Wind Power

Wind Power

The wind turbine, also called a windmill, is a means of harnessing the

kinetic energy of the wind and converting it into electrical energy. This

is accomplished by turning blades called aerofoils, which drive a shaft,

which drive a motor (turbine) and ar e connected to a generator. "It is

estimated that the total power capacity of winds surrounding the earth is

1 x 1011 Gigawatts" (Cheremisinoff 6). The total energy of the winds

fluctuates from year to year. Windmill expert Richard Hills said that the

wind really is a fickle source of power, with wind speeds to low or

inconsistent for the windmill to be of practical use. However, that

hasn't stopped windmill engineers from trying. Today, there are many

kinds of windmills, some of which serve differen t functions. They are a

complex alternative energy source.

What to consider when building a windmill In choosing where to build a

windmill, there are many important factors to consider. First is the

location: 1) Available wind energy is usually higher near the seacoast or

coasts of very large lakes and offshore islands. 2) Available wind energy

is gene rally high in the central plains region of the U.S. because of the

wide expanses of level (low surface roughness) terrain. 3) Available wind

energy is generally low throughout the Southeastern U.S. except for

certain hills in the Appalachian and Blue Rid ge Mountains, the North

Carolina coast, and the Southern tip of Florida. This is because of the

influence of the "Bermuda high" pressure system, which is a factor

especially during the summer. Also important to consider is the wind

where you are going to build: 1) the mean wind speed (calculated my

cubing the averages and taking the mean of the cubes) and its seasonal

variations. 2) The probability distribution of wind speed and of extreme

wi nds. The mean wind speed must be high enough, and the distribution must

be so that all the data points are very similar. 3) The height variation

of wind speed and wind direction. Wind cannot be too high or too low in

relation to the ground or it is too difficult to harness. 4) The gustiness of the wind field in both speed and direction. Gusty winds greatly affect the power output of the

windmills and are usually harmful. 5) The wind direction distribution and

probability of sudden large shifts in di rection. The wind must be

unlikely to suddenly shift direction.