Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which arerenewable (naturally replenished). In 2008, about 19% of global final energy consumption came from renewables, with 13% coming from traditional biomass, which is mainly used for heating, and 3.2% from hydroelectricity.[1] New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2.7% and are growing very rapidly.[1] The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3% from new renewables.[1][2]
Wind power is growing at the rate of 30% annually, with a worldwide installed capacity of 158 gigawatts (GW) in 2009,[3][4] and is widely used in Europe, Asia, and the United States.[5] At the end of 2009, cumulative global photovoltaic (PV) installations surpassed 21 GW[6][7][8] and PV power stations are popular in Germany and Spain.[9] Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 megawatt (MW) SEGS power plant in the Mojave Desert.[10] The world's largest geothermal power installation is The Geysers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production ofethanol fuel from sugar cane, and ethanol now provides 18% of the country's automotive fuel.[11] Ethanol fuel is also widely available in the USA, the world's largest producer in absolute terms, although not as a percentage of its total motor fuel use.
While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development.[12] Globally, an estimated 3 million households get power from small solar PV systems. Micro-hydrosystems configured into village-scale or county-scale mini-grids serve many areas.[13] More than 30 million rural households get lighting and cooking from biogas made in household-scale digesters. Biomass cookstoves are used by 160 million households.[13]
Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization.[14] New government spending, regulation and policies helped the industry weather the 2009 economic crisis better than many other sectors.[15]
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