To provide a power supply system capable of making effective use of electric power supplied from a plurality of independent power supplies, using a power storage device in a relatively low-cost and simple configuration.

A power supply system 10 includes a connection section 20 that connects a plurality of independent power supplies 1-5 with load equipment, and a power storage device 60 that receives at least a part of electric power from the plurality of independent power supplies 1-5 through the connection section 20. The power storage device 60 includes a motor 41 that is driven by at least a part of electric power from the plurality of independent power supplies 1-5, a flywheel 42 in which an input shaft is connected with the motor 41, a generator 43 connected with an output shaft of the flywheel 42, and a secondary cell 61 that stores electric power generated by the generator 43.