Is a heat pump water heater worth it?
A resistance tank cannot pass 100% efficiency. Every certified heat pump starts at 252%.
Every figure below is computed from the catalogue, not written by hand · updated October 19, 2026
What it costs to run, by tank size
| What it is | kWh a year | Cost a year |
|---|---|---|
| Under 45 gallons42 models | 854 | $154 |
| 45–55 gallons184 models | 945 | $170 |
| 55–70 gallons123 models | 1,227 | $221 |
| Over 70 gallons161 models | 1,316 | $237 |
Priced a year at the U.S. average residential rate.
Why the comparison looks lopsided
A standard electric water heater works like a kettle: current runs through an element and the element gets hot. That process cannot be more than 100% efficient, because you cannot get more heat out than you put electricity in. Its Uniform Energy Factor — useful heat divided by energy consumed — is therefore always below 1.0.
A heat pump does something different. It does not make heat, it moves it: a small compressor pulls warmth out of the surrounding air and pushes it into the tank. Because the electricity only runs the pump rather than doing the heating, the ratio can exceed 1.0 — and across the 510 models we hold it runs from 2.52 to 4.5. At 2.52 the machine delivers two and a half times more heat than the electricity it consumed.
That is why there are no standard electric tanks on this site to compare against. ENERGY STAR certifies none, because a resistance element cannot reach the threshold. Every certified electric water heater in the federal database is a heat pump.
Which one you buy still matters
Among the 184 models in the most common size, the most efficient uses 681 kWh a year and the least efficient 1550 kWh — a gap of $157 a year every year, for the same tank size. Over a fifteen-year life that difference is larger than the price gap between most models.
What this figure does not cover
The number above is the appliance, not the installation. A heat pump water heater costs more to buy, needs more clearance around it, and pulls heat out of the room it stands in — welcome in a garage in July, less so in a utility closet in January. Several models switch to resistance heating in cold conditions, which is when their running cost rises toward a standard tank's.
Federal and utility rebates frequently cover a large share of the purchase price, and those change by state and by year. We do not track them, and any payback period that ignores them will be wrong.
See every certified water heater priced at your state's rate, or set your own rate from your bill for an exact figure.
Where these numbers come from
Every ENERGY STAR certified electric water heater is a heat pump — a resistance element cannot reach the threshold, so none are certified. The comparison is against the physical ceiling of resistance heating rather than against models we hold, because there are none to hold.
Costs are that energy use multiplied by a state's average residential electricity price from the U.S. Energy Information Administration. Change the state above and every figure on this page moves with it. Full methodology.