Applying fuel cell experience to sustainable power products

Fuel cell power plants have demonstrated high efficiency, environmental fri endliness, excellent transient response, and superior reliability and durab ility in spacecraft and stationary applications. Broader application of fue l cell technology promises significant contribution to sustainable global e conomic growth, but requires improvement to size, cost, fuel flexibility an d operating flexibility. International Fuel Cells (IFC) is applying lessons learned from delivery of more than 425 fuel cell power plants and 3 millio n h of operation to the development of product technology which captures th at promise. Key findings at the fuel cell power plant level include: (1) an cillary components account for more than 40% of the weight and nearly all u nscheduled outages of hydrocarbon-fuelled power plants; a higher level of i ntegration and simplification is required to achieve reasonable characteris tics, (2) hydrocarbon,on fuel cell power plant components are highly intera ctive; the fuel processing approach and power plant operating pressure are major determinants of overall efficiency, and (3) achieving the durability required fdr heavy duty vehicles and stationary applications requires simul taneous satisfaction of electrochemical, materials and mechanical considera tions in the design of the cell stack and other power plant components. Pra ctical designs must minimize application specific equipment. Related lesson s for stationary fuel cell power plants include: (1) within fuel specificat ion limits, natural gas varies widely in heating value, minor constituents such as oxygen and nitrogen content and trace compounds such as the odorant ; (2) city water quality varies widely; recovery of product water for proce ss use avoids costly, complicated and site-specific water treatment systems , but water treatment is required to eliminate impurities and (3) the embed ded protection functions for reliable operation of fuel cell power conditio ners meet or exceed those required for connection to the utility grid, but: current standards do not recognize embedded protection functions, and, oft en, utilities mandate external protective devices. Consequently, current ac tivity to develop such standards under IEEE auspices is important in elimin ating the cost of extra protection equipment. Key fuel cell lessons learned from IFC's experience base along with the status of development for future vehicle and stationary power plants at IFC are discussed. These lessons ha ve been applied to the 200 kW stationary fuel cell power plant as the infor mation has become available. They are now being applied to a 50-kW, ambient pressure, polymer electrolyte membrane (PEM) fuel cell power plant that us es gasoline as the fuel. This power plant is intended for experimental benc h testing demonstrations associated with vehicle power plans applications. (C) 2000 Elsevier Science S.A. All rights reserved.