Ground Source Heat Pump (GSHP)

A heat pump that draws stable, year-round thermal energy from buried ground loops or boreholes, typically delivering higher efficiency than air source.

A Ground Source Heat Pump (GSHP) circulates a glycol-water mix through pipework buried in the ground, where temperatures stay around 8-12°C all year. That stable source temperature is why GSHPs achieve a SCOP of 4.5-5.0, around 30-40% better than a typical ASHP.

Three loop configurations are common in Cornwall: horizontal trenches (cheapest but need ~2-3x the property footprint of land), slinky coils (compromise on land), and vertical boreholes drilled 80-150m deep (smallest footprint, £15-25k extra). The granite-rich Cornish geology drills cleanly but slowly, which pushes borehole costs toward the upper end.

GSHPs suit rural farmsteads, large detached properties and estates with paddock or unused field. They qualify for the same £7,500 Boiler Upgrade Scheme grant as ASHPs and can be paired with battery storage and solar PV for net-zero running costs. See our GSHP service page or our Cornwall GSHP pillar guide.