Wind Energy is energy harnessed from the wind. Man has used wind energy for over 2000 years. In many places, wind energy was harnessed by windmills for pumping water and grinding grain. Windmills work by slowing down the speed of the wind. The wind flows over the blades causing them to turn.
The blades are connected to a drive shaft that turns an electric generator to produce electricity. Wind turbines need a constant, average wind speed of about 14 miles per hour before the wind turbines can generate electricity. For producing large amounts of electricity, many machines can be installed together to form a wind farm.
Advantages of Wind Energy:
- Since wind energy is the result of temperature changes due to the heat of the sun, and the sun is an inexhaustible source of energy, wind energy is also renewable.
- It is a clean, reliable cost effective source of electricity.
- Electricity generated from the wind does not contribute to global warming and acid rain.
- Compared to energy from nuclear power plants, there is no risk of radioactive exposure from wind power.
How to make a wind turbine at home
The amount of energy produced by a wind machine depends upon the wind speed and the size of the blades in the machine. For a home turbine, the blades would need to span about 5 metres from tip to tip.
This is known as the rotor diameter. When the blades turn the mechanical energy produced by the blades has to be converted to electrical energy with the help of a generator. The generator can be connected to a switchboard to show the electricity produced.
If you are building the wind turbine at a windy spot, then a car alternator may be used as a generator but if you are doing this indoors or as a model, then use a permanent magnet generator to get the wind. You can also use a fan on a vertical stand to create the wind.
You can either install the turbine blades on the rooftop or a small open space. Make sure the area is not closed, as it has to catch the wind. Remember it is better to put safety first when working with a wind turbine. Always ask an adult to help you and work under adult supervision.