Geothermal energy
Geothermal energy is energy in the form of heat stored beneath the surface of the Earth. It is derived from the natural heat of the Earth's interior.
What is geothermal energy?
Geothermal energy is renewable heat stored beneath our feet in the Earth's surface. Between the cool surface and the hot core of the Earth, the temperature gradually increases. Unlike solar or wind energy, geothermal energy is always available. We can use it without depleting it. That makes it a reliable and sustainable, low carbon energy source.
There are different ways to get geothermal energy, often extracted as hot fluids. Geothermal power plants generate electricity from deep wells that tap into high-temperature water or steam. Ground source heat pumps use heat from shallower depths. We can then use the natural heat in various ways, such as heating buildings and generating power.
How geothermal energy is created
Geothermal energy originates from the heat generated within the Earth's core. The heat gradually moves towards the surface, warming rocks and water in the Earth's crust. This heat is mainly due to:
- Radioactive decay of minerals
- Residual heat from the planet's formation
- Solar heat stored near the Earth's surface
The level of heat varies by depth and location. The rate at which temperature increases with depth is called the geothermal gradient. It is higher in areas with active tectonic activity and volcanism and lower in the stable, older interiors of continental plates.
How we use geothermal energy
Geothermal energy is classified by the heat content of the fluid, also known as enthalpy. High enthalpy resources (>150°C) are used for electricity generation.
Low enthalpy resources (<90°C) have more varied uses. These include space heating and cooling, district heating, industrial processes, horticulture and recreational facilities.
Geothermal energy in Ireland
Ireland has excellent geothermal resources. These are low-enthalpy since Ireland isn't near any plate boundaries or volcanic centres. Geothermal has significant potential to decarbonise our heat sector.
Our geothermal map identifies the best locations of geothermal energy in Ireland.
Visit the geothermal mapShallow geothermal resources
Shallow geothermal resources (less than 200 metres deep) are well understood. 94% of the country is either 'suitable' or 'highly suitable' as a stable thermal energy resource. Ground source heat pumps (GSHPs) can use these to provide efficient heat.
Deep geothermal resources
Ireland also has recognised potential for deep low-to-medium temperature geothermal energy resources. These can be suited to large-scale or district heating and cooling in municipal, residential and industrial areas.
Geothermal policy
The Policy Statement on Geothermal Energy for a Circular Economy was published in July 2023. This is an action in the Climate Action Plan 2023. It delivers on the Roadmap for Geothermal Energy published in November 2020.
The policy addresses the barriers to the development of geothermal energy in Ireland. It particularly focuses attention on geothermal's exciting potential.