Revisiting the Deep Geothermal Potential of the Cheshire Basin, UK

Abstract

Deep geothermal energy can aid in the decarbonization of heat within the UK; this is required to meet net zero carbon emissions targets by 2050. The Cheshire Basin represents a significant opportunity for the development of deep geothermal resources; there are vast quantities of high permeability sandstones in hydraulic continuity, with temperatures favorable for direct heat use and, potentially, for power generation. Newly produced basal temperature maps in this study indicate the likely maximum temperatures for the basin, with the hottest temperature expected to be between 100 and 131.2 °C in the Crewe area. There have also previously been a range of estimates highlighting a geothermal resource within the basin to be in the region of 44.1 to 75 × 1018 J; however, previous estimates for heat in place are limited to simple volumetric or geometrical constraints. Therefore, this paper uses digitized depth and temperature maps to provide new estimates for the heat in place. Results suggest the resource has been underestimated and there is a need for more detailed evaluation. Depending on the geothermal gradient, the resource could be between 91 and 144 × 1018 J (1.26 to 1.45 × 1017 J/km2). Although there is a significant amount of heat in place, geological issues preventing development remain, such as the uncertainty in the quality of the reservoir at depth due to data limitations and the lateral continuity of the Manchester Marls Formation, which could act as a barrier to flow. Nevertheless, further regional assessment of the basin and data acquisition is required to build confidence in the reservoir quality and reduce uncertainty. This could unlock the basin for geothermal development.