12 kW Ground Source Heat Pump running cost — Spring/autumn shoulder season (5 h)
A 12 kW Ground Source Heat Pump (COP 3.5, BEIS data) draws 3.43 kW of electricity per hour. Running 5 hours/day uses 17.1 kWh and costs £4.48/day at the Ofgem cap of 26.11p/kWh (1 July to 30 September 2026).
12 kW Ground Source Heat Pump — Spring/autumn shoulder season (5 h): 12 kW ÷ COP 3.5 = 3.43 kW electricity draw × 5 h = 17.1 kWh/day = £4.48/day. Weekly: £31.33. Annual: £1633.74. Context: UK spring/autumn (Mar–May, Sep–Nov). Source: DESNZ/BEIS (OGL v3.0) + Ofgem.
- Per day
- £4.48
- Per week
- £31.33
- Per month
- £136.15
- Per year
- £1633.74
System specification
- Heat output
- 12 kW
- Type
- Ground-source (GSHP)
- Seasonal COP
- 3.5
- Electricity draw
- 3.43 kW/h
- Daily kWh
- 17.1 kWh
- Scenario
- 5 h/day
BEIS Heat Pump Information Note 2024 — 12 kW GSHP, typical SCOP 3.5
How the cost is worked out
- Electricity draw per hour: 12 kW ÷ COP 3.5 = 3.43 kW.
- Daily kWh: 3.43 kW × 5 h = 17.1 kWh.
- Daily cost: 17.1 kWh × 26.11p/kWh = £4.48.
- Weekly: £4.48 × 7 = £31.33.
- Annual: £4.48 × 365 = £1633.74.
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COP 3.5 from DESNZ/BEIS — Heat Pump Information Note: Seasonal Performance Data 2024 (OGL v3.0). Unit rate 26.11p/kWh from Ofgem — Energy price cap unit rates and standing charges (1 July to 30 September 2026).