| Abstract |
Hot sedimentary aquifers represent a substantial low-carbon heating resource in the UK. Previous studies of the geothermal potential of the UK have neglected, or underplayed, the correction to heat flow measurements for the cooling effects from periods of lower temperatures during the Pleistocene. This effect is expected to be particularly acute in the UK, due to the large temperature differential between modern times and past ice ages, largely as a result of the current warming effect of the Gulf Stream. Recent work on correcting measurements of heat flow in boreholes across the UK, accounting for warming since the last glaciation, has resulted in positive corrections to heat flow. A lack of consideration of palaeoclimate corrections has thus far resulted in a significant underestimation of the heat flow, and therefore, the geothermal potential across the UK. The objective of this work is to unravel the effect of palaeoclimate on existing geothermal data in the vicinity of Glasgow, one of Britain’s largest cities, to reveal an estimation of the true geothermal potential in this city and throughout the western Midland Valley of Scotland. Past workers have determined a regional heat flow of 60 mW m-2 in the Glasgow area. This has been based on 4 boreholes; Blythswood, South Balgray, Hurlet and Maryhill. Applying a correction for palaeoclimate to the Maryhill borehole dataset, the estimated heat flow increases to c. 80 mW m-2. The base of the Kinneswood Formation, a hot sedimentary aquifer resource, is estimated at c. 2-2.5 km depth beneath Glasgow; extrapolating the corrected geothermal gradient gives a temperature of c. 80 °C, significantly greater than previously thought, at this depth. The preliminary results of this analysis are highly encouraging: if heat at this temperature can be extracted then it may prove significant for decarbonisation of heat supply and alleviation of fuel poverty in Glasgow, and indeed for other areas of the UK. |