All prices below are the same numbers that power redo.energy's heat pump calculator: the U.S. Energy Information Administration (EIA) heating oil survey for Massachusetts, and the electric rates Eversource and National Grid filed for September 2026. No national averages appear anywhere in this piece.
Every few weeks from October to April, a tanker truck idles in a Massachusetts driveway and pumps a few hundred gallons of heating oil into a basement tank. The price on the delivery slip changes with every visit. This season it averages about $5.38 a gallon, and more than 600,000 homes in the state are paying it, which makes oil the most expensive common heating fuel in Massachusetts. The gap is not close. Let's compare.
What a unit of heat costs you today
A gallon of heating oil holds 138,500 British thermal units (BTU), and a typical oil boiler in decent condition burns it at about 85 percent efficiency. So the heat that actually reaches your rooms, priced per million BTU (MMBtu), costs:
$5.38 / (0.1385 MMBtu x 0.85) = $45.70 per million BTU
A heat pump moves heat rather than making it, which is the entire trick. Over a Massachusetts winter, a cold-climate unit delivers a seasonal average of roughly 2.6 to 3.0 units of heat per unit of electricity, a coefficient of performance (COP) of 2.6 to 3.0. The discounted winter heating rate is 28.1 cents a kilowatt-hour at Eversource and 35.3 cents at National Grid, delivery and supply together. That works out to:
- Eversource, at a seasonal COP of 2.6 to 3.0: $27.45 to $31.70 per million BTU
- National Grid, at the same COP: $34.50 to $39.80 per million BTU
With Eversource, oil costs 44 to 66 percent more per unit of heat than the heat pump that could replace your boiler. With National Grid, it costs 15 to 33 percent more.
Across a season the difference stops being abstract. A typical single-family home here in Massachusetts needs somewhere around 70 million BTU of heat a winter. At the prices above, the oil boiler burns about $3,200. The heat pump burns $1,920 to $2,220 with Eversource and $2,410 to $2,790 with National Grid. Call it $980 to $1,280 a year with Eversource and $410 to $790 with National Grid, every year, before a single rebate enters the picture. Which utility serves your house matters almost as much as the heat pump.
The special rate with extra savings
The numbers above lean on a fact that deserves its own special attention, because it is worth several hundred dollars a year and no one is going to volunteer it to you. Both Eversource and National Grid offer a reduced winter rate to homes that heat with electricity. On the standard residential rate instead, 36.0 cents at Eversource and 39.5 cents at National Grid, the same heat pump delivers heat at $35.20 to $40.60 per million BTU with Eversource and $38.60 to $44.50 with National Grid. Still cheaper than oil, but the annual savings shrink to roughly $360 to $740 with Eversource and $80 to $500 with National Grid. Install a heat pump and stay on the standard rate and you have left roughly 40 to 80 percent of the win on the table: $540 to $620 a year with Eversource, $290 to $330 with National Grid. The fix is one phone call to your utility after the install, asking for the heating rate by name. No equipment upgrade will return more per minute of effort.
Rebates, still good even after the federal credit died
The federal 25C tax credit ended on December 31, 2025, and much of the internet has not noticed yet; any site still promising you 30 percent back from the IRS is quoting a dead program. What survives in Massachusetts is, fortunately, the strongest state program in the country. Mass Save pays up to $8,500 for a whole-home heat pump conversion, and up to $16,000 for income-qualified households. A typical whole-home installed cost lands between $15,000 and $30,000 depending on the house. After the rebate, at the savings above, an oil-to-heat-pump conversion pays itself back in roughly five to twenty-two years with Eversource. With National Grid it takes eight years at best, and at the high end of installed cost the savings never catch up. Our calculator, which escalates oil and electricity prices separately, puts a typical Boston oil home burning $3,200 a year at about $1,180 a year saved and a seven-year payback, and the same house in Worcester at about $630 and ten years. Run your own address and oil usage through it for a number that reflects your home and usage.
The cost that never shows up in a quote
Oil carries one more price that no delivery slip itemizes: you can't predict it. Massachusetts oil has swung between roughly $2.50 and $6.00 a gallon within the past decade, and your supplier resets the price on every delivery. Electricity moves too, but it moves through rate cases measured in months and years, argued in public, in dockets anyone can read. Fixing your heating cost to the electric rate is not just cheaper on average. It is predictable in a way oil never is.
Some honest caveats before you switch
If your boiler is new and your house is leaky, weatherize first. Mass Save pays for most of that too, and every dollar of air sealing improves the heat pump math that comes after. A poorly sized heat pump will not hit the seasonal numbers used here; they assume equipment matched to the house, which is exactly the check our calculator's sizing step performs. And if you keep the boiler as backup, the tank fees and the service plan stay on your bill. The full-conversion math is cleaner than the hybrid math in an oil home, and this only showed you the full-conversion math.
Run your own numbers, with your utility's actual rates and your town's rebates, at redo.energy.