Examples of efficient or renewable energy technologies include:Photovaltaic 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 PowerConcentrating 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 CollectorsLow-temperature solar collectors absorb the sun's heat energy, but the heat is used directly for hot water or space heating for residential, commercial, and industrial facilities.
Wind EnergyWind energy is one of the most cost-competitive renewable energy technologies. The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes and businesses.