Heat pump running costs vs. gas: the SCOP-to-price-ratio rule

The rule

Break-even electricity/gas price ratio ≈ SCOP × boiler seasonal efficiency.

Example: SCOP 3.5 and boiler efficiency 0.88 → ratio ≈ 3.08. If electricity costs less than about 3.08× the gas unit rate (on a kWh basis), the heat pump wins on energy — before standing charges.

SCOP is not peak COP

Marketing COP at mild temperatures is not seasonal performance. Use a design SCOP for your climate and emitters.

Try the heat pump vs boiler calculator with your standing charges included.