Geothermal energy is made inside the Earth.
The world geothermal comes from Greek words meaning ‘Earth’ (geo) and ‘heat’ (thermos).
The technology behind geothermal electricity generation has improved substantially but it still only provides a fraction of world electricity generation.
Geothermal power is clean, reliable and cost effective but its availability is often limited to areas near tectonic plate boundaries.
Geothermal power plants in the Philippines and Iceland contribute around 30% of their electricity production. In the USA it is less than 1%.
As of 2010, 24 countries around the world use geothermal power to generate electricity while around 70 use it for various forms of heating.
Geothermal heating applications include industrial uses, heat pumps, space heating and bathing in hot springs.
Humans have enjoyed geothermal energy in the form of hot springs for thousands of years.
The oldest known spa fed from a hot spring is believed to be a stone pool found on Lisan Mountain in China, built in the 3rd century BC.
In some parts of Iceland, hot water runs from geothermal power plants under pavements and roads to help melt ice.