Cost per million BTU, delivered
Using representative early-2026 Maine energy prices (Efficiency Maine's calculator assumptions: electricity $0.27/kWh, seasonal heat pump COP 3.15; propane $3.38/gal; No. 2 heating oil around $3.40/gal) and typical system efficiencies:
| Heating system | Assumed price | Effective efficiency | $ / MMBtu delivered | vs. heat pump |
|---|---|---|---|---|
| Cold-climate heat pump | $0.27/kWh | 315% (seasonal COP 3.15) | ~$25 | — |
| Oil boiler/furnace | $3.40/gal | 85% combustion × distribution | ~$29–33 | Heat pump ~15–25% cheaper |
| Propane furnace | $3.38/gal | 93% combustion × 90% distribution | ~$44 | Heat pump ~40–45% cheaper |
| Electric baseboard | $0.27/kWh | 100% | ~$79 | Heat pump ~68% cheaper |
| Natural gas (where available) | ~$2.10/therm | 90% | ~$23 | Roughly comparable |
Math for the skeptical: 1 MMBtu = 293 kWh of heat. Heat pump: 293 ÷ 3.15 = 93 kWh purchased × $0.27 = ~$25. Propane: 91,500 Btu/gal × 0.93 × 0.90 = ~76,600 Btu useful per gallon; $3.38 ÷ 0.0766 = ~$44. Oil: 138,500 Btu/gal × ~0.85 = ~117,700 useful; $3.40 ÷ 0.1177 = ~$29. Prices swing season to season — rerun these with your own delivery slips and electric rate.
What that means in dollars per winter
A typical older Maine single-family home needs roughly 60–90 MMBtu of heat per year. Taking 75 MMBtu as a middle case:
Households that switch from propane or electric resistance commonly report $1,000–$2,500 in annual heating savings; oil switchers save less in a cheap-oil year and far more in an expensive one — the heat pump also functions as insurance against fuel-price spikes, since electricity rates are regulated and move slowly.
The most efficient cold-climate units on the market today reach HSPF2 ratings of roughly 11–12 (a seasonal heating COP above 3) and SEER2 cooling ratings above 30. For context, the federal minimums are 7.5 HSPF2 and 14.3 SEER2 — the best units deliver about 50% more heat per dollar than a code-minimum heat pump, which is why Efficiency Maine's rebate list is restricted to verified cold-climate performers. (You may see "up to 30" attached to heat pump marketing — that figure is SEER2, the cooling rating. No heat pump has an HSPF2 anywhere near 30; treat any claim like that as a red flag on the seller.)
Don't forget the summer side
Every dollar figure above is heating-only. The same machine replaces window air conditioners (typically 8–12 SEER-equivalent in real use) with 25–30+ SEER2 cooling and built-in dehumidification. If you currently run two or three window units plus a basement dehumidifier through a muggy Maine summer, expect an additional $100–$300/yr in avoided electricity — with far better comfort.
Energy conservation, not just cost shifting
- Primary energy use drops. Because 2–3 units of delivered heat require only 1 unit of electricity, total energy consumed to heat the house falls even before considering the grid mix.
- Maine's grid is unusually clean. The majority of Maine's in-state electricity generation is renewable (hydro, wind, biomass, and fast-growing solar). A heat pump displacing oil in Maine cuts a typical home's heating CO₂ emissions by roughly half or more today — and the number improves every year the grid gets cleaner. Oil burned in 2035 will emit exactly what oil burned in 2026 does.
- Weatherize first, save twice. Air sealing and insulation shrink the load, letting you buy fewer/smaller heat pump units and stretching every rebate dollar. Efficiency Maine pairs its heat pump rebates with insulation rebates of up to $8,000 for exactly this reason.
See how the up-front cost gets cut down to size on the rebates & incentives page, or what day-to-day life with one feels like under comfort & conservation.