To provide a power supply system capable of supplying electric power with high quality to a load side and delivering electric power with the same high quality in an inverse load flow to a commercial power supply side as well, while a photovoltaic power generation apparatus or a wind power generation apparatus is generating electric power.

The present invention comprises: a photovoltaic power generation apparatus (1); a DC-DC converter (20) that converts DC power supplied from the photovoltaic power generation apparatus (1) to DC power in which a voltage has been adjusted within a fixed range according to characteristics of a storage battery to be charged; storage batteries (21, 22) that charge DC power output from the DC-DC converter (20); and a DC-AC inverter (23) that converts DC power discharged from the storage batteries (21, 22) to AC power. The storage batteries (21, 22) have a plurality of circuits and link a power supply apparatus (D) that concurrently performs charging and discharging using the storage battery with different circuits to a commercial power (4) side and a load (3) side.