Business Green: It might sound like the start of a 1950s B movie, but US energy giant PG&E has this week thrown its considerable weight behind a US startup that plans to begin transmitting usable power from orbiting solar satellites within the next seven years. The utility has requested approval from regulators in its home state of California for a power purchase deal that from 2016 would see PG&E agree to buy 200MW of renewable power over a 15-year period from space solar technology startup …