Solar Calculator for Massachusetts: Costs, Incentives & ROI
Massachusetts has some of the most favorable solar economics in the United States, combining the third-highest average residential electricity rates in the country with a structured long-term incentive program and strong property and sales tax protections. The state's Solar Massachusetts Renewable Target program, known as SMART, provides a flat per-kilowatt-hour Capacity Block payment for ten years to qualifying residential systems installed within the service territories of Eversource, National Grid, and Unitil — the state's three investor-owned electric utilities. SMART replaced the prior Solar Carve-Out II certificate market in 2018 and offers more predictable income than the fluctuating SREC market it succeeded. Massachusetts homeowners benefit from electricity rates that averaged roughly 25 to 27 cents per kilowatt-hour in 2025 — nearly double the national average — which makes each kilowatt-hour of self-consumed solar production exceptionally valuable on a bill-offset basis. The state also exempts residential solar systems from property tax for twenty years after installation under Massachusetts General Law chapter 59 section 5, imposes no sales tax on solar energy equipment or labor under MGL chapter 64H, and allows participation in virtual net metering for customers with community solar subscriptions. Solar production in Massachusetts is lower than in sunbelt states due to the northern latitude and frequently cloudy Atlantic coastal weather, but the combination of high rates, strong incentives, and moderate payback periods makes Massachusetts consistently one of the top ten residential solar markets by new annual installations. Use the calculator below to estimate your specific SMART payment, net metering credits, and 25-year savings.
Incentive data updated: May 2026(may be outdated)
Average Solar Cost in Massachusetts
Average installed solar costs in Massachusetts typically run from $2.90 to $3.60 per watt for residential systems before incentives, based on Lawrence Berkeley National Laboratory Tracking the Sun data and EnergySage marketplace pricing for the region. A typical six-kilowatt system therefore costs roughly $17,400 to $21,600 before the federal Investment Tax Credit — among the higher installed cost tiers nationally, reflecting elevated labor costs in the Boston metropolitan area and along the South Shore and Cape Cod corridors, a dense licensing and permitting framework administered by town building departments, and a mature but competitive installer market. The thirty-percent federal ITC reduces a typical system's net cost to approximately $12,200 to $15,100. Massachusetts does not offer a separate state income tax credit for residential solar (the prior state credit expired in 2018). However, the SMART program's ten-year Capacity Block payments significantly improve project returns beyond what the ITC alone provides. The twenty-year property tax exemption prevents the installed value from increasing annual property tax obligations, which is meaningful in the rapidly appreciating Greater Boston market. System pricing on Cape Cod and western Massachusetts can vary from metro-area pricing depending on local contractor availability and travel costs.
- Avg. installed cost
- $3.25/W
- Typical 6 kW system
- $17,400–$21,600
Top Solar Incentives in Massachusetts
Live incentive data not currently available for Massachusetts. See the federal incentive guidance via our Solar Tax Credit Calculator.
Electricity Rates in Massachusetts
Massachusetts has among the highest residential electricity rates in the United States. The 2025 statewide average runs approximately 25 to 27 cents per kilowatt-hour according to EIA data, with some Eversource territory customers in eastern Massachusetts seeing effective all-in rates above 28 cents when distribution charges, renewable portfolio standard charges, and basic service supply charges are included. National Grid customers in central Massachusetts and the Cape and Islands face similarly elevated rates, and Unitil customers in the northeast corner of the state pay rates in the same range. All three utilities participate in Massachusetts net metering, which credits excess solar production at the full retail rate for residential customers with systems up to 60 kilowatts. The combination of high retail rates and full-retail-rate net metering makes Massachusetts one of the strongest solar-economics states per kilowatt-hour on a bill-offset basis — each unit of solar production is worth substantially more on a Massachusetts bill than on a national-average-rate utility bill. Virtual net metering, available to community solar subscribers, allows the same full retail offset to apply even for homeowners who cannot install panels on their own roof.
