eco home with ground heat source pump in Cornwall

Ground source heat pumps: a buyer’s guide

There's a store of thermal energy beneath our feet that can be harnessed to heat our homes

By Rebecca Foster | 30 September 2021

A ground source heat pump (GSHP) harnesses the store of thermal energy below ground. It is a sustainable way to heat a home.

eco home with ground heat source pump in Cornwall

Tom and Danielle Raffield installed a GSHP when extending their cottage. Photo: Paul Ryan-Goff

Renewable energy

You may be familiar with solar power, but what do you know about ground source heat pumps? A ground source heat pump can transfer three times more energy into the home than they use to extract it.

What is a ground source heat pump?

Two metres below ground the soil maintains a fairly consistent temperature of around 10ºC and is unaffected by cold weather. This thermal energy is something that can be harnessed. Powered by electricity, a ground source heat pump extracts warmth from the earth using collecting pipes buried below the surface. A solution of water and antifreeze flows through the pipes, picking up warmth as it moves. This liquid is channelled to a heat pump unit, most often kept inside the house, where it is concentrated to a higher temperature and distributed to radiators, underfloor heating and hot water storage.

how do ground source heat pumps work?

GSHPs have underground piping outside and a heat pump unit inside. Illustration: Worcester Bosch