Lanchester Wines in north-east England has used heat from a disused coalmine for the last eight winters to maintain ideal storage temperatures at its facilities in Gateshead. The system helps prevent freezing or spoilage of thousands of vintage wines stored in warehouses.
How the system works
Water in the mine near the warehouses sits at roughly 19°C year-round. The company pumps some of the mine water out, extracts a portion of its heat, boosts that heat with a heat pump, and distributes it through pipes. For wine, the ideal temperature is 8-10°C, according to Veronica Cleary, a director at the company. For staff, temperatures are kept slightly higher, though they still wear fleeces.
Few wine companies use geothermal heat to control warehouse temperatures, and fewer still source that heat from disused, flooded mines. Lanchester Wines hopes its experience will help other companies take advantage of subterranean warmth, reducing dependence on fossil fuels and heating bills.
Challenges and breakthroughs
Cleary recalled the early years of the system: "To our mind, it was a relatively simple thing to do. [But] it didn't prove that easy at all." Some boreholes drilled to reach the mine water were poorly located, and a previous access agreement with the government-run Mining Remediation Authority (MRA) caused many headaches. After nearly two years of renegotiations, a new streamlined deal is now in place until 2044.
"It's opened up greater potential," said Joanne Eynon, principal mine water heat-licensing manager at the MRA. "It gives them a better return, I understand, on their system." The redrafted agreement has become a template for others wanting to access heat from mine water in the UK, designed to allow a swifter application process.
Cleary said: "What we wanted to try and do was pioneer a path so others could follow on from our experience."
Potential and existing networks
There are 23,000 flooded coalmines in the UK, and about 25% of UK homes and many businesses are located above or near disused coalmines, indicating huge potential for mine water heat. The north-east currently leads the way, with Great Britain's largest mine water heat network supplying Gateshead college, the Baltic Centre for Contemporary Art, and 350 social homes. Plans exist to expand it to 270 private homes, a conference centre, and a hotel.
Similar networks exist in Heerlen, Netherlands, and Bad Ems, Germany. A study published in February found the mine water heating Bad Ems town hall is 25°C, warmer than most living rooms, and "far from reaching its full potential."
Technical challenges and benefits
Using mine water for heating presents challenges: drilling into old mines can release toxic gases, so venting is important, and minerals in mine water can cause corrosion or blocking of components. Nonetheless, the relatively high temperatures of mine water, even up to 40°C at depths of 1km, make it attractive compared with other geothermal options.
Fleur Loveridge, professor of geo-energy engineering at the University of Leeds, said: "The reward on offer is potentially greater but there's a little more risk in getting there." She added that the Lanchester Wines system "does show that it works, and it works in UK conditions. It's great that they're securing the future of it."
