Gizmodo:

Take 300,000 computer-controlled mirrors, each 7 feet high and 10 feet wide. Control them with computers to focus the Sun's light to the top of 459-foot towers, where water is turned into steam to power turbines. Bingo: you have the world's biggest solar power plant, the Ivanpah Solar Electric Generating System.

Long-mired by regulatory issues and legal tangles, the enormous solar plant–jointly owned by NRG Energy, BrightSource Energy and Google–opened for business today.