Platinum Metals Rev., 1991, 35, (4), 209
Second Grove Fuel Cell Symposium
Platinum-Bearing Fuel Cells Emerge as Initial Choices for Commercialisation
In the year in which the bicentenary of the birth of Michael Faraday is being celebrated, a second Grove Fuel Cell Symposium was held at the Royal Institution, London, from 24th to 27th September, 1991. Following the Introductory Discourse, around two hundred and fifty delegates, mainly from Europe, Japan and the U.S.A., listened to twenty-six papers, addressing the theme of “Progress in Fuel Cell Commercialisation”. After the opening Keynote Review on future prospects for fuel cells, individual sessions examined market development, commercial initiatives, manufacturing and systems development, transport applications, and concluded with visions for fuel cell exploitation in the twenty-first century. Apart from alkaline (AFC) devices, which contain high platinum loadings and which are considered to be fully developed with mainly specialised applications for space and military use, phosphoric acid (PAFC) and solid polymer (SPFC) types are now becoming available commercially from U.S., Japanese and Canadian suppliers; these also use relatively high platinum group metal loadings. Once again, the superior catalytic activity of platiniferous metals is aiding the development and introduction of this entirely new technology.
This conference brought together international figures actively concerned with introducing fuel cells into the market place. Thus, speakers were drawn from leading developers and utilities in the U.S.A., Japan and Germany but also included four contributions from the United Kingdom. Dutch, Italian and Canadian interests were again represented with Spain emerging as an interested party. The level of interest in, and future prospects for, fuel cells was demonstrated by the large attendance.
The meeting was formally opened on Tuesday evening by Dr. G. J. K. Acres, Chairman of the organising committee, and Professor A. J. Appleby of Texas A. & M. University, well-known for his advocacy of fuel cells and sometime presenter of submissions on the subject to U.S. Government assemblies. Professor Appleby then introduced Dr. Francis “Tom” Bacon, who had devised, constructed and operated the world’s first viable fuel cell more than half a century ago. Tom has received many awards in recognition of his pioneering work including an O.B.E., F.R.S. and Fellowship of Engineering — on this occasion he was presented with the first Sir William Grove Medal, cast in platinum. In accepting the medal, Dr. Bacon recalled his numerous collaborators and recounted the continuous battle for funding that he had experienced over many years. He had been lucky, felt his efforts had been worthwhile and encouraged persistence with future fuel cell development.
Following this presentation, Ing. K. Swart, former Managing Director of the Shell Group, gave the introductory discourse on “Trends in the Energy Market after World War II”. This drew heavily on his experiences in the oil industry which has dominated post-war development in the West. Notwithstanding, Swart was able to identify the major socio-political and economic influences over national development, which might point the way forward to a more rational future energy strategy. While oil had initially shown the strongest growth trend in the energy sector during the post-war period, gas finds offshore and in the U.S.S.R. had made a sizeable impact more recently, at the expense of coal utilisation; nuclear capacity had risen to about 20 per cent of energy supply. Electricity had grown steadily as a percentage of the stationary energy generation market. Similarly, as living standards had risen, demand for travel in general and private transport in particular, had grown to monopolise oil supply, requiring conversion of plant to crack more heavy fuel oils to light fractions. He pointed out that the oil supply hiatus in 1972 was a political crisis, and predicted that it was this aspect of human endeavour which would remain least predictable in the coming decades. Environmental issues were now of concern in the West, requiring higher energy efficiency to reduce the pollution burden, although it would be unreasonable to expect constraint by the developing world in this area.
For the future, Swart warned that “nothing can grow forever without … major problems”. Thus, the growth in demand for electricity, lowered by recent improvements in the efficiency of end-use devices, would again increase. Energy demand in Eastern Europe and South East Asia would continue to accelerate. Coal and gas should be retained to prevent dependence on oil, with gasification a promising technology. Governments should sponsor steady research, design and development, and efficient technologies, using the wealth generated from energy taxation. Long term strategies were required — “stop-go” policies were inappropriate. Of all the most promising new technologies, Swart would support biomass for sustainable energy resource. During his address he had deliberately avoided mention of fuel cells. His final comment advocated electrochemical energy conversion as the best contender to meet the needs of a clean, efficient future for both the presently rich and the poorer nations.
At the start of the technical proceedings on the Wednesday morning, the Chairman, Dr. G. J. K. Acres of Johnson Matthey introduced W. P. Teagan of Arthur D. Little, who gave the Keynote Address, based on recently commissioned studies, entitled “The Role of Fuel Cells in the Future Energy Scene”. Teagan’s talk was illustrated with data showing predictions for energy growth according to some of the many suggested scenarios. Again, it was the expected doubling in demand for energy by the developing nations that provided one focus. Although their per capita energy consumption rate would remain relatively small, with their expected population growth an increasing world environment burden would become apparent, with carbon dioxide the most insidious contributor to global warming. Present projections predict only modest improvements in energy efficiency, whereas selection of specific advanced technologies, most notably fuel cells, could dramatically reverse the trend; this would be especially so if end-use efficiencies were raised and electric vehicles were adopted. A Table showed reductions between 20–70 per cent of primary energy sources across the spectrum of possible uses as a result of fuel cell introductions. In large scale stationary applications, cost benefits of fuel cells were compared with alternative advanced technologies; turbines and clean coal devices may prevail in the next decade, especially as multi-MW fuel cells are in their infancy. In smaller and dispersed applications, cogeneration and combined heat and power (CHP) will become important. Here, the innate efficiency, flexibility, modularity and low emission of the fuel cell would be crucial since the types of competing plant to cover this range, when fitted with emission controls, are equally or more expensive. Traction applications are further away and more demanding, even though present developments are both exciting and promising.
