Marine Applications for Fuel Cell Technology

February 1986

NTIS order #PB86-183597

Recommended Citation:U.S. Congress, Office of Technology Assessment, Marine Applications for Fuel CellTechnology—A Technical Memorandum, OTA-TM-O-37 (Washington, DC: U.S. Gov-ernment Printing Office, February 1986).

Library of Congress Catalog Card Number 85-600642

For sale by the Superintendent of DocumentsU.S. Government Printing Office, Washington, DC 20402

Foreword

Fuel cell technology is one of the most promising of the new electric power tech-nologies currently undergoing development. Fuel cell power systems have attracted at-tention because of their potential for high efficiency, low emissions, flexible use of fuels,and quietness. The Federal Government and the private sector have been funding fuelcell R&D for more than 20 years. The state-of-the-art has advanced to the point thatfuel cell manufacturers hope to begin marketing fuel cells in just a few years. Full-scaledemonstration plants are currently being designed.

Much of the available R&D funding has been targeted for phosphoric acid fuel cellresearch, and this is the type of fuel cell technology most nearly ready for commerciali-zation. However, other types of fuel cells are also undergoing development, and thesehold promise for even greater efficiency of power production. The electric and gas util-ity industries have been most interested in using fuel cell technologies. The electric util-ity industry hopes to be able to use fuel cells for peak-shaving, load-following, and,eventually, baseload powerplants. The gas industry, on the other hand, would like toemploy fuel cells to generate onsite electricity and heat for residential, commercial, andsmall industrial applications.

To date, almost no attention has been given to the potential marine applicationsfor fuel cell technologies. Nevertheless, some of the benefits that fuel cells may offerto the utility industry may also apply to some marine uses. Recognizing this possibil-ity, the Senate Committee on Commerce, Science, and Transportation asked OTA’sOceans and Environment Program to evaluate the likely benefits and problems of usingfuel cells for propulsion and auxiliary power at sea. As part of its investigation, OTAheld a 1 day workshop on Sept. 5, 1985, inviting fuel cell manufacturers and partici-pants from the Department of Energy, Maritime Administration, Navy, Army, and in-dustry research organizations. OTA found that fuel cells may offer advantages for somemarine uses, including applications requiring quiet operations, applications where throttlesettings are constantly changed, and for small submarines. However, the marine marketis not in itself large enough to drive fuel cell technology developments. Fuel cells arenot expected to penetrate marine markets until they become firmly established in thecommercial utility sector.

JOHN H. GIBBONSDirector

.,.///

OTA Marine Applications for Fuel Cell Technology Workshop, Sept. 5, 1985

Gary BahamBaham Corp.

Dick L. BloomquistDavid Taylor Naval Ship R&D Center

Frank CritelliMaritime Administration

Lloyd FinkMaritime Administration

Sigurd FolstadInternational Fuel Cells Corp.

Don GlennEnergy Research Corp.

Douglas JewellU.S. Department of EnergyMorgantown Energy Technology Center

Johann JoebstlU.S. Army Belvoir R&D Center

Art KaufmanEngelhard Corp.

William KummArctic Energies Ltd.

Shirley MoralesLegislative AssistantCongresswoman Helen Bentley

James E. NivinAmerican Commercial Barge Lines

Ted StanfordU.S. Navy, NAVSEA

Percival WilsonConsultant

Joe WoenerDavid Taylor Naval Ship R&D Center

Richard R. WoodsGas Research Institute

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OTA Marine Applications for Fuel Cell Technology Project Staff

John Andelin, Assistant Director, OTAScience, Information, and Natural Resources Division

Robert W. Niblock, Oceans and Environment Program Manager

Project Staff

Peter A. Johnson, Project Director

William E. Westermeyer, Policy Ahalyst

Administrative Staff

Kathleen A. Beil Jacquelynne R. Mulder

Contractor

Denzil Pauli

Other OTA Contributors

Peter D. Blair Thomas E. Bull

Contents

Page

OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Some Options for the Federal Government . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

PART ONE: FUEL CELL TECHNOLOGY: DESCRIPTION AND STATUS . . . . . . . . . 4Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Description of Phosphoric Acid Fuel Cell Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Other Types of Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Advantages and Disadvantages of Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Fuel Cell Development Programs: Current and Future Emphasis . . . . . . . . . . . . . . . . . 12Cost Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

PART TWO: MARINE USES OF FUEL CELLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Required Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20Potential Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Other Transportation Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29Some Options for the Federal Government . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

List of Tables

Table No. Page

1.

2.3.4.

Cost and Performance Comparisons for Land-Based Electrical Powerplants -

That Use Technologies Similar to Marine Propulsion Units . . . . . . . . . . . . . . . . . . . . . 18Potential Fuels for Use in Marine Fuel Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Possible Marine Powerplants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Push-Tow Boat Powerplant Comparisons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

List of Figures

Figure No. Page

l. Diagram of Major Components of a Fuel Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52. Schematic Representation of How a Fuel Cell Works . . . . . . . . . . . . . . . . . . . . . . . . . . 63. National Fuel Cell Coordinating Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134, Participants in DOE’s Fuel Cell Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

OVERVIEW

A fuel cell is a device for directly convertingthe chemical energy of a fuel, such as hydrogenor a hydrogen-rich gas, and an oxidant into elec-trical energy. It also produces heat, which in someapplications may be a useful byproduct. Small,specialized fuel cells were first successfully usedin the Gemini space program. Recent technologi-cal advances with other types of fuel cells andsmall-scale demonstrations have encouraged thedevelopment of fuel cell technology for commer-cial land-based use.

The private sector has been conducting fuel cellresearch in the United States for more than 20years. Federal funding also began more than 20years ago with the National Aeronautics andSpace Administration’s (NASA) program. TheDepartment of Energy (DOE) began funding fuelcell research in 1976. Although fuel cells are stillunder development for commercial use, these ef-forts are beginning to bear fruit. Several types offuel cells are being investigated, but phosphoricacid fuel cells are nearly ready for commercial usein sizes ranging from a few kilowatts to a few meg-awatts.

The most promising near-term uses for fuel celltechnology are for applications in the electric andgas utility industries. However, fuel cells have alsobeen considered for automobile, train, and ma-rine applications. The use of non-petroleum-fueledfuel cells in transportation is most desirable fromthe standpoint of oil displacement, but applica-tion of fuel cell technology to the transportationfield in general and to the marine transportationarea in particular is still in the early exploratorystage.

For marine applications, it has been suggestedthat fuel cells be employed to provide propulsionor auxiliary power for cruise ships, powered barges,ferry boats, offshore supply boats, push-towboats, oceangoing tugs, submersibles, and evensubmarine tankers. Fuel cells have also been sug-gested for use as power sources for offshore oilplatforms, for underwater facilities, and for re-frigerated containers on containerships. Some ofthese possible applications may be technically fea-sible and cost-effective in a decade or so. Otherpotential applications (e.g., fuel-cell-powered sub-

marine tankers) may take much longer to develop.In any case, successful development for commer-cial needs will depend on economic factors inaddition to technical feasibility; likewise, success-ful development for military uses will also dependon mission requirements.

If fuel cells prove technically and economicallyfeasible, they could conceivably replace manyelectrical generating systems in use today in amyriad of applications, from small transportationunits to large power stations. Their advantagesover existing systems could include higher efficien-cies, lower cost, reduced emissions, and fewermaintenance problems. Many of the benefits fuelcells could provide to the utility industry couldalso apply in the marine field. Of special interestis the potential of fuel cells for high efficiency,since this efficiency may translate into fuel costsavings. Moreover, fuel cell efficiency is relativelyconstant over a broad range of power settings.Such a characteristic suggests that fuel cells mightbe efficiently employed in ships that frequentlyvary power demand—e. g., towboats, ferries, oroffshore supply boats. Capability of using a va-riety of fuels is another potential advantage. Inaddition to the potential for providing main pro-pulsion, fuel cells could also supply auxiliarypower and other heat needs.

Several other characteristics of fuel cells couldprovide benefits for specific applications. The factthat fuel cell systems are of modular design en-ables flexibility in the arrangement of plant com-ponents and could lead to a more cost-effectivelayout of power and cargo spaces and of basicship structure. However, overall space and vol-ume requirements of the fuel cell system and fuelwill probably be greater than for present systems.As with other electrical powerplants, the maneu-vering problems of ships and tugs might be miti-gated by the advantage fuel cells provide in en-abling electric power to be quickly switched tovarious locations to reverse main propellers or toactivate side thrust propellers or water jets. Fuelcells have few moving parts, suggesting minimalmanning requirements. Since they produce littlenoise, they may have possible uses on anti-sub-marine warfare ships and seismic survey vessels.

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Finally, fuel cells offer greater endurance than bat-teries for some types of submerged operation.

Despite these potential benefits, commercialmarine applications for fuel cells are a long wayoff. None of the advantages stated above havebeen demonstrated for marine fuel cells, and anumber of present problems constrain private de-velopment today. The marine market is not in it-self large enough to drive fuel cell technology de-velopments. Hence, it is not expected that fuelcells will penetrate marine markets before they be-come firmly established in the commercial util-ity sector. Even then, fuel cell systems will havea difficult time capturing a large share of the mar-ket, given competition from other systems. Ship-builders will need to use and adapt products de-veloped first either for the utility industry or forthe Department of Defense (DOD). Moreover,potential cost advantages to onsite shore users dueto large-scale production may not accrue to themarine industry.

Given these constraints, Federal assistance willbe required if the Federal Government wishes toaccelerate the development of fuel cells for thecommercial marine sector. Though OTA has notevaluated the rationale for such Federal assistance,many reasons to do so have been advanced. Forexample, the Federal Government may wish tostimulate commercial development of marine fuelcells in order to reduce dependence on traditionalfuels (e.g., diesel oil), to help ensure the transi-tion to alternative fuels as traditional fuels becomescarce, to help reduce pollutant emissions, or forother reasons. It has also been suggested that ifthe United States does not push development offuel cells, as the Japanese are doing, a develop-ing market in which the United States now hasa technical lead will be lost.

Fuel cell technology may offer benefits to themilitary as well. However, development of fuelcell technology for military purposes can best beconsidered separate from development for com-mercial purposes. If fuel cells prove to be the besttechnology for specific military applications, costconstraints that would slow development in thecommercial sector would be a less limiting factor.

Some Options for theFederal Government

The outlook for using fuel cells in the electricand gas utility industry appears promising. TheFederal Government has supported private sec-tor research and development (R&D) efforts sincethe 1960s. Continued Federal support of fuel celldevelopment programs is probably necessary toadvance the introduction of fuel cell technology

into the land-based utility industry.

The use of fuel cells in the marine industry inthe next 15 to 20 years is far less certain. Whenand if the commercial maritime industry decidesthat fuel cell power systems would provide sig-nificant cost and/or other advantages over com-peting power systems, these fuel cell systems mustbe adapted to the unique demands of the marineenvironment. Very little R&D on fuel cells for ma-rine applications is currently underway inside oroutside the government. Since the R&D programfor land-based applications is so large in compar-ison, some believe that the proper course for themarine industry is just to monitor closely thatR&D and select developments and applicationsas they may occur in the future. Others believethat unique marine requirements warrant special-ized R&D efforts.

Specific research and development could besupported by the Federal Government and/or in-dustry to improve the potential of fuel cells in themarine market. For example, the near-term useof fuel cells in the marine industry could be stim-ulated by developing technology capable of re-forming diesel oil. Other research that could beundertaken includes: laboratory testing, followedby shipboard analysis and testing, of fuel cell com-ponents to determine their suitability and/or vul-nerability to the marine environment; basic elec-trochemical studies to improve catalysts andelectrolytes that would not be contaminated byfuel processed from fuel oil; and accelerated in-vestigation of molten carbonate fuel cells and ofthe vulnerability of this type of fuel cell to the ma-rine environment. The Federal Government’s in-vestment in molten carbonate technology could

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concentrate on those developments needed to sup-port a demonstration of this fuel cell’s higher effi-ciency and fuel flexibility. The private sector couldfocus on the technology and processes needed tomanufacture these fuel cells at a cost competitivewith conventional power generators.

The Maritime Administration, and perhapsother agencies within the Department of Trans-portation, and DOE might be able to offer someassistance for applications more directly relevantfor the commercial transportation sector. For in-stance, funding could be provided to demonstrateand evaluate use of a fuel cell system on a com-mercial ship or locomotive. One suggestion is thatfuture fuel cell research for heavy-duty transpor-tation applications focus on developing the moreefficient molten carbonate fuel cells. Once a small(i.e., 50 kilowatts (kW)) molten carbonate sys-tem has been demonstrated, these agencies couldcoordinate a demonstration of a 2 to 4 megawatt(MW) powerplant for the heavy-duty transpor-tation sector. Different types of incentives to pri-vate industry might also be used, such as tax ben-efits for those who use non-petroleum-based fuelsor accelerated depreciation.

The Federal Government may also wish to en-courage the Navy, Army, Air Force, and CoastGuard to become more involved in developingfuel cells for their mission requirements, OTA’sanalysis indicates potential benefits of marine fuelcell use in naval applications, and suggests thatmore in-depth analysis of the potential applica-

bility of fuel cell technologies for Navy missionsis needed.

The Navy is currently monitoring fuel cell de-velopments, but it may be useful for the Navyto consider supporting specialized research intomarine fuel cell development as well. At present,for example, very little work has been done ondeveloping fuel cells for “quiet” ship operationaboard certain vessels where noise emissions fromconventional engines are a major problem. If fuelcells could match these and other unique Navymissions, then naval fuel cell research, independ-ent of private sector efforts, may be justified.

