Electric power control system and electric power control method

An electric power control method executed by an electric power control system including a vehicle and a plurality of computers, the vehicle being equipped with a battery, the plurality of computers each operating so as to hold a distributed ledger identical to each other, the electric power control method comprising:

• a step of generating, by a generation unit, transaction data including information related to charge-discharge operation of the battery;
• a step of receiving the transaction data and recording the received transaction data in the distributed ledger, by a ledger management unit;
• and
• a step of controlling, by a control unit, charge-discharge operation of the battery,
• wherein
• the control unit is adapted to detect that the battery of the vehicle is connected to an electric power grid,
• the information related to the charge-discharge operation includes intention information, the intention information being information on an intention of a user of the vehicle regarding the charge-discharge operation,
• in the step of generating, when a contract creation request has been received from a first contractor terminal of the user, the generation unit creates the transaction data including vehicle identification information of the vehicle of the user and the intention information, the vehicle identification information and the intention information being extracted from the contract creation request, and
• in the step of controlling,
• the control unit acquires and stores in memory correspondence information in which the vehicle identification information is associated with access information for accessing the intention information included in the transaction data created for the vehicle,
• when subsequently detecting that the battery of the vehicle is connected to the electric power grid, the control unit receives the vehicle identification information from a processor of the vehicle whose battery is connected to the electric power grid, refers to the correspondence information stored in the memory and acquires the intention information on the vehicle whose battery is connected to the electric power grid from at least one of the plurality of computers based on the access information with which the vehicle identification information acquired is associated,
• the control unit executes the charge-discharge operation under an operating condition, the operating condition reflecting the intention of the user based on the intention information which is included in the transaction data recorded in the distributed ledger and which is acquired.