Applying fuel cell experience to sustainable power products

Abstract

Fuel cell power plants have demonstrated high efficiency, environmental friendliness, excellent transient response, and superior reliability and durability in spacecraft and stationary applications. Broader application of fuel cell technology promises significant contribution to sustainable global economic growth, but requires improvement to size, cost, fuel flexibility and operating flexibility. International Fuel Cells (IFC) is applying lessons learned from delivery of more than 425 fuel cell power plants and 3 million h of operation to the development of product technology which captures that promise. Key findings at the fuel cell power plant level include: (1) ancillary components account for more than 40% of the weight and nearly all unscheduled outages of hydrocarbon-fuelled power plants; a higher level of integration and simplification is required to achieve reasonable characteristics, (2) hydrocarbon fuel cell power plant components are highly interactive; the fuel processing approach and power plant operating pressure are major determinants of overall efficiency, and (3) achieving the durability required for heavy duty vehicles and stationary applications requires simultaneous satisfaction of electrochemical, materials and mechanical considerations in the design of the cell stack and other power plant components. Practical designs must minimize application specific equipment. Related lessons for stationary fuel cell power plants include: (1) within fuel specification 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 process use avoids costly, complicated and site-specific water treatment systems, but water treatment is required to eliminate impurities and (3) the embedded protection functions for reliable operation of fuel cell power conditioners meet or exceed those required for connection to the utility grid, but current standards do not recognize embedded protection functions, and, often, utilities mandate external protective devices. Consequently, current activity to develop such standards under IEEE auspices is important in eliminating 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 have been applied to the 200 kW stationary fuel cell power plant as the information has become available. They are now being applied to a 50-kW, ambient pressure, polymer electrolyte membrane (PEM) fuel cell power plant that uses gasoline as the fuel. This power plant is intended for experimental bench testing demonstrations associated with vehicle power plant applications.