Abengoa Solar described the array as the world´s largest parabolic trough plant. The solar arrays use parabolic shaped mirrors mounted on moving structures that track the sun and concentrate its heat. That heat is used to heat water into steam, which is then used to power a conventional steam turbine. Being able to store the power allows the plant to continue distributing energy when the sun goes down or is blocked by poor weather.

via U.S. flips switch on massive solar power array that also stores electricity – Computerworld.