fuel cell industry experts, who have combined experience of more than 60 years in R&D and 

manufacturing and more than 110 years specifically in fuel cells. 

Dr. Hansraj C. Maru is internationally recognized as an expert in fuel cell technology. After 

earning his bachelor’s degree in chemical engineering from the Indian Institute of Technology, 

he earned both his master’s degree (’70) and his Ph.D. (’75) in chemical engineering at Illinois 

Institute of Technology. He is best known for his pioneering contributions in developing and 

commercially introducing ultra-clean, high-efficiency, stationary fuel cell power plants using 

fuel cells (Direct Fuel Cells) that create virtually no air pollution. Maru has overseen the growth 

of these power plants, which are currently installed in many countries and on the verge of largescale deployment. Dr. Maru has total of 40 years of experience in fuel cells, including 29 years at 

FuelCell Energy (FCE). FCE, which produces Direct Fuel Cells, began with only three

employees in 1970 and currently consists of 500 employees. Maru, who has a talent for solving 

multidisciplinary technical problems in the energy industry, has been an integral part of the 

company’s immense growth, holding a number of technical and management positions in the 29 

years since joining the firm in 1977. Over the years, he has served as vice president of research 

and development, executive vice president, and chief technology officer of FuelCell Energy, Inc. 

In addition to carbonate fuel cells, Dr. Maru guided research in phosphoric acid, polymeric 

electrolyte membrane (PEM), and solid oxide fuel cells (SOFC). Dr. Maru retired as CTO, but he 

continues to serve as a consultant in fuel cells. Prior to FCE (previously known as Energy 

Research Corporation), Dr. Maru worked for 8 years at Institute of Gas Technology in the fields 

of fuel cells, hydrogen, and energy storage. Maru holds 13 patents, and he has authored more 

than 160 publications. He has edited four symposia volumes and contributed chapters in two 

books. Maru’s work has been recognized with the 2004 F.T. Bacon Medal Award, which is 

given to those exhibiting leadership and accomplishment in fuel cell technology. He was also 

honored with the 2003 Mass High Tech All Star Award for his contributions to fuel cell 

technology. Dr. Maru was awarded IIT Alumni Professional Achievement Award in 2008. He 

was awarded Electrochemical Society’s New Electrochemical Technology (NET) Award and 

Fuel Cell Seminar Award in 2009. 

Dr. Subhash C. Singhal is a Battelle Fellow and Director, Fuel Cells at Pacific Northwest 

National Laboratory (PNNL). He obtained a Ph.D. in Materials Science & Engineering from the

University of Pennsylvania and an M.B.A. from the University of Pittsburgh. Dr. Singhal joined 

PNNL in April 2000 after having worked at Siemens Power Generation (formerly Westinghouse 

Electric Corporation) for more than 29 years. At PNNL, Dr. Singhal provides senior technical, 

managerial, and commercialization leadership to the laboratory’s extensive fuel cell and clean 

energy programs. At Siemens/Westinghouse, he conducted and/or managed major research, 

development, and demonstration programs in the field of advanced materials for various energy 

conversion systems including steam and gas turbines, coal gasification, and fuel cells. From 1984 

to 2000, he was manager of Fuel Cell Technology there and was responsible for the development 

of high temperature solid oxide fuel cells (SOFCs) for stationary power generation. In this role, 

he led an internationally recognized group in the SOFC technology and brought this technology 

from a few-watt laboratory curiosity to fully-integrated 200-kW size power generation systems. 

He has authored more than 85 scientific publications, edited 14 books, received 13 patents, and 
27 

given almost 300 plenary, keynote, and other invited presentations worldwide. Dr. Singhal is a 

member of the U.S. National Academy of Engineering and the Washington State Academy of 

Sciences; a Fellow of four professional societies (American Ceramic Society, The 

Electrochemical Society, ASM International, and American Association for the Advancement of 

Science); and a senior member of the Mineral, Metals & Materials Society (TMS). He served on 

the Electrochemical Society’s Board of Directors during 1992–1994, received its Outstanding 

Achievement Award in High Temperature Materials in 1994, and continues to serve as the 

Chairman of its International Symposium on Solid Oxide Fuel Cells, held biennially since 1989. 

