A charging-discharging device includes a selection unit to acquire estimated load power data indicating estimation of power to be consumed by an electric load, to acquire estimated solar power-generation power data indicating estimation of power to be generated by a solar power generation system, and to select one of a plurality of specific operations regarding usage of power on the basis of the estimated load power data, the estimated solar power-generation power data, operational mode data indicating an operational mode that identifies a power utilization method, price data indicating a price of AC power to be supplied from a commercial system and a price of AC power to be supplied to the commercial system, power conversion efficiency data indicating power conversion efficiency of a power converter at the time of charging or discharging a storage battery, and current time data.