The UK’s geothermal sector is gaining momentum. While geothermal energy currently supplies less than 0.3% of national heat demand, this figure masks a growing opportunity. Particularly in the decarbonisation of heat, which makes up around half of the UK’s total energy demand, where geothermal can play a uniquely valuable role, writes Mark Griffiths, Associate, Arup
Geothermal energy offers a constant, local, low‑carbon source of heat that is available 24/7, regardless of weather conditions. Unlike wind and solar, geothermal does not fluctuate. It is an “always‑on” energy source, helping reduce dependence on imported fuels and easing pressure on an increasingly constrained electricity grid.
By providing direct heat through district heating networks and ground‑source heat pumps (GSHPs), geothermal can reduce the need to electrify the heating system. This, in turn, limits peak electricity demand, improves grid resilience, and enhances energy security, particularly during cold periods when electricity demand is highest.
Encouragingly, activity in the UK is increasing. New deep geothermal proposals are progressing, district heating schemes are expanding, and GSHP uptake continues to rise, with more than 55,000 installations now in operation. These systems are quietly delivering dependable heat to homes, campuses, hospitals, and commercial buildings, often with very low operating emissions and minimal visual impact.
Progress and momentum
Government support is beginning to follow this growing interest. In 2025, the UK Government appointed Minister Whitehead with responsibility for geothermal, signalling increased national recognition. Public funding is supporting several high‑profile initiatives, including the University of York’s Deep Geothermal project, geothermal‑led NHS hospital decarbonisation schemes, and expansions to established heat networks such as Southampton.
In February 2026, the United Downs Deep Geothermal Power project reached a further milestone by generating the UK’s first geothermal electricity. While electricity generation from geothermal remains limited in the UK, such projects demonstrate the broader value of subsurface heat and its potential role in a diversified energy system.
Further progress is being made through national work on levelised cost models, heat network zoning, and closer engagement between industry, regulators, and policymakers. Detail on this can be found in Arup’s latest DESNZ report.
Challenges to scale
Despite this progress, the UK lags behind other countries with similar geological characteristics. Public awareness of geothermal energy remains low, and there is currently no national geothermal strategy or coordinated programme for exploration and research drilling. Development is led by a small number of specialist developers and progresses largely on a project‑by‑project basis.
Early‑stage drilling is technically complex and capital‑intensive, with commercial returns that accrue over decades, often operating for 30 years or more, requiring patient, long‑term investment.
There is strong potential for cost reduction as drilling markets mature and technology advances as has been demonstrated in the US. AI‑enabled subsurface modelling and improved reservoir management are already helping to optimise performance, extend asset life, and reduce risk.
Reforming regulation
The regulatory landscape for geothermal remains fragmented, with responsibilities split across multiple bodies. This can slow approvals and increase uncertainty. A more unified framework, or clearer national coordination, would help embed geothermal heat within the UK’s broader energy strategy.
Recent reforms are positive. Heat Network Zoning is expected to accelerate district heating deployment; clearer guidance is emerging for open and closed loop systems and underground thermal energy storage.
What comes next?
The UK has the skills, experience, and early success stories to prove that geothermal works. What is now needed is coordination: clear policy direction, long‑term investor confidence, and wider public understanding of the importance of heat.
By delivering reliable, low‑carbon heat and reducing pressure on the electricity grid, geothermal can become a core component of a secure, resilient energy system. The heat beneath our feet is constant, local, and dependable. The opportunity now is to use it.
