To provide an electric power supply system that performs electric discharge adapted to a power use actual condition of a user when discharging from a power storage device to a load apparatus to effectively utilize energy.

A system ECU31 stores an actual condition of power used by a load apparatus to update a past power use actual condition as rewritten learning information, and uses the learning information to control discharge from a storage battery 33 to the load apparatus. The system ECU31 gets a predicted amount of power used by the load apparatus for each time zone of a day using the learning information, and determines a discharge execution time zone for discharging to the load apparatus based on the predicted amount of power use for each time zone. The electric power supply system 100 performs discharge from the storage battery 33 in the determined discharge execution time zone of a day.