When GSHP beats ASHP
GSHP makes economic sense on larger sites with available land, where the borehole field can be amortised over a long base-load. Smaller primary sites rarely justify GSHP on £/tCO2e against the ceiling.
£/kW band
£1,800 to £3,200 per kW installed, mid-band £2,400. Includes borehole field, header room, heat pump and wet-system upgrade.
Site-area requirements
Open-loop where geology supports; closed-loop boreholes need 6-8m spacing. A 300kW system needs roughly 30-40 boreholes at 150m depth. Site survey is mandatory.
Phase 3/4 funded examples
GSHP appears in Phase 3 funded projects [DESNZ] on larger MAT and FE sites; less common in single-school awards because of footprint.