Wind is moving air. It is created when the sun heats the air and cooler air moves in to replace it. This causes wind. Through the ages people have learned to harness the wind's energy. Like the sun, it can also be used to create electricity.
People have learned to use the wind's energy to help them. Sailing boats use the energy of the wind to help them move through the water. Windmills are used in many countries (such as the Netherlands) to capture the wind's energy. You can also find windmills in parts of outback Australia.
The moving sails of the windmill are connected to wheels that turn to operate machinery. The machinery is used "to grind" the wheat and other grains into flour or to pump the water from place to place to help irrigate the land. The term windmill comes from "to mill" – meaning "to grind".
The energy from turning windmills can also be used to drive turbines which generate electricity. Wind energy is useful for making electricity because it is a renewable resource and does not create pollution or cause damage to the environment.
Wind turbines feature a number of components, including blades, a shaft, a generator and a tower. The blades look like propellers, except that instead of creating wind, they catch the wind.
The shaft is connected to the blades, and it rotates as the blades turn with the wind. The shaft runs to the generator. The generator transforms the rotations of the shaft mechanical energy into electrical energy.
Wind power generates less than 1% of the electricity in Australia, but more wind farms are being built every year. Ausgrid has a wind turbine at Kooragang Island where we produce electricity from the wind – using a huge wind turbine.
Advantages of using energy from the wind
- It's free once you install the equipment
- Energy from wind is renewable (ie. it won't run out)
- It is very useful for remote areas that are not connected to the main electricity grid.
- It is environmentally safe (ie it produces no greenhouse gases)
- Land used for wind farms can usually be used for other things as well (like farming)
- Australia has lots of wind!
Disadvantages of using energy from the wind
- The speed of the wind often changes and some days there is no wind at all
- Very windy areas are hard to find, and are often near the coast where land is more valuable
- Generating energy from wind creates noise, so turbines shouldn't be built near houses
- It can harm wildlife (birds can land on them), so turbines shouldn't be built near bird habitats
- They can be quite large and some people think they're an eye-sore