Wind energy is a source of renewable energy generated from wind power. At the end of 2006, worldwide capacity of wind generators was 73,904 MW, producing a little bit more than 1% of worldwide electricity.
Although still a relatively minor source of electricity for most countries, wind energy production has increased almost five times between 1999 and 2006, in some countries the share of wind energy in the total energy consumption is significant: Denmark ( 23%), Spain (8%), Germany (6%).
Winds form because the sun doesn’t heat the Earth uniformly, which creates air movement. Kinetic energy of the wind can be used to rotate some turbines, which are able to generate electricity. Some turbines can produce 5 MW, although this requires a wind speed of approximately 5.5 m /s or 20 km/h. Few areas on earth have these wind speeds, but strong winds can be found at higher altitudes and in oceanic areas.
Wind energy is used extensively today, and new wind turbines are built around the world, wind energy is the energy source with the fastest growth in recent years. Most turbines produce energy over 25% of the time, this percentage increases in the winter, when winds are stronger.
The general idea is that global technical potential of wind energy can provide five times more energy than is used now. This level would require that 12.7% of land area (excluding oceans) would be covered by parks turbines, assuming that the land would be covered with 6 large wind turbines per square kilometer. These figures do not take into account improving turbines efficiency and the used technical solutions.