About the Heat Pump Savings
This calculator compares the annual electricity cost of heating a home with a heat pump against heating the same load with electric resistance heat, using the heat pump's Coefficient of Performance (COP) as the efficiency multiplier. It is aimed at homeowners weighing a heat pump upgrade or comparing it against baseboard or space heaters they already run on electricity.
How It Works
You enter the annual heating energy your home needs (in kWh of delivered heat), the heat pump's COP, and your electricity rate. The tool divides the heating load by the COP to get the heat pump's electricity draw, since a heat pump moves heat rather than generating it directly, then multiplies both that figure and the raw heating load by your rate to get two annual costs, and reports the difference as savings.
Formula & Methodology
Start with the heating load your home needs in kWh of actual heat output, not electrical input. Resistance heating is 100% efficient at converting electricity into heat, so its COP is effectively 1, meaning its electricity use equals the heating load exactly. A heat pump with a COP of 3.2 needs only 1/3.2 as much electricity to deliver that same heat, because it is transferring existing heat from outside air rather than manufacturing it from electrical resistance. Multiply each electricity figure by your rate and subtract to find the dollar savings.
Examples
Cold-climate heat pump
A home needing 12,000 kWh of heat per year with a heat pump rated COP 3.2 and electricity at $0.16/kWh uses 3,750 kWh ($600) instead of 12,000 kWh ($1,920) for resistance heat, a savings of roughly $1,320 per year.
Lower-efficiency unit in a milder climate
With a 6,000 kWh heating load, a COP of 2.5, and a rate of $0.14/kWh, the heat pump uses 2,400 kWh ($336) versus 6,000 kWh ($840) for resistance heat, saving about $504 annually.
Advantages
- Isolates the effect of COP alone, making it easy to see how much efficiency directly translates into dollar savings at your own electricity rate.
- Uses your actual heating load and local rate rather than a generic national average, so the output reflects your specific situation.
- Works as a quick sanity check on manufacturer COP claims by showing the real annual dollar impact of a stated efficiency rating.
Common Mistakes
- Entering a manufacturer's peak or rated COP instead of a realistic seasonal average, which overstates savings since COP falls as outdoor temperatures drop.
- Confusing the 'Annual Heating Energy Need' field with the home's total electricity bill rather than the heat output specifically required.
- Comparing against resistance heat when the home actually uses gas or oil, producing a savings figure that doesn't apply to the reader's real alternative.
Edge Cases to Watch For
- COP is clamped to a minimum of 0.1 in the calculation, so an unrealistically low or zero COP entry won't produce a divide-by-zero error, but it will produce an inflated electricity estimate rather than a warning.
- The comparison is only against electric resistance heat; it does not compare against gas, oil, or propane furnaces, so the result isn't directly usable for a heat pump versus gas furnace decision.
- COP is treated as a single constant for the whole heating season, though real-world COP drops in colder outdoor temperatures, so a single average value entered here smooths over that seasonal variation.
Common Use Cases
- Homeowners with electric baseboard or space heaters considering a heat pump replacement.
- Buyers comparing heat pump models by COP rating before purchase.
- Anyone estimating winter electricity costs after a heat pump installation.