Deep geothermal resource assessment of early carboniferous limestones for Central and Southern Great Britain

•The early carboniferous limestone represents a potential target to deliver heat through direct use of geothermal energy in central and Southern Britain.•A statistical method has been applied to assess depth, distribution and geothermal potential of the early carboniferous limestone.•Total heat in place and recoverable heat distribution maps have been produced across Central and Southern Britain for this geothermal play. Early Carboniferous limestones (ECL) host active geothermal systems in Central and Southern Britain. Equivalent rocks have been successfully developed for geothermal energy in Belgium and the Netherlands, but the ECL has yet to be fully assessed as a geothermal resource in Britain. We use established statistical methods to assess the depth, distribution, and geothermal potential of the ECL in Central and Southern Britain. Total heat in place (HIP) resources of 1415 (P10)–1528 (P90) EJ may be present, with a tentative potential recoverable thermal power of 106–222 GW. Further work is needed to understand the resource by identifying areas with sufficient flow rates for successful development such as enhanced permeability zones around faults, fractures or karsts.