Heat from beneath our feet: Geothermal energy can decarbonise the Irish heat sector and increase energy security

10 Nov, 2022

The first National Geothermal Energy Summit was held on Wednesday at Technological University Dublin, Grangegorman.

Geological Survey Ireland, a division of the Department of the Environment, Climate and Communications, has partnered with TU Dublin to explore the geothermal resource beneath Dublin city centre. In 2021, a temperature of 38°C was measured in an exploratory borehole at a depth of 1km beneath the surface. Given that there should be a constant increase in temperature with an increase in depth, this result indicates that the energy required for district heating, 80-90°C, may be located by drilling to depths of between 2km and 3km.

TU Dublin has ambitions to be the first deep geothermal district-heating demonstration project in Ireland, and is expected to provide valuable lessons for the development of an indigenous geothermal industry in the future.

Speaking at the National Geothermal Energy Summit, Minister of State at the Department of the Environment, Climate and Communications, Ossian Smyth TD, said: “The drivers behind this surge of interest in geothermal energy are the climate emergency and the need to decarbonise our energy systems – particularly our heat sector – and the critical issue of energy security brought into sharp focus by the war in Ukraine. Geothermal energy can help in both of these regards, as it is a low-carbon, economical and local energy source. As a renewable resource, it is also aligned with the circular economy. This event is a great chance for people from different sectors with an interest in accelerating geothermal energy development in Ireland to come together and plan our next steps.”

Geothermal energy is energy stored in the form of heat in the Earth. A range of geothermal technologies are available that can harness this heat from depths of just a few metres to several kilometres. Geothermal energy can be used for heating and cooling, and is an ideal complement to district heating or heat network technology. Many European cities are using and developing geothermal systems, including some with very similar geological conditions to Ireland. Paris, Munich, and Milan are partially heated by geothermal energy, and many EU members have announced ambitious geothermal targets for the next decade and beyond. It is estimated that geothermal district heating networks could provide heat for 25% of the European population.

Geothermal energy is available almost everywhere and 94% of Ireland is suitable for shallow geothermal applications. Our deeper resources are less well understood, but initiatives such as the TU Dublin geothermal project are an important step in quantifying the full potential of these resources. Geothermal heating has proven to be sustainable, secure and cost-effective in many locations across the EU, and geothermal energy can now play a significant role in Ireland’s energy transition to a carbon neutral and circular economy.

For further information see: ‘An Assessment of Geothermal Energy for District Heating in Ireland’.