Heat pump vs gas boiler school payback

At gas 7.97p/kWh and elec 26.32p/kWh, an ASHP at SCOP 2.9 has a per-kWh-heat tariff near 9.1p (electricity divided by SCOP), versus a gas boiler at 88 per cent efficiency near 9.1p. The October 2026 gas cap rise lifts the boiler running cost to roughly level with the heat pump, so there is now no meaningful running-cost gap between them.

Government policy and grid decarbonisation are projected to compress electricity costs relative to gas through 2030. By 2028 most BEIS projections cross ASHP below gas at SCOP 3.0; the trajectory underpins PSDS scoring.

ASHP CAPEX commonly sits 3 to 5 times a like-for-like gas boiler swap, before grant offset. PSDS Phase 4 offset shifts the comparison toward heat-pump favourability.

Salix's payback gateway accepts ASHP scopes that meet the published threshold with reasonable energy and carbon assumptions. The 15-year horizon is what PSDS scoring uses.