Heating and heat pump tools
Heat pump savings calculator
How much less electricity does a heat pump use than resistance heating?
A home using 6,000 kWh of electricity a year for resistance heating is delivering about 6,000 kWh of heat, because at the point of use resistance heating converts essentially all electricity into heat. A heat pump with a seasonal performance factor of 3.0 delivers that same heat from 2,000 kWh of electricity. At $0.180/kWh that changes annual running cost from $1,080 to $360.00 — a difference of $720.00, or 67%. Installation cost is not included.
Your inputs
Annual electricity attributable to heating. If your bill does not separate heating from other loads, this will need to be estimated.
1.0 for electric resistance heating — baseboards, panel heaters, electric furnaces.
A season average, not a rated peak COP. Actual seasonal performance depends on climate, flow temperature, system design and controls.
$720.00
lower running cost per year
Same 6,000 kWh of heat delivered, 67% less electricity cost
- Heat delivered
- 6,000 kWh
- Electricity now
- 6,000 kWh
- Electricity with heat pump
- 2,000 kWh
- Running cost change
- −$720.00
| System | Performance factor | Electricity used | Running cost |
|---|---|---|---|
| Current system | 1.0 | 6,000 kWh | $1,080 |
| Heat pump | 3.0 | 2,000 kWh | $360.00 |
Lower running cost under these assumptions
Method
- Heat delivered: 6000 kWh of heat
- Current: 6000 ÷ 1 = 6000 kWh electricity → 1080 USD
- Heat pump: 6000 ÷ 3 = 2000 kWh electricity → 360 USD
- Difference: 720 USD
Assumptions
- Seasonal performance factor of 3 for the heat pump — a season average, not a rated peak COP.
- Current system performance factor of 1.
- Both systems are assumed to deliver the same amount of heat into the home.
- Electricity rate of 0.18 USD/kWh for both systems, with no standing-charge or tariff difference.
- Installation cost, maintenance, distribution losses and comfort differences are not included.
What can change the result?
- Seasonal performance, which depends on climate, flow temperature, system design and controls
- How much of your bill is really heating rather than hot water, appliances and lighting
- Electricity tariff, including any heating-specific or time-of-use rates
- Building fabric — insulation and air-tightness set the heat demand in the first place
- Sizing, installation and commissioning quality, which can move real-world seasonal performance well away from the rated SCOP
Sensitivity to seasonal performance
The SCOP assumption dominates this calculation, so it is worth seeing the whole range rather than a single figure. Each row assumes the heat pump covers the entire heating demand; any resistance backup heat used in the coldest hours would reduce the difference.
| Heat pump SCOP | Electricity used | Running cost | Difference | Change |
|---|---|---|---|---|
| SCOP 2.0 | 3,000 kWh | $540.00 | $540.00 | 50% |
| SCOP 2.5 | 2,400 kWh | $432.00 | $648.00 | 60% |
| SCOP 3.0 | 2,000 kWh | $360.00 | $720.00 | 67% |
| SCOP 3.5 | 1,714 kWh | $308.57 | $771.43 | 71% |
| SCOP 4.0 | 1,500 kWh | $270.00 | $810.00 | 75% |
What this calculation deliberately excludes
There is no equipment price, no installation cost, no maintenance schedule and no incentive or rebate in these numbers. Adding them requires local quotes and local programme rules, and a national average would make the result look more precise than it is. What you get here is the running-cost difference — the input any payback calculation needs first.
The comparison also assumes both systems deliver identical comfort. In practice a heat pump runs at lower flow temperatures for longer periods, which feels different from a resistance heater cycling hard, and an undersized system in a poorly insulated home may fall back on resistance backup heat in the coldest weather — exactly when the SCOP assumption is weakest.
Your next decision
- Read the physics behind the comparisonWhy a heat pump can deliver more heat than the electricity it uses.
- Understand COP versus SCOP before trusting a numberUsing a rated COP overstates savings.
- Cost your current resistance heating in detailEstablishes the baseline this comparison needs.
- See how running cost changes across seasonal performanceThe same delivered heat at different SCOP values.
Heating and heat pump tools
Related guides
- GuidesThe calculation problems behind the tools.
- Refrigerator wattsA fridge draws its rated watts only while the compressor runs — which is roughly a third of the time. That distinction decides both your bill and your backup sizing.
- Watts vs kilowatt-hoursA watt is a rate. A kilowatt-hour is a quantity. Your bill only charges you for the second one.
- Read your meterTwo readings and a date give you a number no appliance estimate can argue with: your actual consumption.