An electric power supply system has, as multiple storage units, an output type battery of high output and small capacity and a capacity type battery of low output and large capacity. The charge-discharge electric power of each of the storage units is controlled by a controller according to a charge-discharge schedule for a prediction period. Based on a predicted power consumption schedule, a predicted power generation schedule, and a charge-discharge characteristic of each of the storage units, the controller determines a charge-discharge schedule with regards to an optimal evaluation index, and controls the storage units in accordance with the charge-discharge schedule.