Japan has serious plans to send a solar-panel-equipped satellite into space that could wirelessly beam a gigawatt-strong stream of power down to earth and power nearly 300,000 homes.
The satellite will have a surface area of four square kilometers, and transmit power via microwave to a base station on Earth. Putting solar panels in space bypasses many of the difficulties of installing them on Earth: in orbit, there are no cloudy days, very few zoning laws, and the cold ambient temperature is ideal.
A small test model is scheduled for launch in 2015. To iron out all the kinks and get a fully functional system set up is estimated to take three decades. A major kink, presumably, is coping with the possible dangers when a 1-gigawatt microwave beam aimed at a small spot on Earth misses its target.
The $21 billion project just received major backing from Mitsubishi and designer IHI (in addition to research teams from 14 other countries).
A division of JAXA, the Institute of Space and Astronautical Science (ISAS) has already prepared a prototype of the SPS2000, a 10 megawatt demonstration solar-power satellite.
ISAS is also undertaking a project where an experimental satellite will be tested for wireless power supply of several hundred kilowatts. Ground experiments are being held for scrutinizing the influence of high-voltage discharge which is a sheer necessity for large-capacity power generation in space. They are also spending time on the impact of space debris on the solar farm.