Patent ID: 8829720

Claim:
An apparatus for selecting specifications of a power storage system, the power storage system including an inverter configured to receive commercial AC power and convert the AC power to DC power, and a power storage device for storing electrical energy supplied with the commercial AC power by way of the inverter to supply the electrical energy to an electrical load, the apparatus comprising: an interface for input of data obtained by measuring power usage during prescribed hours at a location of power consumption where the power storage system is to be installed; and an operation processing unit for finding annual average power usage during the prescribed hours based on data that is obtained by compensating the measured data with a variation factor, the variation factor is for compensating for an influence depending on a month in which the measured data are acquired, the variation factor is found by monitoring power usage during the prescribed hours at the location of power consumption for at least one year, and determining an output of the inverter based on the average power usage, wherein the operation processing unit presents the average power usage as the output of the inverter.