The Low Carbon Partnership
Solar Power
Ground source heat pumps
Heat pumps use the heat absorbed from the sun and stored in the ground, water or air as a source of energy to heat homes and other buildings. Ground source heat pumps are most commonly used in the UK.
Ground source heat pumps extract the heat energy from the sun that is absorbed and stored in the surface layers of the ground. Although the ground might not seem very warm, it actually stores heat and stays at a fairly constant temperature all year round - around 8-13 degrees Celsius in the UK. Ground source heat pumps work in the same way as a refrigerator. The system pumps a refrigerant through pipes in the ground which absorbs heat energy and then passes through a compressor which increases the temperature. In a fridge this heat is then transferred to the air outside it to reduce the temperature inside the fridge. In a ground source heat pump system the extra heat gained is transferred to radiators or underfloor heating pipes in the building to increase the temperature inside. The cooled refrigerant then returns along the pipes into the ground.
Ground source heat pumps do need electricity to power the compressor pump that moves the refrigerant round the system. Therefore they can only be classed as a truly renewable technology when this electricity is produced from other renewable sources. However, as they can provide 2-4 units of heat energy for every single unit of electricity they use, they can be very efficient and cost-effective. Heat pumps can also work in reverse to transfer heat from indoors and deposit it outside in the ground.
Ground source heat pump
Source: Rayotec UK Ltd
