Geothermal energy harnesses underground reservoirs of hot water and steam to generate electricity or to heat and cool buildings directly. According to the UK Government, it currently provides less than 0.3% of the UK’s annual heat demand, using only a small fraction of the country’s estimated geothermal resource.
In 2025, NHS Grampian conducted a feasibility study into reducing the health board’s heating costs. One option considered was drilling a borehole approximately 1.5 miles deep to extract heat from granite, and funding options are now being explored.
Geothermal heat is commonly classified as shallow or deep. Shallow geothermal energy refers to heat stored in the ground up to about 200 metres deep. This heat mainly comes from solar radiation and human-made structures such as flooded coal mines. Heat pumps are required to raise the temperature so the energy can be used in domestic or commercial buildings.
Deep geothermal energy in the UK usually refers to resources found below 500 metres. Temperatures increase with depth, known as the geothermal gradient, reaching roughly 39 °C at 1,000 m and 139 °C at 5,000 m.
Although resources exist across the UK, usage remains lower than in several European countries. The British Geological Survey identified three main Scottish sources: abandoned mines, hot sedimentary aquifers, and heat-producing granites. Currently, the UK has no deep geothermal plants, and wider adoption will likely require long-term government support and further technological development.
This section provides examples of a research, teaching or innovation taking place at Robert Gordon University related to this topic.
Geothermal system to be used to cool Kenyan homes - A team of researchers from Robert Gordon University are leading an innovative project aimed at reducing heat stress for Kenyans living in informal housing by using a geothermal cooling system which pulls colder air from underground into their homes. https://www.rgu.ac.uk/news/news-2024/7183-geothermal-system-to-be-used-to-cool-kenyan-homes