Recognizing that research funds are limited andmust be carefully targeted to the most productiveavenues of research, it may be best to begin byencouraging the military to develop small fuel cellsystems for auxiliary power on naval surfaceships, As experience is gained, larger fuel cells (onthe order of a megawatt) might be used for navaland Coast Guard auxiliary power. Finally, be-yond 2000, the Navy or Coast Guard could beencouraged to focus on developing larger fuel cellpowerplants for primary propulsion power. TheNavy and Coast Guard have different missionsthan the civilian sector and some applications de-veloped by them may not be directly useful forthe private sector. On the other hand, some ap-plications first developed for military purposesmight stimulate development of applications forcommercial use.

PART ONE: FUEL CELL TECHNOLOGY: DESCRIPTION AND STATUS

Introduction

A fuel cell converts the chemical energy of afuel, such as hydrogen or a hydrogen-rich gas,and an oxidant into electrical energy. It also pro-duces heat, which in some applications may bea useful byproduct. Invented and demonstratedby Sir William Grove, the principles governingfuel cell operation have been known for about 150years. Fuel cells were first successfully used in theGemini space program. However, these solid pol-ymer electrolyte fuel cells were far too expensivefor commercial land use. Recent technological ad-vances with other types of fuel cells and small-scale (40 kW) demonstrations have encouragedthe development of fuel cell technology for com-mercial use. Increased efficiency and low emis-sions are important advantages that fuel cells areexpected to have over most conventional power-plants.

The private sector has been conducting fuel cellresearch in the United States for more than 20years. Federal funding also began more than 20years ago with NASA’s program. DOE beganfunding fuel cell research in 1976. These effortsare beginning to bear fruit. Several types of fuelcells are being investigated, but phosphoric acidfuel cells (PAFC) are most nearly ready for com-mercial use.

The PAFC development effort has proceededprimarily along two tracks. The gas industry, withthe assistance of DOE, has installed and is test-ing 46 natural gas fueled 40 kW PAFC demon-stration units at various locations (including fourat military installations) around the country.These are designed to provide onsite electricityand heat for residential, commercial, and smallindustrial applications. The electric utility indus-try, on the other hand, is interested in develop-ing fuel cells for use at central stations as peak-shaving, load-following, and—eventually—base-load powerplants. To date, two 4.8 MW demon-stration plants have been built, one in New YorkCity and the other in Japan. Much was learnedfrom the New York facility, but it was plaguedby numerous startup problems and was shutdown before it began generating electricity. TheJapanese prototype 4.8 MW PAFC facility, which

also uses U.S. technology, has been tested and re-mains in operation. U.S. companies are currentlydesigning 7.5 and 11 MW commercial demonstra-tion plants.1

Fuel cells have been considered for automobile,train, and marine applications. However, appli-cation of fuel cell technology to the transporta-tion field in general and to the marine transpor-tation area in particular is still in the earlyexploratory stage. The future use of nonpetrole-um-fueled fuel cells in transportation is mostdesirable from the standpoint of oil displacement,but transportation applications are also a diffi-cult target market. One limitation could be theneed to set up a new fuel distribution network forfuel cell fuels. A unique problem related to trans-portation applications is the need for quick startupand rapid, large power variations during oper-ations. 2

Two bills regarding fuel cells have recently beenintroduced in the U.S. Senate. The effect of S.1687, the Fuel Cells Energy Utilization Act of1985, would be to promote development of fuelcell technology. S. 1686, the Renewable Ener-gy/Fuel Cell Systems Integration Act of 1985,seeks to promote research on technologies thatwill enable fuel cells to use nontraditional fuels.

Description of Phosphoric AcidFuel Cell Systems

Fuel cell systems are composed of three basicelements, the heart of which is the fuel cell itself(figure 1). The fuel supply subsystem, usually aprocessor for producing hydrogen gas, and anelectrical converter, for providing electrical powerin a form acceptable to the user, make up the twoother elements. Fuel cell characteristics and per-formance typically vary depending on the mate-

IFor a more detailed discussion of fuel cell applications in the elec-trical utility industry, see U.S. Congress, Office of Technology As-sessment, New Electric Power Technologies: Problems and Prospectsfor the 1990s, OTA-E-246 (Washington, DC: U.S. GovernmentPrinting Office, July 1985).

‘The Los Alamos National Laboratory has conducted studies offuel cells for such transportation applications as locomotives andtugboats. General Motors has also sponsored R&D on fuel cell pow-erplants that could be used in both land and marine vehicles.

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SOURCE National Fuel Cell Coordinatlng Group

rials used for electrodes, electrolytes, and cata-lysts. PAFCs are the most developed of the fuelcell systems currently being considered, but othertypes, such as molten carbonate, solid oxide, alka-line, and solid polymer electrolyte fuel cells (clas-sified by the electrolyte used in the cell) are alsoreceiving research attention.

The Fuel Cell Stack

Fuel cells are composed of two electrodes, acathode and an anode, separated by an electro-lyte (see figure 2). In the typical PAFC, fuel (ahydrogen-rich gas reformed from natural gas oranother fossil fuel) is delivered to the porousanode element. The anode is coated with a cata-lyst, such as platinum, which causes the hydro-gen molecules to dissociate into hydrogen ions andelectrons. The hydrogen ions pass through thephosphoric acid electrolyte to the cathode. A cur-rent is created as the electrons, unable to movethrough the electrolyte, pass instead through aconductor attached to both electrodes. When aload is attached to this circuit, electrical work isaccomplished. At the cathode, oxygen (generallyin the form of air) is introduced. The oxygen com-bines with the hydrogen ions, which have mi-grated from the anode, and with the electrons ar-riving via the external circuit to produce water. 3

‘Arnold P. Fickett, “Fuel-Cell Power Plant s,” Scientific Arnericdn,vol. 239, No, 6, December 1978, p. 70,

The nitrogen and carbon dioxide components ofthe air are discharged. Unlike a battery, a fuel celldoes not have a fixed amount of chemical sup-ply, and thus does not run down. It continues tooperate as long as fuel and oxidant are suppliedto it and an adequate level of electrolyte is main-tained. 4

The individual PAFCs being developed forcommercial use are flat sandwich structures, withsize ranging from about 0.1 to approximately 1square meter. One to two kW are produced persquare meter. The voltage produced by a singlecell is low, between 0.6 and 0.85 volts, after al-lowing for losses within the cell. However, thesesmall voltages add up when cells are connectedin series. A high voltage output is created bystacking the individual cells. A typical 200 kW“stack” of 500 fuel cells would result in about a325 volt output, each cell producing about 400watts of power. Stacks may then be connectedin parallel to provide the desired total power. Thecurrent produced is proportional to the rate atwhich the electrochemical reactions proceed andto the surface area available for the reactions.

‘U.S. Department of Energy and National Aeronautics and SpaceAdministration r Assessment of the Environmental Aspects of theDOE Phosphoric Acid Fuel Cell Program, DOE NASA 12703-3, May1983, p. 3.

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Figure 2.—Schematic Representation of How a Fuel Cell Works

1. Hydrogen gas flows over negativeelectrode (anode).

2. Electrons split away from hydrogen andflow through anode-to external electricload.

3. Hydrogen ions move through electrolyteto cathode. Electrons stream into cathode

4. Hydrogen, electrons, and oxygen combineto form water (steam).

from load. Cathode is bathed with oxygen.

SOURCE Ernest Raia, “Fuel Cells Spark Utllltles’ Interest, ” l+~gh Technology, December 1984

The temperatures at which these reactions oc-cur vary with the type of fuel cell. The choice ofphosphoric acid as the electrolyte in PAFCs de-termines an operating temperature of between1500 and 2000 Celsius. Other types of fuel cellsoperate at much higher temperatures. Below 1500C the phosphoric acid is not a good hydrogen ionconductor. Above 2500 C, the electrode materi-als become unstable. Heat is given off in this elec-trochemical reaction, some of which is used to main-tain the temperature of the electrolyte. However,most of the heat is transported away by air or liq-uid coolants and, if it can be used in the fuel proc-essor and/or for other heating needs, it improvesthe overall conversion efficiency of the fuel cell.

An important characteristic by which fuel cellsare compared with other powerplants is the heatrate. Heat rate refers to the amount of thermalenergy required to produce a unit of electricpower, and is measured in terms of British ther-mal units per kilowatt-hour (Btu/kWh). Presentlyavailable PAFC systems providing alternating cur-rent have heat rates of about 8,500 Btu/kWh, Themost efficient power generator now available, theoil-fired powerplant operating on a combined cy-cle, also requires about 8,500 Btu/kWh. Commer-cialization of fuel cells depends in part on reduc-ing heat rates, thereby improving cell poweroutput and efficiency. Realistic future goals forPAFC heat rates are thought to be about 7,500

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Photo cred(t Engelhard Corp

5 kW Fuel Cell Stack

Btu/kWh. One way to achieve these rates is bydeveloping cells that can run at higher operatingtemperatures and pressures, Another is by usingadvanced “super acids” that are more active elec-trochemically than phosphoric acid. Such acidsmay be able to lower the heat rate to about 7,000Btu/kWh. Phosphoric acid, for example, may inprinciple be substituted directly for phosphoricacid without having to change the design of pres-

ent cells. However, super acids cannot yet be syn-thesized in great quantities, and they remain lab-oratory curiosities. 5

The Fuel Processor

The fuel processor or reformer performs twoimportant functions. One is to convert the stockfuel to a hydrogen-rich gas for use in the fuel cellstacks. The second is to remove impurities, Tominimize contamination of the fuel cell electrodes,sulfur and carbon monoxide are removed by thefuel processor through the use of special desul-furizers and carbon monoxide shifters (the shifterstransform CO to CO2). Water vapor producedby the reforming process is also removed fromthe hydrogen-rich gas prior to its delivery to thefuel cell stack. Fuel processing requires differenttechnology for each stock fuel. Since no poweror heat is available from the fuel cell stack whenthe system is initially started, a separate sourceof power is required to start both the reformerand the stack. This power source must be ableto generate steam for the reformer and to preheatthe stock fuel. Startup times of several hours ormore are required for 40 kW and larger systems,a factor that could affect the use of fuel cells forsome forms of marine transportation.

The Power Conditioner

The power conditioner receives electrical powerfrom the fuel cell stack and converts it to matchthe required output. Fuel cells produce direct cur-rent (DC), and if the application uses DC current,as may be the case for some marine applications,the current may be used as it comes from the fuelcell stack after providing for voltage and powermonitors and controls, and power cutoff devices.If alternating current (AC) is required, an inverteris incorporated into the power conditioner. Thisconversion device is about 90 percent efficientwith present designs. In many cases the cost ofAC motors and the inverter is less expensive thanthe equivalent DC system, and it is therefore likelythat the AC conditioner would be incorporated.

‘Ernest Raia, “Fuel Cells Spark Utilities’ Interest, ” High Techrtol-ogy, December 1984, p. 56,

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Photo credit” Engelhard Corp

25 kW Fuel Cell Stack

The Controller

The fuel cell controller has a number of func-tions. It must control supplemental power dur-ing the startup operations, stack cooling and gasflow during power and hold operations, and fi-nally control the close-down operations. Numer-ous temperature, gas flow, and other sensors and

microprocessors are used by the controller in per-forming its functions.

Other Types of Fuel Cells

Although the PAFC is the most developed andclosest of the various types of fuel cells to becom-ing commercially available, several other prom-ising development approaches are being pursuedby government and private industry. Each of thefuel cell types discussed below requires consider-able technological advances before commerciali-zation, but these other approaches promise to beeven more efficient than PAFCs, as well as pro-vide other benefits. Since each operates at a differ-ent temperature, each has different advantagesand limitations.

Molten Carbonate Fuel Cells (MCFC)

Development of MCFCs is still at a relativelyearly stage. The program is about 5 to 10 yearsbehind the state-of-the-art of phosphoric acid sys-tems. Therefore, MCFCs will probably not becommercial before the late 1990s. However,MCFCs are appealing for several reasons. SinceMCFCs operate at temperatures of from 6000 to7000 C, a catalyst is not needed to speed up thechemical reactions; expensive platinum use canbe eliminated. Moreover, this type of fuel cell iseven more efficient than the PAFC. MCFCs alsoappear to be able to use more types of fuels. Fur-thermore, it may be possible to use the wastesteam to convert hydrocarbon fuel into hydro-gen within the fuel cell itself, thereby eliminatingthe need for an external reformer. This may in-crease efficiency and lower costs, but the feasi-bility of this process has not yet been verified.

The high operating temperatures that MCFCsrequire and the corrosive electrolyte create ma-terials problems. For example, the present nickeloxide cathodes do not have an adequate operat-ing life. Technical challenges include developinganodes with improved dimensional stability dur-ing operation; maintaining the desired electrolytedistribution during cell operation; and maintain-ing adequate corrosion resistance at a reasonablecost. In addition, some investigators of transpor-tation applications have noted that thermal iner-tia may be a problem in operations with rapidload fluctuations.

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use traditional marine fuels may also makeMCFCs attractive for marine applications.

Photo credit Engelhard Corp

50 kW Methanol Reformer

MCFCs are now under development principallyfor large industrial or central power-generatingplants. It is believed that heat rates can be as lowas 6,500 Btu/kWh, and that eventually moltencarbonate heat rates may be reduced to as littleas 5,900 Btu/kWh, whereas the present PAFCheat rate is about 8,500 Btu/kWh. The ability to

Solid Polymer Electrolyte (SPE)

SPE technology is still highly exploratory. Theo-retically, however, this technology could providegreater performance than PAFC technology. Theadvantages could be high efficiency and almostinstantaneous startup and shutdown. However,at present the electrolyte, a proton-exchangemembrane, is intolerant to high temperatures.This means there are limited cogeneration appli-cations and that control problems could be se-vere.’ The Los Alamos National Laboratory hasevaluated the feasibility of using SPE fuel cells forselected heavy-duty transportation systems, andbelieves further R&D of SPE fuel cells to be po-tentially very important.7 Likewise, General Mo-tors is investigating the possible use of SPE fuelcells for land transportation.

