· HVAC
Mass Save in Municipal Light Plant Towns: What You Can and Can't Get
If your electric bill comes from Eversource, National Grid, or Unitil, you can use Mass Save. If it comes from your town's own utility, you cannot use Mass Save for electric measures, but that is not the end of the answer, and almost every competing page stops there and gets it wrong. Fifty Massachusetts municipalities are served by one of the state's 41 municipal light plants (MLPs). Whether a home in one of them can still get a Mass Save rebate, and which kind, depends on two more things: who sends the gas bill, and, for a heat pump specifically, what heating system you are replacing. Weatherization like windows and insulation follows a simpler rule than heat pumps do, and both are below. This guide is the decision tree, and as far as we can tell it is the only version online that gets all four outcomes right.
The whole answer in one table
Three questions decide it: who is your electric utility, who is your gas utility, and what are you replacing.
| Your situation | Mass Save result |
|---|---|
| Electric from Eversource, National Grid, or Unitil | Eligible. You pay into Mass Save, you can draw from it. |
| Electric from an MLP, gas from a Mass Save gas sponsor | Depends. A heat pump replacing that gas heat qualifies through your gas account, though replacing oil, propane, or electric resistance does not. Weatherization, including windows and insulation, qualifies through any participating gas account, even gas that only runs a water heater. |
| Electric from an MLP, and gas is also municipal | No Mass Save path. Neither bill pays in. Holyoke, Westfield, Middleborough, and Wakefield are in this group. |
| Electric from an MLP, and no gas service at all | No Mass Save path. Every home is oil or propane, so no account participates. Lakeville and Gosnold are in this group. |
Everything below is the detail behind those four rows.
Why MLP customers can't use Mass Save electric rebates
Mass Save is not a state agency and not a public program in the way most people assume. It is a joint efficiency plan run by the investor-owned utilities (Eversource, National Grid, and Unitil for electric, those three plus Berkshire Gas, Liberty, and Cape Light Compact for the full sponsor list), approved and overseen by the Massachusetts Department of Public Utilities on a three-year cycle.
The money comes from a line item on the electric and gas bills those utilities send, often labeled the energy efficiency reconciliation factor or similar. If your monthly electric bill comes from your town's MLP, you do not pay that surcharge, so you have no claim on the electric side of the pool. That is the whole logic. It is not a snub of MLP customers, it is how the funding rule works. The Massachusetts DPU publishes the register of municipally-owned electric companies, and per that list 41 MLPs serve all or part of 50 municipalities.
The heat pump rule almost everyone gets wrong
Here is the correction that flips the answer for a lot of families. Mass Save does not classify the whole-home heat pump rebate as an electric-only measure. It classifies it by the fuel you are replacing:
- Replacing a natural gas heating system: eligible if Berkshire Gas, Eversource, Liberty, National Grid, or Unitil is your Mass Save gas sponsor. You apply on your residential gas account.
- Replacing oil, propane, or electric resistance: eligible if Cape Light Compact, Eversource, National Grid, or Unitil is your Mass Save electric sponsor. You apply on your residential electric account.
Read those two rules against an MLP-electric home. If you heat with gas from one of the sponsors above, you are replacing gas, so you apply on the gas account, and the MLP on your electric bill does not disqualify you. If you heat with oil, propane, or electric resistance, the only door is the electric account, and a municipal electric customer does not have a participating electric sponsor. So the honest one-line verdict for an MLP-electric home is "depends on what you heat with," not "not eligible," and not "depends on your gas," which would tell an oil-heated household maybe when the answer is no.
Reading Municipal Light Department states the general principle in its own rebate FAQ: RMLD customers served by a Mass Save participating natural gas provider may be eligible for natural-gas-specific rebates from Mass Save. The rule is statewide, not a Reading quirk. Read the top of your gas bill. If it names Eversource, National Grid, Berkshire Gas, Liberty, or Unitil, do not let a contractor tell you MLP customers "get nothing from Mass Save." That is the flat wrong answer.
