Solar Calculator Massachusetts 2026
Some of the nation's priciest electricity meets a 15% state tax credit, SMART production payments, and battery income from ConnectedSolutions.
1 Your location & bill
Sets a representative residential rate and sun-hours for your state — edit the rate below to match your actual bill.
US residential average is ~18.2¢/kWh (EIA, January–August 2026), from ~12.5¢ (ND) to ~46¢ (HI). The higher your rate, the faster solar pays back.
2 Federal credit
For owned systems installed in 2026, the calculator applies no federal credit (the 25D residential credit expired end-2025). For a lease/PPA, it applies the credit the provider passes on — set the effective amount below.
Defaults to 0% for owned (2026 reality) and 30% for lease/PPA. Edit if your situation differs (e.g. a state credit, or future federal changes).
3 Net metering
Net metering varies hugely by state and utility. California's NEM 3.0 pays roughly a quarter of retail for exports, which is why self-consumption and batteries matter so much there. Pick what matches your utility.
Share of your solar used on-site (saves full retail). The rest is exported. A battery raises this toward ~70–80%, which matters most under reduced-export rules.
4 System & cost
US residential averages ~$2.50–3.50/W before any credit. Enter your quoted price.
Indicative estimates only. Federal, state and utility rules change and vary widely — net-metering terms and rates differ by utility even within a state. The federal credit situation is in flux; confirm current rules (and your ownership type's eligibility) before deciding. Not tax advice.
How this is calculated
Federal credit (2026): the residential 30% ITC (Section 25D) expired for owned systems placed in service after 31 December 2025. So this defaults to 0% for cash/loan purchases. A lease or PPA can still pass through ~30% because the provider claims the commercial 48E credit (through ~2027) — selecting "Lease/PPA" applies that. Net cost = gross cost − federal credit applied.
Payback = net cost ÷ annual savings; 25-year savings applies modest rate escalation and panel degradation. State rates and sun-hours are representative defaults (EIA-based) — edit them to your actual figures. Verify current federal/state/utility rules before purchasing.
Massachusetts Solar in 2026: Expensive Power, Deep Incentives
Massachusetts residential electricity averages about 29 to 30 cents per kWh — Eversource and National Grid supply rates routinely spike higher in winter — so even the state's modest 4.1 peak sun hours per day convert into outsized savings. A kWh you generate on your roof in Boston is worth roughly double the same kWh in Texas. Start with the USA solar calculator for your baseline, then stack the Bay State programs below.
Net Metering and the SMART Program
Residential systems up to 10 kW on investor-owned utilities receive net metering credits at close to the full retail rate, carried forward month to month (municipal light plants set their own rules, so check locally). The SMART program then adds a production payment on top. The original design was a declining block — the per-kWh rate stepped down as each utility's capacity blocks filled — and it has since been reworked: the proposed SMART 3.0 pays residential systems a flat 3 cents per kWh for 20 years, doubled for low-income households, with an adder for pairing storage. Final tariff approval was still pending at the Department of Public Utilities as of mid-2026, so verify current status and rates with MA DOER before counting the income.
The State Credit, ConnectedSolutions, and Tax Exemptions
- The Massachusetts residential energy credit — 15% of system cost up to $1,000 off your state income tax — still applies in 2026.
- ConnectedSolutions pays home-battery owners around $275 per average kW delivered during summer peak events, commonly $1,000 to $1,500 per year for a typical battery.
- Solar equipment is exempt from the 6.25% sales tax, and the added home value is property-tax exempt for 20 years.
The Federal Situation in 2026
The 30% federal residential credit (Section 25D) ended for owned systems placed in service after December 31, 2025, so 2026 cash and loan buyers get no federal credit. Leases and PPAs can still pass through roughly similar value because the provider claims the commercial 48E credit (expected through about 2027) — but third-party deals may also claim the SMART payment, so read the contract. Model both routes in the solar savings calculator.
A Worked Massachusetts Example
A 7 kW system at $3.30 per watt costs about $23,100; the state credit trims that to roughly $22,100. At 3.8 kWh per kW per day it produces near 9,700 kWh per year, worth about $2,870 against 29.5-cent power, plus roughly $315 per year if SMART 3.0 payments are approved as proposed — a payback around 7 to 7.5 years with zero federal help. Add a battery and ConnectedSolutions revenue can shave another year off; size it with the battery bank calculator and sanity-check outage coverage in the battery runtime calculator. Heating with oil or propane? Pairing solar with heat pumps sized in the mini-split calculator is often the bigger win.
