Waltham, MA Solar Panels

Massachusetts homeowners who install solar panels on their primary residence can claim a state income tax credit worth 15% of the net system cost, capped at $1,000. This credit is applied directly against your Massachusetts state income tax liability, reducing what you owe dollar-for-dollar. If the credit exceeds your tax liability in the year of installation, it can be carried forward for up to three years.

To claim the credit, you must file Schedule SC along with your Massachusetts state tax return. The credit is calculated on the total cost of the system after any upfront rebates have been subtracted. The system must be installed on your primary residence to qualify — vacation homes or rental properties are not eligible.

While the $1,000 cap limits the absolute dollar value, this credit stacks with other Massachusetts incentives such as the SMART program, net metering, and tax exemptions, helping to meaningfully reduce your overall payback period.

When you purchase solar panels and related equipment in Massachusetts, you pay zero state sales tax on those purchases. Massachusetts law (M.G.L. c. 64H, sec. 6(dd)) automatically exempts residential solar electric system equipment from the state’s 6.25% sales tax — no application or special form is required.

The financial benefit is straightforward: on a $20,000 solar system, this exemption saves you approximately $1,250 that you would otherwise owe in sales tax. The exemption applies to solar panels, inverters, mounting hardware, and other components that are part of the solar electric system.

This is an automatic, upfront savings that reduces your out-of-pocket cost from day one. It applies to both cash purchases and financed systems, and it stacks with other Massachusetts incentives like the state tax credit, SMART program payments, and the property tax exemption.

Installing solar panels typically increases your home’s market value — but in Massachusetts, that added value is completely shielded from property taxes for 20 years under MGL Chapter 59, Section 5. This means your annual property tax bill will not increase as a result of your solar installation, regardless of how much value the system adds to your home.

In towns with higher property tax (mill) rates, this exemption can save homeowners an estimated $300 to $800 per year, adding up to thousands of dollars in savings over the 20-year exemption period. The exemption applies automatically to qualifying solar energy systems — you do not need to reapply each year.

This incentive is especially valuable in high-value real estate markets across Massachusetts, where solar systems can add $15,000–$30,000 or more to a home’s appraised value. Combined with the sales tax exemption, state tax credit, and SMART program, the property tax exemption is a key part of Massachusetts’ comprehensive solar incentive stack.

The Solar Massachusetts Renewable Target (SMART) 3.0 program, launched in October 2025, is Massachusetts’ primary production-based solar incentive. Administered through the state’s investor-owned utilities (Eversource, National Grid, and Unitil), SMART pays residential solar owners a fixed rate for every kilowatt-hour (kWh) their system produces over a 10-year contract period. Payments are made monthly by your utility, providing a predictable, guaranteed income stream to offset your solar investment. Compensation rates are reviewed and reset annually.

Residential systems up to 25 kW qualify for a flat per-kWh incentive rate. Additional adders are available on top of the base rate: pairing your solar system with battery storage adds approximately $0.04/kWh, building-mounted systems add $0.02/kWh, and low-income households can qualify for double the standard rate (approximately $0.06/kWh adder). Low-income eligibility can be established through participation in qualifying needs-based programs or via self-attestation.

SMART is only available to customers of the three investor-owned utilities — Eversource, National Grid, and Unitil. Customers of municipal light plants (MLPs) are generally not eligible for SMART but may have access to local MLP rebate programs. Program Year 2026 is open for applications from January 1 through December 31, 2026, with 900 MW of available capacity.

Net metering allows Massachusetts homeowners with solar panels to earn bill credits for any excess electricity their system sends back to the grid. When your panels produce more than you use, the surplus flows to the grid and your utility credits your account. When you need power at night or on cloudy days, you draw from the grid and those credits offset what you owe — often reducing your electric bill to near zero. As of February 2025, the residential system size cap for automatic net metering eligibility was expanded from 10 kW to 25 kW AC, allowing homeowners to install larger systems.

Massachusetts net metering is among the most favorable in the country because credits are valued at the full retail electricity rate — including supply, distribution, transmission, and transition components. Most other states only credit the lower wholesale or supply-only rate. The only charges excluded from the credit calculation are the energy efficiency and renewable energy surcharges. For systems under 1,000 kW, the credit equals the exported kWh multiplied by the sum of all eligible rate components.

A key advantage of Massachusetts net metering is that credits never expire — they roll over from month to month and year to year indefinitely. This means surplus production in sunny summer months can be banked and used to offset higher winter bills, maximizing the value of your solar investment throughout the year. Net metering is available to customers of Eversource, National Grid, and Unitil.