Peak Sun Hours in Massachusetts
Massachusetts averages between 4.0 and 4.7 peak sun hours per day — at the lower end of the continental United States range but adequate for positive solar economics given the state's high electricity rates. The eastern coastal areas, including Greater Boston, the South Shore, and Cape Cod, tend to see slightly more solar exposure than the Pioneer Valley in the west and the hillier interior of Worcester County, which can have more overcast days due to elevation and orographic cloud formation. Winter months from December through February see production fall to roughly 20 to 35 percent of the summer peak, and periodic snow cover on panels can reduce output further during extended cold stretches. Despite the lower annual production per kilowatt compared to southern states, Massachusetts solar systems remain economically attractive because the high per-kilowatt-hour value of avoided electricity and SMART program payments compensate for the lower energy yield. NREL's PVWatts uses ZIP-code-level Typical Meteorological Year data for production estimates specific to your address.
Example ROI for a 6 kW System
- Estimated annual savings
- $1,900
- Payback period
- 8.5 years
- 25-year net savings
- $34,000
Run a personalized estimate with your ZIP code using the Solar ROI Calculator.
Major Cities in Massachusetts
- Boston02108
- Worcester01601
- Springfield01103
- Cambridge02139
- Lowell01852
Common Questions About Solar in Massachusetts
What is the SMART program and how does it work for homeowners?
The Solar Massachusetts Renewable Target program pays residential solar owners a flat per-kilowatt-hour incentive for ten years based on the capacity block their application falls into at approval. Each of the three investor-owned utilities — Eversource, National Grid, and Unitil — administers its own series of capacity blocks. Earlier blocks offer higher payment rates; as each block fills, the rate steps down for new applicants. Homeowners apply through a licensed solar installer, and payments begin after the system achieves Permission to Operate. SMART payments are separate from and in addition to net metering credits — the homeowner receives bill credits for exported production plus the fixed SMART incentive for every kilowatt-hour the system generates.
Does Massachusetts have property tax and sales tax exemptions for solar?
Yes. Massachusetts provides two significant tax protections for residential solar. First, Massachusetts General Law chapter 59, section 5, clause 45 exempts solar energy systems from property taxation for twenty years from the date of installation — meaning the added value the system contributes to your home's assessed value is excluded from the property tax base for two decades. Second, Massachusetts General Law chapter 64H, section 6(dd) exempts the sale of solar energy systems and components from the five-percent state sales tax. Both exemptions apply without a separate application; the contractor documents the sales tax exemption at point of sale, and the property assessor recognizes the exclusion upon review of the building permit record.
What is the difference between SMART and the old Solar Carve-Out II program?
The Solar Carve-Out II program compensated solar owners by issuing Solar Renewable Energy Certificates for each megawatt-hour produced. SREC values fluctuated based on supply and demand in the certificate market, creating uncertainty about future income. SMART replaced SRECs in 2018 with a fixed per-kilowatt-hour payment called the Capacity Block incentive, which is determined at the time of application and locked in for ten years. This eliminates market-price uncertainty and allows homeowners to more confidently underwrite the economics of an installation. For most homeowners, SMART provides a more predictable income stream that simplifies financial planning and system sizing compared to the variable SREC market.
How does Massachusetts net metering work for residential solar?
Massachusetts net metering credits excess residential solar production at the full retail rate, including supply and distribution charges, for systems up to 60 kilowatts. Unused credits roll forward month to month as a monetary credit on the utility bill. At the end of the annual billing cycle, any remaining credits are either rolled forward indefinitely or paid out at the avoided-cost rate depending on the utility and tariff. Customers on time-of-use rate schedules should verify that their net metering credit rate aligns with their highest-rate period, since excess production during off-peak hours may be credited at a lower rate than evening peak consumption. Eversource and National Grid both offer net metering in their service territories.
Can I go solar in Massachusetts if I have a shaded or north-facing roof?
Solar production in Massachusetts is already modest by national standards — roughly four to four and a half peak sun hours per day. North-facing roof sections generate approximately 30 to 40 percent less annual production than south-facing sections at the same tilt, extending payback periods by two to four years and reducing SMART payments proportionally. Significant shading from trees, chimneys, or neighboring structures further reduces production. Community solar subscriptions offer a practical alternative for homeowners who cannot viably install rooftop panels — virtual net metering allows subscribers to receive full retail-rate bill credits from an off-site solar array without any roof modifications or equipment installation on the subscriber's property.