POWER CONTROL SYSTEM AND POWER CONTROL METHOD

A power control system and method for suppressing purchase power peaks or controlling surplus power household consumption according to changes. The power control system comprises a monitoring unit, an electricity storage quantity acquisition unit, and an electricity storage controller. The monitoring unit monitors a generated power quantity which an electricity generator generates using renewable energy and a purchase power quantity which a consumer purchases via a power grid. The electricity storage controller executes processes of discharging power from an electricity storage cell if the purchase power quantity is greater than or equal to a first threshold value; charging the storage cell if the generated power quantity is greater than zero and the purchase power quantity is less than or equal to a second threshold value less than the first threshold value; and charging and discharging the storage cell such that the acquired electricity storage quantity reaches a target value.