Windows, insulation, and weatherization work differently
Weatherization is not a heat pump, and the rule is not the same. You are not replacing a heating system, so there is no "what you heat with" branch. Mass Save weatherization, which includes the ENERGY STAR window rebate, insulation, and air sealing, is open to any customer of a participating utility, electric or gas. For a municipal-electric home the electric side is closed, so it comes down to a single question: do you have a participating gas account?
If your gas comes from Eversource, National Grid, Berkshire Gas, Liberty, or Unitil, that route is open, and the account is enough on its own. It does not matter what the gas actually heats. A home that burns oil for heat but runs a gas water heater on a National Grid account still has a participating gas account, and so still has a window and insulation route. The only municipal-electric homes fully shut out of weatherization are the ones with no participating gas account at all: the four towns whose gas is also municipal (Holyoke, Westfield, Middleborough, Wakefield) and the towns with no gas main, where every home is oil or propane. So for windows the honest question is not what you heat with, but whether any gas bill in the house comes from a Mass Save sponsor.
The towns with no Mass Save path at all
For most MLP towns, gas comes from an investor-owned sponsor, so the household-level rule above applies. Six towns are different, because the second bill closes the last door.
Four towns run their own municipal gas utility alongside their municipal electric: Holyoke (Holyoke Gas and Electric), Westfield (Westfield Gas and Electric), Middleborough (Middleborough Gas and Electric), and Wakefield (Wakefield Municipal Gas and Light). In these towns both the electric bill and the gas bill come from the town, so neither pays into Mass Save. There is no gas-account path and no electric-account path. The DPU electric register cannot show you this, because it only lists electric companies, which is exactly why "Wakefield Municipal Light Department" on that list hides the word Gas.
Two more towns have no natural gas service at all: Lakeville (Middleborough Gas and Electric serves it electricity but pipes gas only to Middleborough) and Gosnold (Cuttyhunk Island, with no gas infrastructure). Every home is oil or propane, so there is no participating gas account to reach.
One boundary case worth naming: Holyoke Gas and Electric also pipes gas into Southampton and Leverett, but those two towns have investor-owned electric, so they still qualify through the electric account for most measures. If you are in Southampton or Leverett and heat with that municipal gas, the gas-replacement heat pump path is closed to you, but the oil-or-resistance path through your electric utility is open. Confirm with a Mass Save assessment.
Outside Mass Save is not automatically worse
The lazy shorthand is that MLP customers lose out. For a one-shot install that is often true. For a phased project it can be the opposite, and the reason is structural: several MLPs cap their heat pump rebate per calendar year with an annual reset, where the Mass Save whole-home rebate is a once-per-home limit. If you split electrification across two winters, an annual-reset cap can be claimed twice. That structural point is the durable one. The figures below prove it, and each is dated so you can see when we last checked; confirm the current schedule with the utility before you sign.
- Concord (CMLP): $3,000 per ton, up to $10,000 per home per calendar year, and the cap resets every January. Ground-source is a separate $15,000 per year. A two-winter Concord project can pull the whole-home cap twice. (CMLP heat pump rebate page, as published July 2026.)
- Reading (RMLD): $2,000 per ton up to $8,000 for a new install, or $400 per ton up to $4,000 for a replacement, with weatherization required and covered at 50% up to $3,500, plus a 0% interest heat loan. (RMLD heat pump page, as published July 2026, reflecting the April 2026 enhancement.)
- Wellesley (WMLP): $8,500 if you remove and decommission the existing fossil-fuel or electric-resistance system, or $6,500 if you keep it as backup, for a whole-home system carrying 90% to 120% of the heating load. Partial-home is $1,125 per ton up to $5,000. (WMLP heat pump program page, as published July 2026; the higher 2025 grace-period levels expired February 28, 2026.)