Requirements across the market sectors for power generation equipment were outlined in order to evaluate the overall market size; this led to projections of a total of 800 GW, with 580 GW of new capacity, needed within the decade, of which 55 per cent would be centralised. Assuming a 5–15 per cent market share for <50 MW capacity, fuel cells could fulfil 4 GW/year by the year 2000 in stationary applications. This would depend on their achieving reliability beyond 25,000 hours, efficiencies of at least 40 per cent (HHV to electricity) and approximate costs of $1500–1700/kW for early models and $1200/kW for mature models.
Finally, Teagan addressed the availability of the necessary high value materials to meet the manufacturing requirements of the various fuel cell types. Due to the gradual lowering of platinum loadings in PAFCs, this now accounted for only $60–70/kW stack costs, so that 4 GW installed by the year 2000 would only require 14 per cent of platinum production, or 500,000 ounces which is well within the capability of the industry. Contentiously returning to the political theme, he was concerned about government (sic) largesse towards competing military technologies such as nuclear and aerospace-derived gas turbines. Governments need to be aware of the prospects offered by fuel cells and directly fund early commercialising efforts. So far, fuel cells had been relegated to a “well-kept secret”; this had to be reversed.
Development of the Market
The morning programme was continued with three contributions describing the market possibilities for fuel cells in Europe, America and Japan. M. C. F. Steel of Johnson Matthey began by updating his Company’s 1985 study for the Commission of the European Communities with an altogether more optimistic prospect. In the European Economic Community, the 5 per cent growth of electricity demand to 350 GW in the 1970s, had fallen back to 3 per cent by the mid-1980s, and was now approximately 1–2 per cent. Similar trends had occurred throughout the rest of Europe, except that there the growth rate remains at 2–3 per cent. Additional growth into the next century could remain around 2 per cent overall, although ~ 140 GW of replacement plant will be required by 2010. Steel then outlined the limits to growth for nuclear plant post-Chernobyl and for hydro-electric on environmental grounds. These factors profoundly affect the energy policies in Italy, Germany, Austria, Netherlands, Sweden, Norway and Spain — some on both counts. Acid rain considerations were strongly influencing German and Swedish policy against thermal cycle plant.
Thus, two strategies towards fuel cell demonstration and introduction in Europe were emerging: one involving the purchase of available Japanese or American stacks or plants, and the other in attempting to develop an all-European technology. According to the first option, Milan was due to demonstrate an International Fuel Cells Corporation (I.F.C.) 1 MW PAFC stack in 1992, using a Haldor-Topsøe reformer and Ansaldo plant, this being the largest system presently envisaged in Europe. Elsewhere, I.F.C. 200 kW PAFC units were destined for Germany, Sweden and Denmark; a Westinghouse 400 kW PAFC would be hybridised into a Norsk Hydro chloralkali plant; Fuji Electric PAFC plants of 50–200 kW were scheduled for Italy, the Netherlands and Germany (the latter for Solar Wasserstoff Bayern’s (S.W.B.) solar hydrogen project), while Energy Research Corp. (E.R.C.) MCFCs would be supplied to the Danes and Germans (through Messerschmitt Boelkow Blohm (M.B.B.) — a shareholder).
Alternatively, AFC and solid oxide (SOFC) technologies are already available in Europe, the former at Elenco, Siemens, GEC Alsthom and in Austria, the latter at Asea Brown Bouveri (A.B.B.), Dornier and Siemens, among others. Meanwhile, the Dutch have established a strong presence in MCFC using Institute of Gas Technology (I.G.T.) configurations, M.B.B. will construct 2 MW/year of MCFC using E.R.C. designs, with Spain and Sweden also actively promoting this high-temperature cell. The most promising SPFC technology was being acquired by Germany, Italy and the U.K. amongst others. Steel defined the European markets for fuel cells and concluded optimistically, suggesting fuel cell interest was now being converted into action.
E. A. Gillis of Electric Power Research Institute (E.P.R.I.), California, provided a comprehensive account of fuel cell development during the last three decades; this had culminated in a lack of user acceptance. He felt that fuel cell commercialisation had been retarded by a failure of potential users to fully appreciate the benefits. Head-to-head cost competition is problematic for any new technology unless niche markets are available. However, a radical change is now underway in the U.S.A., with publication of the Clean Air Act. This will deliberately distort energy market forces by direct government interference which has become necessary to prevent further environmental decay. The law particularly affects sulphur dioxide emissions nationwide, but is region-specific for nitrogen oxides and ozone reductions. The requirement for 2 per cent zero-emission vehicles ordained for California has been internationally publicised. A more subtle consequence of the Act surrounds the trading market established in emission allowances. If any organisation underscores its target, then the balance of emissions permitted can be sold elsewhere. Thus, the installation of virtually zero-emitting fuel cells could lead to substantial rewards over and above those accruing from lower maintenance, higher efficiency, etc. Furthermore, additional environmental legislation is in prospect, certainly including carbon dioxide emissions. Together with regulations, yet to be enacted, on mandatory fuel substitution and restriction on electrical transmission systems, the tangible benefits of fuel cell technology promise to bring immediate financial reward since their attributes would become quantifiable. Both utility and transport could expect to benefit.
