Patent ID: 8222858

Claim:
An electric power supply system comprising: an electric power generator for generating electric power; an electricity storage device that is charged with the electric power from the electric power generator, and supplying electric power to an electrical load; an electric power distributing device for distributing electric power to the electrical load from the electric power generator and the electricity storage device according to a sharing ratio; and a control unit for determining the sharing ratio of the electric power and for causing the electric power distributing device to output the electric power from the electric power generator and the electricity storage device according to the sharing ratio, wherein the control unit determines a frequency distribution representing a frequency of a given magnitude of electric power that is demanded from the electric power supply system over a period of time, the frequency distribution determined for a plurality of magnitudes, the frequency distribution including an assist region and a fuel cell following region, the assist region comprising a range of magnitudes in the frequency distribution for which an amount of power demanded from the electric power supply system is demanded less frequently than a range of magnitudes in the fuel cell following region, and a value of the sharing ratio of the electricity storage device in the assist region is higher than a value of the sharing ratio of the electricity storage device in the fuel cell following region.