Massive solar thermal plant feeds the grid

MIT Technology Review : The world’s largest solar thermal energy plant, built by Brightsource Energy in Ivanpah, California, has delivered electricity to the power grid for the first time in a demonstration test. The $2.2 billion plant is expected to be fully operational by the end of the year. Solar thermal energy plants use mirrors to reflect and focus sunlight on a tower filled with water. The heat turns the water to steam that spins turbines and generates electricity. The Ivanpah plant has three arrays that incorporate a total of nearly 200 000 mirrors. Whether the plant recoups its cost—$1.6 billion of which was provided by Department of Energy loans—over its lifetime is still uncertain. Current estimates suggest that the cost per kilowatt-hour may be higher than fossil fuels. It may also be more expensive than traditional solar panels, the cost of which has fallen significantly over recent years.