A breakthrough beneath our feet: York’s geothermal project could change how the UK heats its buildings – unlocking cleaner energy for generations to come

If passion and enthusiasm alone could solve the climate crisis, Paul Bushnell might already have done it.

A physicist by background with engineering training, Bushnell has spent his career bringing people together across disciplines and borders to turn complex ideas into reality. Today, he is leading one of the UK’s most ambitious geothermal energy projects at the University of York - a scheme that could transform how large institutions decarbonise their heat supply.

Speaking on episode 32 of The Decarbonisation Dialogue, Bushnell explains how the project’s initial three-year phase is progressing. The goal is bold but clear: to develop a sustainable geothermal heat source capable of supplying the majority of the university’s buildings, dramatically reducing reliance on fossil fuels.

Paul is certainly a ‘can-do’ person.

He says: “I like getting things done. I hate talking about things without actually making them happen. When it comes to decarbonisation, sometimes we just need to take those steps, small or large, and get on with finding solutions.”

Paul is also passionate about the University of York itself and its role in the city.

He says: “The university really wants to be part of York. It has a very public desire to be a university for the public good, and it genuinely takes that to heart.

“York is a hidden gem. It has all the benefits of a city, but still feels like a community.”

That sense of responsibility underpins the geothermal project, which has received £35 million from the Public Sector Decarbonisation Scheme, delivered by our team at Salix on behalf of the Department for Energy Security and Net Zero.

At its heart, the project aims to harness the Earth’s natural heat to decarbonise the campus, while also creating long-term research and educational opportunities.

“In very simple terms, geothermal is about harnessing naturally occurring heat beneath the Earth’s surface,” Paul says.

At York, the plan is to drill between four and five kilometres underground to access a deep reservoir of naturally heated water. That hot water will be brought to the surface through large pipes, the heat extracted to warm university buildings with the water then returned underground slightly cooler, where it reheats naturally.

“In many cases, geothermal is used to heat homes or buildings,” he says. “And if the temperature and flow are sufficient, it can even be used to generate electricity as well.”

While geothermal energy is well established in countries likes the United States, Turkey and Argentina - and increasingly across Europe - the UK has been slower to adopt it.

“We are a little behind countries like Germany and the Netherlands,” Paul admits. “But the UK is actually in a great position to catch up. We have world-leading expertise, from deep drilling skills developed in oil and gas to geological knowledge at places like the British Geological Survey.”

Drilling several kilometres into the Earth is not new territory.

Paul explains the work in simple terms. He says: “If you break it down, we’re drilling a hole, something the oil and gas industry has done for decades.

“The techniques are well understood, and many of the skills already exist in the UK.”

Although the procurement process for drilling contractors is still underway, Paul is confident the expertise and equipment can be sourced, whether from the UK or overseas.

“What matters is that the investment and demand are there,” he says. “If geothermal grows, the equipment and experience will follow.”

While the current funding covers only the university’s needs, Paul and the university are ambitious and hope the project could eventually benefit the wider community.

Although this depends on the success of this first phase, future funding we well as the learning through research.

Paul explains that a huge advantage of geothermal is its minimal long-term impact at ground level because one it is built, most of the investment is underground with very little visible infrastructure. This is important as it means limited disruption to the local community.

Nevertheless, community engagement is central to the project. The university has already held good neighbour events and open days, inviting residents onto campus to meet the teams involved and ask questions. More than 100 local people are also hosting seismic testing nodes in their gardens.

“People don’t always know much about geothermal,” Paul says. “So, we’re working hard to be open, share information, and keep that dialogue going.”

During drilling, there will inevitably be some disruption, including the presence of a large drilling rig on campus for around a year. But Paul says York’s campus layout offers flexibility.

“We’re fortunate to have space to manoeuvre,” he explains. “And we’re thinking right from the start about what the site will look like afterwards, what legacy we leave behind for the university and the community.”

That long-term thinking extends beyond York. Paul sees geothermal as a potential replacement for gas-fired combined heat and power plants, widely used across universities, hospitals and towns.

“We’ve struggled to find low-carbon solutions that can deliver large amounts of heat,” he says. “Heat pumps can work well, but they need a lot of electricity and aren’t suitable everywhere. Geothermal could be a real alternative.”

Geothermal projects are capital intensive and carry geological uncertainty, particularly at greater depths and this is something Paul acknowledges. He says: “Until you drill the well, you never fully know what performance you’ll get. That uncertainty has been a barrier in the past.”

To reduce risk, the York project includes extensive preparatory work, including a 3D seismic survey to build a detailed picture of the geology below the campus. Drilling is expected to begin in around 18 months.

Crucially, geothermal is only part of a wider decarbonisation programme at York, which also includes extending the district heating network, upgrading insulation and improving lighting.

“That means we’re delivering guaranteed carbon savings with or without geothermal,” Paul explains. “But if geothermal performs as we hope, it could be transformative.”

Once operational, geothermal offers a major advantage: reliability.

“It works when the wind isn’t blowing and the sun isn’t shining,” he says. “It’s constant, it’s there, and over time it’s very cost-effective.”

The project has made life busier for Paul and his team, particularly as public engagement grows, but he wouldn’t have it any other way.

“That’s part of the fun,” he says. “If we can help unlock geothermal for the UK, that’s incredibly exciting.”

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