WHAT IS GEOTHERMAL
Geothermal means heat from the ground.
The earth’s crust contains a virtually limitless amount of thermal energy which is being continuously replenished by heat conduction from the mantle below it. As a result, the temperature of the rocks beneath our feet increases at an average rate of about 25ºC for every 1,000m of depth.
In volcanic areas and at some tectonic plate boundaries the temperature gradient is much higher and temperatures of several hundred degrees can be found within 2,000m of the surface. Where these temperatures coincide with suitable geology, underground reservoirs of steam or hot water can develop. These can be tapped by drilling to bring the energy to surface where it can be used for electricity generation.
But geothermal resources exist away from these areas too. Lower temperature resources are used for direct heating and industrial or agricultural processes in 90 countries around the world and developers are now drilling much deeper wells in non-volcanic areas to access the temperatures they need because they recognise the environmental benefits of the technology. It is a clean, sustainable, renewable, low carbon energy source that has a very small surface footprint and minimal environmental impact.
Wherever there is a need for heat, geothermal can provide a solution.