Solid Oxide

Solid oxide fuel cells are theoretically highly ef-ficient and are at about the same stage of develop-ment as molten carbonate systems, at least 5 to10 years from commercial use. A major attrac-tion is that these fuel cells are conceptually sim-ple. Since they are solid state, there should befewer maintenance problems, no liquids to con-tain, no migrating electrolyte, and no corrosionproblems. Compared to other fuel cell technolo-gies, sulfur tolerance is high. In addition, sincesolid oxide fuel cells operate at close to 1,0000 C,high-quality heat for bottoming cycles and inter-nal reforming is generated. High temperature oper-ation also eliminates the need for special catalysts.However, at these high temperatures, stability ofmaterials is a problem. Materials must also haveclosely matched thermal expansion coefficients toprevent delamination of ceramic layers, and notmany materials meet these requirements. All such

bPeter S, Hunt, “Analysis of Equipment Manufacturers and Ven-dors in the Electric Power Industry for the 1990s as Related to FuelCells, ” prepared for the Energy and Materials Program, Office ofTechnology Assessment, U.S. Congress, Washington, DC, Dec. ].5,1984, p. 34.

7W. J. Walsh and J.B. Rajan, “Advanced Batteries for Electric Ve-hicles, ” Argonne National Laboratory, April 1985, p. 7. See alsoJ.R. Huff and H.S. Murray, “Feasibility Evaluation of Fuel Cellsfor Selected Heavy-Duty Transportation Systems, ” Los Alamos Na-tional Laboratory, March 1982.

10

materials currently being investigated are ratherexotic. In addition, solid oxide fuel cells currentlyunder development are small, so the power out-put is low. Hundreds of thousands of these wouldbe needed to construct a multi-megawatt power-plant, and this could be a major problem for asystem designer. 8 The National Fuel Cell Coordi-nating Group sees the initial market for solid ox-ide fuel cells in electric utilities and industrial co-generation applications using natural gas fuel.Eventually coal-fueled powerplants might becomepractical. 9 Solid oxide fuel cells may also havesome transportation applications because theycould be small and light.

Alkaline

Alkaline fuel cells, which operate at about 65°C, were first developed by NASA for use in thespace program. First used on Gemini 5 to supplyelectricity and drinking water, they have subse-quently been used on Apollo, Skylab, and SpaceShuttle missions. The most advanced alkaline fuelcells used on the Space Shuttle provide about eighttimes as much power as the first versions devel-oped. Alkaline fuel cells are highly efficient, witha heat rate of about 5,000 Btu/kWh, but giventheir high expense, industry sees few applicationsfor them. Alkaline fuel cells do not tolerate car-bon in the fuel stream, so must rely on pure hy-drogen and oxygen. Producing high purity fuelsis very expensive, and therefore alkaline fuel cellsare not considered commercially practical at thepresent time for other than very specialized ap-plications (e.g., in the chlor-alkali industry wherepure hydrogen is produced as a byproduct). NASAis more concerned with weight, however, not fuelcell expense.

Advantages and Disadvantagesof Fuel Cells

Generation of electricity by fuel cells promisesnumerous benefits. General advantages are likelyto include:

1. High efficiency. The fuel cell converts thechemical energy of a fuel directly to elec-trical energy without combustion. Thus, itstheoretical efficiency is not limited by theCarnot cycle. The conversion efficiency ofPAFC stacks, from input fuel to output

8Raia, op. cit., p. 56.91rwin Stambler, “Fuel Cell Systems Aiming at 5,000 Btu/kWh

Heat Rates, ” Cogerteration, November December 1984, p. 26.

2.

.

electricity, is between 40 and 44 percent.Since the efficiency of a fuel cell stack is de-termined largely by the characteristics ofthe individual cell, the efficiency of the fuelcell power system is (to a degree) independ-ent of the size of the plant. Overall, thegreater efficiency that fuel cells may pro-vide could mean a significant fuel conser-vation potential.Low emissions. Since most undesirable con-stituents are stripped from the fuel in thereformer, emissions from the fuel cell itselfare negligible, consisting mostly of water,which is emitted as a result of reactionswithin the reformer. Water is emitted as aresult of the reduction of oxygen at thecathode. Carbon dioxide is emitted as aresult of the reduction of oxygen at thecathode. Carbon dioxide emissions maycontribute to world climate warming (the“greenhouse effect”), but the quantities ofcarbon dioxide produced are not greaterthan quantities produced by conventionalfossil fuel powerplants.

The major source of undesirable emis-sions is in the preparation (reformation) ofhydrocarbon fuels for use in the fuel cell.In reforming petroleum or coal for use infuel cell powerplants, sulfur dioxide and ni-trogen oxides are produced. However, sul-fur dioxide emissions are expected to beabout 0.0001 pound per million Btu (lb/MMBtu), almost nonexistent when com-pared to emissions from oil- and coal-firedpowerplants, and nitrogen oxide emissionsabout 0.2 lb/MMBtu, about three timeslower than present Federal standards fornew coal-fired powerplants. 10 In the envi-ronmental assessment they conducted forDOE and NASA, Lundblad and Cavagrot-ti concluded that “sizable improvements innational air quality can be expected whenfuel cells penetrate the energy supply mar-ket in substantial quantities."11

3. Quiet. Fuel cell powerplants are quiet com-pared to conventional powerplants. Becausethe fuel cell has no moving parts, the only

1OFickett op. Clt., p. 73. Present Federal standards are discussedin U.S. Congress, Office of Technology Assessment, Acid Rain andTransported Air Pollutants: Implications for Public Policy, OTA-0-204 (Washington, DC: U.S. Government Printing Office, June1984).

“U.S. Department of Energy and National Aeronautics and SpaceAdministration, “Phosphoric Acid Fuel Cell Platinum Use Study, ”DOE/NASA/2701/2, May 1983, p. 156,

11

4.

5.

6.

7.

noises are those produced by the pumps andfans of the fuel cells auxiliary equipment.This fact means that investments in noisecontrol equipment can be reduced and thatfuel cell plants can be sited closer to theloads they serve.Ease of siting. Low emissions and quietnessare qualities that are likely to make sitingof utility fuel cell powerplants easier thansiting of conventional powerplants. Hence,fuel cells are more easily located in urbanareas where construction of conventionalpowerplants would be difficult. This samequality may be important for some marineapplications—e. g., on cruise ships.Opportunities for cogeneration. The fuel uti-lization efficiency of fuel cells can be fur-ther increased by utilizing the waste heatgenerated by the electrochemical process.When PAFCs are used to produce both elec-tricity and heat, overall efficiencies of 80percent or more maybe reached. The eco-nomics for cogeneration systems look muchbetter than for those systems producingonly electricity. A shipboard system couldalso take advantage of cogeneration.Modularty. Fuel cells can be manufacturedin modules. Unlike restrictions on conven-tional powerplants, the size of a fuel cellpowerplant can be easily increased in elec-tric utility applications to match load re-quirements. By increasing capacity incre-mentally as needed, utilities may be able toavoid some of the initial capital investmentsotherwise required of steam or nuclearplants, which are sized for some distantyear’s consumption. The conventional largeplant is not operated at its most efficient levelfor many years. For shipboard applications,adding capacity incrementally probablydoes not apply. However, the fuel cells canbe distributed to points of load concentra-tion, which offers advantages in certain mil-itary and specialized vessel applications.Short construction lead time. Because fuelcells can be factory mass-produced, leadtimes necessary to construct a fuel cell pow-erpIant can be significantly reduced, Where-as a conventional coal or nuclear plant mayrequire 10 to 12 years to license, design, andconstruct, it is estimated that once a fuel

8.

9.

10.

cell manufacturing plant is operating, a fuelcell powerplant could be installed in lessthan 3 years. These short construction leadtimes in turn will reduce utility reliance onfrequently inaccurate long-term demandprojections, thereby reducing business riskand improving utility economics. For cer-tain naval operations, short constructionlead time may also be a substantial ad-vantage.Flexible fuel usage. Fuel cell systems can bedesigned to use a variety of fuels. The fuelusually selected for commercial onsitePAFCs is natural gas. Other fuels that couldbe used include waste site methane, naph-tha, liquid hydrocarbon fuels such as bu-tane or propane, low and medium Btu coalgas, methanol or ethanol, coal-derived liq-uid fuels, biomass derived fuels, and hydro-gen or hydrogen-rich byproduct gases fromindustrial processes. However, the fuel proc-essor must be specially designed for eachfuel. Since fuel cells will, to some degree,displace conventional powerplants, theircapability to use alternative fuels could re-duce dependence on premium oil and gasused in conventional powerplants.

Fuel usage for a particular type of fuel cellis largely dependent on the characteristicsof the electrodes, electrolyte, and catalystused in the cell. Since these components maybe sensitive to contamination by “poisons,”the fuel processor must be designed to elim-inate contaminants. For example, thecathodes of PAFCs can be readily contami-nated with any sulfur in the enriched hydro-gen fuel. Thus, fuels containing significantamounts of sulfur must undergo consider-able desulfurization to be usable. An alka-line fuel cell can tolerate only pure hydro-gen and oxygen and is readily poisoned evenby carbon dioxide.Efficient part load application. Fuel cellshave the ability to maintain efficiency

through a range of loads—i. e., at loads be-tween 30 to 100 percent of rated output. Con-ventional systems, on the other hand, areless efficient at the lower end of this range.Easy to operate and maintain. Fuel cells aresimple to operate because there are few mov-ing parts. Fuel cells could potentially oper-

12

ate unmanned. Hence, operation and main-tenance costs are likely to be low.

Assuming fuel cells function as desired, therewould still be several potential drawbacks to theirwidespread use. These include:

1.

2.

3.

4.

5.

Capital cost. Relatively high cost for a newand unproven technology is the principal de-terrent to early, widespread commercial useof fuel cells, especially in the marine indus-try where difficult economic conditions pre-vail and no one is taking large risks.F’reduction of carbon dioxide in amounts sim-ilar to those emitted by conventional fossilfuel plants (when a fossil fuel is used as aninput fuel). Thus, like use of conventionalpowerplants, fuel cell use could contributeto global climate warming.Possible material vulnerability. Some of thematerials used in fuel cells are in scarce sup-ply in the United States. Among these are plat-inum, used as a catalyst in PAFCs. Domesticplatinum deposits are capable of supplyingonly about 10 percent of annual U.S. require-ments today.12 If fuel cells gain wide accept-ance, demand for these materials could in-crease significantly, and, consequently U.S.dependence on sometimes unstable foreignsources of supply would grow. CumulativeU.S. platinum demand for PAFC marketpenetration of 20,000 to 40,000 MW is esti-mated to be between 1.1 and 2,2 million troyounces. ’3 The world supply of platinum ap-pears sufficient to handle the estimated in-creased demand, and platinum prices are ex-pected to rise only moderately, ’4Some public exposure to fuels. If fuel cell pow-erplants were located in urban areas, therecould be more exposure to fuels transportedthrough populated areas than would be thecase with conventional powerplants locatedaway from densely populated areas.Fuel supply. Wide availability of fuel fortransportation applications could be a prob-

IZT, F, Anstett, D.I. Bleiwas, and C. Sheng-Fogg, “platinum Avail-ability—Market Economy Countries, ” U.S. Department of the In-terior, Bureau of Mines, information circular 8897, p. 12.

“DOE and NASA, DOE/NASA/2701/2, op. cit., pp. 109 and110.

14 DOE and NASA, DOE/NASA/2701 /2, op. cit., p. 155.

6.

lem. Use of some fuels considered appropri-ate for fuel cells would require emplacementof an entirely new distribution network. Thisissue is considered in more detail below.Fuel cell life. Periodic replacement of fuel cellstacks is required for some systems after aslittle as 5 years of use; thus, life-cycle costsmay be a negative factor.

Fuel Cell Development Programs:Current and Future Emphasis

Fuel cell research is funded by the Federal Gov-ernment, by industry research institutes, and byprivate manufacturers and utility companies.Since 1960, total expenditures for government-sponsored R&D have exceeded $500 million.Within the Federal Government, most of the re-search money comes from DOE, but DOD andNASA also have active fuel cell programs. Thetwo major industry research institutes funding re-search are the Electric Power Research Institute(EPRI) and the Gas Research Institute (GRI).These five entities comprise the National Fuel CellCoordinating Group (see figure 3). This groupprovides an ad hoc forum for coordinating thenational fuel cell development effort. The costsof many fuel cell technology development projectsare often shared between two or more of theseorganizations. Several fuel cell users groups,established to assist members in the developmentand commercialization of fuel cells, have also beenformed. The Onsite Fuel Cell Users Group is com-prised primarily of gas utilities, while the Elec-tric Utility Fuel Cell Users Group is comprisedmostly of electric utilities.

U.S. Department of Energy

The Department of Energy’s Office of Fossil En-ergy runs the Federal Government’s most exten-sive fuel cell R&D program. DOE’s overall goalin funding fuel cell research is to foster the devel-opment of environmentally acceptable technolo-gies that will help reduce the Nation’s use of oiland natural gas. In general, DOE does this by sup-porting high-risk, high-payoff technology devel-opment. Thus, a major objective is:

. . . to establish, in concert with the activities ofother funding organizations and fuel cell manu-

facturers, a verified technology base upon whichthe private sector can, at lower risk, develop andcommercialize [fuel cell systems] for early entryinto U.S. markets. 15

DOE’s fuel cell program is divided into two ma-jor subprograms. The objective of one is to de-velop multi-megawatt fuel cell powerplants forelectric utility and large industrial applications;of the other, to develop multi-kilowatt power-plants for onsite use by residences, light indus-try, and small businesses, Many research projectsmay help foster commercialization of both typesof systems.

