1. Ground-source heat pumps

The ground-source heat pump, used either in borehole or slinky installations, is a long-established technology in many areas of northern Europe. As targets for reducing carbon loom ever closer and energy prices continue to rise in the UK, the technology is becoming increasingly attractive. Heat pumps extract energy from the Sunlight that heats up the Earth. They convert this low-grade heat into high-grade heat. Even taking into account energy losses from electricity transmission, ground-source heat pumps offer impressive efficiencies. Most ground-source heat pumps have a coefficient of performance of around four.