The logical approach to fuel cell commercialisation being adopted in Japan was outlined by A. Fukutome of the National Energy Development Organisation (N.E.D.O), Tokyo. Attractive applications had initially been identified, time and size targets had been determined, then resources had been directed towards the necessary research, design and development to achieve those goals. In the first part of this approach, government agencies had established the break-even costs for fuel cells in utilities (dispersed, centralised and remote), for on-site cogeneration and in industrial and transport sectors. Next, the market was assessed for dispersed PAFC in CHP/cogeneration modes in both industrial and residential sites; the commercial sector alone would require 2.4 GW/year in the 2000s, amounting to about $150m/year in platinum sales according to Teagan’s formula!
M.I.T.I. had contributed with a long range study of Japan’s energy needs: energy saving and a 70–fold increase in fuel cell introductions by 2010 were advocated. At present, two different 200 kW and one 1 MW PAFC plants had been developed for N.E.D.O. as well as an advanced 5 MW sized turbo-compressor. Both square and rectangular MCFCs have been developed, the former up to 25 kW for pressurised operation; 100 kW designs were scheduled for 1991 and 1993, respectively. Meanwhile, a 5 kW internal reforming MCFC was being studied. Associated balance of plant technologies for 1 MW MCFC are being developed. Four planar and one tubular SOFCs are being evaluated — scale up to tens of kW are envisaged in a new programme.
For the future, N.E.D.O. is beginning a new five year PAFC programme to develop a 5 MW pressurised and a 1 MW unpressurised plant. In addition private sector activities, including the 11 MW demonstration unit from Tokyo Electric Power Company (TEPCO)/I.F.C., were proceeding. Goals still remaining are cost reduction and reliability, and provision of economic, political and infrastructure support.
Chairing the afternoon session, Dr. A. L. Dicks of British Gas called upon J. A. Serfass of Technology Transition Corp. and D. R. Glenn of E.R.C. to jointly outline their cooperative approach and progress in the American Public Power Association’s (A.P.P.A.) Notice of Market Opportunity (NOMO). In this unique venture, E.R.C. had successfully responded to A.P.P.A.’s invitation to develop multi-MW fuel cells in a shared partnership leading to a product available for Public Power members in the mid-1990s. Initially, a 2 MW gas fuelled, internally reforming MCFC had been selected for trial. A document of “Principles … for Commercialising … Fuel Cell(s) …” delineated the respective responsibilities of the supplier and the users, and included agreed milestones, risk and royalty sharing as well as user commitment and incentives.
Technically, a fuel cell with a projected heat rate of 6350 Btu/kWh at 54 per cent efficiency (LHV), operating at 1200°F, should be constructed at a cost of $1000/kW (1990 $); a later version should have a lower heat rate, higher efficiency, be water-independent, but will cost more. Longer term targets anticipated 100 MW units and coal-gas fuelling. The first demonstration should begin this year, with the first unit operating in 1994, with 100 MW of initialled orders by the end of that year at $1500/kW. These are early target dates which could accelerate MCFC displacement of PAFC if met. The NOMO is now supported by twenty-three utilities, with a hope to raise this to thirty-five. Santa Clara is the lead demonstrator, obtaining financial and technical support from E.P.R.I, and other south west Pacific Coast interests. A 20 kW stack with full balance of plant has been successfully tested, grid-connected, by Pacific Gas and Electric (P.G.E.) at San Ramon.
J. Doelman of N.V.Nederlandse Gasunie focused on CHP applications of fuel cells in a Dutch context and from the viewpoint of a gas utility. While gas prices are State regulated and differ for domestic and industrial consumers, there already exists some commonality between gas and electricity distribution companies who may themselves be electricity generators. Furthermore, some energy-intensive and chemical industries are already CHP users, with Gasunie support, but cheaper electricity had blocked further moves to grid independence. Notwithstanding, Doelman foresaw the small, dispersed CHP market as the best growth prospect for fuel cells, especially as they offered a diminished carbon dioxide inventory, coupled with very low nitrogen oxides emission. He illustrated the other perceived advantages of fuel cells by reference to PAFC, suggesting that claims of efficiency, modularity and variable heat/power ratio were suspect, whilst reliability was unproven. The efficiencies of MCFC and SOFC were not without attraction, if overstated, but these technologies were not yet mature. Nevertheless, the integrated systems described by Blomen, see below, could lead to very high overall electrical efficiencies. Gas utility experience with presently available turbine and engine CHP plant will prepare for later fuel cell demonstrations.
K. Shibata of Tokyo Electric Power Company (TEPCO) painted a more inspiring and bullish approach. The Company had actively participated in demonstrating PAFC technology for many years with the result that Japan expected to install ~ 1 GW capacity by 2000. All aspects of installation and testing had been examined since the early United Technologies Corp. (U.T.C.) 4.5 MW design in 1981: the International Fuel Cells Corporation (I.F.C.)/Toshiba 11 MW, the Sanyo (air-cooled) 220 kW and the I.F.C. 200 kW units had now begun trials. Two pre-prototypes of the latter design had accumulated around 7000 hours and 10,000 hours of satisfactory operation, although their gradual decline in performance requires improvement. The second of these had been incorporated into the district heating plant at Shibaura in order to assess its capability for various heating and cooling functions. Emissions were very low and maintenance tasks routine.
