The British Geological Survey (BGS) has released a new assessment of the UK's geothermal potential, describing it as 'abundant but expensive'. The report, published today, urges government and industry to invest in deep geothermal projects to diversify the nation's energy mix and reduce reliance on fossil fuels.
Geothermal energy harnesses heat from the Earth's interior. In the UK, this heat is primarily accessible through deep aquifers or hot dry rocks at depths of 1 to 5 kilometres. The BGS estimates that geothermal could supply up to 20% of the UK's heating demand, a significant portion given that heating accounts for nearly half of the country's energy consumption.
However, the technology remains costly. Drilling deep wells can cost between £5 million and £20 million per project, with no guarantee of sufficient heat flow. The levelised cost of heat from geothermal is currently around 5-10 pence per kWh, compared to 3-4 pence for natural gas. This price gap has deterred private investment.
'The Earth's heat is a constant, carbon-free resource,' said Dr. Helena Vance, Science and Climate Correspondent. 'But the upfront costs are a barrier. We need a policy framework that de-risks exploration and encourages long-term investment.'
The BGS report recommends a combination of government grants, tax incentives, and a feed-in tariff for geothermal heat. It also highlights successful examples abroad: Iceland generates 25% of its electricity from geothermal, while France's Paris Basin uses geothermal for district heating.
There are technical challenges as well. The UK's geology is less favourable than volcanic regions, requiring deeper drilling and enhanced geothermal systems (EGS) that fracture rock to create reservoirs. These techniques are still being developed.
Environmental concerns are minimal. Geothermal plants have a small land footprint and emit negligible greenhouse gases. However, there is risk of induced seismicity, though typically at levels imperceptible to humans.
The timing is critical. As the UK aims for net-zero emissions by 2050, every low-carbon technology must be evaluated. Geothermal offers baseload heat and power, complementing intermittent renewables like wind and solar. 'We cannot afford to ignore any tool in the box,' Dr. Vance added. 'The cost of inaction on climate change far exceeds the cost of drilling a few wells.'
The BGS is calling for a national geothermal strategy, including a dedicated research centre and pilot projects. If successful, the UK could tap into a virtually limitless energy source beneath its feet. The question is whether the commitment will be made before the opportunity warms away.
