Wind energy is the energy obtained from the wind. This renewable energy takes advantage of the kinetic energy generated by the effect of air currents, and is transformed into other forms useful for human activities. Wind power has been used since ancient times to move sail-driven boats or operate milling machinery when moving its blades.
When operating by wind, an inexhaustible resource is considered that wind energy is a renewable energy.
Wind power is an abundant, renewable, clean resource that helps to reduce greenhouse gas emissions by replacing thermoelectric plants that run on fossil fuels, which makes it a type of green energy. However, its main drawback is its intermittency.
Wind energy indirectly depends on solar energy. When the Sun heats the air (that is, thanks to solar energy) it changes density. The difference in density between different air masses causes movement and air currents. The denser (cold) air weighs more and tends to fall.
Origin of the wind
Wind energy is related to the movement of air masses that move from areas of high atmospheric pressure to adjacent areas of low pressure, with velocities proportional to the pressure gradient.
The winds are generated because of the non-uniform heating of the Earth's surface by solar radiation. Between 1 and 2% of the energy coming from the sun turns into wind. During the day, the masses of air over the oceans, seas and lakes remain cold in relation to the neighboring areas located on the continental masses. In this sense, wind energy is related to solar energy.
The continents absorb a smaller amount of sunlight, and therefore, the air that is on the earth expands, and becomes lighter and rises. The coldest and heaviest air that comes from the seas, oceans and great lakes is set in motion to occupy the place left by the hot air.
Production of electricity from wind power
To be able to take advantage of the renewable energy of wind energy it is important to know the diurnal and nocturnal and seasonal variations of the winds, the variation of the wind speed with respect to the height above the ground, the entity of the bursts in short periods of time , and maximum values occurred in historical data series with a minimum duration of 20 years. It is also important to know the maximum wind speed. To be able to use the wind energy, it is necessary that it has a minimum speed of 12 km / h, and that it does not exceed 65 km / h
Wind energy is used through the use of wind machines (or windmills) capable of transforming wind energy into usable mechanical rotation energy, either to directly drive the operating machines, or to produce electricity. In the latter case, the conversion system, which comprises a kinetic generator with its control and network connection systems, is known as a wind turbine.
The low energy density of wind energy per unit area, has as a consequence the need to proceed with the installation of more machines for the use of available resources. The most common example of a wind installation is represented by the "wind farms" (several wind turbines implanted in the territory connected to a single line that connects them to the local or national electricity grid).
Currently it is used, above all, to move wind turbines. In these, the wind energy moves a propeller and by means of a mechanical transmission system, the rotor of a generator, normally an alternator, which produces electrical energy is rotated. For a facility to be profitable, they are usually grouped into concentrations called wind farms.
Last review: May 31, 2016