DOE is currently supporting development ofthree types of fuel cells that may be used in bothmulti-megawatt and multi-kilowatt systems—phosphoric acid, molten carbonate, and solid ox-ide fuel cells (see figure 4). DOE began fundingfuel cell research in 1976. To date, most of theresearch it has funded has been for developmentof PAFC technology. However, DOE now be-lieves that phosphoric acid research is sufficientlyadvanced that the private sector no longer needsas much support.

1 ~~OE and ~AsA, DOE NASA ‘ 2703-3, op. cit., P. 7,

SOURCE U S Department of Energy

Most DOE funding for fuel cell research hasgone to four private contractors for electric util-ity and onsite fuel cell development. These includeUnited Technologies Corp. and its subsidiary, therecently established International Fuel Cells Corp.;Westinghouse; Engelhard Corp.; and Energy Re-search Corp. There has been very little fundingof the possible transportation applications for fuelcell technologies, but DOE has funded the LosAlamos National Laboratory to evaluate the po-tential of fuel cells for selected heavy-duty trans-portation systems. DOE has also funded one com-mercial ocean transport system study. This wasa feasibility study for submarine tankers propelledby PAFCs.

Between 1976 and 1984, DOE spent about $260million on fuel cells, Since 1978 funding for DOE’sfuel cell program has averaged about $35 millionper year. Of this, the bulk of funds (over 65 per-cent) have been expended on phosphoric acid re-search. Molten carbonate systems have receivedabout 28 percent of DOE’s funding support, andsolid oxide systems about 7 percent. DOE has pre-ferred to focus program effort on phosphoric aciddevelopment, since this technology is most ad-vanced and since commercialization of a specific

14

SOURCE U S Department of Energy

fuel cell technology is likely to be necessary be-fore potential users are likely to become very in-terested in fuel cell technologies that, howeverpromising, are not yet very advanced. Success ofPAFC systems will likely stimulate industry com-petition to further advance alternative fuel celltechnologies. The present administration has re-peatedly sought to reduce funding for the fuel cellprogram. However, Congress has been a strongsupporter of fuel cell research and has consistentlyreinstated research funds that the present Admin-istration has sought to cut.16

National Aeronautics andSpace Administration

In the 1950s and 1960s, NASA funded the de-velopment of alkaline fuel cell powerplants for usein spacecraft. The current NASA program is di-rected toward development of low temperature,hydrogen-oxygen fuel cells for regenerative andprimary space mission applications, and towarddevelopment of advanced concepts for futurespace applications .17 Fuel cells developed for usein outer space are not cost-effective for terrestrialtransportation uses. In addition to its other activ-

16 Hunt, Op. cit., P. 19 “U.S. Department of Energy, Office of Fossil Energy, “Fuel CellSystems Program Plan, ” October 1984, p. 11.

15

ities, NASA (Lewis Research Center) has been des-ignated by DOE to implement DOE-funded PAFCprojects.

U.S. Department of Defense

The armed services are interested in the possi-ble applications of fuel cell technology primarilyas a means to support field operations. Charac-teristics of fuel cells that make them particularlyuseful for the military include low noise, low ther-mal signature, and high efficiency. The BelvoirResearch and Development Center of the U.S.Army has had a fuel cell program since the mid-1960s, and is currently sponsoring the develop-ment of fuel cells for mobile applications to sup-port troop operations. Phosphoric acid units havebeen designed for power ranges between 1.5 and5 kW. Thus far, the Army’s portable fuel cell pow-erplants have been designed to run on methanol;however, future units will be developed to runon diesel fuel, since it is both less expensive and(since all Army vehicles use it) readily availablein the field. Work on developing reformers fordiesel-powered fuel cells is in progress.18

The Army also manages a fuel cell program forthe U.S. Air Force. The Air Force is primarily in-terested in using fuel cells in remote areas, suchas at Distant Early Warning radar sites in the Arc-tic. Currently, diesel drive electric generators areused at these sites, but because the cost of pro-viding fuel and maintenance services is high,PAFCs are being considered as an alternative.

The U.S. Navy does not have a significant fuelcell R&D program. However, several of its re-search offices monitor other agency and indus-trial programs and occasionally conduct reviewsto keep abreast of fuel cell developments that maybe applicable for Navy missions. Several smallSPE fuel cells are currently being tested at theDavid Taylor Naval Ship Research and Develop-ment Center in Annapolis. In the past, the Navyhas supported development of fuel cells for power-ing small submersibles and submarines, but it hasno plans at the present time for using fuel cellsfor main or auxiliary ship power.

‘HAllayne Adams, U.S. Army, Ft. Belvoir, interview, July 8, 1985.

U.S. Department of Transportation

The Maritime Administration (MARAD), with-in DOT, has funded a small amount of work in-vestigating the potential marine applications forfuel cells. One study assessed a broad range ofadvanced merchant vessel power systems andconcluded that fuel cells are one of four contenderswith some potential.19 Another MARAD-spon-sored study examined a plan to evaluate at seaa methanol-fueled PAFC used as an auxiliarypower system, 20 MARAD has decided not to pro-ceed with the proposed test.

Gas Research Institute

GRI is the gas industry research organization.Its budget of about $170 million per year is gen-erated by an R&D surcharge on natural gas con-sumption of 1.35 mills/MMBtu, as approved bythe Federal Energy Regulatory Commission (FERC).Much of the research it funds is coupled with Fed-eral and private efforts. A primary objective ofGRI is to promote the development of fuel cellsthat can use pipeline gas.21 Hence, GRI has fo-cused its effort on developing and demonstratingfuel cells that can be operated independent of anelectric utility grid. The size of these onsite fuelcell powerplants will likely be between 40 and 500kW. Since a 40 kW plant generates about 150,000Btu/hr of heat, these units can be used as cogen-erators to maximize net efficiency. Commerciali-zation of these onsite units would mean load losses(and thus direct competition) for the electric util-ity industry.

A major facet of GRI’s onsite program is fieldtesting of phosphoric acid units. The program isjointly sponsored by DOE, GRI, and a numberof participating utilities. Customers of the utilityuser group include hospitals, stores, restaurants,etc., and are spread all over the country. No ma-rine users, however, are in the user’s group. To-

1’Gary J. Baham, “Merchant Vessel Advanced Power Systems, ”final report to the Maritime Administration, U.S. Department 01Transportation, NTIS #PB-82-185240, ]anuary 1982.

JoArctic Ener@e5 Ltd., “Development of Marine Rated PhosphoricAcid Fuel Ce]]s, ” fina] report to MARAD, NTIS #1’ B-85-164879,September 1984.

“Gas Research Institute, 1985-1Q8Q Five-yedr Research and De-velopment Plan and 1Q85 Research and Development Program, April1984, pp. 135-142.

16

tal project costs for the 1981-85 period have beenabout $60 million. The purpose of the field testproject is to verify performance, demonstrate in-stallation and maintenance, and stimulate user ac-ceptance. The onsite field test program has pro-gressed from tests in the 1960s of some sixty 12.5kW fuel cell powerplants to the present testing ofover forty 40 kW PAFC powerplants. The presentinstallations began operating in 1983. Perform-ance data will continue to be collected throughmid-1986. At the present time, 46 powerplantshave been placed in the field and over 215,000operating hours have been obtained. Primaryproblems seem to relate to supporting equipment,such as pumps, and to the coolant system. It isexpected that the 40 kW field tests will be followedby the design, development, and commercial in-troduction of an approximately 200 kW capac-ity unit in the future.

GRI is also helping to fund PAFC technologydevelopment by the private sector (primarilyUnited Technologies Corp. (UTC)). The objec-tives of the technology development project areto improve onsite components, system perform-ance, reliability, and maintainability; and to re-duce fuel cell manufacturing costs, thereby pro-moting early commercialization.

Electric Power Research Institute

EPRI is the major electric utility industry re-search organization. Like GRI, EPRI fuel cell pro-grams are coordinated with Federal and privateefforts. EPRI funding is also derived from a levyon ratepayers approved by FERC. However, un-like GRI, EPRI interest focuses more on large,multi-megawatt central power generating systems.With DOE, UTC, and a utility consortium led byContinental Edison, EPRI participated in devel-oping a 4.8 MW pre-prototype phosphoric acidpowerplant located in New York City.22 EPRI isalso contributing funds to the UTC effort to de-velop an 11 MW PAFC and to the Westinghouseeffort to build a 7.5 MW powerplant.

In addition to promoting phosphoric acid re-search, EPRI promotes R&D of advanced fuel cell

ZZThe New York [aci]ity cost $85 mi]]ion, of which 57 percent wascontributed by DOE, 20 percent by EPRI, 16 percent by UTC, and7 percent by Consolidated Edison of New York and its partners.

concepts that may prove useful for the electric util-ity industry. Thus, EPRI has a program whosemajor goals are to develop molten carbonate fuelcells capable of 25,000 hours of operation undera wide range of conditions, and to verify an ad-vanced stack concept that can reform natural gasor methanol within the fuel cell stack and pro-duce power at approximately 60 percent efficien-cy. Achievement of this latter goal initially couldresult in a relatively small (2 MW), modular, high-ly efficient (50 to 60 percent), and very simplepowerplant that does not require an external fuelprocessor. 23 Such a powerplant could have po-tential marine transportation applications.

EPRI budgeted $9.6 million for fuel cell and hy-drogen technology research in 1985, and it hasbudgeted a total of $81.6 million for the 1985-89period. 24

Major Company Efforts

There are relatively few companies involved infuel cell research, development, and manufactur-ing. All are, to some degree, supported by DOEand/or other Federal agencies. Industry estimatesthat the ratio of private sector spending to Fed-eral funding has been historically approximately2 to 1,25 but this figure is very difficult to verify.Perhaps the company with the longest involve-ment in fuel cell R&D is UTC. UTC is involvedin development and manufacturing of PAFCs forboth the electric utility multi-megawatt programand the gas utility onsite program. UTC and theToshiba Corp. recently established a joint ven-ture, the International Fuel Cells Corp., to design,develop, and market an 11 MW fuel cell power-plant for electric utility use. UTC is also fundedby DOE to conduct research on MCFCs, and ithas an ongoing program to develop alkaline fuelcells for military and space applications.

Westinghouse is developing a multi-megawattPAFC system independent of the UTC effort. Ithas received funding support from DOE and EPRI

ZJElectric power Research Institute, 1985-1989 Research & Devel-opment Plan, EPRI P-3930-SR, January 1985, pp. 474-475.

241 bid., p. 469.Zssidney Law, Statement of Sidney Law, member, Fuel cell Users

Group, before the Subcommittee on Energy Research and Devel-opment of the Committee on Energy and Natural Resource, U.S.Senate, May 3, 1983, p. 745.

17

for the design of two 7.5 MW DC air-cooledPAFCs, which it hopes to have operating in 1987and 1988, However, as of October 1985 no utili-ties had offered sites for a commercial demonstra-tion of these units. Both UTC and Westinghouseexpect to have multi-megawatt commercial PAFCpowerplants for sale before 1990. Westinghouseis also conducting research on solid oxide systems,and as a result of recent technical accomplish-ments, believes that commercial introduction ofsolid oxide systems may become available as soonas 1990.26

The Engelhard Corp. is designing an integratedonsite energy system, which includes a PAFCpowerplant; a heating, ventilating, and air-conditioning subsystem; and an energy storagesubsystem. The overall plan is to develop a full-size 100 kW system made up of four 25 kW fuelcell stacks, two 50 kW fuel conditioners, and two50 kW power processors to provide adequate re-liability and redundancy .27 DOE funding for theproject has been applied to improve the state-of-the-art of fuel cell stack and fuel processor tech-nologies.

The Energy Research Corp. (ERC) is primarilyinvolved in developing molten carbonate fuel cellsfor large-scale industrial cogeneration applica-tions. ERC has licensed its PAFC technology toWestinghouse.

Finally, and perhaps most significantly with re-spect to transportation applications for fuel celltechnologies, the Allison Gas Turbine Divisionof General Motors has an ongoing program tostudy the feasibility y of using fuel cells as a powersource for automobiles and other transportationapplications.

Japan

Japan can be expected to be a major U.S. com-petitor in the future fuel cell market. z” Five Japa-nese firms are involved in an ambitious R&D pro-gram, and Japan’s New Energy Development

2’G. W. Weiner and J.T, Brown, “Solid Oxide Fuel Cell po~,erPlants–The New Perspective for Commercialization, ” 1985 Fuel CellSeminar: Abstracts, sponsored by the National Fuel Cell Coordi-nating Group, Tucson, AZ, May 19-22, 1985.

‘“DOE and NASA, DOE ~ ,NASA 2703-3, op. cit., p. 16.2’Irwin Stambler, “Fuel Cell Outlook Brightens as Technical Ob-

stacles Fall, ” Research and Development, December 1984, p, 52

Organization is supporting efforts aimed at hav-ing full-sized phosphoric acid plants on utilitygrids by about 1990. The goal of Japan’s Moon-light Program is to develop a 1 MW commercialsystem in 1986. Research is also progressing ondevelopment of other types of fuel cells. All butone of the Japanese firms has an operating alli-ance with a U.S. company: Toshiba with UnitedTechnologies, Mitsubishi with Westinghouse, En-gelhard with Fuji, and Sanyo with Energy Re-search Corp. Only Hitachi currently lacks a part-ner. 29 The Tokyo Electric Power Co. has beensuccessfully operating a 4.8 MW PAFC power-plant designed by UTC since late 1983. This plantis similar to the one UTC installed in New York,but it is an improved version that takes advan-tage of several of the lessons learned at the NewYork site.

