The UK is searching for answers to one of the defining challenges of our time: how to build an energy system that is clean, secure and affordable. Yet one of the country’s most valuable resources receives only a fraction of the attention it deserves.

Geothermal is, quite literally, energy beneath our feet.

Geothermal energy is available around the clock, every day of the year, providing reliable, low-carbon energy. Most importantly, it complements rather than competes with the technologies already transforming our energy system.

Europe has already shown what is possible
Geothermal is often perceived in the UK as an emerging technology. But this is simply not true. Across much of Europe, it is already established infrastructure.

Paris, France, has been heating homes with geothermal since the 1970s. Munich, Germany, is working towards meeting around half of its heating demand from geothermal. The Netherlands has set out a masterplan to supply 23% of national heat demand from geothermal by 2050, building on commercial success in the horticulture sector.

The UK has the same fundamental resource but has not yet developed it at scale. Southampton has supplied geothermal heat through its district heating network since 1986. The Eden Project uses geothermal to help heat its famous biomes. Earlier this year, United Downs in Cornwall generated geothermal electricity for the grid. These projects demonstrate what is possible, but they remain isolated successes rather than the foundation of a national industry.

Heat at scale is the immediate opportunity 
Much of the UK’s energy debate focuses on electricity. Heat deserves equal attention.

Heating buildings accounts for a substantial share of the UK’s power demand. As more homes and businesses electrify their heat, demand will continue to increase on a grid that is already experiencing capacity challenges.

This is where geothermal offers something different.

The near-term opportunity is not primarily electricity generation, but reliable heat delivered directly to large energy users such as hospitals, universities, industrial sites and public estates and more widely through heat networks. Used in this way, geothermal can significantly reduce pressure on the electricity grid while providing long-term, predictable energy costs.

The earth also provides something increasingly valuable in a warming climate: sustainable cooling.

The biggest challenge is above ground, not below it
The barrier to scaling geothermal is not geological.

The UK has extensive knowledge of its subsurface through evidence from more than 2,000 onshore oil and gas wells and hundreds of thousands of water wells, such as through The National Geoscience Data Centre (NGDC). The deeper we drill, the hotter the earth becomes, opening opportunities through shallow geothermal systems enhanced by ground-source heat pumps, geothermal energy in water in abandoned mines, deep geothermal heat, accessing the energy in underground aquifers, and, eventually, electricity generation, drilling into granite around 5km below the surface.

The real challenge sits above ground.

We need more heat networks, clearer market structures and greater understanding that heat and cooling can be delivered as utilities rather than simply as fuels (think ‘heating and cooling as a service’). Encouragingly, these conditions are beginning to emerge as the government expands heat network policy, and businesses and communities seek more resilient, lower-carbon energy supplies.

An investment story as much as an energy story
Geothermal should not be viewed solely through the lens of climate policy. It is also an economic opportunity.

Unlike internationally traded fuels, geothermal draws on a domestic resource. Once operational, projects offer stable operating costs, long asset lives and predictable revenues that appeal to infrastructure investors. They create skilled jobs across exploration, drilling, engineering, construction and operations, while helping businesses manage long-term energy costs.

The UK is particularly well placed to benefit. Decades of expertise developed through the oil and gas sector – from drilling and subsurface engineering to project delivery – can help accelerate geothermal deployment. The International Energy Agency’s recent report The future of geothermal energy has highlighted the strong overlap between the two industries’ capabilities, making geothermal a compelling opportunity for a just transition that retains highly skilled people and supply chains.

Geothermal should not be viewed solely through the lens of climate policy. It is also an economic opportunity.

The opportunity is ours to seize
Geothermal will not displace wind, solar or other low-carbon technologies, which have attracted high levels of investment and attention. All solutions can exist in a balanced and resilient energy system.

The UK government already wants heat networks to supply around 20% of UK heat demand by 2050. As those networks are developed, geothermal should be considered as a core source of reliable, low-carbon heat. European countries have already demonstrated how supportive policy can unlock private investment, reduce development timelines and create confidence throughout the supply chain.

Success will not be measured by one flagship project. It will come when geothermal becomes an integral part of the UK’s infrastructure – heating and cooling hospitals, universities, businesses, communities and cities while reducing emissions, strengthening energy security and attracting long-term investment.

Now is the time for investors, policymakers and industry to get involved, engage with the sector and help turn the sustainable energy potential beneath our feet into investment, infrastructure and long-term economic value that will serve the UK for generations.

The views and opinions expressed in this article are strictly those of the author only and are not necessarily given or endorsed by or on behalf of the Energy Institute.

• Further reading: ‘Geothermal sector to adopt oil and gas investment framework’. Discover more about recent developments in the US geothermal sector.
• ‘World’s hottest enhanced geothermal system reaches record 331°C’. Mazama Energy reports that its pilot enhanced geothermal system project in Newberry, Oregon, US, has achieved a bottomhole temperature of 331°C (629°F), setting ‘a new global benchmark’ in geothermal innovation, according to the company.