Mapping mine water heat opportunities in areas of abandoned underground coal mines in Great Britain

Across Great Britain an estimated 25% of all addresses are located above a coalfield. Decarbonising heating for buildings is a key challenge, with one technology-ready solution being heat networks utilising mine water from flooded underground coal mines. However, there have been challenges at a strategic planning level identifying areas with the best potential for mine water heat. To support local area energy plans and pilot heat network zoning projects, we describe a methodology to map mine water heat opportunities at a scale suitable for high level assessments. Datasets including depth to workings, mine water levels, geological disturbances, mine water treatment schemes and discharges were used, with areas ranked into ‘Good’, ‘Possible’ and ‘Challenging’ opportunities for open loop mine water heat schemes. The methodology is illustrated with a case study from part of a national opportunity assessment completed across the coalfields of Wales. The case study area covers Caerphilly County Borough Council, where 24.6% of addresses were located in ‘Good’ opportunity areas. Opportunity maps were also created for the following cities in England; Birmingham, Bristol, Coventry, Leeds, Manchester, Newcastle, Nottingham, Sheffield, Stoke-on-Trent and Sunderland. Data limitations include; a lack of fully digitised mine plans and areas with limited hydrogeological information, whist the approach itself could be easier to repeat if more automation was included. The opportunity maps have proved useful for stakeholder engagement, raising the profile of mine water heat and integration into heat network planning, however they do not remove the need for site specific feasibility studies.