POWER SUPPLY SYSTEM

A demand measurement unit measures demand power of a load, and a power generation measurement unit measures power generated by a solar cell. A threshold storage unit stores a discharge control threshold value for remaining amount (amount of remaining power) of a storage cell, which is used to determine whether to discharge the storage cell. When the demand power is larger than the generated power, a command unit creates a control command to control discharge of the storage cell based on a result of comparison between the remaining amount of the storage cell and the discharge control threshold value and transmits the control command to a control unit of a power conditioner. In this event, when the remaining amount of the storage cell is larger than the discharge control threshold value, the command unit gives a control command to discharge the storage cell. A threshold setting unit variably sets a value of the discharge control threshold value, and updates the discharge control threshold value in the threshold storage unit every time the value is changed.