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Heat Pump · Ofgem 1 July to 30 September 2026

8 kW Air Source Heat Pump running cost — Always-on low-modulating (6 h equivalent)

A 8 kW Air Source Heat Pump (COP 2.7, BEIS data) draws 2.96 kW of electricity per hour. Running 6 hours/day uses 17.8 kWh and costs £4.64/day at the Ofgem cap of 26.11p/kWh (1 July to 30 September 2026).

8 kW Air Source Heat PumpAlways-on low-modulating (6 h equivalent): 8 kW ÷ COP 2.7 = 2.96 kW electricity draw × 6 h = 17.8 kWh/day = £4.64/day. Weekly: £32.49. Annual: £1694.25. Context: Inverter heat pump in modulating mode, UK average. Source: DESNZ/BEIS (OGL v3.0) + Ofgem.

Per day
£4.64
Per week
£32.49
Per month
£141.19
Per year
£1694.25

System specification

Heat output
8 kW
Type
Air-source (ASHP)
Seasonal COP
2.7
Electricity draw
2.96 kW/h
Daily kWh
17.8 kWh
Scenario
6 h/day

BEIS Heat Pump Information Note 2024 — 8 kW ASHP, typical SCOP 2.7 for UK climate

How the cost is worked out

  1. Electricity draw per hour: 8 kW ÷ COP 2.7 = 2.96 kW.
  2. Daily kWh: 2.96 kW × 6 h = 17.8 kWh.
  3. Daily cost: 17.8 kWh × 26.11p/kWh = £4.64.
  4. Weekly: £4.64 × 7 = £32.49.
  5. Annual: £4.64 × 365 = £1694.25.

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COP 2.7 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).