Massachusetts solar calculator
Size a Massachusetts home solar system from your electric bill — kW, panel count, roof area, true cost with no federal credit for 2026 installs, and payback.
Quick answer: At $0.296/kWh and 4.2 peak sun hours, a $200/month bill needs about 6.97 kW — 17 × 410 W panels covering ~34 m². Gross cost is ~$20,248 with no federal credit for systems installed after 2025, offsetting $2,400 a year for a ~8.4 year payback.
Your details
Ballpark, not gospel. Sized at 78% real-world output with the Massachusetts sun-hour average — confirm shading, roof angle and your utility’s net metering terms with a local installer before buying. Massachusetts net meters residential solar at near-full retail with month-to-month credit rollover — and 2026 raised the residential cap-exempt threshold from 10 kW to 25 kW.
The 30% credit ended — what changed
The residential clean energy credit (26 U.S.C. § 25D) gave homeowners a 30% credit on solar installed from 2022 through 2025. The July 2025 tax law ended it: no credit is available for property placed in service after December 31, 2025. That is why every figure on this page is ~30% higher than pre-2026 guides show. If your system went live by the end of 2025, tick the box above to see the credit applied; leased systems may still benefit because the leasing company claims the commercial credit. Source: IRS — Residential Clean Energy Credit.
Typical Massachusetts system sizes by monthly bill
| Monthly bill | System size | Panels (410 W) | Net cost (no 2026 federal credit) | Payback |
|---|---|---|---|---|
| $100 | 3.69 kW | 9 | $10,719 | 8.9 years |
| $200 | 6.97 kW | 17 | $20,248 | 8.4 years |
| $300 | 10.66 kW | 26 | $30,967 | 8.6 years |
Computed at $0.296/kWh, 4.2 peak sun hours and $2.91/W installed, with no federal credit for 2026 installs. Run your exact bill above.
Solar in Massachusetts: the details
Solar cost in Massachusetts
Solar sits in the middle of the national price range in Massachusetts. The EnergySage marketplace averaged about $2.91 per watt installed in 2026, with market quotes typically landing $2.47–$3.34/W — within the $2.50–$3.50/W national band. A typical ~13 kW Massachusetts system grosses around $37,765, with no federal credit for 2026 homeowner installs.
What moves the number: roof complexity, panel tier, and how competitive the quote market is in your metro. Get at least three quotes — spreads of $0.50/W between installers are common.
Export rules: getting paid for surplus power
Massachusetts net meters residential solar at near-full retail with month-to-month credit rollover — and 2026 raised the residential cap-exempt threshold from 10 kW to 25 kW, so typical home systems skip the queue entirely. New large projects interconnecting from 2026 move to a lower Supply Rate Credit under energy bill H5175, but home systems keep near-retail treatment.
Practical takeaway: residential terms are the best-protected in this group.
Massachusetts solar incentives
The SMART program pays residential systems of 25 kW or less a flat ~$0.03/kWh production incentive for 20 years ($0.06/kWh for low-income) — paid on every kWh you generate, not just exports. Massachusetts adds a 15% state income tax credit up to $1,000 on top. Few states stack this much.
Is solar worth it in Massachusetts?
Verdict: strong. ~8.4-year payback with no federal credit, the fastest in this group. Near-full-retail net metering, a 20-year SMART production incentive, a 15% state income tax credit, and 29.6¢/kWh power prices stack into the strongest economics of any state here.
Questions people actually ask
Straight answers, no fluff. Then run your own numbers above.
How many solar panels do I need in Massachusetts?
It follows your bill. At the Massachusetts average of $0.296/kWh and 4.2 peak sun hours, a $200/month bill needs about a 6.97 kW system — roughly 17 × 410 W panels covering ~34 m² of roof.
What is the average cost of solar panels in Massachusetts in 2026?
The EnergySage marketplace averaged about $2.91 per watt installed in 2026, with market quotes typically $2.47–$3.34/W — within the $2.50–$3.50/W national band. A typical ~13 kW system grosses around $37,765, with no federal credit for 2026 homeowner installs.
Does Massachusetts have net metering?
Massachusetts net meters residential solar at near-full retail with month-to-month credit rollover and cap exemption up to 25 kW. New large projects interconnecting from 2026 move to a lower Supply Rate Credit under energy bill H5175.
Does Massachusetts offer any solar tax credit or rebate?
The SMART program pays residential systems of 25 kW or less a flat ~$0.03/kWh production incentive for 20 years ($0.06/kWh for low-income). Massachusetts also offers a 15% state income tax credit up to $1,000.
Is the 30% federal solar tax credit still available?
Not for homeowner purchases anymore. The residential clean energy credit (26 U.S.C. § 25D) is not available for property placed in service after December 31, 2025, under the July 2025 tax law (Public Law 119-21). Systems installed by the end of 2025 can still claim 30%, and leased systems may still benefit because the leasing company claims the commercial credit instead. (Source: IRS — Residential Clean Energy Credit.)
Is solar worth it in Massachusetts?
Strong: a ~8.4-year payback with no federal credit. Near-full-retail net metering, the 20-year SMART production incentive, and a 15% state income tax credit (up to $1,000) make this the strongest economics of any state in this group.
Figures last checked October 2026. Sources: EIA Electric Power Monthly (July 2026: 29.61¢/kWh), NREL PVWatts/NSRDB (~4.2 peak sun hours), DSIRE, Massachusetts Department of Public Utilities; IRS — Residential Clean Energy Credit.
More US solar calculators
Compare other states: Texas, Florida, California, Arizona, North Carolina, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland. And the national US solar calculator for country averages.
Comparing quotes? The solar cost calculator breaks down cost per watt and the solar ROI calculator maps your payback year by year. Going deeper: installation cost guide, how net metering works, how much you can save with solar and the solar batteries guide.