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Geothermal energy explained

By OVO Energy Wednesday 28 February 2018

What is geothermal energy?

Geothermal energy is heat created deep in the earth’s core. It is a clean, renewable resource that we can harness as heat or turn into electricity.

How does geothermal energy work?

The earth is a bit like an enormous Gobstopper. It’s made up of layers that get hotter and hotter as you go down. 1,800 miles deep is the earth’s core – a solid 5,430°C ball (not magma as people often think). It’s as hot as the sun!

So why is it so hot down there? Some of the heat was created more than 4 billion years ago when the earth began. But most of it is constantly being produced from radioactive decay.

You don’t even need to dig that deep to feel the heat. It’s a fairly constant 11-12°C just 2 meters down. And 370˚C in the earth’s crust. So, even if the ground feels cool, there’s valuable heat energy there. And innovative geothermal energy technology helps us to bring it to the surface or turn it into electricity.

What geothermal technology is there?

  1. Direct geothermal energy. This is when hot water is pumped directly into buildings from hot springs or geothermal reservoirs to heat them. It dates back thousands of years to when people would use hot springs for bathing and cooking.

  2. Geothermal power plants. This is when hot water and steam from deep beneath the earth are piped into wells and used to generate electricity in a power plant.

  3. Geothermal heat pumps (GHPs) or ground source heat pumps. This is when a network of liquid-filled pipes is buried in loops 2 metres beneath the ground, where it’s 11-12°C. The liquid circulates in the pipes, heating a central heating system in a home or office.

Does OVO’s plans contain geothermal energy?

Yes. Our renewable electricity comes from many green sources such as wind, solar, geothermal, wave, tidal, hydro, biomass, landfill gas, sewage treatment plant gas and biogas.