Geothermal energy
Hot water and steam from deep underground can be used to drive turbines: this is called geothermal energy.
In volcanic areas, the hot rocks may heat water so that it rises to the surface naturally as hot water and steam.
Geothermal power stations are located in places such as Iceland, California and Italy.
In some places, the rocks are hot, but no hot water or steam rises to the surface.
In this situation, deep wells can be drilled down to the hot rocks and cold water pumped down.
The water runs through fractures in the rocks and is heated up.
It returns to the surface as hot water and steam, where its Energy which an object possesses by being in motion. can be used to drive turbines and generate electricity.
The diagram shows how this works.
Heat energy \(\rightarrow\) kinetic energy of hot water and steam.
Kinetic energy of hot water and steam \(\rightarrow\) electrical energy.
Advantages
- Geothermal energy is a renewable energy resource and there are no fuel costs.
- No harmful polluting gases are produced.
Disadvantages
- Most parts of the world do not have suitable areas where geothermal energy can be used.