Present status and future prospects for fuel cell power systems

Fuel-cell generating plants, which convert chemical energy directly into electric energy, differ from conventional generating plants by the absence of rotating machines. Such plants are expected to see increasing practical use. Fuel-cell systems under development for practical use are phosphoric acid (PAFC), molten carbonate (MCFC), solid oxide, (SOFC), and proton exchange membrane (PEMFC). PAFC, which is the closest of these systems to commercialization, has been developed vigorously by the United States and Japan. The authors describe the history of fuel-cell development, state of PAFC development, and key inverter technologies