Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides, and geothermal heat—which are renewable (naturally replenished). In 2006, about 18% of global final energy consumption came from renewable, with 13% coming from traditional biomass, such as wood-burning. Hydroelectricity was the next largest renewable source, providing 3% of global energy consumption and 15% of global electricity generation.
Wind power is the conversion of wind energy into a useful form of energy, such as electricity, using wind turbines. At the end of 2008, worldwide nameplate capacity of wind powered generators was 121.2 gig watts (GW). In 2008, wind power produced about 1.5% of worldwide electricity usage; and is growing rapidly, having doubled in the three years between 2005 and 2008.
Solar power is the result of converting sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaic (PV), or indirectly with concentrating solar power (CSP), which normally focuses the sun’s energy to boil water which is then used to provide power.