Japan is also one of the world’s leading mari-time nations, and Japanese developers are awarethat if high efficiency fuel cells can be developed,they could possibly be used for shipboard appli-cations. 30

Cost Considerations

The installed capital costs of the first commer-cial demonstration PAFC powerplants are cur-rently expected to be about $3,000/kW. However,no manufacturer has made a public offering, andwithout any commercial units in place, cost esti-mates should not be considered firm. With matur-ing technology and mass production of fuel cells,capital costs for both large and small powerplantshave been projected to fall below $1,000/kW(1985 dollars) by 1995.31 Estimates of the installedcapital cost that will enable fuel cells to competewith other utility and cogeneration alternativesvary, but are between $750 and $1,500/kW, de-pending on the specific application .32 These figures——

29 Hunt, Op, cit., p. 9.‘“U.S. Department of Energy, “Japanese Research and Develop-

ment ot Fuel Cells, ” DOE I SF ~ 10538, T6, prepared under the direc-tion of Dr. Chico Fujishima of Galaxy N]M, February 1Q81, p. 22,

“U.S. Congress, Office of Technology Assessment, New E~ectricPower Technologies: Problems and Prospects for the 1900s, OTA-E-246 (Washington, DC: U.S. Government Printing O[tice, luly1985), pp. 107, 313,

12’’ Electric Utility and Gas Industry’s Fuel Cell Models in ResearchRacer” Electric Utility WeeL, Mar, 4, 1985, p. 13; and Lee Catalano,“Can Fuel Cells Survive the Free Market in the 1990s?” Power, Feb-ruary 1984, p. 61,

do not take into account various benefit values,which, if taken together, could reduce present andprojected costs per kilowatt by an estimated $200(1985 dollars), Among these potential benefits aresavings related to air emission offsets, spinningreserve and load following, transmission and dis-tribution, and most importantly, cogeneration po-tential. 33 Cost and performance parameters com-paring large and small PAFC powerplants withtwo conventional technologies are presented intable 1.34

A number of factors influence the overall costsof fuel cells. These include:

1.2.

3.

4.5.

the state-of-the-art of fuel cell technology,the cost to manufacture the cells and buildthe powerplant,the cost to operate and maintain the pow-erplant,cell replacement frequency, andthe cost of fuel.

Naturally, in order for fuel cell powerplants tobe competitive with other alternatives, these costsmust be minimized.

“Electric Power Research Institute, “System Planner’s Guide forEvaluating Phosphoric Acid Fuel Cell Power Plants, ” EPRI EM-3512,July 1984, p. 4-3.

“0TA, New Electric Power Technologies, op. cit., pp. 142, 313.

Although PAFC technology is well-advanced,incremental technical improvements of fuel celland related-system components can still help re-duce costs. For example, development of:

1.

2.

3.

4.

5.

inexpensive, corrosion resistant cell structur-al materials;less expensive and more effective catalyststhat can operate at higher temperatures andpressures;improved automated fabrication and han-dling processes for large area cells;cheap, reliable, and efficient fuel processingunits; andtechniques for reducing electrolyte consump-tion, as well as improvements in various otherstandard components,35 will lower costs andenhance the ability of fuel cell units to com-pete with other powerplants.

One of the advantages that fuel cells will haveover conventional alternatives for producing elec-tricity is that they can be factory mass-produced.Thus, quality control can be maintained, and fuelcell stacks can be prefabricated, enabling reduc-tion of the expensive onsite work required of othertypes of powerplants. Improvements in the man-ufacturing process will enable further reduction

351 bid., p. 108,

Table 1 .—Cost and Performance Comparisons for Land-Based Electrical Powerplants That Use TechnologiesSimilar to Marine Propulsion Units

Combustion Slow-speed PAFC PAFCturbine diesel large small

General:Reference year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1990 1990 1995 1995Reference-plant size (MWe) . . . . . . . . . . . . . . . . . . . . . . . . . 150 40 11a 0.2Lead-time (years) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 2 3-5 2

Performance parameters:Operating availability (o/o) . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 95 80-90 80-90Duty cycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Peaking Intermediate Variable VariablePlant lifetime (years) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 30 30 20Plant efficiency ( 0 /0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30costs.=

39 40-44b 36-40 b

Capital costs ($/kWe) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 1,200 700-3,000 d 950-3,000d

O&M costs (mills/kWh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4.7 5.1-8.2 4.2-1 1.5e 4.2-1 1.5eFuel costs (mills/kWh) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48.6 42 27-30f 30-33’aA typical Commercial powerplant WIII be much larger than 11 MwbDoes not Include Cogeneration potenttal. Cogeneratlon efficiency could be as high as 85 PercentCAII cost figures are reported in mid-19t33 dollarsdLower end of range assumes mature technology and mass productlorl, high end represents the estimated cost of the first commercial Unlk

elncludlng cell replacement costs‘Natural gas fuel

SOURCE U S Congress, Off Ice of Technology Assessment, New E/ecfr/c Power Techr?o/og/es Problems and Prospects for the 1990s, OTA. E246 (Washington, DCU S. Government Printing Off Ice, July 1985), pp 142, 313.

19

of total costs, However, one “chicken-and-egg”type problem is that cost savings from mass pro-duction cannot be realized until utilities and otherpotential users begin ordering fuel cells, but thecurrent cost of fuel cells is still too high for mostpotential users to be willing to invest. This situa-tion, according to fuel cell manufacturers and po-tential users, may warrant continued strong gov-ernment participation in helping to bring costsdown and in demonstrating fuel cell technolo-gies. 36

The cost to build certain plants, however, com-pares favorably with competing technologies be-cause modular construction permits incrementalcapacity to be added only as needed. Therefore,funds do not have to be tied up in expensive,many-year construction projects. Moreover, it isfrequently years before the capacity of a newlyconstructed conventional powerplant is fully uti-lized. Fuel cell powerplants can be built to closelymatch load needs, adding capacity only as needed.

Several costs are associated with operating andmaintaining (O&M) fuel cell powerplants. Thecost of labor is one such cost. Smaller plants arebeing designed to operate unmanned; plants in themulti-megawatt range may require manning forsafety. A second important O&M cost occurs be-cause fuel cells must periodically be replaced, Fuelcell voltage and efficiency decrease with time be-cause the platinum catalyst undergoes a reductionin surface area and performance due to sintering

“Brian E. Curry, “The Fuel Cell: Electric Utility Planning Per-spectives, ” address before the New England Conference of PublicUtilities Commissioners, Farmington, CT, June 14, 1983, The FuelCell Users Group, p. 16.

Table 2.—Potential Fuels.

Extent of Ease of

(agglomeration of a solid by heating without melt-ing) as the cells operate. In addition, the heat rateslowly increases over time if cells are not replaced,and as a result, the amount of fuel required in-creases .37 The cost of producing electricity can beminimized by optimizing the fuel cell module re-loading frequency.

The most important variable cost is the cost offuel. As noted above, fuel cells are capable ofusing a variety of fuels. Moreover, since fuel cellsconvert fuel to electricity with high efficiency,they have an advantage over many competingtechnologies in that the cost of fuel per kilowatt-hour can be substantially less. Present and pro-jected fuel prices for six potential fuel cell fuelsare given in table 2, and table 1 compares the esti-mated cost of fuel for competing power supplysystems in terms of mills per kilowatt-hour. TheFuel Cell Users Group (FCUG) believes that nat-ural gas will remain the preferred fuel cell fuel forutilities at least through the mid-1990s, but theyalso predict that propane will eventually becomethe less expensive and preferred fuel. Methanol,typically made from natural gas, continues to bepriced above most other fuels suitable for fuel cellapplication, and the FCUG predicts that its highprice per Btu will continue into the foreseeablefuture, 38

‘7J.R. Lancer B.L. Pierce, and M.S. Barrett, “Economics and Per-formance of Utilit y Fuel Cell Power Plants, ” Westinghouse ElectricCorp., Advanced Energy Systems Division, Pittsburgh, PA, 1984,p. 825.

“The Fuel Cell Users Group, “Report on the Availability andPrices of Alternative Fuels to Supply Fuel Cell Power Plants, ” July1983, pp. 8-9; see also, Chevron U. S. A., Inc., “The Outlook forUse of Methanol as a Transportation Fuel, ” January 1985,

for Use in Marine Fuel Cells

Heat distribution processing Estimated Volume per unitcontent infrastructure for fuel Complexity Recent price 1990 price energy (compared(Btu/gal) and availability cell use of storage ($/MMBtu) (1985$/MMBtu) to diesel)

Methanol . . . . . . . . . 64,000 Medium Easy Moderate 7.00a l0.50 b 2.2LNG . . . . . . . . . . . . 78,000 Low Easy Complex 5.00’ 5.20C 1.8LPG . . . . . . . . . . . . . . 91,000 Medium Difficult Moderate 7.00d 7.00d 1.5Diesel No. 2. ..., . . . 138,000 High Difficult Simple 6.20e 6.50d 1.0Naphtha . . . . . . . . . . 125,000 Medium Difficult Simple 6.60 e 6.60e 1.1JP-5 (Jet fuel) . . . . . . 122,000 Medium Difficult Simple 6.00d 6.75d 1.1aDewl!t ~ C. , Inc , k?ethano/ Newsletter, Oct 18, 1985bElectrlc Power Research Institute, “Fuel Forecast Rewew, Energy Resources Program, No 1,“ March 1985Cphtlllps pet ro leum phllllps IS currently expofllng LNG t. Japan This ,s the only act ive LNG operation in the IJnlted States The price of LNG has r(?C6311!ly f luctuated

between $470 and $5 30/MMBtudu s Department of Energy, 1984 Annual Errergy ~u~/oo~‘The Fuel Cell Users Group “Report on the Avallablllty and Prices of Alternative Fuels to Supply Fuel Cell Power Plant s,” July 1983

PART TWO: MARINE USES OF FUEL CELLS

Introduction

Why consider fuel cells for marine applications?As with land-based applications, economic fac-tors drive the search for improved commercialmarine power generation. These factors includecapital and operating costs of propulsion and aux-iliary power systems, cost and availability of fuel,and powerplant efficiency and reliability. Each ofthese factors has a strong influence on the designof ships and other equipment and powerplants.Fuel cells have been considered as one of severalalternative propulsion systems for the ships of thefuture. Baham, for instance, has evaluated non-traditional propulsion systems for the commer-cial shipping industry (under contract to the Mar-itime Administration), and concluded that foursystems show merit worthy of further investiga-tion: nuclear, closed Brayton cycle, Stirling cy-cle, and fuel cells .39

Some of the benefits fuel cells would provideto the utility industry could also apply in the ma-rine field. Of special interest is the potential offuel cells for high efficiency, since this efficiencymay translate into fuel cost savings. Moreover,fuel cell efficiency is relatively constant over abroad range of power settings. Such a character-istic suggests that fuel cells might be efficientlyemployed in ships that frequently vary power de-mand—e.g., towboats, ferries, offshore supplyboats, or icebreakers. In addition to the poten-tial for providing main propulsion, fuel cells couldalso supply auxiliary power and other needs.

Several other characteristics of fuel cells couldprovide benefits for specific applications. The factthat fuel cells are of modular design enables flex-ibility in the arrangement of plant componentsand could lead to a more cost-effective layout ofpower and cargo spaces and of basic ship struc-ture. However, overall space and volume require-ments of the fuel cell system and fuel will be greaterthan for present systems. As with other electri-cal powerplants, the maneuvering problems ofships and tugs might be mitigated by the advan-tage fuel cells provide in enabling electric powerto be quickly switched to various locations to re-

.—3qBaham, op. cit,

20

verse main propellers or to activate side thrustpropellers or water jets. Fuel cells have few mov-ing parts, suggesting minimal manning require-ments. Fuel cells are quiet, suggesting possible useson anti-submarine warfare ships and seismic ves-sels. Finally, fuel cells offer greater endurance overbatteries for some types of submerged operation.

Despite potential benefits, the marine marketis not in itself large enough to drive fuel cell tech-nology developments. Hence, it cannot be ex-pected that fuel cells will penetrate marine mar-kets before they become firmly established in thecommercial utility sector, and shipbuilders willneed to use and adapt products developed firsteither for the power industry or for DOD. In addi-tion, cost advantages to onsite shore users due tolarge-scale production may not accrue to the ma-rine industry.

Technical barriers, of course, also remain to beresolved. Barriers relating to the commercializa-tion of fuel cells for transportation have beennoted by Walsh and Rajan.40 Most bear directlyon cost, and include:

●

●

●

●

●

●

●

●

●

●

●

●

high cost of platinum and other catalysts;thermal control problems;difficult fuel processing requirements;system complexity;startup time, especially in PAFCs;high reformer cost, especially in small systems;low volumetric power density;carbon monoxide intolerance of electrodes;high cost of membranes (for solid polymerelectrolyte fuel cells);low efficiency of the oxygen electrode;deterioration of the cost/performance ratioin small systems; andneed to replace cells periodically.

Required Characteristics

Fuel cells must be competitively priced, relia-ble, and durable if they are to be accepted by themaritime industry, They will be competing withother types of powerplants, especially with well-established diesel-electric plants, for a share of the

towalsh and Rajan, op. cit., P. g.

21

marine market. Current low-speed diesels oper-ating on residual fuel are very nearly as efficientas present PAFC powerplants, and the efficiencyof the conventional powerplants of the future isexpected to improve (see table 3). For example,diesel manufacturers are continuing their effortsto improve the heavy fuels capability of their en-gines. Shipowners will not likely try new propul-sion systems without some very clear and con-vincing reasons to do so. Substantial advantagesmust be demonstrated, not just incremental im-provements in efficiency in order to induce po-tential buyers to switch from a long-establishedpowerplant to a new and relatively untested typeof unit,

What would it take in order for the fuel cell tobecome competitive in the commercial marine in-dustry? One view is that, for applications suchas tugboat propulsion, total efficiency improve-ments of 10 to 20 percent would be required, thatinstalled capital costs would have to be on the or-der of $300 to $500 (1985 dollars) per kilowatt(to compete with direct drive diesels), that powerdensities (kW/cubic foot and kW/lb) would haveto be reasonably close to those of the diesel en-gine, and that the fuel cell (in the near term, atleast) must be capable of running on distillate pe-troleum-type fuels customarily widely available.