Against the Mass Save whole-home rebate (see the heat pump rebates guide for current sourced figures), a single-year Concord project runs neck and neck, and a two-year Concord project wins on total dollars because the cap resets. The other 47 MLPs vary widely, and some pay less than Mass Save. The point is only that "MLP town equals worse rebate" is not automatic. For dollar figures on any other MLP, that utility publishes its own current schedule; amounts and rules change by year, so confirm before signing.
One footnote competitors keep getting wrong: the federal 25C tax credit expired December 31, 2025 under Public Law 119-21 and does not apply to any 2026 or later install. Do not budget around it.
The 50 municipal light plant towns
Each town links to its local HVAC contractor page. The path column is the quick read: electric only means the household rule (depends on your gas and what you heat with) applies, no path means both bills are municipal or there is no gas.
| Town | Municipal electric utility | Mass Save path |
|---|---|---|
| Ashburnham | Ashburnham Municipal Light Plant | electric only |
| Belmont | Belmont Municipal Light Department | electric only |
| Berkley | Taunton Municipal Lighting Plant | electric only |
| Boxborough | Littleton Electric Light and Water Department | electric only |
| Boylston | Boylston Municipal Light Department | electric only |
| Braintree | Braintree Electric Light Department | electric only |
| Chester | Chester Municipal Electric Light Department | electric only |
| Chicopee | Chicopee Municipal Lighting Plant | electric only |
| Concord | Concord Municipal Light Plant | electric only |
| Danvers | Danvers Electric Division | electric only |
| Dighton | Taunton Municipal Lighting Plant | electric only |
| Georgetown | Georgetown Municipal Light Department | electric only |
| Gosnold | Gosnold Electric Light Company | no path (no gas) |
| Groton | Groton Electric Light Department | electric only |
| Groveland | Groveland Municipal Light Department | electric only |
| Hingham | Hingham Municipal Light Plant | electric only |
| Holden | Holden Municipal Light Department | electric only |
| Holyoke | Holyoke Gas and Electric Department | no path (municipal gas too) |
| Hudson | Hudson Light and Power Department | electric only |
| Hull | Hull Municipal Lighting Plant | electric only |
| Ipswich | Ipswich Municipal Light Department | electric only |
| Lakeville | Middleborough Gas and Electric Department | no path (no gas) |
| Littleton | Littleton Electric Light and Water Department | electric only |
| Lynnfield | Reading (RMLD) or Peabody (PMLP), by address | electric only, split |
| Mansfield | Mansfield Municipal Electric Department | electric only |
| Marblehead | Marblehead Municipal Light Department | electric only |
| Merrimac | Merrimac Municipal Light Department | electric only |
| Middleborough | Middleborough Gas and Electric Department | no path (municipal gas too) |
| Middleton | Middleton Municipal Light Department | electric only |
| North Attleborough | North Attleborough Electric Department | electric only |
| North Reading | Reading Municipal Light Department (RMLD) | electric only |
| Norwood | Norwood Municipal Light Department | electric only |
| Paxton | Paxton Municipal Light Department | electric only |
| Peabody | Peabody Municipal Light Plant | electric only |
| Princeton | Princeton Municipal Light Department | electric only |
| Raynham | Taunton Municipal Lighting Plant | electric only |
| Reading | Reading Municipal Light Department (RMLD) | electric only |
| Rowley | Rowley Municipal Lighting Plant | electric only |
| Russell | Russell Municipal Lighting Company (north only) | electric only, split |
| Shrewsbury | Shrewsbury Electric and Cable Operations | electric only |
| South Hadley | South Hadley Electric Light Department | electric only |
| Sterling | Sterling Municipal Light Department | electric only |
| Stow | Hudson Light and Power Department | electric only |
| Taunton | Taunton Municipal Lighting Plant | electric only |
| Templeton | Templeton Municipal Lighting Plant | electric only |
| Wakefield | Wakefield Municipal Gas and Light Department | no path (municipal gas too) |
| Wellesley | Wellesley Municipal Light Plant | electric only |
| West Boylston | West Boylston Municipal Lighting Plant | electric only |
| Westfield | Westfield Gas and Electric Light Department | no path (municipal gas too) |
| Wilmington | Reading Municipal Light Department (RMLD) | electric only |
Two split towns you have to check by address
Lynnfield is split between two MLPs. Some addresses are served by Reading Municipal Light Department (RMLD), others by Peabody Municipal Light Plant (PMLP). The boundary follows historical service territory, not the town line, so the electric bill is the only reliable answer.
