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Wind power

From Wikipedia, the free encyclopedia

Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2008, worldwide nameplate capacity of wind-powered generators was 121.2 gigawatts. Wind power produces about 1.5% of worldwide electricity use, and is growing rapidly, having doubled in the three years between 2005 and 2008. Several countries have achieved relatively high levels of wind power penetration, such as 19% of electricity production in Denmark, 11% in Spain and Portugal, and 7% inGermany and the Republic of Ireland in 2008. As of May 2009, eighty countries around the world are using wind power on a commercial basis.

Large scale wind farms are typically connected to the local electric power transmission network, with smaller turbines being used to provide electricity to isolated locations. Utility companies increasingly buy back surplus electricity produced by small domestic turbines. Wind (and solar) energy as a power source is favoured by environmentalists as an alternative to fossil fuels, as they are plentiful, renewable, widely distributed, clean, and produces no greenhouse gas emissions; although the construction of wind farms is not universally welcomed due to their visual impact and other effects on the environment.

Wind power, along with solar power, is non-dispatchable, meaning that for economic operation all of the available output must be taken when it is available, and other resources, such as hydropower, must be used to match supply with demand. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.