Wind power has been around for thousands of years, first appearing approximately 5,500 years ago. Wind power was used for shipping and sailing, to provide natural ventilation, and to create power for ventilation systems. Over hundreds of years wind power continued to evolve, pumping water and being used for grinding. Wind power largely disappeared during the modern era, eventually returning with a contemporary design in the early 1980s. It was at this point that wind power began to be used more broadly.
The wind power is converted from kinetic energy into electric energy and is considered to be a solar energy. This energy is popular because of its renewable nature, its clean production, and the fact that it does not emit greenhouse gases. There are some who dislike wind power for aesthetic reasons, believing that wind turbines distract from the natural beauty of the land. It would, in fact, be difficult for wind power to run out. Wind power is created from the uneven heating from the sun, which is due to the rotation of the earth, its uneven topography, and more. These facts suggest that, unlike fossil fuels, wind will never run out.
The use of wind power continues to grow, with wind power doubling between 2005 and 2008. In the European Union there over 25,000 wind farms currently operating. Wind power is used globally in over 80 countries.
The technology of wind power is growing. Initially, wind turbines were made of tall shafts with vertical blades attached to the top. Over the several generations of wind turbines, changes were made, modifying the vertical blades to horizontal blades. These large, rectangular blades are covered with stiff cloth or ratting. When the blades are spun by the power of the wind, the inner shaft is twisted, creating power which is then transferred either to a private location or an energy network.
The market for residential wind turbines is also growing. A small singular wind turbine can generate up to 50 kW daily. Any excess wind power generated can be sold for a profit back to the network, where the wind power will be stored for future use.
Wind power is also generated at wind farms, of which there are three basic types: off-shore farms, on-shore farms, and land farms. Off-shore farms are by far the most expensive to build and maintain, but they are also the most profitable. The wind travels most easily across the open expanse of water. The energy generated by the off-shore wind farms is transferred back to land networks with large underground cables.
On-shore farms are either directly on shore or are immediately off the shore. These are beneficial wind farms, but they also create noise pollution.
Land farms are increasingly popular, with the land being carefully chosen based on the topographical location and the average amount of wind in the area.