Table 3. —Possible Marine Powerplants

Fuel Efficiency (o/o)

Current:Steam turbine with reheat steam

(1,450 psig, 150 F) . . . . . . . . . Residual 32-36Low-speed diesel ., ... . . . . . . . Residual 39-41

Future conventional:Steam turbine with heat pressure,

high temperature reheat(2,400 psig, 1,050’ F) . . . . . . . Residual 35-39

Adiabatic diesel . . . . . . . . . . . . . . Diesel 49Naval Academy heat balance

engine . . . . . . . . . . . . Diesel 43Heavy-duty gas turbine,

combined cycle . . . . . . . . Residual 36-40Closed-cycle combustion turbine Residual 40-41

Fuel cells.a

Phosphoric acid . . . . . . . . . . . . . . Naphtha 41Molten carbonate . . . . . . . . . . . Distillate 50Alkaline . . . . . . . . . . . . . . . . . . . . . Hydrogen 60awlthout cornbltled cycle or other forms of heat recovery

SOURCE U S Department of Energy, A/ternatfve Energy Sources for Non.lflgh.way Trar?sportaf~on, DOE/CS/05438-T 1, Ju ne 1980

Requirements for specific uses could vary consid-erably, but these will be difficult targets to reach.

The major factor inhibiting fuel cell usage forcommercial marine applications is high cost. Formilitary applications—e. g., for submersibles,small surface ships, and other specialized vehi-cles—mission requirements rather than cost aregenerally more important. Thus, if fuel cell tech-nology is determined to have unique advantagesfor a defined mission, high cost may not be themajor concern.

Other important factors to consider in select-ing a fuel cell or other unconventional powerplantinclude compatibility with salty air and water;system and fuel safety; ability to withstand theshocks, vibrations, and ship motions commonlyencountered at sea; ability to withstand and/orcontrol transient thermal shocks due to rapidchanges in load; training and manning require-ments; and constraints on weight and volume ofthe powerplant, auxiliary systems, and fuel. Thequestions of fuel storage and possible additionalen route refueling time, as well as other elementsrelated to fueling along the transportation route,have not been considered in most studies. The vol-ume of fuel required to travel between two pointsmay be much greater for certain types of fuel (e.g.,methanol). This may either place additional spaceand therefore size requirements on the vessel ornecessitate additional refueling stops.

The ability to burn less expensive, widely avail-able fuel would be advantageous, as would thecapability to cogenerate steam, since, typically,ships have well-established uses for steam. Finally,fuel cells, like any other marine propulsion sys-tem, will need to be certified by the U.S. CoastGuard and/or ship classification societies (e.g.,the American Bureau of Shipping or Lloyd’s ofLondon) that they are safe, durable, and performto acceptable specifications. Listed below are fivesignificant issues that will affect future marine fuelcell use.

Capital, Operating, and Maintenance Costs

There is no question that it is technically feasi-ble to propel a ship and/or generate auxiliarypower using fuel cells. The issue is whether and/orwhen fuel cells will be economical to purchase,

22

i ns t a l l , o p era te , and main ta in . Manufa c t ur e r s o ffue l ce l l s for the u t i l i ty indust ry mainta in tha t

$1,000/kW (1985 dollars) is a realistic installedcapital cost goal for a mature fuel cell system. A st echnica l improvements a re made (e .g . , by im-

prov ing power dens i ty , ce l l s tack coo ler a r rays ,

catalyst material , electrolyte management, and/or

inverter efficiency) and as automated productiontechniques improve, the capital costs may be re-

duced further. However, in order for fuel cells tobe competitive with direct drive diesel power-plants in the commercial marine industry, capi-tal costs may have to be considerably lower than$1,000/kW .

Several studies of specific marine applicationshave considered the question of capital costs indetail. Notably, the Los Alamos National Labora-tory (LANL) did a levelized life-cycle cost studyof a typical 7,000-horsepower (hp) vessel capa-ble of operating on inland or coastal waters.LANL concluded that such a vessel powered byan advanced PAFC using methanol costing $12.30/MMBtu could not compete with a similar vesselpowered by a medium- to high-speed diesel pow-erplant, even if the capital costs for the fuel cellswere zero. They then considered the case of fuelcells capable of using less expensive fuels, resid-ual bunker fuel and coal, noting that handling andprocessing technology for these fuels has not yetbeen developed. Although their conclusions aretentative, they suggest that the capital costs nec-essary to make fuel cells competitive for this ap-plication would be significantly below $500/kW,even when using low-cost coal .41 One of OTA’sworkshop participants estimated the total cost ofa fuel cell system for a 5,000-hp vessel, assumingit can be installed for $500/kW, at $2 million .42The cost for a comparable diesel would be about$800,000.

The duty cycles and specific requirements ofother potential marine applications could varyconsiderably. Thus, it is not suggested that therequired competitive capital cost per kilowatt willbe as low for all potential marine fuel cell appli-

4]J.H. Altseimer and J.A. Frank, “An Assessment of Fuel Cell Pro-pulsion Systems, “ Los Alamos National Laboratory, LA-9954-MS,November 1983.

‘zFrancis )(. Critel]i, Maritime Administration, OTA workshopcomment, Sept. 5, 1985.

cations. However, what little evidence there issuggests that fuel cells will have a difficult timecapturing a large share of the market for most ma-rine propulsion systems.

The relatively small size of the marine marketwill not likely encourage volume-based cost re-ductions; nor is the marine market large enough,by itself, to stimulate development of alternativefuels. For example, it has been estimated that, atbest, the U.S. domestic towboat industry mightacquire 50 fuel cell powerplants per year.43 Evenif all potential Navy applications utilized fuel cells,the domestic market could still not be consideredlarge. Moreover, there are other reasons why de-velopment of marine fuel cells may be difficult.Baham notes that it is possible that competingpowerplants could enter the market first and es-tablish long-term commitments with major cus-tomers; that ship operators and builders tend tobe conservative in their attitude toward changesin propulsion machinery and would likely beskeptical about changes that involve unknownrisks; and that potential PAFC users may wishto wait for development of molten carbonate fuelcells, which may offer better performance andcost .44

Fuel Costs and Supply

Methanol has been identified in several studiesof the possible marine applications for fuel cellsas one of the most practical fuels for marine trans-portation applications. Among its advantages,methanol can be derived from a number ofsources (including natural gas and coal, and woodand other renewable resources), it is clean andrelatively easy to store (although it takes up morespace per unit energy than hydrocarbon fuels),it is easily reformed at low temperatures usingconventional heat exchangers, and methanol re-forming technology is in a relatively advancedstage. Nevertheless, there are some significantproblems and uncertainties associated with the useof methanol as a fuel cell fuel.

It is apparent from the few studies that havebeen commissioned that the competitiveness of

“James Niven, American Commercial Barge Lines, OTA work-shop comment, Sept. 5, 1985.

44 Baham, op. Cit., P. 6-6.

23

fuel cells in the marine industry will be sensitiveto the cost of fuel. Researchers who have assumedmethanol will be used for marine fuel cells havereached both optimistic and pessimistic conclu-sions about the future competitiveness of fuelcells .45 The assumed price of methanol in thesestudies varied widely. The price of methanol dur-ing the mid-1990s—the earliest time that fuel cellscould be expected to enter the marine market—is highly uncertain. A 1983 study by FCUG esti-mated that by 1990 methanol would cost $16.00/MMBtu (1983 dollars).” Recently, the same grouplowered their estimate to approximately $10.00/MMBtu (1983 dollars). (The current price is about$7.30/MMBtu. ) Although FCUG’s estimate hasbeen reduced, methanol is still expected to bemore expensive than No. 2 diesel, propane, andnaphtha (see table 2). Moreover, fuel cost is notthe only important factor. Experience has shownthat improvements to reduce fuel costs are notacceptable if poor reliability is a consequence.

Perhaps as significant as the issue of cost is thefact that methanol and other alternative fuels(e.g., naphtha) are not widely available as trans-portation fuels and that no network exists to dis-tribute these at present. It is not a simple matterto shift from a well-established fuel to a new fuel,and residual fuel, bunker C, and diesel will likelybe available for at least another 20 years. The U.S.Navy considers the fuel availability problem soimportant that it has all but eliminated methanolfrom consideration as a potential fuel for its fleet.S imi lar ly , the U .S . Army has ma jor reservat ionsabout using methanol as a fuel cell fuel in the field.All Army vehicles use diesel fuel. Thus, the logi-

cal fuel to use with the portable fuel cell genera-

tors the Army is developing is also diesel. It is not

surpr i s ing tha t the Army has in i t i a ted deve lop-ment of reformer technology capable of process-ing No. 2 diesel fuel.

For the short term, methanol appears to sufferfrom a chicken-and-egg problem. Automotive andv e s s e l m a n u f a c t u r e r s a r e h e s i t a n t t o p r o d u c e

4%ee, for example, Arctic Energies Ltd., op. cit.; and Los AlammNational Laboratory, “Assessment of Fuel Cell Propulsion Systems, ”November 1983.

‘“The Fuel Cell Users Group, “Report on the Availability andPrices of Alternative Fuels to Supply Fuel Cell Power Plants, ” July1Q83.

methanol-powered vehicles because the fuel dis-tribution network does not exist. Fuel suppliers,on the other hand, will not be motivated to pro-vide methanol until there are enough vehicles onthe road or at sea that require it. From an eco-nomic point of view, the future cost of methanolhas been estimated to be twice as much as gaso-line, on a mileage equivalent basis, if new meth-anol plants must be built to satisfy U.S. de-mands. 47 However, methanol may well deservea much closer look when the traditional fuels,such as No. 2 diesel, become scarcer and moreexpensive. It is the least expensive high-grade liq-uid fuel that can be produced from abundant U.S.coal resources, and can be derived from othersources as well. Some automotive industry peo-ple believe that a methanol distribution networkfor automobiles could evolve naturally from thepresent distribution system, since methanol is al-ready used in small quantities in some places asa gasoline additive .48 It is not too far-fetched,then, to envision the distribution system expand-ing to include small boat marinas and eventuallyto facilities for larger ships, but the costs of estab-lishing such a network are very difficult to es-timate.

Several additional concerns have been noted.Methanol has a low flashpoint, which could beparticularly troublesome for some military appli-cations. Thus, special precautions would likelyneed to be taken in handling methanol. Second,a safety problem could arise because methanolburns without a visible flame; hence, a methanolfire cannot be easily detected. And finally, verylittle information is available on the effects of lowconcentration, chronic exposure to methanol.

Reformer Technology

Development of reformer technologies capableof using logistic fuels could be an important break-through for the acceptance of fuel cells for trans-portation. The logistic fuel of choice appears tobe No, 2 diesel. It is currently widely availableand relatively inexpensive. However, currentlyavailable reformers are not capable of efficiently

‘; Chevron, U. S. A., Inc., op. cit., pp. 4-5.‘*Gene Helms, Allison Gas Turbine Division, General Motors,

telephone conversation, Nov. 6, 1985.

2 4

producing the hydrogen needed by the fuel cellfrom No. 2 diesel fuel. If efficient reformer tech-nology could be developed enabling fuel cells touse No. 2 diesel, the fuel logistics and safety prob-lems associated with methanol and some otherfuels would be moot for the near term. The keychallenge is to develop a reformer for liquidhydrocarbon fuels that works for relatively smallto medium capacities. As noted above, the U.S.Army has initiated work on this significant prob-lem. Specific development needs include stablecatalysts, the reduction of the water-to-carbon ra-tio, and desulfurization.

Survivability in Marine Environment

For the most part, fuel cells have been designedfor terrestrial use and have not had to cope withthe special problems related to the marine envi-ronment—presence of salty air and water, vibra-tions, shocks, corrosion, etc. The durability offuel cells under harsh marine conditions is notknown. However, the design of fuel cell systemsthat can withstand these elements is not expectedto be a major challenge. For instance, althoughit is not yet known how salt will affect fuel celloperation, the filtering system designed for a ma-rine gas turbine might reasonably be expected toremove salt in the air so fuel cells and reformersare not contaminated. Similarly, it is likely thatfuel cells can be “hardened” to withstand marineshocks. The Navy, for instance, designed their al-kaline fuel cell to withstand the stress associatedwith a 5G landing in a C5A transport plane, andNASA designed its alkaline fuel cell for use inspace. Still, no long-term testing of commercialfuel cells under typical marine conditions has beenconducted. The specific mission will control de-sign requirements.

Transient Energy Response

Little is currently known about the response ofmarine fuel cells to abrupt changes in tempera-ture due to sudden, very large changes in load.It has been suggested49 that present fuel cells maynot be able to withstand the temperature changesassociated with abrupt power changes (i. e., chang-

JW--ene Helms, A]]ison Gas Turbine Division, General Motors,personal communication, Oct. 9, 1985,

ing from full load to “all stop”) that occur aboardships. If this is true, fuel cell durability may besignificantly decreased. Problems resulting fromtemperature changes could include fuel cell firesand acid leaks, either of which would render thefuel cell inoperative. Long-term testing, undercontrolled conditions, of responses to electricaland thermal transients is needed to determine thenature of the problem.

If design changes of marine fuel cells are re-quired to address this potential problem, the costof fuel cells for marine applications may increase.Thus, a more sophisticated control system maybe needed, requiring the development of quick re-sponse sensors imbedded in the cell stack and gascontrol system. Electrodes, electrolytes, and fuelprocessors may also need modification.

PAFCs have been the type of fuel cell investi-gated in most studies of marine applications forfuel cells. Other types of fuel cells offer the po-tential for greater efficiency than PAFCs, andthese may be considered for use as marine pow-erplants in the more distant future. Molten car-bonate fuel cells using distillate fuel, for instance,may be more than so percent efficient, and in ad-dition, have the capability to cogenerate high-quality steam, for which ships have well-estab-lished uses. In a 1980 study done for DOE, theExxon Research & Engineering Co. concluded thatfuture molten carbonate systems will be very closeto being competitive with diesel engines and there-fore deserved closer examination. so Alkaline fuelcells using pure hydrogen fuel, although expen-sive, have already demonstrated efficiencies in ex-cess of 60 percent in the space program.