The 11 MW PC–23 I.F.C. PAFC has now begun trials at Goi; palletised, pre-assembly modularised design reduced site construction time to just over 1 year. Process and control testing had been completed in two-thirds of the allotted period, which included run-up to stand-by readiness on a 30 per cent simulated load. Full output was achieved on April 26th 1991, with all specifications being met or exceeded. Gross HHV efficiency was 43.6 per cent, with nitrogen oxides emission at 1 ppm. At July 31st, 1991, some 927.5 hours of operation, amounting to 6598 MWh had been recorded, although during his lecture Shibata was able to update that to 1414 hours of operation (875 hours continuous) providing 10,263 MWh of power (presumably mid-September 1991 data). Only minor maintenance had been required so far. Testing is to continue for two years in order to confirm reliability, flexibility and heat utilisation characteristics in the dispersed power supply, CHP mode. It later emerged that TEPCO is now considering an extension of testing beyond 10,000 hours. In spite of early successes, cost reduction remains a major goal; some will come from automated mass production, but additional innovation, especially in the stack, is desirable. International co-operation would be the cornerstone of successful introductions of fuel cells to the market. The present successes with platinum-based PAFC plants, would be a prelude, however, to later MCFC and perhaps SOFC technologies, in which TEPCO is now beginning studies.
J. Packer of Combined Power Systems proposed that fuel cells could become viable in the small-scale CHP market, especially following the 1983 Energy Act in the U.K. which had stimulated demand. Packer enumerated the key elements of a CHP system together with their typical present applications. Based on the perceived advantages of fuel cells, he indicated that they could become the only prime mover in sub-30 kW systems, as well as having certain attractions above that rating. Through-life costs are more important than capital costs; security and stability of the manufacturer are equally important for assured endurance. Nevertheless, it is too early to obtain accurate information on fuel cell reliability, hence field demonstrations are urgently required. Detailed technical formulae were provided for assessing fuel cell cost-benefits; these showed up to four-fold savings compared with conventional sets, allowing over three times higher installed costs with greater payback. Lifetimes needed to achieve 40,000 hours. Analysis suggested that SPFC units, using platiniferous catalysts, could meet the requirements for low pressure, hot water systems. Packer raised many questions concerning fuel cell suitability and, in spite of later discussion which tried to define who the “customer” was, he indicated that he was a purchaser on behalf of his power-using clients. In the complete package, users were not concerned as to the means of power generation–only cost and reliability.
R. Vellone of ENEA described the present status of Italian fuel cell programmes. Like Japan, the nation depends on imported fuel and like Sweden, it has voted against nuclear power. Since coal is environmentally problematic, natural gas fuel cells providing 4–15 GW capacity by 2010 appear attractive, particularly if deployed in dispersed mode. The Government’s National Energy Plan is supporting growth of municipal electric utilities and equipment suppliers. As an early step, some 0.25–1 MW on-site fuel cell capacity is envisaged: additional focus on transport applications is underway. In Milan, the 1 MW PAFC I.F.C. stack has been installed and engineered by Ansaldo at Bicocca, supported by Milan Energy Municipal (A.E.M.) and ENEA, and using a Haldor-Topsøe reformer. Testing is planned for 1992 prior to full commissioning at the end of that year. Elsewhere a 25 kW Fuji PAFC has been engineered by Kinetics Technology International (K.T.I.) near Rome and a similar 50 kW unit near Milan. In 1992, an I.F.C. 200 kW PAFC will be constructed by Ansaldo, in Bologna in co-operation with ENEA and the Commission of the European Communities (C.E.C.) THERMIE programme. Small generators in the range 1–5 kW are also under study.
Ansaldo has designed, built and tested a 1 kW MCFC stack and will co-operate with I.F.C. towards a 100 kW plant for 1994. Ginatta is bringing its extensive experience of molten salt and electrochemical systems to bear on internal reforming MCFCs. A number of collaborative SOFC programmes are underway, including C.E.C., JOULE and BRITE ventures and a CNR-TAE-U.S.S.R. co-operation. SPFC development for transport applications is making rapid progress at de Nora towards a 10 kW stack for 1992; in the meantime, ENEA will evaluate a 4 kW Ballard stack. A well co-ordinated series of government funded programmes across the spectrum of fuel cell types and applications is gathering pace in Italy.
In an extra paper to the programme, G. J. Sandelli of I.F.C., co-author R. J. Spiegel of the U.S. Environmental Protection Agency (E.P.A.), reported an interesting new application for fuel cells in energy recovery from landfill gas. A Phase I study of the concept had begun in January 1991 at I.F.C. under an E.P.A. contract. Phase II, starting in September, concerned construction and testing of the four 200 kW PAFC plants required for the 800 kW module, including operation of the critical pretreatment plant designed to remove catalyst poisons such as sulphur and halides. Phase III would entail demonstration at Penrose, California, around January 1993.
Sandelli indicated that this application offered several benefits simultaneously over present practice; thus, methane consumption would mitigate one contribution to atmospheric pollution and global warming, and heat and power would be generated competitively in high energy cost locations, providing new revenue for site owners.
