How we produce hydropower
When energy is generated by mechanical means, a magnet is moved inside a coil of wire and an electric current is produced. In a commercial power station this is done on a large scale – giant electro-magnets are spun inside huge coils of conductor.
The magnets are turned by a turbine, which is turned by the force of falling water.
Water is stored in a lake or river and then is directed down pipes into a power station. This water is under great pressure due to the downward direction of pipes or canals and the effect of gravity. The water then forces the turbine to spin around, generating electrical energy.
What makes hydropower renewable
Hydro-electric generation uses a natural source – water. Unlike fossil fuels, it can be reused after it has generated electricity.
Put simply, water is returned to lakes and rivers by the natural water cycle. The steps in the cycle are:
- Once the water has run though a hydro power station, its journey continues downstream to the sea
- When at sea level it absorbs heat from the sun, which causes it to evaporate
- The resulting water vapor rises up through the atmosphere and as the air cools, the water vapor condenses which forms clouds
- In Tasmania the clouds are forced up by the mountains which causes more cooling and condensation and often results in precipitation (rain, hail or snow)
- The water falls to highland lakes and rivers, where it can be used again. Making this a renewable energy source