Compare annual heating costs
| Boiler heat cost | $0.063/kWh |
| Heat-pump heat cost | $0.056/kWh |
| Annual boiler cost | $755 |
| Annual heat-pump cost | $675 |
| Annual operating difference | $80 less with the heat pump |
| Simple payback | 62.7 years |
Important: use a seasonal COP rather than a best-case rating. Gas energy content, tariff structure, equipment sizing, maintenance and extreme-weather performance can change the real result.
How it works
Fuel price is converted to a fuel-energy cost, adjusted for boiler efficiency, then compared with electricity price divided by the heat pump's seasonal COP.
A comparison, not a system design
Equipment capacity, local climate, emitter temperature, hot-water demand and installer design can substantially affect the actual seasonal result.
Cost of one kilowatt-hour of heat
A heat pump moves heat rather than making it, so one kilowatt-hour of electricity can deliver several kilowatt-hours of heat. The ratio is the coefficient of performance (COP), or the seasonal average (SCOP) over a winter. A gas boiler turns at most about 90% of the gas energy into useful heat.
| System | Efficiency | Example energy price | Cost per kWh of heat |
|---|---|---|---|
| Gas boiler | 90% | $0.08 per kWh of gas | $0.089 |
| Heat pump | SCOP 3.0 | $0.25 per kWh of electricity | $0.083 |
| Heat pump | SCOP 2.5 | $0.25 per kWh of electricity | $0.1 |
| Electric heater | 100% | $0.25 per kWh of electricity | $0.25 |
The break-even point is when electricity price / SCOP equals gas price / boiler efficiency; enter your own tariffs, because the ratio between gas and electricity prices differs widely between countries.