Solid oxide fuel cell technology

The use of high-temperature solid oxide fuel cell (SOFC) systems is discussed. Such cells show great promise for economical production of electricity and heat in a variety of commercial, industrial cogeneration, and electric utility systems applications. Pioneered by Westinghouse in the 1960s, this technology is based on the ability of stabilized zirconia to operate as a solid electrolyte at elevated temperatures. It is illustrated that the cells readily conduct oxygen ions from an air electrode (cathode) where they are formed, through the zirconia-based electrolyte to a fuel electrode (anode), where they react with fuel-gas CO or H₂ or any mixture, e.g., steam-reformed natural gas, and deliver electrons to an external circuit to produce electricity. These fuel cells operate at temperatures near 1000°C and are the basic building blocks for highly efficient combined heat and electric power, or all electric-power generators