The Massachusetts solar property tax exemption removes the added value of a qualifying solar system from your property’s assessment for 20 years, so installing panels will not raise your property tax bill even though the system increases the home’s market value. The exemption sits in General Laws Chapter 59, Section 5, Clause 45, and it also covers wind systems and battery storage paired with solar or wind.1General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 5
Which Systems Qualify
The statute gives you three separate paths. Your system only needs to meet one.
- The 125 percent capacity test. The system produces no more than 125 percent of the annual electricity needs of the property where it sits. “Property” here includes contiguous and non-contiguous parcels in the same municipality under common ownership. Most home installations qualify this way.
- The 25-kilowatt cap. The system’s capacity is 25 kilowatts or less, verified by Department of Energy Resources incentive program documentation or your electric utility’s permission-to-operate paperwork.
- A PILOT agreement. The system owner and the municipality have signed a Payment In Lieu Of Taxes agreement covering the system. This path is common for larger commercial or community solar projects that exceed the residential thresholds.
The exemption applies to owned or leased solar systems, wind systems, and solar or wind installations co-located with battery storage. Battery storage qualifies when it is paired with a solar or wind system on the same property.1General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 5
What the Exemption Actually Removes From Your Bill
The exemption strips the added value of the solar equipment out of your total assessment. If your home is worth $400,000 and the solar installation adds $40,000 in market value, the town continues to assess the property at $400,000. You do not get a discount on your existing tax bill, and no cash changes hands. The benefit is that your taxes do not go up because of the system.
The land underneath stays on the tax rolls at its normal assessed value. Other structures on the lot, like a detached garage or shed, are also unaffected. The exemption reaches only the solar hardware, racking, inverters, and any co-located battery storage.2DSIRE. Renewable Energy Property Tax Exemption
PILOT agreements work a little differently. When the system owner also owns the land, the PILOT covers personal property taxes on the system, real property taxes tied to the system, and taxes on the land where the system sits. When the system and land have different owners, the PILOT covers only the personal property taxes on the equipment itself.1General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 5
How Long the Exemption Lasts
The exemption runs 20 years from the date of installation. After that, the system’s value becomes part of your regular property assessment and is taxed like anything else on the parcel.1General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 5
The law also allows an extension beyond 20 years if the property owner and the municipality agree in writing. This is not automatic. You have to negotiate it with the town, and any agreement must be in writing. If you are approaching the end of the exemption window, it is worth raising the option with your local assessor’s office.3Mass.gov. Ask DLS: Solar Abatement Applications
How to Apply
You apply through your local Board of Assessors using State Tax Form 128, the standard Massachusetts property tax abatement application. Some towns use a customized version, so ask your assessor’s office before filing.4Secretary of the Commonwealth of Massachusetts. Property Tax Information
The filing deadline follows the general abatement rules under Chapter 59, Section 59. You must file on or before the last day to pay the first installment of the actual tax bill without incurring interest. In most Massachusetts municipalities, that falls on or around February 1 of the fiscal year. If the deadline lands on a weekend or holiday, the window extends to the next business day.5General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 59
If you are qualifying through the 25-kilowatt path, you will need documentation of the system’s capacity. The statute accepts Department of Energy Resources incentive program documentation or your electric distribution company’s permission-to-operate letter. The interconnection agreement from the utility is the standard proof of both capacity and the date the system went live on the grid. Hold on to all installation documents, including the installer’s name and total project cost, because assessors routinely ask for this during their review.
Once the assessors verify the system meets one of the three qualifying criteria, the exemption appears on your subsequent tax bills. The adjusted valuation carries forward automatically for the rest of the 20-year period.
Systems That Do Not Qualify
Two categories are excluded by statute. Systems developed under Section 1A of Chapter 164 do not get the exemption, and solar, wind, or energy storage systems owned by electric distribution companies are also excluded.1General Court of Massachusetts. Massachusetts General Laws Part I, Title IX, Chapter 59, Section 5
A system that does not meet any of the three qualifying paths will not qualify either. If a residential installation produces well over 125 percent of the property’s annual electricity needs and also exceeds 25 kilowatts, and there is no PILOT agreement in place, it falls outside the exemption. This is where the line between a home installation and a commercial power plant matters. Systems built to sell wholesale electricity, rather than serve the property they sit on, generally cannot use the first two paths and would need a PILOT agreement with the town.