Lucas123 writes "A solar power array that covers three square miles with 3,200 mirrored parabolic collectors went live this week, creating enough energy to power 70,000 homes in Arizona. The Solana Solar Power Plant, located 70 miles southwest of Phoenix, was built at a cost of $2 billion, and financed in large part by a U.S. Department of Energy loan guarantee. The array is the world's largest parabolic trough plant, meaning it uses parabolic shaped mirrors mounted on moving structures that track the sun and concentrate its heat. A first: a thermal energy storage system at the plant can provide electricity for six hours without the concurrent use of the solar field. Because it can store electricity, the plant can continue to provide power during the night and inclement weather."