Manufacturing and Systems Development
On Thursday morning, Mrs S. Fleet of the U.K. Department of Energy, introduced R. Anahara of Fuji Electric, who described the continuing progress in PAFC manufacturing in his Company. So far, 17 demonstration plants, totalling 2 GW of capacity had been supplied. A further 63 plants totalling 9.7 MW capacity were expected to be ordered; one for Korea had only just been ratified in the previous week. Of these, the largest are the 5 MW PAFC units, designed for pressurised operation and destined for electric utilities. Construction times would be under four years. The improved 0.8 m2 electrodes had superior performance to those used in the 1 MW developmental models, with a voltage decay of only one-third of that projected for 40,000 h life in the first 5000 hours and a mere one-fifth in the next 5000 hours. Over 70 sets of 50 kW and 100 kW were planned, four for Europe, with a total capacity ~4.7 MW. Ten such cogenerating plants are presently in operation in Japan, including six sets under test at Rokko, for Kansai Electric. Power densities approaching 5 kW/m3 have been achieved. Equipment improvements and system simplifications would lead to cost reductions, particularly with mass production.
Apart from natural gas, Fuji has also developed methanol, liquified petroleum gas and naphtha fuelled plants; methanol was favoured for remote sites and transport, since it could be stored and transported as a liquid at ambient and could be reformed at low temperature ( ~300°C). Presently, three 50 kW PAFC sets are under construction for the U.S. Department of Energy bus demonstration. Anahara was confident that Japanese Government support, through M.I.T.I.’s Long Term Energy programmes, was providing the correct framework for successful fuel cell introductions. Aggressive acceleration of PAFC development in co-operation with utilities and government agencies would soon lead to a viable commercial product.
Recent progress achieved in SOFC technology by Westinghouse Electric was described by W. J. Dollard. Their configuration was based on tubular cells, with direct reforming of natural gas or coal gas and cogeneration with coupled thermal-cycle plant to use the high-grade exhaust heat. Following the recent trials of two 3 kW sets in Japan, a further two 25 kW units were under construction for imminent delivery. Small bundles had demonstrated 5000 hours of operation, with single, laboratory cells exceeding 20,000 hours. Scale-up of the present 50 cm long cell to 100 cm was initiated this year, which would enable plants to be constructed with outputs of hundreds of kW; longer cells were required for MW units. The U. S. Department of Energy is supporting a further five year development programme with $64m, with a view to demonstrating a 2 MW plant in 1995.
L. J. M. J. Blomen of K.T.I./Mannesmann, The Netherlands, outlined a decade of fuel cell related systems development, culminating in the construction of two 25 kW and one 80 kW plants using imported stacks. Their market surveys had suggested that small ( ~25 kW) fuel cell systems become competitive at production levels of a few hundred, while 250 kW sets achieve viability at a smaller volume rate. Above 3 MW sizing, advanced thermal cycles are competitive if environmental constraints are ignored. Decentralised stations of ~100 MW could also show cost-benefits in favour of fuel cells.
The first (Engelhard) 25 kW PAFC had now been dismantled for analysis after one year of operation. The second unit (Fuji stack) had been installed at Delft, but was compromised by water ingress and had to be rebuilt. A third unit for ENEA had also been delayed during the recession. An 80 kW unit, incorporating Fuji stacks, has been installed and successfully started in Bavaria in the S.W.B. advanced solar storage-electrolysing hybrid fuel cell plant; early data confirmed operation within specification. Present strategy envisaged capacity expansion, increases in sizing to 1–10 MW together with substantial cost reductions arising from acquired experience and economies of scale; only 1–3 units of 10 MW need be ordered to achieve $1500/kW, whereas a production run of 50 units would be needed at the 250 kW size to attain this costing. Hybridising fuel cells with rotating machines could bring electrical efficiencies above 60–65 per cent. The market share for such plant would depend on the extent of the growth in dispersed installations: transmission costs could be determining.
C. M. Seymour of Vickers Shipbuilding & Engineering Ltd., (V.S.E.L.) related details of a long-term, joint venture with CJB Developments to package power systems based around Ballard SPFC stacks. Markets included military, on-site small commercial and transport, the project being applications driven. Information sharing with Ballard would bring hardware improvement benefits. With reasonable market penetration, this should add another new outlet for platinum catalysts, especially as other more exotic substitutes capable of operating at low temperatures (80–120°C) would prove too expensive, if available.
Initially, a 20 kW methanol-fuelled device would be demonstrated; other fuel compatibility would be introduced later. In designing the total system, conflicting aspects of good engineering practice, performance optimisation and costs had to be rationalised. Thus, a model had been devised capable of accepting data variables emanating from stack trials. Other stack testing aimed to establish performances on synthetic reformates and in the presence of carbon monoxide. Applications studies were examining fuel cell/battery hybrid systems, auxiliary and field generators, submersibles and extended duration air-independent power systems for submarines. A target specification for market acceptance of SPFC technology was provided; if met, acceptance could occur within five years. Notwithstanding, a 5 kW stack was operated during the Symposium in the “static” exhibition, where it powered one of the famous Emmett models.
H. Wendt of the Chemical Technology Institute, Darmstadt, reviewed past and present developments in fuel cells in Germany. Activities were being funded and co-ordinated by the Government in collaboration with industry; an DM80m (~£27.5m) programme had been initiated this year, and included both SOFC and MCFC technologies. Being a 13 per cent shareholder in E.R.C, M.B.B. — part of the Daimler-Benz empire — would participate in the construction of their 2 MW/year pilot manufacturing facility in the U.S.A., under a license agreement. Some of the 100 kW MCFC demonstration units produced would go to Germany and would be fuelled by both natural gas and coal gas.
