Method and device for operating power system, and rechargeable-battery management device

A method and device for operating a power system, and a rechargeable-battery management device that extracts maximum performance from rechargeable batteries and uses the batteries evenly while taking into consideration cost and the operation of the batteries are provided. According to the method for operating a power system provided with a plurality of rechargeable-battery devices and a plurality of electric generators, the amount of power that a rechargeable battery available during a scheduled time period on a scheduled date will be able to supply is determined, an economic-dispatch calculation including the determined amount of power that the aforementioned rechargeable battery will be able to supply is performed for the power system, and the rechargeable battery is used to supply power during the scheduled time period on the scheduled date.