Skip to main content
Heat Pump · Ofgem 1 July to 30 September 2026

8 kW Ground Source Heat Pump running cost — Mild winter day (8 h)

A 8 kW Ground Source Heat Pump (COP 3.5, BEIS data) draws 2.29 kW of electricity per hour. Running 8 hours/day uses 18.3 kWh and costs £4.77/day at the Ofgem cap of 26.11p/kWh (1 July to 30 September 2026).

8 kW Ground Source Heat PumpMild winter day (8 h): 8 kW ÷ COP 3.5 = 2.29 kW electricity draw × 8 h = 18.3 kWh/day = £4.77/day. Weekly: £33.42. Annual: £1742.66. Context: UK winter (Nov–Mar), outdoor temp 5–10°C. Source: DESNZ/BEIS (OGL v3.0) + Ofgem.

Per day
£4.77
Per week
£33.42
Per month
£145.22
Per year
£1742.66

System specification

Heat output
8 kW
Type
Ground-source (GSHP)
Seasonal COP
3.5
Electricity draw
2.29 kW/h
Daily kWh
18.3 kWh
Scenario
8 h/day

BEIS Heat Pump Information Note 2024 — 8 kW GSHP, typical SCOP 3.5

How the cost is worked out

  1. Electricity draw per hour: 8 kW ÷ COP 3.5 = 2.29 kW.
  2. Daily kWh: 2.29 kW × 8 h = 18.3 kWh.
  3. Daily cost: 18.3 kWh × 26.11p/kWh = £4.77.
  4. Weekly: £4.77 × 7 = £33.42.
  5. Annual: £4.77 × 365 = £1742.66.

Get a heat pump installation quote

A MCS-certified heat pump installer can assess your home and give you a detailed cost and savings estimate. GeraHome connects you with qualified HVAC engineers.

Find a heat pump installer

Same scenario — other systems

Track heat pump running costs

Updated each time the Ofgem cap changes. No spam.

No spam. Unsubscribe anytime. A Gera Services product.

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).