Ivanpah Solar Power Plant, California

When it went online in early 2014, Ivanpah was likely the largest solar power plant in the world. It is certainly the largest thermal solar power plant, with 3,500 acres of mirrors mounted on 173,500 heliostats, which track the sun, focusing it on three 450 foot tall towers full of flowing water, which generates steam, then electricity–as much as 392 megawatts. Construction started on the plant in 2011, built by Bechtel, Birightsource, NRG, and Google, at a cost of $2.2 billion. It is a futuristic landmark next to the Interstate, next to the state line, south of Las Vegas.