Is solar worth it in Massachusetts in 2026?

How Massachusetts pays for your solar power

Net metering at the retail rate. Exports from home systems get net metering bill credits near the retail rate (efficiency, renewable and solar charges excluded); SMART 3.0 adds a flat per-kWh payment for 20 years.

In the calculator, 40% of your solar output is used at home at the retail price and the rest is exported at about 100% of retail (our default for this kind of rule), so each solar kWh is worth 100% of the retail price on average. Change it if your utility pays more or less. Method

State or utility incentive	What it is worth
SMART 3.0 (Solar Massachusetts Renewable Target)	$0.03/kWh flat for most systems up to 25 kW ($0.06/kWh low-income), locked for 20 years; 2026 program year
Massachusetts residential renewable energy income tax credit	15% of net cost, up to $1,000
State sales tax exemption on residential solar equipment	Exempt from state sales tax when used as a primary or auxiliary energy source at a principal residence

How exports are credited

Massachusetts uses net metering, set by state law and run by the three investor-owned utilities (Eversource, National Grid and Unitil). Home systems are “Class I” net metering facilities, which covers systems of 60 kW or less. Each month, what you send to the grid is subtracted from what you draw. Any surplus appears as a bill credit that rolls forward. Credits cannot be cashed out, and leftover credits are lost if you close the account unless you transfer them to another account on the same utility.

The credit is close to the retail rate, but not equal to it. Eversource says systems of 10 kW or less earn a rate “slightly lower than the full retail rate”, because charges for energy efficiency, renewable energy and distributed solar are left out. Systems larger than 10 kW may get a reduced rate. As an example of the size, Eversource’s September 2026 table lists $0.32295 per kWh for a Greater Boston residential R-1 customer with a Class I solar system. The figure changes with the utility, territory and rate class, and it moves as rates change.

Systems under 10 kW AC single phase (or up to 25 kW AC three phase) are “simplified” and are exempt from the cap allocation step. Municipal light plant towns are outside this system and have their own rules, so check your local utility if you are not served by an investor-owned company.

State incentives in 2026

• SMART 3.0. The Solar Massachusetts Renewable Target program pays a monthly amount per kWh your system produces, on top of net metering credits. For most residential systems of 25 kW or smaller, the 2026 flat rate is $0.03 per kWh, or $0.06 for low-income households, locked in for 20 years. The 2026 program year opened January 1, 2026. Rates are reset each year. A system qualifies if its owner has not received SMART or RPS incentives before and construction started on or after June 20, 2025. Municipal light plant customers are not eligible. Leased systems and power purchase agreements are different, because the third-party owner holds the incentive. MassCEC says issuing SMART 3.0 payments needs a utility payment mechanism approved by the Department of Public Utilities (DPU), and DOER expects a decision in 2026. That status could not be re-checked after June 10, 2026.
• State income tax credit. 15% of the cost of residential solar or wind equipment, capped at $1,000, under M.G.L. c. 62 section 6(d). The state budget lists it as active in fiscal 2027, and it covers equipment that produces solar or wind energy for residential properties. Check the Department of Revenue instructions for the filing form.
• Sales tax. Solar equipment used as a primary or auxiliary energy source at a principal residence is exempt from state sales tax (M.G.L. c. 64H section 6(dd)).

What it means for payback

Because credits track the retail rate, each kWh you export is worth almost as much as one you use, so sizing to your annual use is reasonable. SMART adds a small payment per kWh over a long term, so it matters more for higher-producing systems. The $1,000 state credit is small next to the cost of a system. Without the federal credit, SMART and net metering do most of the work.

Other rules worth knowing

Utilities set interconnection steps and may need a new meter, and SMART participants get a second meter. Boston-area network locations can be harder to interconnect, according to Eversource. Eversource’s table also lists a lower “Alt On Bill Credit (SMART)” rate, so ask your installer which credit rate applies to your system.