ALTERNATIVE ENERGY
Alternative energy is energy that is produced without burning fossil fuels. Alternative energy includes geothermal power, hydroelectric power, solar power, wind power, tidal power and wave power.
Alternative power has several advantages. It's sources, such as wind and energy from the Sun, will never run out. Also, they do not cause pollution like fossil fuels.
There are however, not enough alternative energy schemes yet to supply the energy needs of the world.
1 Geothermal Power
Geothermal power is produced by using the heat inside the Earth. Most geothermal power stations are built near volcanic areas, where the underground rocks are very hot. When water trickles into the hot rocks, it heats up and turns to steam. The steam is piped to power stations.
2 Hydroelectric Power
Hydroelectric power is electricity that is produced by using the energy in flowing water. In a typical hydroelectric power station, water from a reservoir is pumped to water turbines. They drive electric generators to make electricity.
2.1 Turbine
A turbine is an engine with wheels that are spun around by liquids or gasses. Water turbines are used to drive the generators in hydroelectric power stations.
2.2 Generator
A generator is a machine that produces, or generates, electricity. It is built like an electric motor but it works in a different way. Electricity is produced in the coils of the rotor (rotating part) when the rotor spins round.
3 Solar Power
Solar power is produced by using energy from the Sun.
Houses can be heated by solar power. Solar panels on the roofs trap the Sun's energy.
3.1 Solar Power Station
4 Wind Power
Wind power is the use of the energy blowing in the wind, which is used to generate electricity. The windmill was the first machine to use the wind's energy. Windmills have now been replaced by wind turbines. Most of them have huge propellers, which spin round when the wind blows. The propellers turn generators to produce electricity. In places, groups of wind turbines have been built to create wind "farms".
5 Tidal Power
Tidal power is produced by using the energy in the tides of seas and oceans. In some parts of the world, the difference between high and low tides can be 10 meters or more. The energy of the water as it flows backwards and forwards with the tides can be used to spin water turbines, which then turn electricity generators.
6 Wave Power
Wave power is produced by using the energy of the waves in seas and oceans. Several ways of using wave energy have been invented, but none are suitable yet for large-scale use.
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