He served as President of the International Society for Solid State Ionics during 2003–2005. He 

received the American Ceramic Society’s Edward Orton Jr. Memorial Award in 2001; an Invited 

Professorship Award from the Japan Ministry of Science, Education and Culture in 2002; the 

Christian Friedrich Schoenbein Gold Medal from the European Fuel Cell Forum in 2006; the 

Fuel Cell Seminar Award for outstanding leadership and innovation in the promotion and 

advancement of fuel cell technology in 2007; and the prestigious Grove Medal in 2008 for 

sustained advances in fuel cell technology. 

Dr. Charles Stone, sole proprietor of EON Consultants Ltd., specializes in fuel cell technologies 

and provides strategic business and technical consulting services in various fields of green 

energy. Dr. Stone began his career with Ballard Power Systems in 1990 as a research scientist 

after completing his Ph.D. at the University of British Columbia. He took on increasingly senior 

roles at Ballard, becoming vice president of research and development in 2002. In this role, Dr. 

Stone had overall responsibility for fuel cell stack technology development, in addition to 

executive responsibility for intellectual property. During his tenure at Ballard, he developed 

significant expertise in establishing and managing key strategic supplier and end-user partner 

relationships. Dr. Stone left Ballard in March 2007 to start his own consulting firm in the area of 

green energy. Dr. Stone completed a double M.B.A with the University of California at Los 

Angeles and the National University of Singapore in 2008. In these studies, he received the C.H. 

Wee Gold Medal of accomplishment as the top ranking student in his graduating year. He has 

advised various government and private entities on technology and product development 

strategy, supplier and end-user development activities, and technology and product portfolio 

management. 

Mr. Douglas Wheeler, sole proprietor of DJW TECHNOLOGY, LLC, provides complete 

services in the areas of manufacturing, cost analysis, and market analysis for fuel cell systems, 

hydrogen production technology, and hydrogen purification technology. Mr. Wheeler was 

manager of technology and government contracts at UTC Fuel Cells (now UTC Power) for 18 

years. At UTC Fuel Cells, he managed the Advanced Technology team during UTC Fuel Cells’ 

transition from phosphoric acid fuel cells to PEM fuel cells. DJW TECHNOLOGY’s expertise in 

proton exchange membrane fuel cells, phosphoric acid fuel cells, and reforming of hydrocarbons 

to fuel cell grade hydrogen provides the basis for contracts with the U.S. Department of Energy 

through the National Renewable Energy Laboratory, the U.S. Department of Defense, the 

University of Hawaii, and private industry. Research and development programs support the 

Office of Naval Research and the Naval Research Laboratory. DJW TECHNOLOGY’s technical 

expertise in stationary, portable, and transportation fuel cells is complemented by expertise in 

renewable energy and energy efficiency. Management experience and communications skills 

allow DJW TECHNOLOGY to provide a full range of services. 
28 

Appendix B. List of Stakeholders Contacted

Companies

• Acumentrics Corporation 

• Advent Technologies 

• Ballard Power Systems

• BASF

• Baxi Innotech 

• Ceres Power

• Engineer Research and Development Center/Construction Engineering Research 

Laboratory (ERDC/CERL)

• Ceramic Fuel Cells Limited (CFCL) 

• ClearEdge Power

• Delphi Corporation 

• e4tech

• FuelCell Energy

• Fuji Electric Group 

• Hydrogenics Corporation 

• IdaTech

• Intelligent Energy

• Kyocera Ceramics

• Logan Energy 

• Nuvera Fuel Cells

• Plug Power 

• Samsung SDI

• Siemens Stationary Fuel Cell Systems

• Tokyo Gas Company 

• Topsoe Fuel Cells

• Toshiba America Electronic Components, Inc. (TAEC)

• UTC Power

• Versa Power Systems

• Zentrum für BrennstoffzellenTechnik (ZBT GmbH) 
29 

Organizations

• DOE-Fossil Energy Solid State Energy Conversion Alliance (SECA)

• Battelle

National Laboratories

• National Renewable Energy Laboratory (NREL)