Potential Applications

The marine industry may have a wide varietyof applications for fuel cells of various power out-puts. To date, however, virtually all of the fuelcell development efforts undertaken by manufac-turers and funded by government agencies and

‘“U. S. Department of Energy, “Alternative Energy Sources forNon-Highway Transportation, ” prepared by Exxon Research & En-gineering Co., DOE/CS/05438-Tl, June 1980, pp. 6-27. Exxon alsoconcluded that a coal-fired steam boiler/turbine should be able toundercut the molten carbonate system by $lOO/hp-yr, given coalpriced at $0.90 to $1 .60/MMBtu.

2 5

industry have been associated with advancing thestate-of-the-art of fuel cell technology for land-based gas and electrical utility applications. Thusfar, the only fuel cell designed and tested specifi-cally for marine use has been an alkaline fuel cellbuilt by UTC for a very specialized Navy deep-sea search mission (this application is describedin some detail below). Other than this one project,studies of fuel cell applications in the marine fieldhave been confined to a handful of conceptual andplanning studies initiated by DOE, the MaritimeAdministration, and the Navy.

Given the sparse information available, the Of-fice of Technology Assessment recently invitedsome industry and government experts to brain-storm about some of the possible marine uses forfuel cells. The suggestions may be broadly placedinto seven major categories:

1. Applications in which quiet operation is use-ful or desired:. research ship propulsion and auxiliary

power,• seismic vessel propulsion and auxiliary

power, and● anti-submarine warfare vessel propulsion

and auxiliary power.2. Applications in which power settings are

constantly changing:• tow boat propulsion,• Coast Guard cutter propulsion,• ferry propulsion, and• supply vessels for the offshore oil and gas

industry.3. Submarines and submersibles:

. submersible propulsion (military or com-mercial),

● submarine tanker propulsion, and• remote underwater vehicles.

4. Commercial transport ship propulsion:• tankers,● bulk carriers,● containerships, and• cruise ships.

5. Naval ship propulsion power.6. Commercial and naval ship auxiliary power.7. Other applications:

● offshore platform auxiliary power;● power for remote navigation, radar, or

oceanographic data acquisition and trans-mission systems; and

● power for refrigerated containers.

Very little effort has been devoted to the spe-cific requirements of the above (or any other) pos-sible marine applications for fuel cells relative totheir mission cycles, or to the physical and oper-ating constraints that must be considered for eachapplication and how fuel cells measure up to theseconstraints relative to competing power systems.Until mission requirements and physical and oper-ating constraints are determined for potential ap-plications, it will be impossible to reach defini-tive conclusions about the applicability of fuelcells to specific cases.

Quiet Operation Applications

One of the most logical potential applicationsfor fuel cells is for propulsion and/or auxiliarypower for ships that require or could benefit fromquiet operations. Fuel cells appear to offer a dis-tinct advantage over other powerplants for thispurpose. Moreover, cost considerations are notas severe a constraint if quiet operation signifi-cantly improves the ability to accomplish the ves-sel’s mission. This is particularly true for theNavy’s Anti-Submarine Warfare vessels, wherethe mission requirement, and not cost, is the mainfactor controlling selection of the powerplant. Itmay also be true, but perhaps to a lesser degree,for commercial seismic vessels and for oceano-graphic acoustic research ships, both of whichwould be able to collect better quality data if thepowerplant made less noise. In addition to propul-sion, the fuel cell system could be used for the aux-iliary power and hotel load requirements on suchvessels.

Applications inAre Constantly

Some vessels

Which Power SettingsChanging

are constantly changing speedand/or varying load requirements. - Push= towboats are a prime example. This type of applica-tion may deserve a close look given the capabil-ity of fuel cells to maintain their efficiency overa broad range (30 to 100 percent) of power frac-tion. This capability translates into significant

26

operational savings—in some instances—over die-sel powerplants, which lose efficiency unless oper-ated at full power. However, as noted above, sud-den large changes in power loads may have neg-ative consequences for marine fuel cell operation.Several conceptual studies of these types of ap-plications have been done.

Inland Waterways Push-Tow Boats .—The LosAlamos National Laboratory (LANL) began study-ing possible transportation applications for fuelcells in 1981 when it began a fuel cell R&D pro-gram jointly funded by DOE’s Division of EnergyStorage and Office of Vehicle and Engine Researchand Development. In particular, Huff and Mur-ray of LANL have investigated the feasibility ofusing fuel cells for propelling inland-water, 5,000to 6,000 hp push-tow boats .51 The push-tow boatsnow operating on the Ohio and Mississippi Riversare currently powered by two locomotive dieselengines with direct coupling from each engine tothe propeller through a gear reduction and revers-ing gearbox. The usual tow consists of 15 barges,arranged in 5 rows of 3. With this arrangementthe boat can move a 22,500 ton payload at speedsof 5 mph upstream and 11 mph downstream. TheLos Alamos researchers determined that it is tech-nically feasible to use fuel cells fueled by metha-nol to power push-tow boats. Fuel cell systemsmeet weight and volume constraints, are compat-ible with existing propulsion components, andprovide adequate performance relative to opera-tional requirements.

However, while technically feasible, the re-searchers concluded that using fuel cells for thisapplication is not particularly attractive. Althoughthe efficiency of both PAFC and SPE powerplantsfor push-tow boat use was determined to be great-er than diesel power efficiency (see table 4), dieselsare considered to be very efficient for this appli-cation. Methanol was chosen as the likely mostpractical fuel cell fuel for this application. How-ever, the researchers noted that “the addition ofelectrical systems reduces the fuel cell system effi-ciency to the point where the energy cost disad-vantage of methanol cannot be overcome. ” More-

51J.R, Huff and H.S. Murray, “Feasibility Evaluation of Fuel Cellsfor Selected Heavy-Duty Transportation Systems, ” Los Alamos Na-tional Laboratory, March 1982.

Table 4.—Push-Tow Boat Powerplant Comparisons

PAFC SPEFC Diesel

Total power (hp) . . . . . . . . . . . . . . . . . 5,760 5,760 5,140Powerplant efficiency. . . . . . . . . . . . . 0.55 0.50 0.36Fuel consumption (gal/h)

(methanol/diesel) . . . . . . . . . . . . . . . 411 457 273Upstream energy consumption

(Btu/net ton mile) . . . . . . . . . . . . . . 294 327 401Downstream energy consumption

(Btu/net ton mile) . . . . . . . . . . . . . . 126 140 172Average energy consumption

(Btu/net ton mile) . . . . . . . . . . . . . . 210 234 286Upstream range

(miles for 120,000 gal tank) . . . . . . 832 1,182 1,976SOURCE J R. Huff and HS Murray, “Feasibility Evaluation of Fuel Cells for Se.

Iected Heavy-Duty Transportation Systems, ” Los Alamos National Lab-oratory, October 1982, p 28

over, fuel consumption (in gallons/hour) wascalculated to be greater in both fuel cell systemsconsidered than in the current diesel system, sothat the range possible before refueling is muchreduced. In the case considered, two fueling stopswould be required for the PAFC-powered vesselto travel the 1,890 mile distance from New Or-leans to Pittsburgh. Additional onboard fuel stor-age could be a problem.

Coast Guard Cutters.–Arctic Energies, Ltd.(AEL) reached a more optimistic conclusion in astudy of the potential fuel cost savings that useof PAFCs on Coast Guard cutters might bring. 52AEL combined data on fuel usage and duty cy-cles to determine fuel consumption at variousthrottle positions. They concluded that for thisapplication fuel cost savings (over diesel-poweredcutters) of between 32 and 51 percent were ob-tainable by methanol-fueled fuel cells and DC pro-pulsion drive. The price of methanol used in cal-culations was $0.42/gal. It should be pointed outthat this study was limited to consideration of fuelcost savings only, and that other factors, such asrange, availability of fuel, etc., were not consid-ered. The conclusions reached do suggest, how-ever, that fuel cells used for this application mayeventually deserve a closer look.

SZArctic Energies, Ltd., “Evaluation of the Ship Fuel Cost Sav-ings Potential of Phosphoric Acid Fuel Cell Power Plants and DCDrive for Coast Guard Cutters,” AEL/CGORD 85-1, May 1985.The Coast Guard provided the data for this study but did not sponsorthe research and does not necessarily agree with the study’s con-clusions.

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Fuel cell being installed

Submarines and Submersibles

A major constraint faced by submerged vessels,whether submarines or submersibles, is endur-ance. Fuel cells have been considered for sub-merged operations because they enable underseavessels to remain submerged for a greater lengthof time than the batteries that typically propelsmall submersibles.

The Deep Submergence Search Vehicle (DSSV)and the Deep Submergence Rescue Vehicle (DSRV).—The only fuel cell system developed thus far fora marine application has been the one designedby UTC, using the alkaline fuel cell technologydeveloped by NASA, for use in a deep submer-gence search vehicle for the U.S. Navy, In 1978,Lockheed installed and tested the UTC 30 kW al-kaline fuel cell on board its deep submergencesearch vehicle, Deep Quest. Deep Quest madeabout 50 successful dives with its fuel cell power

Photo credit U S Navy

in submersible Deep Quest

system. Nevertheless, the U.S. Congress termi-nated the program, and the alkaline fuel cell nolonger had a mission. The fuel cell was reconfig-ured for possible application on the DSRV; how-ever, the mission requirements for the DSRV weresufficiently different from those of the DSSV thatit did not require a fuel cell propulsion system.The DSRV is designed to be carried piggy-backon a nuclear submarine, so it could get its batter-ies recharged by the mother submarine, Thus, theinitial power supply was more than adequate forthe submersible’s rescue mission. Moreover, al-though the fuel cell was technically satisfactory,doubts persisted about reliability and system safe-ty in a real rescue situation. High pressure hydro-gen and oxygen to fuel the alkaline fuel cell wouldhave to be stored aboard the mother submarineand transferred to the DSRV for refueling, a po-tential safety problem. In addition, if large quan-tities of hydrogen and oxygen were stored on

28

board, it would be necessary to take off a weap-ons system. In other words, the alkaline fuel cell,technically adequate though it was, did not fillthe mission requirement .53 This example illustratesthe fact that for military applications, the missionrequirement, and not cost, is the major consid-eration.

The Navy has no current effort to develop sub-mersible/submarine fuel cell power systems.However, some believe that small submarines areone type of naval vessel for which fuel cells wouldbe well-suited, providing, perhaps, a less expen-sive alternative to nuclear-powered submarines.For instance, SPE technology is currently beinginvestigated in West Germany as an alternativeto diesel power for submarines.

Submarine Tankers. —Several conceptual engi-neering and economic studies have been done in-vestigating the feasibility of building large sub-marine tankers to transport oil or products suchas methanol and liquefied natural gas from Alas-ka’s North Slope under Arctic Ocean ice to Eu-rope or the U.S. East Coast. In 1982 Arctic En-terprises, Inc., prepared a report for DOE on thefeasibility of building a fuel cell propelled subma-rine tanker system .54 Although the report con-cluded that no engineering or R&D breakthroughswere required to build such a vessel, neither tech-nical nor economic feasibility have yet been dem-onstrated. No oil company at this time is seriouslyconsidering transporting oil or oil products un-der Arctic ice, and the idea is considered by mostto be ahead of its time.

Remote Underwater Vehicles.—Remote under-water vehicles used for search, salvage, inspec-tion, and scientific purposes are also constrainedby onboard energy sources. The principal usersof these vehicles are the oil industry, the Navy,other government agencies such as the NationalOceanic and Atmospheric Administration, andthe scientific community. It is expected that as theneeds arise within the industry and the Navy, sys-tems similar to the DSRV system will be built.

sJTed Stanford, U.S. Navy, NAVSEA, discussion in OTA work-shop, Sept. 5, 1985.

“U.S. Department of Energy, Fuel Cell Propelled SubmarineTanker Svstem Studv, prepared by Arctic Enterprises Inc., DOE/FE I 15086, June 1982.

The scientific community will probably first ride“piggy-back” on industry or Navy fuel cell equippedremote vehicles until it becomes clear that suffi-cient need and funding can be identified for suchequipment to become a part of the community’sUniversity National Oceanographic LaboratorySystem fleet.

Commercial Transport Ships

Fuel cells have been considered as well for com-mercial transport ships. The competition with al-ternative systems is likely to be even stiffer fortankers, containerships, bulk carriers, and thelike. This is because these ships operate at con-stant speeds and currently use high efficiency,low-rpm diesel engines. Use of fuel cells will belimited by industry reluctance to change from apropulsion system that is reliable and efficient.In general, commercial applications for fuel cells,unlike military applications, must prove cost ef-fective. Unless there are clear and significant eco-nomic advantages for fuel cells, they are unlikelyto be used. These advantages have not yet beendemonstrated.

Naval Ships

Cost is not necessarily the major concern inbuilding naval surface ships. Fuel cells will be usedif they prove to be the best technology for a par-ticular application. The Navy has not yet deter-mined that there are any missions for which fuelcells are uniquely suited, although some analyti-cal work has been done.55 Limited availability offuel cell fuel and the low power density are thebiggest constraints in developing fuel cells for na-val ships. As presented above, it is no easy taskfor a fleet to switch to a new fuel. In the Navy’scase, before it would do so, the fuel would haveto be available worldwide. Thus, the Navy willlikely continue to depend on traditional logisticfuels as long as they are available and fulfill mis-sion requirements. A second special military prob-lem concerns the use of low flashpoint fuels suchas methanol. A low flashpoint increases the po-tential for fires, and fuels with low flashpoints

SsFor example, Naval Sea Systems Command, A Total ship Anal-ysis of Future Candidate Naval Fuel Alternatives, report No. 313-011-81, July 1981.