Dornier, Siemens and A.B.B. are engaged in SOFC development, the former two on flat-plate designs, the latter on a thin-layer type. It was hoped that these companies could test kW stacks within three years.
The last paper in the morning session by E. H. Cámara of M-C Power directly addressed that Corporation’s aim to build and sell I.G.T. internally-reforming, internally-manifolded IMHEX® MCFC plant, fuelled by natural gas. The attractions of this design are compelling: carbonate electrochemical pumping by differential migration in the stack is eliminated, gas sealing is enhanced, less corrodible pipework is required and dimensional changes during operation are automatically accommodated. Market entry sizing would range from 500 kW to 3 MW both for on-site and dispersed loads. 30 to 50 MW centralised, baseload plant with coal gasification could follow. Initialled orders by 1995 could be filled by 1997. The Burr Ridge manufacturing facility would produce 3 MW/year. An industrial support group/alliance (ACCT) had been formed to monitor the technical aspects and provide market intelligence. Since incorporation, M-C Power had this year assembled and tested a 70 cell stack, and confirmed stable performance. A 10 ft2 stack is under construction for testing this year as a prelude to a 250 kW proof-of-concept plant for 1993. Technical milestones include field trials in 1995 and 1996, following integrated systems verification during 1993-94. With Ishikawajima-Harima-Heavy-Industries (I.H.I.) balance of plant technology this MCFC variant may offer the winning combination, subject to lifetime and cost considerations.
The afternoon’s proceedings were chaired by C. M. Seymour, who introduced P. G. Patil of the U.S. Department of Energy. Fuel flexibility, energy saving and environmental benignity were driving forward a strong government-led programme which aimed to advance fuel cell technologies through research and development, optimisation and scale-up, to demonstration in cars, trucks, buses and locomotives. This fervour was imperative for the 130 million Americans whose air quality was below the national standard.
In the immediate future, a methanol-fuelled PAFC powered bus with diesel performance but with a 99 per cent reduction in emissions would be constructed for 1996. Analysis indicated this vehicle would be entirely viable economically during its life-cycle, even though higher initial costs were envisaged. Both E.R.C. and Fuji had engaged in Phase I, proof of feasibility studies, with Fuji selected for Phase II, power plant integration into buses.
For cars and vans, SPFC units were proposed for mid-term goals, and possibly SOFC later. General Motors, Los Alamos National Laboratories, Ballard Power Systems and Dow Chemical were examining design concepts for 1993 based on a 10 kW stack, to be scaled up to 50 kW in later phases. The attractions of SOFC lie in potential weight and volume reductions accrued by internal reforming, but 2010 is the earliest target date. In the meantime, reformer technology developments need to address size/cost reduction, start-up and load-following, as well as fuel (liquid) flexibility. In order to compete with internal combustion engines in the 10–40 kW range, which cost $150/kW, fuel cell systems should show savings in operating and maintenance costs and environmental nett credit. Notwithstanding, the National Energy Strategy group foresees fuel cell propulsion systems as a route to better energy security.
More detailed data on SPFC development, including improved power density, air operation and synthetic fuelling were provided by K. B. Prater of Ballard. A 35-cell stack, built with the latest Dow membrane, could sustain 5 kW on 50 psig air or 10 kW on 30 psig oxygen, with 2000 hours of operation now accumulated. The absence of gas permeability changes in the membrane during this period suggests that long life may result. An earlier 35-cell stack had successfully completed vibration testing, simulating 5000 miles of operation in a bus.
The Canadian and British Columbia Governments were funding Phase I of their bus project with C$4.84m for completion in 1993; on-board hydrogen was chosen as the fuel to avoid the cost, weight and maintenance expenses of a mobile reformer. Twenty-one stacks of 5 kW each, delivering 75 kW to the wheels, are to power this 16-seater coach. Separate trials demonstrated immediate start-up from 3°C, with 50 per cent power in 45 seconds.
In a departure from purely fuel cell considerations, M. Appleyard of Lucas described the important parallel developments occurring in advanced batteries and electric drive systems. In the near term, advanced lead-acid and sodium-sulphur were considered closest to providing acceptable performance for the proposed “zero-emitting” electric cars. The advantages conferred by hybrid power plants were considered for auxiliary units as low as 2–3 kW, in respect of both range and performance. While the supplement might be internal combustion engine-based, such a combination would no longer be zero-emitting and could incur unacceptable cost, weight and volume penalties. The SPFC might meet this challenge if cost, performance and lifetime targets were achieved.
An additional contribution to the programme, by P. L. Adcock of Loughborough University, concerned the prospects for the use of fuel cells in electric vehicles. Based on a real city-to-city power requirement duty cycle, a SPFC (5 kW)-nickel/cadmium battery (200 kg, 50 Wh/kg) hybrid power pack could provide a 400 km maximum range at 65 km.p.h., derated to 100 km per 5 hour rest period under mixed driving conditions. These figures pertain to methanol fuelling, with 70 per cent reformer efficiency, leading to a 50 per cent reduction in carbon dioxide emission compared with an internal combustion engine and negligible emissions of other pollutants. Alternatively, use of an iron-titanium hydride hydrogen storage system would reduce mobile emissions to zero at the expense of a 50 per cent reduction in range.
