Heat pump running cost in Wales
Cardiff, Swansea and the rest of South Wales sit in the South Wales supply region run by National Grid Electricity Distribution, while North Wales is on the Merseyside and North Wales network, where electricity is capped a little higher. In Wales, electricity is capped at about 26.33p/kWh and gas at about 7.42p/kWh (Ofgem cap, Jul-Sep 2026). A typical 3-bedroom semi (around 12,000 kWh of heat a year) would cost roughly £903/yr to run an air source heat pump (SCOP 3.5), versus about £1,095/yr on gas. That is about £193 saved a year. Enter your own home below to see your figure.
Your standard rate. The tariff scenario is shown separately.
Efficiency. 3.5 is typical.
On a standard tariff (price cap)
electricity at 26.33p/kWh
£193 /yr saved
Heat pump £903/yr · payback 19.5 yrs
On a heat pump tariff (~15p/kWh)
cheap-rate electricity
£581 /yr saved
Heat pump £514/yr · payback 6.5 yrs
Heat pump tariffs (Octopus Cosy, EDF, Scottish Power) offered off-peak rates of about 14p to 15p/kWh in June 2026. The ~15p scenario assumes most heating runs in the cheap hours.
- Now: mains gas heating
- £1,095/yr
- Gas standing charge saved
- £106/yr
- Indicative system size
- ~6kW
- Install after grant
- £3,750
- CO₂ saved
- 1,730 kg/yr
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Estimate only. Real figures depend on your home, install and tariff. Prices: Ofgem cap, Jul-Sep 2026.