The Japan Aerospace Exploration Agency (JAXA) will launch a demonstration satellite for space photovoltaic generation in 2017. Unlike photovoltaic generation greatly affected by bad weather, space photovoltaic generation allows for stable power supply regardless of the weather. The demonstration satellite weighs about 400 kg, and the agency will launch the satellite using its self-developed Epsilon Launch Vehicle. It will have a generation capacity of 2 kW. The generated electricity will be converted to microwave and sent to the earth with the help of an antenna 2 m in diameter, and subsequently converted again to power. The satellite will go around the orbit 370 km above the ground.
Space photovoltaic generation is expected to have about 10 times more output than photovoltaic generation on the earth. Although a large-scale antenna is required to receive microwaves, space photovoltaic generation can get two times more output per installation area than the existing mega solar. The agency plans to launch several generation satellites with a view to starting commercial generation in 2040. However, various innovations are required in such areas as solar battery and antenna for commercialization because it costs more than one trillion yen to build a satellite with the same generation capacity as one nuclear power plant.
Space solar power systems by the JAXA