When the AC voltage effective value at an interconnection point is higher than a first threshold voltage, a solar-panel power conversion device controls an output of reactive power so that the voltage at the interconnection point matches a first target effective voltage. When the power generated from an energy creation apparatus is higher than a first reference power and the AC voltage effective value at the interconnection point is higher than a second threshold voltage, then a storage-battery power conversion device controls an output of reactive power so that the voltage at the interconnection point matches a second target effective voltage.