http://www.aviationweek.com/aw/generic/story.jsp?id=news/asd/2010/11/05/04.xml&headline=Indian, U.S. Experts Team On Space Solar Power&channel=space
Because of the military implications, this technology has a potential customer willing to front its development. This is the way to go for space development.Such a system would deliver 10 megawatts of power, cost less than $10 billion to build and launch, and be ready in less than 10 years. The system would consist of a large satellite to collect the Sun’s energy and convert it into microwaves, which would be beamed to an antenna on Earth that would collect the microwaves for conversion to electricity and transmission through the existing power grid.
The antenna would be as open as chicken wire, Hopkins says, which would permit farmers to grow crops under it. And the beam would be so diffuse that “you can walk through the beam, even if you’re naked, and it’s not going to hurt you.”