What is wind energy?
Wind energy is generated by converting wind currents into other forms of energy using wind turbines. Winds are generated by complex mechanisms involving the rotation of the Earth, the heat capacity of the sun, the cooling effect of the oceans and polar ice caps, temperature gradients between land and sea, and the physical effects of mountains and other obstacles.
Humans have used the wind for centuries
We still use the energy of the wind for leisure and industry: winds move boats and propel hang gliders, parasails and hot air balloons. Wind energy is used to generate electricity, pump water, grind grain and dry the washing.
Wind energy becomes electrical energy
A wind turbine is made up of two or three propeller-like blades called the rotor. The rotor is attached to the top of a tall tower. As the wind blows it spins the rotor. As the rotor spins the energy of the movement of the propellers gives power to a generator. There are some magnets and a lot of copper wire inside the generator that make electricity.
Winds are stronger higher up off the ground, so wind turbine towers are about 30 metres tall to allow the rotor to catch more wind energy. The turbines are built with a device that turns the rotor so that it always faces into the wind. Just one wind turbine can generate enough electricity for a single house, or the electrical energy to pump water, or to power a mill which grinds grain. The electrical energy can also be stored in batteries. Or it is sent to cables that carry the electricity to our houses and to factories where it powers machines.
Wind farms are places where many wind turbines are clustered together. They are built in places where it is nearly always windy. The electricity that is generated at a wind farm is sold to electricity companies that provide the electricity to people living in cities and towns.
What are the advantages of wind turbines?
They are pollution free.
The energy they generate is renewable. This means that as long as the winds blow there is power to turn the blades of the rotor.
Using wind energy means that less fossil fuel (coal and oil) needs to be burned to make electricity. Burning fossil fuel pollutes the atmosphere and adds greenhouse gases to it. This pollution is a cause of global warming.
What are the disadvantages of wind turbines?
Adapted from: Thomas, Ron. & Sydenham, Shirley. 2016. Wind and wind energy. [online] www.kidcyber.com.au