Solar Incentives in Massachusetts

SMART is Massachusetts's flagship residential and commercial solar incentive, replacing the closed SREC programs. The base compensation rate is a declining-block tariff: each megawatt of statewide capacity exhausted reduces the rate for subsequent applicants by ~4%. Base rates vary by utility territory (National Grid, Eversource West, Eversource East, Unitil), with current 2026 residential rates around $0.10–$0.15/kWh. The storage adder pays additional cents per kWh delivered through a paired battery — Tier 1 storage (≥ 25% of PV nameplate) earns the highest adder. Income-eligible (low-income) and behind-the-meter (BTM) adders stack on top of base. The 10-year contract length is fixed; the rate locked in at commissioning. SMART payments come via the customer's electricity utility — no separate enrollment beyond an interconnection-and-incentive application. The successor SMART 2.0 program is in regulatory development; existing SMART contracts are honored through their full 10-year term regardless of programme changes.

Under Massachusetts General Laws Chapter 62 § 6(d), residents may claim an income tax credit for 15% of the net expenditure on a renewable energy source installed at their primary residence. The maximum credit is $1,000 per residence. The credit is claimed on Massachusetts Form 1, Schedule CMS. The credit is non-refundable: it reduces tax liability but does not generate a refund beyond what was withheld. Unused credit may be carried forward for up to three subsequent tax years. Net expenditure is calculated after subtracting any rebates or grants (state, federal, or utility), so the credit is computed on the post-incentive cost. For a typical $15,000 PV system, the maximum claimable amount is $1,000 (15% of $6,667 or any greater post-incentive expenditure).

Massachusetts maintains net metering for solar PV under three classes: Class I (≤ 10 kW for individual customers; ≤ 60 kW for non-residential) receives 1:1 compensation at full retail rate. Class II (10 kW–1 MW) and Class III (1–2 MW) receive compensation at the utility's 'basic service' rate, which excludes distribution charges and is meaningfully lower than retail. Most residential PV installations qualify under Class I. The Class I net metering is preserved indefinitely for participating systems. SMART program participants may stack net metering on top of SMART payments — SMART pays for generation, net metering credits the consumption offset. Statewide net metering caps periodically constrain new applicants on private (non-public-entity) projects; check current cap availability with your utility.

Mass Save is the joint efficiency programme of Massachusetts utilities (Eversource, National Grid, Unitil, Berkshire Gas) funded by ratepayers. Rebates target whole-home efficiency, including heat pumps, insulation, and ConnectedSolutions battery demand response. ConnectedSolutions enrols batteries to provide grid services 30–60 times per summer; participants receive an annual payment of approximately $225 per kW of dispatchable capacity (so a 5 kW battery earns ~$1,125/year). Five-year participation commitment is typical. ConnectedSolutions is in addition to SMART storage adder — both can apply to the same battery. ConnectedSolutions is one of the most lucrative grid-service programmes available to US residential prosumers; combined with high MA electricity rates, batteries pencil aggressively in this state.

Under Massachusetts General Laws Chapter 59 § 5(45), solar PV and wind energy systems used to provide heat or other forms of energy for the property owner's primary use are exempt from local property tax for a 20-year period from installation. The exemption is claimed by filing State Tax Form 3ABC with the local Board of Assessors. The exemption applies only to the value added by the renewable system; the underlying real estate continues to be assessed normally. Some municipalities have voted to extend the exemption beyond 20 years or to apply it more liberally. Battery storage installed alongside qualifying solar is generally covered.