What happens when the grid goes down
A grid-tied system without storage disconnects during an outage. People reasonably assume panels plus daylight equals electricity, and learning otherwise during a nor'easter is the expensive way to find out.
If keeping part of the house running matters, ask any installer to be specific rather than general. Which circuits stay live, for how long at a realistic load, and does the battery recharge from the array while the grid is down.
Be concrete about the load you want to carry. A system keeping a fridge, some lighting, the heating controls and a few outlets going for days is a very different proposition from one attempting to run everything, and that conversation belongs before the contract.
Ask how a battery sized for outage cover compares with one sized for everyday bill savings, because they are frequently not the same system and knowing which you are being quoted is essential before comparing prices.
Coastal conditions and your insurer
Ask what the mounting is specified to withstand, how attachments are detailed, and whether the installer has done coastal work before. Salt air and wind-driven rain are harder on a roof and on hardware than inland conditions.
Ask where the inverter and any battery would be sited and how that placement relates to your property's exposure. Equipment location is a design decision made once, so raise it deliberately rather than leaving it to convenience.
Talk to your home insurer before installation. Ask whether a rooftop array and any battery are covered under your policy, whether either changes your premium or deductible, and what documentation they want on file afterwards.
Check the roof covering while you are at it. Panels outlast most coverings, and coastal exposure plus freeze and thaw cycling age one faster than the calendar suggests, so ask for a condition assessment rather than an age estimate.
The everyday economics, kept separate
Resilience is one reason to buy and the everyday arithmetic is another, and they should be discussed separately rather than blended into one number. Only one of them goes honestly into a spreadsheet.
Massachusetts credits exported solar through net metering at or near the retail or basic service rate, and the SMART incentive is paid on metered production for a fixed term of 10 years for residential systems under 25 kW.
Confirm eligibility first, since SMART is provided to customers of Eversource, National Grid and Unitil and customers of municipal light plants are not eligible. Then confirm a production meter is included and reporting.
Ask for the battery to be costed on its own: what it adds, what it saves on the bill if anything, and what it delivers during an outage. Those are three separate answers and a single combined figure has hidden two of them.
Three state benefits, and the federal one that ended
Under 830 CMR 62.6.1 an owner or tenant of a residential property who occupies it as their principal residence is allowed a solar and wind energy credit against personal income tax equal to fifteen percent of the net expenditure for renewable energy source property, or $1,000, whichever is less, claimed on Schedule EC. It being available to a tenant as well as an owner is unusual and worth knowing.
Massachusetts also provides a property tax exemption of 100 percent for 20 years for solar installations, so the improvement does not raise your property tax bill the way a renovation of similar cost would.
And equipment for a solar system used as a primary or auxiliary energy source in a principal residence is exempt from sales and use tax. Check that your quote reflects that rather than assuming, and ask your municipal assessor what if anything they need for the property tax exemption at your address.
On the federal side, the 30 percent Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase now receives no federal credit. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements, so ask any such provider what they claim and what of that value reaches you, and confirm with a tax advisor.