POWER SUPPLY AND DEMAND SYSTEM

An electric power supply and demand system used in a factory for manufacturing a vehicle includes: an on-vehicle secondary battery, in a manufacturing process of a factory, mounted on a vehicle capable of running in a factory by remote control; a central storage battery configured to be capable of supplying electric power to an equipment in the factory; a charging device configured to be capable of supplying electric power stored in the central storage battery to the on-vehicle secondary battery; a power receiving device configured to be capable of supplying electric power stored in the on-vehicle secondary battery to the central storage battery; and a power generating facility located in the factory and configured to be capable of supplying the generated electric power to the central storage battery.