The ConnectedSolutions program, administered through Mass Save and participating utilities (Eversource, National Grid, and Cape Light Compact), pays homeowners annual incentives for enrolling their battery storage system and allowing the utility to draw power from it during periods of peak grid demand — typically hot summer days. Residents of Waltham receive $275 per kilowatt (kW) for their battery’s average contribution during summer peak events. A typical battery with a 5 kW continuous output can earn up to $1,375 per year, with some participants averaging around $1,500 annually.

The program operates on a five-year incentive contract, with payments made twice a year (summer and winter seasons). Eligible battery systems include major brands such as Tesla Powerwall, SolarEdge Home Battery, and Enphase IQ Battery, provided the inverter size is under 50 kW. You must be an existing customer of Eversource or National Grid to participate.

As an added benefit, ConnectedSolutions participants may qualify for 0% financing on their battery system through the Mass Save HEAT Loan program, with financing available up to $25,000. When combined with the annual incentive payments, this financing option can make battery storage highly affordable. Enrolling in ConnectedSolutions does not prevent you from also participating in the SMART storage adder or other utility rebate programs.

Eversource customers in Massachusetts can receive a $500 rebate for installing a qualifying residential battery storage system. The rebate is applied directly as a credit on your electric bill once your application is approved. There is no minimum or maximum system size requirement, making this rebate accessible for a wide range of battery installations.

To receive the rebate, you must submit your application within six months of installation. Missing this deadline will disqualify you from the rebate, so it’s important to apply promptly after your battery is installed and commissioned. Your battery system must meet Eversource’s qualifying equipment standards.

This rebate can be combined with the ConnectedSolutions annual incentive program, the SMART 3.0 storage adder (if paired with solar), and the federal battery tax credit, making it one piece of a larger incentive stack available to Eversource customers investing in battery storage.

The SMART 3.0 Battery Storage Adder is an additional per-kWh incentive layered on top of the base SMART program rate for residential solar systems that are paired with a qualifying battery storage system. The storage adder is approximately $0.04 per kWh of solar production, paid monthly by your utility for the duration of your 10-year SMART contract. This adder is designed to encourage solar-plus-storage installations, which provide greater grid reliability benefits.

To qualify for the storage adder, your battery must be installed alongside your SMART-enrolled solar system and meet the program’s technical requirements. The adder is available to customers of Eversource, National Grid, and Unitil — the three investor-owned utilities that administer the SMART program. Exact adder rates may vary slightly by utility territory and are subject to annual review under SMART 3.0.

The storage adder can be combined with other battery incentives, including the ConnectedSolutions annual payments and utility-specific battery rebates, creating a powerful stacked incentive for homeowners in Waltham who invest in solar-plus-storage systems. Contact your solar installer or your utility’s SMART program office to confirm the current adder rate applicable to your project.

The Residential Clean Energy Credit (Section 25D) provides a 30% federal income tax credit for the cost of qualifying battery storage systems installed in your home. Unlike the solar ITC, this battery credit remains available for homeowner-owned systems in 2026. The credit is applied directly against your federal income tax liability, reducing what you owe dollar-for-dollar.

There is one critical eligibility requirement: the battery must be charged primarily from a renewable energy source — specifically, at least 80% of the energy stored in the battery must come from solar panels (or another qualifying renewable source). Batteries charged primarily from the grid do not qualify. This makes the credit most accessible to homeowners who install battery storage alongside a solar panel system.

The 30% credit rate is in effect through 2032, after which it is scheduled to step down. For a $10,000 battery installation, the credit would be worth $3,000. This federal credit can be stacked with Massachusetts state incentives including the ConnectedSolutions program, utility battery rebates, and the SMART storage adder, significantly reducing the net cost of adding battery storage to your home.

Community solar is an alternative to rooftop solar for Massachusetts residents who rent, have a shaded or unsuitable roof, or simply prefer not to install panels. By subscribing to a share of a local solar farm, you receive credits on your utility bill for the electricity your share produces — typically saving 5% to 10% on your electricity costs with no upfront investment or installation required.

Community solar is available to customers of Massachusetts’ investor-owned utilities (Eversource, National Grid, and Unitil). Subscribers sign up through a community solar provider, who handles all the paperwork and billing. Your utility bill is reduced by the value of the solar credits generated by your share of the farm each month. Most programs offer month-to-month or short-term contracts, making it a flexible option.

While community solar doesn’t provide the same long-term financial benefits as owning a rooftop system, it is an accessible way for a broader range of Waltham residents — including renters and condo owners — to participate in the clean energy economy and reduce their electricity costs immediately, with no installation, maintenance, or ownership responsibilities.