Solar Thermal

Solar thermal energy (STE) is a technology for harnessing solar energy for thermal energy (heat). Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are flat plates generally used to heat swimming pools. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use. High-temperature collectors concentrate sunlight using mirrors or lenses and are generally used for electric power production. STE is different from and much more efficient than[1][2][3] photovoltaics, which converts solar energy directly into electricity. While existing generation facilities provide only 600 megawatts of solar thermal power worldwide in October 2009, [note 1] plants for an additional 400 megawatts are under construction and development is underway for concentrated solar power projects totalling 14,000 megawatts.[4]