Disclosed is an electric power supply system which has: a common power source which stores and supplies a power via a local power grid; and a distributed power source which supplies a power to buildings and a surplus to the common power source. The electric power supply system further includes a first power meter measuring the amount of power supplied from a commercial power source, a second power meter measuring the amount of power received from and supplied to the common power source via the local power grid, and a distribution control device which distributes a power from the common power source to the area based on the amounts of power as measured by the first power meter and the second power meter.