Geothermal energy is a renewable source of energy that can be used in the place of fossil fuels in order to heat a property or object and is often used for keeping swimming pools at a pleasant temperature. It achieves this by heating water which it runs through a piping system deep underground and it does this completely free of charge and while creating no emissions. But how does it work?

The way that geothermal energy works can be understood by breaking down the etymology of the word. ‘Geothermal’ is a word made up of two parts those being ‘geo’ as in ‘geographic’ or ‘geology’, and ‘thermal’ as in ‘thermostat’ or ‘thermometer’. In other words this then is heat that comes from the ground and this heat is garnered originally from the sun.

As the sun is constantly shining onto the ground it is no surprise that over time this causes it to heat up. If you touch the ground right now then you won’t notice this because the soil on the surface will have been cooled down over time by a range of other effects – by the wind for instance and by the rain. As it is right on the surface it is easy for the heat to escape here (and interestingly this is actually way causes air to rise and for wind to be generated), however deeper underground this heat is well insulated and it stays warm much longer meaning that it’s almost constantly at a very high temperature.

Geothermal energy then takes full advantage of this by running a series of pipes through the ground and by pumping water through them. This water then heats up simply by being surrounded by the warm soil and it then retains this heat while it is returned to the surface to be used as a form of heating. This then means it can be run into radiators or used as warm water for a swimming pool and it won’t have cost any money to heat that water up or any non-renewable energy. The only other energy that you will be using will potentially be to pump the water through the piping and back up again – which would be significantly less than powering an electric boiler.

For geothermal energy to work there are certain requirements that must be met. For instance the piping must the piping needs to be significantly deep underground in order to get hot enough and the deeper you go the more powerful the energy source will be. This does present some obstacles in terms of how much energy can be garnered from geothermal energy which is why it’s currently used mostly only for small scale uses such as heating pools. However research is being done into ways to get around the considerable logistical and financial challenges of laying piping so deep underground. For instance in certain areas much hotter rock is found far closer to the Earth’s surface – in a part of Australia near Cooper Creek there is rock only two miles beneath the surface that is 455 degrees Fahrenheit – and it is believed that the Cooper River basin might be enough to provide 10,000 megawatts of electricity. This would be enough to replace 20 large power plants currently running on coal.