Wind is formed due to the differential heating of the air by the sun and the rotation of the earth. The sun heats up the atmosphere unevenly; the layer of the air which is just near the earth’s surface is heated up the most. So, being hot it tends to raise high up while the cooler air from the nearby areas will try to settle down there, thus causing the movement of air. Simultaneously, the rotation of the earth also causes the turbulence of air. The energy from the wind thus created can be harnessed using a wind turbine. Many wind turbines together constitute a wind farm.

Components of a wind turbine:

A typical wind turbine consists of the following main parts:

1.Tower: It is the tall structure on which the other parts are mounted. It not only acts as a support for the whole structure but make it accessible to the steady flow of the wind. So, higher the tower, higher will be the efficiency of the turbine to capture the wind energy. For efficient performance, a tower should be at least 30 meters tall. A turbine is made of steel.

2.Blade: It is the flat structure which collects the wind energy. It can be either placed horizontally or vertically. As the wind blows the blade rotates and creates the mechanical energy. Blades are usually made of materials that are light weight and also resistant to corrosion and lightning such as fiberglass or plastic. In order to avoid turbulence, proper distance needs to be maintained in between the blades. So, a turbine usually has only two or three blades.

3.Nacelle: It is a box like structure and is the main part of the turbine and contains the generator, gearbox, controller, anemometer and other parts.

• Anemometer-It measures the speed of the wind and sends the data to the controller.
• Gear box- often the wind speed collected by the blade is not sufficient to start the turbine, so a gearbox increases the speed of the wind to the optimum level at which the generator can start functioning.
• Generator: It changes the mechanical energy of the wind into electricity by electromagnetic induction. Electromagnetic induction is the phenomenon in which electricity is produced when a coil is rotated in the magnetic field. Inside the generator are large permanent magnets. When a coil rotates in between these magnets, electricity is produced.
• Controller: It is a computer system which starts the functioning of the turbine or stops it in case of very high wind speed. When the speed of the wind is more than 45m/hour, it damages the turbine. So, the control system shuts down the whole apparatus.

Basic working mechanism:

When a wind with a speed higher than 15km/hour blows over the blades, it rotates them. This in turn rotates the gearbox which is connected to the blades by a shaft. The gearbox then increases the speed of the motion. Another shaft connects the gearbox to the generator. This shaft turns the coil inside the generator and produces electricity.

Disadvantages:

Some of the didadvantages associated with the wind energy are as follows:

• Being dependent on the speed of the wind, it can be harnessed only at specific regions. And even in such places, it could become unreliable depending on the weather conditions of the day. As one can never get a steady supply of energy from it, it can only be harnessed along with other source of energy.
• The wind turbine creates noise while generating electricity. So, if the wind farm is installed near the residential area it can be a problem.
• The initial cost of installing wind farms is also quite expensive.
• Another major disadvantage of the wind farm is that sometimes birds are caught up in the blade which leads to their death.

Advantages:

• It is a renewable and eco friendly source of energy.
• It does not release any pollutants when generating electricity.
• After the in initial investment, there is no recurring cost for producing electricity or for maintenance.
• Installation of wind mill requires only small area for its base. As all other parts of the windmill lies above the ground, the areas near the base of the turbine can be utilized for other purposes.
• Wind farms are an excellent option for generating energy in remote locations. .

• Written by jabeen.
• In category General Reference.
• 12 years ago.

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