“WIND ENERGY”,The Renewable Energy.

“Wind energy is a form of solar energy. Wind energy (or wind power) describes the process by which wind is used to generate electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. A generator can convert mechanical power into electricity.”

Wind Energy Basics:-

The Wind is caused by the uneven heating of the atmosphere by the sun, variations in the earth’s surface, and rotation of the earth. Mountains, bodies of water, and vegetation all influence wind flow patterns. Wind turbines convert the energy in wind to electricity by rotating propeller-like blades around a rotor. The rotor turns the drive shaft, which turns an electric generator. Three key factors affect the amount of energy a turbine can harness from the wind: wind speed, air density, and swept area.


The amount of energy in the wind varies with the cube of the wind speed, in other words, if the wind speed doubles, there is eight times more energy in the wind (2^3=2×2×2=8). Small changes in wind speed have a large impact on the amount of power available in the wind.


The more dense the air, the more energy received by the turbine. Air density varies with elevation and temperature. Air is less dense at higher elevations than at sea level, and warm air is less dense than cold air. All else being equal, turbines will produce more power at lower elevations and in locations with cooler average temperatures.


The larger the swept area (the size of the area through which the rotor spins), the more power the turbine can capture from the wind. Since swept area is A=pi(r)^2 , where r = radius of the rotor, a small increase in blade length results in a larger increase in the power available to the turbine.


Wind farms. A wind farm is a group of wind turbines in the same location used for production of electricity. A large wind farm may consist of several hundred individual wind turbines distributed over an extended area, but the land between the turbines may be used for agricultural or other purposes.

How efficient is a wind turbine?

Wind turbines convert around 45% of the wind passing through the blades into electricity (and almost 50% at peak efficiency)6,7. Over time, coal power stations operate at around 85% of full capacity (known as the capacity factor).e, coal power stations operate at around 85% of full capacity (known as the capacity factor).


Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines.

Wind turbine size and power rating:-

Wind turbines are available in a variety of sizes, and therefore power ratings. The largest machine has blades that span more than the length of a football field, stands 20 building stories high, and produces enough electricity to power 1,400 homes. A small home-sized wind machine has rotors between 8 and 25 feet in diameter and stands upwards of 30 feet and can supply the power needs of an all-electric home or small business. Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping.

ADVANTAGES Of Wind Energy:-

1)  Wind Energy is an inexhaustible source of energy and is virtually a limitless resource.

2) Energy is generated without polluting environment.

3)  This source of energy has tremendous potential to generate energy on large scale.

4)  Like solar energy and hydropower, wind power taps a natural physical resource.

5)  Windmill generators don’t emit any emissions that can lead to acid rain or greenhouse effect.


1)  Wind energy requires expensive storage during peak production time.

2)  It is unreliable energy source as winds are uncertain and unpredictable. 

3)  There is visual and aesthetic impact on region.

4)  Requires large open areas for setting up wind farms.

5)  Noise pollution problem is usually associated with wind mills.


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