The Department of Energy’s Solar Energy Technology Program, managed by the Office of Energy Efficiency and Renewable Energy accelerates the development of solar technologies as energy sources for the nation and world. The solar program also educates the public about the value of solar as a secure, reliable, and clean energy choice.
Developing technologies that take advantage of the clean abundant energy of the sun is important to reducing greenhouse gasses and helps stimulate the economy. Examples of solar technologies being developed by the Department of Energy and Industry are Photovoltaic cells, concentrating solar power technologies and low temperature solar collectors.
Photovoltaic cells convert sunlight directly into electricity and are made of semiconductors such as crystalline silicon or various thin-film materials. Photovoltaics can provide tiny amounts of power for watches, large amounts for the electric grid, and everything in between.
Concentrating solar power technologies use reflective materials to concentrate the sun's heat energy, which ultimately drives a generator to produce electricity. These technologies include dish/engine systems, parabolic troughs, and central power towers.
Low-temperature solar collectors also absorb the sun's heat energy, but the heat is used directly for hot water or space heating for residential, commercial, and industrial facilities.
You can also find statistical information relating to the use of solar thermal and solar photovoltaic energy through the Energy Information Administration.