Net metering credits, and a separate production payment
Massachusetts offers net metering for residential systems, crediting exported solar at or near the retail or basic service rate, and layers the SMART production incentive on top of that.
SMART payments are made directly by the utility company to the system owner, via the same billing structure as net metering, following approval of the application by the Solar Program Administrator and the Department of Energy Resources.
Each month the utility reads the production meter, and the owner receives a payment representing the difference between the SMART rate and the value of the energy already credited through net metering. So the two are related rather than simply additive, and a projection should show how they interact rather than presenting one combined figure.
Ask your installer to show the net metering credit and the SMART payment separately across a year, and to explain how the difference is calculated. If they cannot, the projection has not been built from how the programme actually pays.
Ten years, at a rate set when you enrol
For residential systems under 25 kW, SMART incentive payments last for a fixed term of 10 years, and the compensation rate is determined at the time a participant enrols and is locked for the 10-year duration.
That makes the enrolment date matter in a way installation dates do not. Ask what the current residential rate is, what determines which rate your system receives, and get the answer in writing from the programme rather than from an article.
Under SMART 3.0, launched in October 2025, residential systems under 25 kW are no longer subject to capacity block limits, which replaced the earlier declining block model where the incentive fell as each block filled. That removes the race to enrol before a block closed, but the rate is still set at enrolment.
Ask what your projection assumes happens after year ten, when the SMART payments end. A twenty-five year model that carries the incentive all the way through is describing something that does not happen, and the difference is not marginal.
Confirm the production meter, and check it keeps reporting
Because the incentive is paid on metered production, a production meter has to be installed and reporting for you to be paid. Confirm in writing that one is included, who supplies and installs it, and how its readings reach the programme.
Then ask how you can verify it is still reporting months later. A meter that quietly stops costs you part of a ten-year entitlement without any obvious signal, and missing incentive payments are much easier to overlook than a missing bill credit.
Ask when the first payments should appear and set a reminder to check. Silence is not evidence that everything is working.
Keep the paperwork: the interconnection approval, the SMART application approval, the production meter details and the readings. That file is what you need if something has to be corrected, and it is what a buyer of the house will want to see.
Three state benefits, and the federal one that ended
Massachusetts has a state income tax credit of its own. 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. It is claimed on Schedule EC.
Note that it is available to a tenant as well as an owner, which is unusual and worth knowing if you are paying for a system on a property you occupy but do not own. Ask a tax advisor how it applies to your circumstances, since a credit is only worth what you can use against tax owed.
There is also a property tax exemption of 100 percent for 20 years for solar installations, 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. Neither arrives as a cheque, which is exactly why both get left out of people's own arithmetic.
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.