In the final paper of the day, K. Strasser of Siemens extended his account from the First Grove Fuel Cell Symposium concerning the Company’s development of fuel cells as air-independent propulsion systems for sub-marines. Having sailed with AFC power in 1989, Siemens now saw SPFC as a better prospect and were actively developing plant based on these. Stacks had undergone more than 300 on-off cycles of testing with hundreds of hours on standby, cold start-up at full load from 30°C and low loading down to 3 per cent without observing any deterioration. The revolutionary suggestion that these same cells could be reversed into the electrolyser mode and used to charge a hydride store off-peak was offered; Strasser considered that materials problems were not insuperable, and metal shields might be used in the construction of the stack. While no cost reduction could be envisaged for SPFC in low volume military and aerospace applications, the substantial markets for electric vehicles and emergency power supplies could introduce the necessary incentives, especially if backed by increasingly stringent emissions regulations. The principal attractions of SPFCs included their advantageous overload capability, extended lifetime with low performance decay rate, reasonable operating temperature range and carbon dioxide-tolerance. Apart from naval applications, the Company envisaged SPFCs as well-matched for land transport due to their compatibility with regenerative and energy storage systems—probably superior to advanced batteries such as sodium-sulphur, if hydride storage and air oxidant were employed in 40 kW units. In 1994, Siemens planned to demonstrate some of this advanced equipment in a forklift truck.
Beyond the Year 2000
Technical and Commercial Visions
Planned as a preview for the utopian future, this final session on the Friday morning was introduced by Professor B. C. H. Steele of Imperial College. A. J. Appleby of Texas A. & M. University began proceedings with a brief history of innovation in fuel cells from Mond and Langer in 1892 to the 20 kW E.R.C. MCFC for P.G.E. today. He then compared state-of-the-art fuel cells, showing the inherent performance advantage of AFCs (high platinum metals loadings); however, their efficiency was degraded after fuel required for reformer heating was included, leaving MCFC as the most efficient overall, especially in the internal reforming mode. Often the equation was reduced to plant costs versus attainable emissions. Innovative combined cycles could achieve nitrogen oxides emissions of 23 ppm, but MCFC would always win, presently producing less than 3 ppm. Power densities of fuel cell systems were too low at approximately 1 kW/m2 (the target was 1.8 kW/m2) and costs were too high at ¥193,000/kW; cost reduction will be made by increasing current density.
As for MCFCs, there had been rapid progress, but again the power density was too low. Anodes and bipolar plates might revert to copper-based materials: cadiode dissolution appeared to be the only serious problem remaining and eventually this would be overcome. Using coal as feedstock in a chemically integrated gasifier, efficiencies of approximately 66 per cent could be achieved at 100 per cent utilisation. The SOFC was still embryonic and many advanced structural concepts were being examined—they were eminently suited to integration with complex and efficient plants, such as that envisaged by the (non-fuel cell) “integrated energy facility” in a recent E.P.R.I. report.
New solid electrolytes were under active consideration and it might be possible to devise an alkaline ion-exchanger based on carbon dioxide-rejecting amines. In this way, weights could be reduced and power densities increased, with the rewards of lower Tafel slopes and higher outputs accruing from AFCs. More than 5 A/cm2 might be achievable from AFCs; this figure had certainly been achieved in SPFCs, even with advanced, low platinum metals loading (0.3 mg/cm2) electrodes.
For vehicle applications, atmospheric air had to be used to avoid the need for pressurisation energy. Here, some 0.3 A/cm2 at 0.6 V had been achieved in SPFC at 0.4 mg/cm2 loading. A brief reference to the Billings car suggested that the range claims were exaggerated, but calculated performances might still be acceptable. Use of U.T.C.’s edge current-collecting configuration might be appropriate, since the bipolar plates could be substituted with plastic separators.
Appleby did not doubt the future with a hydrogen economy. Initially, reformed natural gas would be used, but this would later be displaced by electrolyser systems. Significantly, this could herald a return to the platinum-bearing AFC.
Finally he foresaw an all-gas house with a small (2 kW?) base-loading fuel cell, battery peaking and inefficient reformer supplying hot water and space heating.
Raising the spectre of perhaps the best-publicised and most urgent need for a cleaner, fuel cell-driven future, A. C. Lloyd of South Coast Air Quality Management District, California, outlined the full extent of national air quality violations on the health of the 13 million population in that region. Official figures call for around 80 per cent reduction in emissions in 2010, although new estimates may require 88 per cent reduction of reactive organic gases. Furthermore, ground-level ozone concentrations may be more pernicious than earlier suspected.
Fuel cells offer a new technology which could dramatically reduce nitrogen oxides emissions, in particular, and all pollutants in general. This applies to both stationary and mobile applications, although alternative fuelling of internal combustion engines, for example by methanol, might have short-term benefit. A new, low emission vehicle/clean fuel programme is already influencing thinking in the automotive sector worldwide. Apart from implementation of the zero-emission vehicle policy, additional strategies, including hybrid propulsion systems, were being encouraged. Realistically, however, the politics and economics of oil supply and national debt were also driving the Legislators! Confidence in technological progress as well as public support, has led to an increased goal of 200,000 electric vehicles in the area by the year 2000, in place of the previous target of 40,000. Significantly, fuel cells as well as batteries qualify as zero-emitting power sources, so that on-board reforming (for larger vehicles) would not be contentious. The immediate cost-benefits of greater efficiency and fuelling with renewable energy sources are not lost on the Administration.
