By the Numbers
By the Numbers: Heat Pump COP — Turn Efficiency Into kWh and Running Cost
IEA heat pump sales data is a market story; this calculator-led guide turns COP into kWh and estimated running-cost examples.
The International Energy Agency (IEA) says global heat pump sales fell by about 2% in 2025, while Europe’s annual sales rose by 11% (the first year of growth since 2022) in its Global Energy Review 2026.
Those market stats are interesting, but the consumer-facing question is usually more practical: if a heat pump is “efficient”, what does that mean in electricity use (kWh) and estimated running cost?
This article uses a simple COP → kWh chain and the appliance running cost calculator to turn “efficiency” into a number you can sanity-check. It is an estimate and not advice.
The story number
From the IEA’s Global Energy Review 2026 heat pumps section:
- Global heat pump sales: about -2% in 2025
- Europe annual heat pump sales: +11% in 2025
The number to run
The key idea is COP (Coefficient of Performance):
- COP = heat output ÷ electricity input
So if you know (or assume) how much useful heat you need, electricity use is:
- electricity (kWh) = heat needed (kWh) ÷ COP
That single line explains why “COP 3” is a big deal: it turns 30 kWh of heat into about 10 kWh of electricity.
Run the numbers (daily heating-demand examples)
Pick an illustrative daily heat demand and a heating runtime window:
- Useful heat needed: 30 kWh per day (illustrative)
- Heating runtime: 10 hours per day (illustrative)
Now compare different COP assumptions:
| Scenario | COP | Useful heat (kWh/day) | Electricity (kWh/day) | Avg electric power over 10h (kW) |
|---|---|---|---|---|
| “Lower COP” example | 2.0 | 30 | 15.0 | 1.50 |
| “Mid COP” example | 3.0 | 30 | 10.0 | 1.00 |
| “Higher COP” example | 4.0 | 30 | 7.5 | 0.75 |
To translate that into money, multiply electricity (kWh) by your electricity unit rate.
For example, at an illustrative rate of 30p/kWh:
- COP 2.0: 15.0 kWh/day × £0.30 ≈ £4.50/day
- COP 3.0: 10.0 kWh/day × £0.30 ≈ £3.00/day
- COP 4.0: 7.5 kWh/day × £0.30 ≈ £2.25/day
That’s a £1.50/day difference between COP 2 and COP 3 in this worked example — around £45/month if the pattern held every day.
How to use the appliance running cost calculator for this
The appliance running cost calculator works with “watts” and “hours”.
To approximate the COP math in that format:
1) Decide your electricity use (kWh/day) from `heat ÷ COP`. 2) Choose a runtime window (hours/day). 3) Convert to average power:
- average kW = kWh ÷ hours
- average watts = average kW × 1,000
Using the COP 3 example above:
- Electricity needed: 10 kWh/day
- Over: 10 hours/day
- Average power: 1 kW = 1,000 W
Enter 1,000 W and 10 hours (plus your unit rate) to get a comparable daily cost estimate.
What the result means (and what it doesn’t)
This framing is useful because:
- It separates “how much heat you need” from “how efficiently you make it”.
- It shows why small changes in COP can matter over a season.
But it does not tell you what your real COP will be or what your bill “will” be.
Try your own numbers
Use the appliance running cost calculator with:
- Your assumed average power (watts) and runtime (hours)
- Your electricity unit rate (p/kWh or your local currency per kWh)
If you want to do the COP step explicitly first, you may find these useful:
- Unit converter (kW ↔ W)
- Percentage calculator (for “what if COP is 15% higher?” sensitivity)
Caveats and source notes
- The IEA figures are about heat pump sales (market trends), not household running costs.
- COP varies with outside temperature, flow temperature, system design, home insulation, and how the system is run. Seasonal performance is often lower than a lab/test COP.
- “Useful heat needed per day” varies hugely by climate, dwelling type, insulation, floor area, thermostat setting, and occupancy.
Source: IEA Global Energy Review 2026, “Technology: Heat pumps”.
Reader questions
Is COP the same as what I’ll get at home?
Not necessarily. COP varies over time, and many sources quote seasonal performance (which averages over different conditions). Use this post as a way to understand the math, not as a promise.
Why use “heat needed” instead of “heat pump watts”?
Because the useful heat demand is the thing you’re trying to satisfy. COP tells you how much electricity you need to deliver that heat.
Is this advice on whether I should buy a heat pump?
No. It’s an educational worked example to explain the COP → kWh → cost chain.
