The Wind

Where does wind energy come from? Like most land-based sources of energy, ultimately comes from the Sun. The Sun radiates 174.423.000.000.000 kilowatt hour of energy to Earth. In other words, in an hour the Earth receives 1.74 x 1017 Watts of energy. Approximately between 1 and 2 per cent the energy from the Sun is converted into wind. That amount is 50 to 100 times more than the energy converted into biomass by all plants of the Earth. Temperature differences drive air circulation. The regions around Equator, latitude 0 °, are heated by the Sun than the rest of the planet. Hot air is lighter than cold air and rises up to about 10 kilometers (6 miles) of altitude and will separate in two streams one is directed towards North and another to the South. If the globe is not rotara, the air would simply come to the North Pole and South Pole fall and returned to ecuador. The prevailing winds are combined with local factors, such as the presence of hills, mountains, trees, buildings and water bodies, to determine the particular characteristics of the wind in a specific location. Because air has mass, air movement in the form of wind carries kinetic energy with him. A wind turbine converts kinetic energy into electricity. The contents of a specified volume of wind energy is proportional to the square of its speed. Thus doubled the speed with which this volume of air passes through a wind turbine will lead to an increase of four times the power that can be extracted from the air. In addition, double the wind speed will allow that twice the volume of air passing through the turbine in the same amount of time, resulting an increase of eight times the power generated. This means that with only a slight increase in wind speed can be obtained significant increases in the production of energy.

The amount of a mass of air (Ek) kinetic energy is equal to half of the product of their (m) total and the square of its velocity (v). The amount of power (p) exerted by wind is proportional to the cube of its speed (v).

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