The Mining Remediation Authority – operator of more than 80 treatment schemes across the UK – identified an opportunity for low-carbon heat recovery at its Lindsay treatment scheme near Ammanford, Carmarthenshire.

At Lindsay, 25 litres of mine water per second is pumped and treated – a process that removes approximately 28 kg of iron each day, preventing it from entering local watercourses.  

The mine water is naturally warm due to geothermal energy from the earth’s crust, which is retained by the water after time spent circulating through underground rock layers and former coal mines.

The project utilises heat exchangers submerged in one of the settlement ponds to recover heat from the mine water, which is then transferred to a nearby industrial unit to supply low-carbon heating and hot water. It is predicted to save 17.5 t/y of CO₂.

Working in collaboration with local business Thermal Earth, the project, constructed in two weeks, secured funding through Innovate UK’s New Innovators in Net Zero Industry, South-West Wales initiative.

Andrew Simpson, Head of Innovation, By-Products and Services at the Mining Remediation Authority, comments: ‘This scheme demonstrates how Wales’ industrial heritage can be repurposed to support a low-carbon future. By unlocking the potential of mine water heat, we’re not only reducing emissions but also creating a blueprint for sustainable energy that can be replicated across the country.’