Lloyd recommended that the large resources directed to advanced battery development should be extended towards fuel cell research and development. Great promise for electric vehicles in a cleaner future was foreseen.
Continuing to focus attention on Southern California, D. M. Moard of Southern California Gas Company (SoCalGas), explained how they had engaged in co-operative programmes of fuel cell research, design and development over a number of years with manufacturers, institutions and government departments. This will now lead to provision of a partial service based on PAFC capacity, fuelled by natural gas and ranging in capacity from a few kW, to multi-MW systems fitted with downstream thermal cycle plant. To date, cost had been a hindrance to commercial exploitation, but the break-even point was in sight for PAFC. Indeed, figures were produced to show that in certain selected high energy cost sites, fuel cell installations would bring immediate financial returns. Hopefully, similar trends would emerge for MCFC and SOFC from the mid-1990s.
Thus, SoCalGas was presently installing 200 kW PAFC sets, manufactured by ONSI (a joint venture between I.F.C. and Toshiba to develop ON SIte energy generators), based on the I.F.C./U.T.C. design; a twenty-year life was optimistically predicted, with intermediate stack replacement. Being an on-site package, customers could expect to benefit from energy cost savings, while SoCalGas would benefit by progressing fuel cell introductions to the market. Following the initial order of 10 units for 1992, the Company is negotiating further orders in collaboration with local property developers and others.
Revitalising the whole “Hydrogen Economy” debate B. Rohland of Zentrum für Sonnenenergie-und-Wasserstoff-Forschung, Stuttgart, surmised that hydrogen would play a significant role as a storage and transport fuel derived from renewable sources. Thus, in Germany, one scenario envisaged an increasing share of energy from renewables, being 13 per cent in 2005 up to 69 per cent in 2050, of which hydrogen would be 11 per cent in 2025, and 34 per cent in 2050. An inter-related electricity and gas market was proposed for a future clean energy system.
Fuel cells represented the most important option for efficient storage and interconversion of energy. Contrasting with one earlier prediction, Rohland considered that medium and high temperature fuel cells would operate at high efficiency and provide high-grade waste heat at competitive cost. Medium temperature units would prevail if pure (stored) hydrogen were used, and high temperature devices could advantageously be deployed with biogas-hydrogen mixtures.
The final paper of the meeting, by T. Satomi of Tokyo Gas, encapsulated all of the excitement, drive and vision surrounding the prospect of fuel cell powered cities in the future. Being one of the few speakers to publicly acknowledge the inextricable interdependence of all aspects of social development, he related the activities of the Japanese Community Amenity Network (C.A.N.) towards integrated city construction. With a fuel cell at their heart, these units would redeploy by-product heat and fuel, and recycle all waste and water. He confidently predicted that, through innovation and mass production, PAFCs would achieve necessary cost and performance targets by 2000. At that time coal-gas fuelled, dispersed MCFC capacity of 1 MW and above could be expected to enter service; SOFC might follow for on-site applications sometime later provided durability could be improved.
Reiterating earlier projections, Satomi predicted a 30 per cent increase in energy demand for 2000, with electricity taking the major share. Coupled with increasing energy supply problems and environmental decay, a rational approach to future social needs had become imperative. Waste heat reuse, refuse recycling and water resources needed much more serious consideration than the ad hoc, short-term policies of previous generations.
The essential element of the C.A.N. proposal was integration, efficiency and recycling of the total energy and resource inventory for a whole city, built on approximately 100 hectares, with nearby industrial complexes assimilating waste heat. Solar energy, biogas, heat-pumps and pond heat-stores were a few of the advanced technologies which could contribute. One design has 8,000 dwellings devouring 10 MW of electricity generated from fuel cells coupled to thermal cycle, steam plant, absorption chillers and heat pumps. With a PAFC unit, overall efficiency could be 70 per cent representing a 28–35 per cent saving in energy, 25 per cent saving in water and 30 per cent reduction in effluent.
Dramatic artists’ impressions of possible skyscraper cities up to 2000 metres high were shown; these would address land shortage problems. Natural gas was the fuel of choice, and fuel cells the power units. Infrastructure was three-dimensional. These would be “intelligent” buildings with state-of-the-art control networks. Each one would require up to 100 MW of power; this would be supplied by zoned 5 MW fuel cells. Satomi considered a return to DC power supply for such autonomous cities. In combination with other DC devices such as computers, solar cells, etc., an ideal hybrid system could be designed. However, in discussion, it emerged that DC was not a viable solution due to switching complexities and bus-bar sizing/weight; new AC technologies were becoming available. Ultimately, Satomi hoped that hydrogen would displace natural gas as the cleanest fuel of all, leading to even cleaner and more efficient power generation. In conclusion, it was apparent that some Japanese philosophers are already formulating solutions to problems that the rest of the world prefers to ignore.
Professor Steele closed the proceedings with a brief review. He highlighted the continuing progress being made towards fuel cell commercialisation. Despite this, greater technical efforts must accompany initiatives to secure the role of fuel cells in the market place, and additional commitment and investment was needed. Nevertheless, the Arthur D. Little report was encouraging and early air quality legislation should assist these commercial initiatives.
During the meeting formal and informal discussions took place, perhaps the most animated concerned the cost and performance of our favourite status symbol: the (electric?) car. The full proceedings of this Symposium will be published in a forthcoming issue of the Journal of Power Sources.