Welsh Government Cabinet Secretary Rebecca Evans has opened Wales' first commercial mine water heat scheme in Ammanford, showcasing low-carbon energy from former coal mines.

The pioneering project was developed by the Mining Remediation Authority, at its existing Lindsay mine water treatment scheme, in partnership with local renewable energy company Thermal Earth Ltd and Innovate UK.

Low-carbon heating and hot water is now being delivered to an industrial unit and offices on the Capel Hendre Industrial Estate in a flagship example of how Wales is turning its industrial past into a sustainable energy future.

The Lindsay scheme uses heat exchangers submerged in treatment ponds to extract warmth from naturally heated mine water, which is then boosted to replace fossil fuel heating, saving an estimated 17.5 tonnes of CO₂ annually.

It was identified as a prime opportunity through detailed mine water heat mapping commissioned by the Welsh Government and delivered by the Mining Remediation Authority.

The work forms part of the Heat Strategy for Wales and highlights areas where mine water schemes could play a significant role in decarbonising heat and supporting local energy planning.

Andrew Simpson, head of Innovation, By-Products and Service Delivery at the Mining Remediation Authority, said:

“This isn’t just a technical achievement, it’s a statement of intent. We’re showing that mine water heat can be a practical, scalable solution for decarbonising heat. It’s a model we hope to see replicated across Wales and beyond.”

Nick Salini, managing director of Thermal Earth Ltd, added:

“This project is proof that local innovation can drive national change. As a business rooted in Ammanford, we’re proud to be part of a scheme that’s not only reducing our carbon footprint but also demonstrating what’s possible when public and private sectors work together with a shared vision.”

Project partners and stakeholders toured the site, which has been operational since March 2025 and forms part of a broader programme by the Mining Remediation Authority to explore the geothermal energy potential of Britain’s coalfields, including any opportunities at more than 80 mine water treatment sites it already operates to protect and enhance the environment.

This latest development builds on the success of earlier projects in the North East of England, including the privately funded scheme at Lanchester Wines, Gateshead, which has been using mine water to provide low-carbon space heating since 2018.

More recently, the Gateshead Energy Company mine water heat network, the UK’s first large-scale scheme of its kind, began supplying heat to homes, public buildings and businesses in 2023.

The projects have demonstrated the reliability and potential of mine water heat, laying the groundwork for wider adoption across the UK.

Further momentum is building with the Seaham Garden Village project in County Durham, currently under development, which aims to use mine water heat to supply 750 new homes, showcasing how mine water energy can support large-scale, sustainable housing developments.

The Mining Remediation Authority is also progressing discussions with local authorities and industry partners across Great Britain. This includes scoping of potential sites in Wales with Rhondda Cynon Taf, Caerphilly, Flintshire and Blaenau Gwent councils, as well as wider engagement to identify and develop future mine water heat schemes that can support the transition to low-carbon heating at scale.