Geothermal Energy

Let's Get Deep

Geothermal Sulfur Pool

Hot springs are evidence of geothermal activity.

In a Flash

Geothermal Energy

Geothermal energy comes from the heat inside the Earth. It can be used to produce electricity, to heat homes and buildings, and to provide hot water. Geothermal energy is the only renewable form of thermal energy.

Burning Questions

What is geothermal energy?

Geothermal energy comes from the heat contained within the Earth.
The word 'geothermal' comes from two Greek words:
Geo, meaning earth; and
Therme, meaning heat.


Geothermal power creates energy from hot water and steam.

Where does the heat inside the Earth come from?

The Earth's core - about 4000 miles below the surface - is made up of very hot molten iron which surrounds a solid iron centre.

Surrounding the Earth's core is the mantle, which is partly made of rock and partly of hot magma.

The outermost layer of the Earth is the crust – this acts like an insulating layer.

As the plates that make up the Earth's crust drift apart and push against each other, they can cause the crust to crack or thin, allowing plumes of hot magma to rise up into the crust.

How do we access geothermal from below the Earth's surface?

To find geothermal reservoirs close to the Earth's surface, exploratory wells are drilled to search for reservoirs.

Once a reservoir is found, production wells are drilled to bring hot water and steam to the surface.

The hot water and steam are used to generate electricity at power plants close to the production wells.

Injection wells return used geothermal fluids back to the reservoir.

Geothermal Power Plant Diagram

Geothermal power plants harness the Earth’s heat to generate electricity.

How is geothermal energy used?

Heating: Geothermal energy can be used to heat buildings.

Industry: The heat from geothermal water is used for dying cloth, drying fruit and vegetables, washing wool, manufacturing paper, pasteurising milk, and drying timber products.

Hot Spring Bathing & Spas: For centuries, people have used hot springs for cooking and bathing. The early Romans are famous for their love of geothermal baths!

Agriculture & Aquaculture: Water from geothermal reservoirs can be used to warm greenhouses that grow flowers, vegetables and other crops. It can also help speed up the growth of fish, reptiles and amphibians.

What Do You Mean?

Geothermalenergy comes from the heat within the Earth.

Exploratory wells are used to search for geothermal reservoirs located close to the Earth's surface.

Production wells bring hot water and steam to the Earth's surface, which is used to generate electricity.

Injection wells return used geothermal fluids back into the geothermal reservoir.

Renewable energy comes from a source that will never run out. Geothermal energy is renewable because it will always be available from the Earth's natural heat.

Cool Facts

Temperature estimates for the Earth's core range between 5000 and 11,000 degrees Fahrenheit. Now that's hot!

Cool Facts

The Earth's mantle (the layer surrounding the core) is around 1800 miles thick.

Speedy Summary

Geothermal energy comes from the heat contained within the Earth. This energy is harnessed in the form of water and steam, which can be used to generate electricity.

Geothermal Power Plant Diagram

Energy from geothermal power plants is used in industry and farming.