How much potential for geothermal power is there?
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. Advances in drilling technology have increased the interest in this area. Geothermal hot water with medium temperatures provides energy for a combined heat and power system and dominates the binary type plants commonly installed in the US. Ground-source heat pumps, which exploit lower grades of thermal energy (1020C) just beneath the surface, have much greater potential in the US, and can provide a highly efficient method of heating.
