Understand your estimate
How to use this result
Heat pump electricity use is the heat the home needs divided by the pump’s seasonal efficiency, then priced at your electricity rate. The comparison shows the same heat from direct electric heating and, if you enter it, your current fuel.
Method reviewed · Calculation methods · Evidence and source policy
Find the right inputs
Heat the home needs
kWh of heat per period
Use an annual space-heating demand from an energy survey or the heat your current system delivers.
Seasonal efficiency
SCOP or seasonal COP
Use the design or label figure for your climate and flow temperature, not a best-case test point.
Your electricity price
GBP, USD or EUR per kWh
Enter major currency units; 28 pence means 0.28. Optionally enter your current fuel price and efficiency.
The calculation
Electricity (kWh) = heat demand ÷ SCOP. Cost = electricity × price per kWh. Direct electric cost = heat demand × price. Current-fuel cost = heat demand ÷ system efficiency × fuel price.
A worked arithmetic example
Illustrative arithmetic: 12,000 kWh of heat at a SCOP of 3.2 needs 3,750 kWh of electricity, or $750 at $0.20/kWh. The same heat from direct electric heating costs $2,400. From a 90% efficient system burning fuel at $0.08/kWh it costs about $1,067. These values are assumptions, not a survey or design.
What the estimate can tell you
A heat pump saves most against direct electric heating and less, or nothing, against cheap fuel. The break-even efficiency shows what SCOP you need to match your current fuel; check that your installer’s design figure clears it for your climate.
Questions about this calculation
What SCOP should I enter?
Use the seasonal figure from the installer’s design or the product label for your climate and heating temperature. A seasonal figure includes colder weather; a test-point COP at mild conditions overstates savings.
Does this include hot water?
Only if the heat demand you enter includes it. Cylinder losses, immersion boosts and defrost cycles are not modelled, so include them in the demand or add them separately.