Write an explanatory note on WIND ENERGY.

ANS:

* Sun's energy is the main factor responsible for the movement of air. Moving air is called wind and it possesses kinetic energy.

* Windmills, invented 250 years ago by Persians, are once again gaining popularity.

* Modern windmills convert wind energy into either mechanical energy or electrical energy.

* A windmill consists of a fan-like structure mounted at some height on a strong support. Its blades are so designed that when wind strikes them, a pressure difference is created between them. This difference produces a turning effect and makes them rotate.

* The height of the windmill, the number of blades and their shape, etc. are decided on the basis of average wind velocity and local environmental factors.

* The rotational motion of the windmill is utilised to obtain mechanical work like in a water-lifting pump.

* If a turbine is connected to the windmill, electricity can be generated but the electricity generated by one windmill cannot be used commercially.

* To generate a lrage amount of electricity, a wind energy farm is established where there are several windmills erected in a large area.

* In Gujarat, wind-energy farms are located at following places : Lamba near Porbandar, Okha, Mandavi and Dhank.

* The largest windfarm in India is near Kanyakumari in Tamilnadu and it generates 300 MW electricity.

* The greatest advantage of wind-energy farms is that the electricity is generated from a renewable source and it is pollution-free.

* LIMITATIONS

1. Wind energy farms can be established only at places with continuous flow of wind.

2. The average wind velocity should be 16 km/h to enable its working.

3. It requires a large area of land and cost of installation is very high.

4. It creates noise pollution.