It was an unrealized dream of Nikola Tesla, but
the U.S. Naval Research Laboratory says it has successfully transferred 1.6
kilowatts of electric power over a distance of one kilometer using a 10-GHz
beam. 
A "rectifying antenna" connected
to the receiving
antenna converts the 10-GHz RF energy into
electricity. (NRL
Photo by Gayle Fullerton)
According to Newsline, transfer of electrical energy from point to point via microwaves is an emerging technology that could eventually open the door for transmitting power from space to earth. The project leader, by the way, is KJ4IKI, so care is presumably being taken not to fry any amateur satellites sharing the 10-GHz band with the military.