Similarly to air source heat pumps, ground source heat pumps (GSHP) also provide renewable heat and qualify for RHI payments. This system uses buried pipes to extract heat from the ground, or deep boreholes drilled vertically outside. They are more efficient than air source heat pumps, but more expensive to install. They can be used to heat radiators, under floor heating and hot water in the home. Four times as much heat is generated for every kWh of electricity used to drive the heat pump.
Pros: Renewable heating source, qualifies for Government’s Renewable Heat Incentive (RHI) payments, efficiency is unaffected by outside air temperature, converts 1kWh of electricity to 4kWh heat.
Cons: Expensive to install, external excavation is required, works best with underfloor heating, takes time to warm up.
Indicative annual cost: with central heating – £893, with underfloor heating – £632