How much potential for geothermal power is there in the UK?
Geothermal power, using high temperature grades of heat, is only relevant to certain geographical and geologically suitable areas. It requires the presence of ‘hot rocks’ that are fractured and relatively near to the surface, and that can be tapped into by drilling. The Weardale Granite, which underlies much of the North Pennines, is a good example of fractured hot rock. Advances in drilling technology have increased the interest in this area. There are similar areas of hot rock underneath parts of southern England and Derbyshire, but the only area where these have been successfully exploited to provide power is in Southampton, where geothermal hot water provides energy for a combined heat and power system, administered by the City Council. The economics of this type of geothermal energy mean that, compared with countries such as New Zealand or Iceland, the UK is unlikely to exploit it significantly. Ground-source heat pumps, which exploit lower grades of thermal energy (10–20°C) just
