9. Outlook of the Virtual Power Plant: A Japan Perspective

Taking Japan as an example, the number of installed building multi-type air-conditioners in Japan estimated to be 1.52 million outdoor units. Here, the building multi-type air-conditioner is not an entire commercial air-conditioner, but a part of a packaged air-conditioner in which multiple indoor units are piped to an outdoor unit. There are about 5–10 indoor units per outdoor unit of a building multi-type air-conditioner, the order of indoor units is estimated to be 10 million units. There are various types of outdoor units with different air-conditioning capacities, but 10 H.P class, which is the representative model, that is, the rated cooling capacity is about 28 kW, the rated power consumption per unit is about 10 kW. It can be said that the total installed power is about 15 million kW. Of course, since it is partly operated on a daily basis and the average power consumption is less than the rated value, it goes without saying that only a few percent can be used as negative wattage resources. However, there is no doubt that the installed capacity is a useful load type.