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% in Germany 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 favored 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.