Solar generation in Massachusetts, month by month
From PVGIS 5.3 (European Commission Joint Research Centre), ERA5 solar data 2005-2023: a 1 kW grid-tied system at the best fixed angle with 14% system losses. Figures are the average of Boston, Worcester, Springfield. The calculator above uses 3.8 kWh per kW per day as its default.
| Month | kWh per kW per day | 3 kW system, kWh in the month |
|---|---|---|
| January | 3.3 | 310 |
| February | 4.0 | 340 |
| March | 4.4 | 410 |
| April | 4.3 | 390 |
| May | 4.1 | 382 |
| June | 4.0 | 358 |
| July | 4.1 | 378 |
| August | 4.1 | 378 |
| September | 3.9 | 351 |
| October | 3.3 | 308 |
| November | 3.2 | 285 |
| December | 2.7 | 255 |
Solar output by city
| City | kWh/kW/day | kWh/kW/year | 3 kW, kWh/year | Best tilt |
|---|---|---|---|---|
| Boston | 3.8 | 1,390 | 4,171 | 40° |
| Springfield | 3.8 | 1,380 | 4,140 | 40° |
| Worcester | 3.8 | 1,373 | 4,120 | 40° |
What each system size produces in Massachusetts
| System | kWh per day | kWh per month | kWh per year |
|---|---|---|---|
| 1 kW | 3.8 | 115 | 1,381 |
| 2 kW | 7.6 | 230 | 2,762 |
| 3 kW | 11.4 | 345 | 4,144 |
| 5 kW | 18.9 | 575 | 6,906 |
| 10 kW | 37.8 | 1,151 | 13,812 |
Solar calculators for other US states
Localized rates, net-metering and incentive context for more states — or use the national USA solar calculator (all 50 states + DC selectable).
Frequently asked questions
Yes, with a caveat. The program has been restructured from its old declining-block design into a proposed flat-rate model — about 3 cents per kWh for 20 years for residential systems, doubled for low-income households, with a storage adder — and residential systems up to 25 kW are exempt from the annual capacity cap. However, final tariff approval was still pending at the DPU as of mid-2026, so confirm current status with MA DOER.
Yes. The residential energy credit remains in place: 15% of your system cost, capped at $1,000, taken against Massachusetts state income tax, with unused amounts carried forward up to three years. With the federal residential credit gone for purchases after 2025, this is now the only direct tax credit available to Bay State solar buyers — small, but it still applies.
Eversource and National Grid pay roughly $275 per average kW your battery delivers during summer peak-demand events, which typically works out to $1,000 to $1,500 per year for one home battery — often more for larger or multiple units. Payments run each summer season for the length of your enrollment. Rates are reviewed periodically through the Mass Save process, so confirm the current offer with your utility.
No — the Section 25D residential credit ended for owned systems placed in service after December 31, 2025. Leasing or a PPA can recapture much of that value because the installer claims the commercial 48E credit through about 2027 and typically bakes it into pricing, but the company may also keep SMART payments and the equipment. Massachusetts' own stack — the 15% state credit, net metering, SMART, and ConnectedSolutions — is what keeps purchased systems attractive.
About 11 kWh a day or 4,144 kWh a year on average, from about 8.2 a day in December to 13.2 a day in March, according to PVGIS data for panels at the best fixed angle. Shading, dust and orientation change the result.
Learn more
Sources & standards
Rate, net-metering and incentive figures in this Massachusetts calculator are drawn from the following state and federal sources — verify current values before signing a contract.
- PVGIS 5.3 — Photovoltaic Geographical Information System — European Commission, Joint Research Centre
Monthly and annual output per kW for Boston, Worcester, Springfield (ERA5, 2005-2023; 14% losses, optimal fixed angle). Retrieved 2026-11-09. - Database of State Incentives for Renewables & Efficiency — DSIRE, N.C. Clean Energy Technology Center
Cross-referenced for the current status of Massachusetts' state and utility solar incentive programs. - Solar Massachusetts Renewable Target (SMART) Program — Massachusetts Department of Energy Resources (DOER)
Source for the per-kWh SMART incentive rate and low-income adder used in this calculator's worked example. - Massachusetts Department of Public Utilities — DPU
Oversees net-metering tariffs and approves the SMART program filings referenced on this page. - Residential Clean Energy Credit — Internal Revenue Service (IRS)
Confirms the Section 25D federal credit's expiration for owned systems placed in service after December 31, 2025. - Electric Power Monthly, table 5.6.B: average price of electricity by state — U.S. Energy Information Administration
Residential prices by state, year to date through August 2026. Used for the state electricity rates in the state list.