In California's Mojave Desert, about 40 miles southwest of Las Vegas (Google map), lies a five-square-mile solar thermal power project called the Ivanpah Solar Electric Generating System (SEGS). The $2.2 billion facility consists of three power plants, each with a 40-story tower surrounded by thousands of sun-following mirrors called heliostats. The mirrors focus sunlight onto boilers atop the towers, creating steam, which drives turbines that generate enough electricity to power 140,000 California homes. The facility, owned by NRG Energy, Google and BrightSource Energy formally opened on February 17 and has a capacity of 392 megawatts. Getty Images photographer Ethan Miller made several trips to Ivanpah recently, returning with these great shots of the massive power plant, now up and running.