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could be particularly dangerous in a battlefieldsituation, where fires are to be expected. Thus,methanol-fueled fuel cells probably would not fitsome Navy missions even if fuel cells offered othersignificant advantages. A different logistic fuelwould have to be found, or reformer technologywould have to be developed for No. 2 diesel.

Auxiliary Ship Power

Auxiliary power units provide electricity to allsystems aboard a ship except main propulsion.These systems include hotel services (lighting,plumbing, and pumps for water); bilge and bal-last pumps; fuel transfer systems; cargo-handlingsystems; navigation systems; etc. Fuel cells couldprovide electricity for these auxiliary systems. Lesscapital investment, and hence, less risk would berequired than would be the case for investmentin main propulsion systems. Hence, the outlookfor near-term testing of fuel cells for auxiliary pur-poses may be better than the outlook for the useof fuel cells as main propulsion units. However,there are some potential drawbacks to be consid-ered. One would not want to have one fuel forthe main power units and another fuel for auxili-ary power units. Generally, the simpler the fuellogistic system, the better. In addition, althoughfuel cell auxiliary systems may be more efficientthan alternative powerplants, the potential sav-ings possible are not very large compared to sav-ings potentially achievable by switching to moreefficient main propulsion units. Cruise ships maybe an exception to this rule, because they havebig hotel loads; hence, quiet, unobtrusive fuel cellauxiliary power units may be particularly suitedfor this type of ship.

Other Potential Applications

Several other potential marine applicationshave been considered. Fuel cells could be used asa power source on offshore oil platforms. Com-mercial diesel engines and gas turbines providepower at present. Fuel cells could also be used topower remote navigation, radar, or oceanograph-ic data acquisition and transmission systems. Aswith other marine uses, the long-term reliabilityof fuel cells used for these purposes has never beentested. Another possibility is to use fuel cells asan auxiliary power source for refrigerated con-

tainers. Such containers are transferred from shoreto ship and must be kept refrigerated at all times.Sea-Land Corp. has investigated the use of fuelcells for this application and concluded that theidea is not economically attractive at the presenttime. Finally, large, floating fuel cell power gen-eration systems can be envisioned. Such floatingplants might provide power for overseas marketsand could be an export opportunity for U.S. com-panies; however, development of this applicationis not likely at any time soon.

Other Transportation Applications

Train Applications

Investigations of the application of fuel cells totrain transportation systems have been conductedby DOE’s Los Alamos National Laboratory. Com-parisons were made of phosphoric acid and solidpolymer electrolyte fuel cell systems with a con-ventional General Motors’ SD40-2 diesel electriclocomotive. The simulation results show that per-formance goals can be met and that overall ener-gy consumption of heavy-duty fuel cell power-plants can be substantially improved over dieseloperation of locomotives. If development of fuelcells for locomotives is pursued, it may eventu-ally stimulate more interest in fuel cells on the partof marine operators. Powerplants developed forlocomotives have many of the features and per-formance characteristics required for a numberof marine uses.

Automotive Applications

Potential applications of fuel cell technology forland vehicles have ranged from automobiles tobuses and trucks. For automobiles, estimates havebeen made that the fuel cell equipped auto mightbe able to achieve 60 miles per gallon. However,the use of a fuel cell alone for automotive propul-sion leads to a serious deficiency. In the automo-tive field, fast acceleration and changing powerrequirements place quick response requirementson the power system. While fuel cell systems aregenerally considered good load following systemsfor industrial applications, they are too slow torespond to fast and often unpredictable car, bus,and truck power changes. Research is underwayto combine heavy-duty battery power sources

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with the fuel cell system to obtain the responseneeded to accommodate the almost instantane-ous peak power increases required by on-road andoff-road vehicles. The fuel cell would be used torecharge the battery during steady, low demanddriving periods.

Walsh and Rajan are not optimistic about theuse of fuel cells in the automotive industry. Theynote that transportation economics demand rad-ical reductions in the cost of fuel cell systems.PAFCs are currently about 10 times too expen-sive to be considered for transportation markets.56

For fuel cells to become competitive with heat en-gines, major cost breakthroughs must be achieved.Significantly, heat engines can be modified to burnnonpetroleum fuels such as methanol, and there-fore, fuel cells will be in direct competition withheat engines. “Present fuel cell technology is gross-ly inadequate for most transportation applica-tions, and quantum advances are needed. In ouropinion, 10 or 20 years of intensive R&D withstrenuous attempts at invention will be re-quired.” 57 Other factors, such as higher fuel effi-ciency, reduced maintenance costs, and reducedpollution may compensate, to some degree, forproduction costs. General Motors, on the otherhand, is more optimistic, and is currently inves-tigating the potential of phosphoric acid and SPEfuel cells for land transportation uses. ’g

Some Options for theFederal Government

The outlook for using fuel cells in the electricand gas utility industry appears promising. TheFederal Government has supported private sec-tor R&D efforts since the 1960s. Continued Fed-eral support of fuel cell development programsis probably necessary to advance the introductionof fuel cell technology into the land-based utilityindustry.

The use of fuel cells in the marine industry inthe next 15 to 20 years is far less certain. Whenand if the commercial maritime industry decidesthat fuel cell power systems would provide sig-

s~w~l~h and Ili=ijan, op. cit, I p” 6““Walsh and Rajan, op. cit., p. 9.“Gene Helms, Allison Gas Turbine Division, General Motors,

telephone conversation, Nov. 6, 1985,

nificant cost and/or other advantages over com-peting power systems, these fuel cell systems mustbe adapted to the unique demands of the marineenvironment. Very little R&D on fuel cells for ma-rine applications is currently underway inside oroutside the government. Since the R&D programfor land-based applications is so large in compar-ison, some believe that the proper course for themarine industry is just to monitor closely thatR&D and select developments and applicationsas they may occur in the future. Others believethat unique marine requirements warrant special-ized R&D efforts.

Specific research and development could besupported by the Federal Government and/or in-dustry to improve the potential of fuel cells in themarine market. For example, the near-term useof fuel cells in the marine industry could be stim-ulated by developing technology capable of re-forming diesel oil. Other research that could beundertaken includes: laboratory testing, followedby shipboard analysis and testing, of fuel cell com-ponents to determine their suitability and/or vul-nerability to the marine environment; basic elec-trochemical studies to improve catalysts andelectrolytes that would not be contaminated byfuel processed from fuel oil; and accelerated in-vestigation of molten carbonate fuel cells and ofthe vulnerability of this type of fuel cell to the ma-rine environment. The Federal Government’s in-vestment in molten carbonate technology couldconcentrate on those developments needed to sup-port a demonstration of this fuel cell’s higher effi-ciency and fuel flexibility. The private sector couldfocus on the technology and processes needed tomanufacture these fuel cells at a cost competitivewith conventional power generators.

The Maritime Administration, and perhaps otheragencies within the Department of Transporta-tion, and DOE might be able to offer some assis-tance for applications more directly relevant forthe commercial transportation sector. For in-stance, funding could be provided to demonstrateand evaluate use of a fuel cell system on a com-mercial ship or locomotive. One suggestion is thatfuture fuel cell research for heavy-duty transpor-tation applications focus on developing the moreefficient molten carbonate fuel cells. Once a small(i.e., 50 kW) molten carbonate system has been

31

demonstrated, these agencies could coordinate ademonstration of a 2 to 4 MW powerplant for theheavy-duty transportation sector. Different typesof incentives to private industry might also beused, such as tax benefits for those who use non-petroleum-based fuels or accelerated depreciation.

The Federal Government may also wish to en-courage the Navy, Army, Air Force, and CoastGuard to become more involved in developingfuel cells for their mission requirements. OTA’sanalysis indicates potential benefits of marine fuelcell use in naval applications, and suggests thatmore in-depth analysis of the potential applica-bility of fuel cell technologies for Navy missionsis needed.

The Navy is currently monitoring fuel cell de-velopments, but it may be useful for the Navyto consider supporting specialized research intomarine fuel cell development as well. At present,for example, very little work has been done ondeveloping fuel cells for “quiet” ship operationaboard certain vessels where noise emissions from

conventional engines are a major problem. If fuelcells could match these and other unique Navymissions, then naval fuel cell research, independ-ent of private sector efforts, may be justified.

Recognizing that research funds are limited andmust be carefully targeted to the most productiveavenues of research, it may be best to begin byencouraging the military to develop small fuel cellsystems for auxiliary power on naval surfaceships. As experience is gained, larger fuel cells (onthe order of a megawatt) might be used for navaland Coast Guard auxiliary power. Finally, be-yond 2000, the Navy or Coast Guard could beencouraged to focus on developing larger fuel cellpowerplants for primary propulsion power. TheNavy and Coast Guard have different missionsthan the civilian sector and some applications de-veloped by them may not be directly useful forthe private sector. On the other hand, some ap-plications first developed for military purposesmight stimulate development of applications forcommercial use.

GLOSSARY

alkaline fuel cell: Fuel cell using alkali (a type of solublesalt) as the electrolyte. Operates at 650 C. First de-veloped for NASA. Uses pure hydrogen andoxygen.

anode: The negative electrode or terminal of a fuel cell.base load: The normal, relatively constant demand for

energy on a given system.bottoming cycle: A means to increase the thermal effi-

ciency of an electric generating system byconverting some waste heat into electricity ratherthan discharging all of it to the environment.

British thermal unit (Btu): The amount of heat requiredto raise the temperature of 1 pound of water 10 Funder stated conditions of temperature and pres-sure. It is the standard unit for measuring quantityof heat energy.

Carnot cycle: An ideal heat engine cycle in which thesequence of operations forming the working cycleconsists of isothermal expansion, adiabatic expan-sion, isothermal compression, and adiabatic com-pression back to its initial state. An ideal Carnotcycle engine converts heat into work with the max-imum theoretical efficiency.

catalyst: A substance that changes the rate of a reac-tion without itself undergoing any net change; asubstance that induces catalysis.

cathode: The positive electrode or terminal of a fuelcell.

carbon monoxide shifter: Used in processing fuel.Transforms carbon monoxide (CO) to carbon di-oxide (CO2).

closed Brayton cycle: An external combustion gasturbine engine. Potential propulsion system forfuture ships.

cogeneration: Production of electrical (or mechanical)energy and thermal energy from the same primaryenergy source.

controller: In a fuel cell system, controls supplemen-tal power during the startup operations, stackcooling and gas flow during power and holdoperations, and close-down operations. Usestemperature, gas flow, and other sensors andmicroprocessors to perform its functions.

distillate fuel: The lighter fuels distilled off during therefining process. Includes Nos. 1 and 2 heating oils,diesel fuels, and No. 4 fuel oil.

electrochemical: Chemical action employing a currentof electricity to cause or to sustain the action.

electrode: Reactive materials, such as metals and metaloxides, attached to grids that conduct electricity.

electrolyte: A conducting medium in which the flow

of electric current takes place by the migration ofions.

flashpoint: The lowest temperature at which thevapors arising from a liquid surface can be ignitedby an open flame.

fuel processor: Same as reformer. Converts a stock fuelto a hydrogen-rich gas for use in fuel cells. Alsoremoves impurities.

fuel cell stack: A stack of individual fuel cellsconnected in parallel to provide the desired totalpower.

heat rate: A measure of thermal efficiency, generallyexpressed as Btu per kilowatt-hour.

inverter: A device for converting direct current to alter-nating current.

kilowatt: A unit of power equal to 1,000 watts.life-cycle cost: The accumulation of all funds spent for

the purchase, installation, operation, and mainte-nance of a system over its useful life. The accumu-lation generally includes a discounting of futurecosts to reflect the relative value of money overtime.

load: The energy tapped from any power source. Inthe electric industry, the amount of electric powerdelivered or required at any specified point or pointsin the system.

load following: A utility power generator used to copewith swings in the load.

megawatt: One million watts, or 1,000 kilowatts.molten carbonate fuel cell: Fuel cell using molten car-

bonate as the electrolyte. Operating at from 6000to 7000 C. Able to use a variety of fuels. Internalreforming potential.

oxidant: A chemical element or compound that is ca-pable of gaining electrons, i.e., of being reduced.

peak-shaving: A type of utility powerplant operatedonly when the need for additional power is tempo-rarily high.

phosphoric acid fuel cell: Fuel cell using phosphoricacid as the electrolyte. Operates at 1500 to 200° C.

power conditioner: Receives electrical power from thefuel cell stack and converts it to match the requiredoutput .

power density: The amount of power per unit of cross-sectional area.

reformer: Same as fuel processor. Converts a stock fuelto a hydrogen-rich gas for use in fuel cells. Alsoremoves impurities.

sintering: The agglomeration of solids at temperaturesbelow their melting point, usually as a consequenceof heat and pressure.

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solid oxide fuel cell: Fuel cell using solid oxide as the elec-trolyte. Operates at temperatures close to 1,000° C.Less developed than phosphoric acid fuel cells.

solid polymer electrolyte fuel cell: Fuel cell using solidpolymer as the electrolyte.

steam turbine: A machine powered by high pressuresteam and used to drive mechanical apparatus. Ithas a rotary motion in contrast to a reciprocatingmotion.

Stirling cycle: An external combustion engine underdevelopment. Has the ability to use any heat source.Prospects for high efficiency. A potential propulsionsystem for future ships.

3 3

thermal inertia: The tendency for a heat machine togenerate heat at the same level at all times.

thermal signature: The heat trace that may be detectedfrom an energy source, such as a submarine.

thermal transient: Abrupt changes in temperature dueto sudden changes in load.

watt: A unit of power that equals 1 absolute joule persecond. It is analogous to horsepower or foot-pounds per minute of mechanical power. Onehorsepower is equivalent to approximately 746watts.