Russell is only partly on the Russell Municipal Lighting Company. The northern part of town is on the MLP, and the rest is served by an investor-owned utility and is Mass Save eligible. Again, the electric bill decides it.
How to read your own electric bill
The utility that sends your electric bill is your electric utility, full stop. Look at the top:
- Eversource, National Grid, or Unitil means an investor-owned utility, and Mass Save electric rebates apply.
- A town name (Belmont Light, Concord Municipal Light Plant, Reading Municipal Light Department, and so on) means an MLP, and Mass Save electric rebates do not apply. Ask your MLP about its own heat pump and weatherization program, and check your gas bill for the paths above.
- A competitive supplier name (Constellation, Direct Energy, a municipal aggregation brand) is only generation. Look at who runs the delivery, or wires, side. That is your utility for Mass Save purposes.
Municipal aggregation changes the price of generation, not the utility running the wires, and the wires utility is what controls eligibility.
If you are on an investor-owned utility: weatherize first
Skip this if your bill comes from an MLP. On Eversource, National Grid, or Unitil, the sequence for the whole-home heat pump rebate is the part most people get wrong. For a home built before 2000 with no weatherization on file, Mass Save requires sufficient weatherization before it pays the heat pump rebate:
- Book the no-cost Mass Save Home Energy Assessment first. The assessor documents your insulation and air sealing.
- Complete the air sealing and insulation it identifies (Mass Save covers most of the cost, see insulation rebates).
- Then book the heat pump install and submit the whole-home application.
Homes built in 2000 or later, or with an assessment showing under $1,000 of recommended weatherization, skip the prerequisite. Everyone else needs the assessment first, and skipping it is the most common reason a rebate is denied after the install. Equipment financing is available through the Mass Save HEAT Loan.
Frequently asked questions
Am I eligible for Mass Save rebates in an MLP town?
Not for electric-side rebates. But if you heat with gas from a Mass Save gas sponsor (Eversource, National Grid, Berkshire Gas, Liberty, or Unitil), a heat pump replacing that gas heat, and gas-specific rebates, are still available through your gas account. If your gas is also municipal (Holyoke, Westfield, Middleborough, Wakefield) or you have no gas (Lakeville, Gosnold), there is no Mass Save path, and your MLP's own program is the route.
Can I get the Mass Save heat pump rebate if my electric is an MLP?
Only if you are replacing gas heat and your gas utility is a Mass Save sponsor. You apply on the gas account. Replacing oil, propane, or electric resistance requires a participating electric sponsor, which a municipal electric customer does not have, so that path is closed.
Is the federal 25C tax credit available for MLP-town heat pumps?
No. The 25C credit expired December 31, 2025 under Public Law 119-21 and does not apply to any equipment placed in service in 2026 or later. Some competitor pages have not updated this.
How do I find which utility serves my address?
Read the top of your electric bill and your gas bill. For split towns (Lynnfield, Russell) the electric bill is the only reliable answer, because service territory does not follow the town line.
Are MLP rebates always smaller than Mass Save rebates?
Not automatically. Concord pays $3,000 per ton up to $10,000 per calendar year with an annual reset, which for a two-year phased project beats Mass Save's once-per-home cap on total dollars. Confirm the current schedule with your utility before signing.
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