Geothermal Energy
Physics: Cambridge International GCSE Supplement, topic 1.11.3
Geothermal Energy
In volcanic places, magma (underground lava) has lots of internal energy. The magma heats rocks, which heat water in pipes so it boils to produce steam. This steam rotates a turbine, which turns a generator.
Advantages
- Renewable.
- Reliable.
Disadvantages
- It is most efficient in areas with volcanic activity close to the surface.
- However, it is possible to create geothermal power plants in areas with no volcanic activity by fracturing hot rocks such as granite.
United Downs Deep Geothermal Project
- The United Downs project is located near Redruth in Cornwall.
- It is the UK’s first deep geothermal power plant.
- Engineers drill deep wells into hot granite rocks.
- Water is pumped down into the rocks, where it absorbs heat from the Earth’s natural geothermal energy.
- The heated water or steam is then brought back to the surface.
- The steam turns turbines, which generate electricity. The leftover hot water can also be used to heat homes and buildings nearby.
Test yourself on Geothermal Energy
Which one of the following is a disadvantage of geothermal power?
Converting Geothermal Energy to Electrical Energy
How is electricity produced at the United Downs geothermal site?