Spurred by economies re-opening after the global pandemic and with fuel supply chains drastically affected by the Russian invasion of Ukraine, the UK has been gripped by an energy crisis since the Autumn of 2021 with energy prices steadily climbing to reportedly be higher than all but three EU states.
This, in turn, has fired a wider cost of living crisis with an estimated six million households across the UK living in fuel poverty.
According to a report by the Energy Crisis Commission, the UK was hit hard during this period due to its high dependence on gas for power generation and home heating, making it highly exposed to supply disruptions and price spikes on international markets. In fact, the International Monetary Fund suggested the country was the worst hit of any Western European country.
The Commission found that the energy crisis may not have been as detrimental if it was not for years of underinvestment in demand reduction measures and clean energy technologies. Further, without decisive, urgent action and investment, the UK remains dangerously underprepared for a future energy crisis.
The most reliable renewable option?
Against such a backdrop, the clamour for greater emphasis on renewables is becoming deafening, amidst this chorus, there are a number of proponents who seek to cast more light on the underutilised potential of geothermal energy.
With the potential to cover around 25% of heating and cooling and around 10% of electricity in Europe by 2030 (according to the European Geothermal Energy Council), momentum around geothermal energy has been building across the continent. According to the organisation, the market is now supplying electricity to 11 million consumers and providing heating and cooling to around 20 million people and 400 cities and factories. “We are facing a significant moment of growth and anticipation for the European geothermal market,” said Miklos Antics, EGEC President. “2023 was a year of significant transformation for geothermal.”
This success is punctuated by a number of impressive projects that highlight the resource’s capacity to make meaningful change. In the Greater Paris area, for instance, homes have been receiving geothermal heat for more than 40 years with the current network suppling more than 250,000 households from the Paris Basin. And, according to Bentley, a new digital twin of the geothermal network could help unlock even more of the system’s potential.
Elsewhere, a geothermal district heating system in Szeged, Hungary, has been expanded to displace more than 2.2mn cu/m of natural gas. As one of the largest geothermal district heating overhauls in Europe, the project is expected to make district heating in Szeged 60% less polluting, providing a local and more economical energy supply.
The answer for the UK?
While the UK is recognised as a global leader in wind energy and much has been made of its potential within the geothermal space, its activity here has been limited. Quoting the IEA, the Government Office for Science made note that the UK has an estimated 43,700 installed ground source heat pump systems, a relatively poultry number compared to Germany’s 440,000 (in 2020) and France’s >210,000 (in 2018). Overall, geothermal sources supplied just 0.3% if the UKs’ heat demand in 2021.
Given that heating accounts for an estimated 40% of energy use in the UK, geothermal could be a vital outlet here, and a particularly useful tool within this arsenal could be mine water geothermal energy. Following the ‘geothermal gradient’, the deeper mine water is, the warmer it tends to be, with temperatures typically ranging from 10-20°C (but can reach 40°C). This water can be abstracted with heat exchangers and pumps then used to recover the heat which is distributable via district networks.
According to the Durham Energy Institute (DEI), there are approximately 23,000 mines across the UK with roughly one in four homes built on such sites. With heat pump technology increasing the temperatures to 40-50°C, this could supply almost 50% of the UK demand for heating and cooling. The institute also suggests that there is enough heat within the UK’s coalfields to meet the demands of all the buildings above them. To add to this, TownRock Energy has noted that this resource is also most prevalent beneath ex-mining communities who tend to experience a higher incidence of fuel poverty and deprivation.
This year, the Coal Authority and Ordnance Survey carried out and published research to investigate and promote how water in disused coal mines could be used as a low-carbon heat source to support former mining communities. The interactive map that was a product of the collaboration can be accessed here. https://datamine-cauk.hub.arcgis.com/
The DEI is another leading voice here and, from 17-18 September 2024, it held a conference around the topic at Durham University. Here, attendees addressed crucial points such as the technical challenges if extracting and utilising geothermal heat from mines and the social, economic and policy considerations for installing mine water solutions. At the forefront of the meeting point was the DEI interdisciplinary project ‘Geothermal Energy from Mines and Solar-Geothermal’ (GEMS) which, in close collaboration with the British Geological Survey (BGS) and industrial and government experts, is assessing and addressing the barriers to exploiting coal mines for this purpose.
Seizing the opportunity
As a result of efforts to drive the resource towards wider development, there have been a selection of projects being pursued within the country.
Most notably, the mine water energy scheme at Gateshead became the first operational large-scale mine water heat network in the country. Taking about three years to deliver and going live in March 2023, the project uses mine water contained in workings 150 m beneath Gateshead town centre. A 6MW water source heat pump recovers heat and distributes it via a network to the local area, saving an estimated 72,000 tonnes of CO2 per year and “showing what is possible when you invest in this technology,” according to Councillor John McElroy.
Following in Gateshead’s wake, other projects are being investigated. Amongst this is the Seaham Garden Village, a new site that will provide 1,500 homes, a primary school, shops, a health and wellbeing hub along with an innovation centre and will be supplied by the Dawdon Mine Water Treatment Plant. It is projected as an important step in Durham County Council’s aims to reduce carbon emissions by 60% by 2030 and reach neutrality by 2050.
While such progress is commendable, it is limited given the remarkable potential mine water geothermal energy offers to the UK. The new Labour Government has made clear its plans to transform the country into a ‘clean energy superpower’ but, while the Party has promised to double onshore wind, triple solar power and quadruple offshore wind by 2030 in order to do so, there was no mention of geothermal within its manifesto.
Moreover, in the time since it has taken over 10 Downing Street, the Party has taken steps to invest in CCUS, approved three large new solar farms, lifted the ban on new onshore windfarms in England, but has made little progress around geothermal energy. In the House of Commons Debate around the Great British Energy Bill, Ed Miliband, Secretary of State for Energy and Climate Change of the UK, stated “the truth is that we need to accelerate the deployment of wind, solar, tidal, hydrogen, carbon capture and nuclear,” – the omission of geothermal here (and indeed in the wider debate) is glaringly obvious. Indeed, in the ensuring discussions it received little mention, although MP Kieran Mullan, did suggest that the exploitation of geothermal should be included as part of Great British Energy’s strategic priorities, with support for the industry helping to “propel us closer to solving one of the most difficult challenges we have faced in relation to heat… If we dig deep on geothermal, we will help level up the UK and reap the rewards this will provide.”
Whether this advice will be taken on board and the UK will truly take advantage of this unique, impressive opportunity, time can only tell.