What are Ground Source Heat Pumps?

Ground source heat pumps provide a new and clean way of heating buildings in the UK. They make use of renewable energy stored in the ground, providing one of the most energy-efficient ways of heating buildings. They are suitable for a wide variety of building types and are particularly appropriate for low environmental impact projects. They do not require hot rocks (geothermal energy) and can be installed in most of the UK, using a borehole or shallow trenches or, less commonly, by extracting heat from a pond or lake. Heat collecting pipes in a closed loop, containing water (with a little antifreeze) are used to extract this stored energy, which can then be used to provide space heating and domestic hot water. In some applications, the pump can be reversed in summer to provide an element of cooling, but these systems are not currently eligible for UK grants.

The only energy used by Ground Source Heat Pump systems is electricity to power the pumps. Typically, a Ground Source Heat Pump will deliver three or four times as much thermal energy (heat) as is used in electrical energy to drive the system. For a particularly environmental solution, green electricity can be purchased.

Ground Source Heat Pump systems have been widely used in other parts of the world, including North America and Europe, for many years Typically they cost more to install than conventional systems; however, they have very low maintenance costs and can be expected to provide reliable and environmentally friendly heating for in excess of 20 years.

Ground Source Heat Pumps work best with heating systems which are optimised to run at a lower water temperature than is commonly used in UK boiler and radiator systems. As such, they make an ideal partner for underfloor heating systems.

What do heat pumps cost? 

Typical costs of a Ground Source Heat Pump for an owner-occupier in a small, new house in the UK:

Gas Heating system

Capital cost                            £2,500

Gas consumption per year    12,000 kWh/yr (space and DHW

Gas consumption per year     heating )

CO2 (at 0.1876 kg/kWh) )      9,000 kWh/yr (space heating only)

                                               1,690 kg/yr 

Ground Heat Pump (incl. auxiliary and DHW heating)*