Patent ID: 7572529

Claim:
A method of starting up at a subzero temperature a solid polymer electrolyte fuel cell, the method comprising the steps of: providing a solid polymer electrolyte fuel cell stack that is formed by stacking a plurality of layers of separators that are made from metal and have a cross-sectional waveform structure and membrane electrode assemblies having a solid polymer electrolyte membrane and electrodes, the solid polymer electrolyte fuel cell stack also including a space formed between at least a portion of the separators and separators that are placed adjacent to this portion of the separators which is used as a coolant flow passage, wherein the solid polymer electrolyte fuel cell stack has a predetermined heat capacity that is determined based on a preset start-up commencement temperature and on characteristics of the membrane electrode assembly; supplying a reaction gas to the fuel cell stack so as to obtain electrical current at a subzero temperature; obtaining self-generated heat due to power generation by the fuel cell stack at a subzero temperature; and raising a temperature of the membrane electrode assemblies to 0° C. or higher before the membrane electrode assemblies become unable to generate power due to freezing of water created by power generation.