Japan is putting a satellite into orbit that will collect and send energy back to earth... The satellite will beam (via microwave) one gigawatt of power back to earth (enough to power 300,000 homes).
The surface area of the solar panels will cover 4 square kilometers (more than 13,000 square feet) at a cost of 21 billion dollars. A smaller "test" version will be in place by 2015 with the "full scale" version being put into operation over the next 30 years...