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Heat Pump Running Cost Calculator

Annual heating cost of a heat pump against a gas boiler, with the SCOP needed to break even.

Results

Saved per year 516.30
Heat pump running cost 754.29
Boiler running cost 1270.59
Electricity used by the heat pump 3428.6 kWh
Fuel used by the boiler 14,117.6 kWh
SCOP needed to break even 2.078
How it changes
Saved per yearSeasonal efficiency (SCOP) 1.5 – 6.0. Saved per year: -489 → 831Saved per year-500050010002.03.04.05.06.0Seasonal efficiency (SCOP)

The dashed line marks the value you entered.

What this tool does

A heat pump uses electricity, which costs more per kilowatt-hour than gas almost everywhere — but it delivers three or four kilowatt-hours of heat for each one it consumes, while a boiler delivers less than one. Whether that wins depends entirely on the ratio between the two fuel prices in your country and on the seasonal efficiency the system actually achieves, not the figure on the brochure.

Formula

cost = heat demand / efficiency x energy price

Variables

SymbolMeaningUnit
hdAnnual heat demandkWh/ano
scSeasonal efficiency (SCOP)
peElectricity price/kWh
beBoiler efficiency%
pgGas price/kWh
SVSaved per year
CHHeat pump running cost
CBBoiler running cost
EHElectricity used by the heat pumpkWh
EBFuel used by the boilerkWh
BCSCOP needed to break even

Worked example

  • Annual heat demand12,000 kWh/ano
  • Seasonal efficiency (SCOP)3.5
  • Electricity price0.22 /kWh
  • Boiler efficiency85 %
  • Gas price0.09 /kWh
  • Saved per year516.30
  • Heat pump running cost754.29
  • Boiler running cost1270.59
  • Electricity used by the heat pump3428.6 kWh
  • Fuel used by the boiler14,117.6 kWh
  • SCOP needed to break even2.078

Limitations

  • The result is an estimate based only on the values you type. Real situations often include factors this calculator does not know about.
  • Tax rates and rounding rules differ between countries and sometimes between regions. Use the rate that applies to your invoice.
  • The tool works with whatever currency you use for the inputs; it does not convert between currencies.

Frequently asked questions

What SCOP do I need for a heat pump to be cheaper?

Exactly the ratio between the electricity price and the gas price, multiplied by the boiler efficiency — the break-even figure shown here. With electricity at two and a half times the price of gas and an 85% boiler, you need a SCOP above about 2.1 just to break even on fuel. Real seasonal figures range from below 3 for a poorly commissioned system on radiators to above 4.5 with underfloor heating and a low flow temperature.