Running cost comes down to wattage, hours and your rate. In Maine the rate is 28.63 cents per kWh, which is 55.3 percent above the national average. Here is what that means for a air-source heat pump.
A air-source heat pump drawing 3,000 W costs $0.86 per hour in Maine. Run 8 hours a day that is $6.87 daily, $206 a month and $2,508 a year, which is $893 more than the same appliance at the US average rate.
Air-source heat pump cost at Maine rates
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Planning estimate. The rate box is prefilled with a regional average; the figure on your own bill is the one that matters. Power is draw while running, not while switched on.
Cost by hours used per day in Maine
| Hours/day | Energy | Per day | Per month |
|---|---|---|---|
| 1 h | 3.00 kWh | $0.86 | $25.77 |
| 2 h | 6.00 kWh | $1.72 | $51.53 |
| 4 h | 12.00 kWh | $3.44 | $103 |
| 6 h | 18.00 kWh | $5.15 | $155 |
| 8 h | 24.00 kWh | $6.87 | $206 |
| 12 h | 36.00 kWh | $10.31 | $309 |
| 24 h | 72.00 kWh | $20.61 | $618 |
Cost by wattage at 28.63 cents
| Rated power | Per hour | Per day | Per month |
|---|---|---|---|
| 1,200 W | $0.34 | $2.75 | $82.45 |
| 2,000 W | $0.57 | $4.58 | $137 |
| 3,000 W | $0.86 | $6.87 | $206 |
| 4,500 W | $1.29 | $10.31 | $309 |
| 6,000 W | $1.72 | $13.74 | $412 |
Find the row matching the nameplate on your own unit. Within a single appliance category the spread is often wider than the difference between categories, so the label is worth reading.
Heating season in Maine
Maine has a long, hard heating season, and that makes electric resistance heat expensive here in a way it is not in milder states. A heat pump delivering two to three units of heat per unit of electricity changes the arithmetic substantially, though capacity does fall as outdoor temperature drops, so sizing for design temperature matters more here than almost anywhere.
Why Maine pays what it does
Maine has a competitive retail electricity market, so the rate used here blends households on the utility default with households on shopped supply plans. If you have never switched supplier you are probably on the default, which is usually the more expensive side of that blend. Only the generation portion of your bill changes when you switch; delivery and outage response do not.
At 28.63 cents, Maine ranks 46 of 51 from cheapest to most expensive. The Northeast regional average is 25.91 cents. Roughly half of any residential bill is transmission and distribution rather than generation, which is why rates keep climbing even when fuel prices fall.
How this compares across the country
The same air-source heat pump on the same schedule, in the cheapest and dearest states:
| State | Rate | Per month | Per year |
|---|---|---|---|
| Idaho | 12.35¢ | $88.92 | $1,082 |
| Utah | 12.96¢ | $93.31 | $1,135 |
| Maine | 28.63¢ | $206 | $2,508 |
| California | 33.25¢ | $239 | $2,913 |
| Hawaii | 52.00¢ | $374 | $4,555 |
Lowering the number in Maine
- Leave the thermostat alone. Heat pumps work best holding a steady temperature; deep setbacks trigger expensive resistance backup on recovery.
- Avoid emergency heat unless the pump has failed. That setting is pure resistance heating and costs several times as much.
- Keep the outdoor unit clear. Snow, leaves and shrubs against the coil cut capacity.
- Change filters regularly. Airflow restriction hurts a heat pump more than a furnace.
- Size for design temperature. Capacity falls as it gets colder, which is exactly when you need it.
- In Maine, air sealing pays back faster than equipment upgrades. A long heating season multiplies every draft, and sealing is cheap compared with replacing hardware.
Offsetting it with solar in Maine
This load uses about 24.00 kWh a day. Covering that would take roughly 17 standard 400 W panels at typical sun hours, an array of about 6.80 kW. Because it offsets electricity worth 28.63 cents rather than the national 18.44 cents, the same array is worth more here than the national payback figures suggest.
A heat pump delivers three or more units of heat per unit of electricity, which is what makes solar heating arithmetically possible at all. Full sizing, including battery and inverter requirements, is on the solar sizing page for this appliance.