Solar Panel Cost in Massachusetts: $2.91/W, 8.3-Year Payback

Solar in Massachusetts costs about $23,280 for 8 kW at $2.91/W and pays back in roughly 8.3 years at 30.5¢/kWh with the federal credit at $0.

Updated September 2026 · Source: EIA Electric Power Monthly Table 5.6.A (July 2026 data) · next EIA update ~Oct 23

By SolarCostData Data Desk · Reviewed September 2026 · Corrections log

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Why this number

Solar panels in Massachusetts cost about $2.91 per watt — $23,280 for a typical 8 kW system — and pay back in roughly 8.3 years at the state’s 30.5¢/kWh average rate, with the 2026 federal credit at $0. Full-retail net metering is assumed; confirm with your utility.

Everything below uses Massachusetts’s real average residential electricity rate (30.5¢/kWh, EIA) and a production band of about 1,250 kWh per kW per year. Both are stated openly because they are the two inputs that decide the answer. These are estimates for sanity-checking a quote, not a quote.

Run it with your own numbers

Why Massachusetts’s payback lands where it does

Massachusetts electricity ticked up slightly to 30.5 cents per kilowatt-hour this July from 30.07 cents a year ago, a small rise of about one percent that still leaves the state at the fourth-highest rate in the country. Paired with an unremarkable yield of 1,250 kilowatt-hours per installed kilowatt, that rate is doing essentially all the work behind the state’s fast 8.3-year payback. The real story sits with NSTAR Electric, the largest utility with over 1.3 million residential customers: it bills just 19.9 cents on average, nearly ten cents below the statewide figure, meaning the blended state number is being pulled up sharply by other utilities and competitive suppliers charging well above 20 cents. Full retail net metering credits exports at whichever rate applies locally, so an NSTAR customer’s real payback likely runs meaningfully longer than 8.3 years, even though the statewide average paints a faster picture.

Electric utilities in Massachusetts

The state average hides real spreads between utilities. The largest residential utilities EIA-861 lists for Massachusetts, with each one’s own average bundled residential price (2024 — revenue ÷ sales, the audited annual figure, not this month’s tariff):

Your utility decides Massachusetts’s real number — the ZIP lookup finds it in three clicks; the 2024 annual utility averages above sit apart from the June-2026 monthly 30.5¢ state figure.

Massachusetts’s rate, the last 24 months

July 2025 → July 2026: 30.07¢ → 30.49¢. The rate tracker has every month against the US average.

An 8 kW system in Massachusetts, priced out

The $2.91/W used above comes from EnergySage marketplace quotes (August 2026). Those are quotes in a competitive online market, not signed contract prices.

Read that table with one caveat: $2.91/W is Massachusetts’s market average, and it is the input most likely to differ for you. A quote $0.50 per watt above or below the $2.91 used here moves the payback by roughly a year and a half in either direction.

How much sun Massachusetts actually gets

A kilowatt of panels in Massachusetts produces about 1,250 kWh a year on an unshaded, south-facing roof at a 20-degree pitch. Sites that swap Massachusetts’s 1,250 kWh for a single national average are how Arizona and Washington end up with identical paybacks despite a 1.6x real difference in output.

That figure is a five-point cluster around Massachusetts’s largest metro area, which keeps it representative of where most people actually live rather than of the state’s best site.

City-level figures for Massachusetts

We have separately modeled production for 3 Massachusetts cities, and they are 3% apart — Springfield at 1,220 kWh per kW against Boston at 1,257. Installed cost held at $2.91/W; paybacks use each city’s own utility tariff and export treatment where we have official EIA-861 data, which is why some differ sharply from this page’s state-average model.

• Boston — 1,257 kWh per kW, payback about 12.4 years (on its own utility’s tariff)
• Worcester — 1,252 kWh per kW, payback about 10.8 years (on its own utility’s tariff)
• Springfield — 1,220 kWh per kW, payback about 12.8 years (on its own utility’s tariff)

Those are real PVGIS-NSRDB location points, not the state figure scaled by guesswork. All Massachusetts and other city figures .

Two adjustments matter before you apply this to your own roof:

• Shading and orientation. The 1,250 kWh figure assumes an unobstructed south-facing array. A real Massachusetts roof — its own azimuth and pitch, a tree or a chimney — typically produces 10-25% less; this page models 90% of the ideal, so the 9,000 kWh/year above is already derated from 10,000. A genuinely unshaded south roof can adjust upward in the calculator.
• Year-to-year weather moves output by roughly ±5% either way.

How Massachusetts compares with the other 49

Massachusetts ranks 4th of 50 on electricity price and 4th on annual output value per kW installed — close enough that its rate is a fair proxy for its solar case, which is not true everywhere. Its immediate neighbors on price are Maine (32.4¢) just above and New York (29.9¢) just below.

New York is Massachusetts’s closest comparable-rate analogue — 29.9¢/kWh, roughly 1,270 kWh per kW, and a payback within about a year of this one (7.9 vs 8.3 years). If you find Massachusetts quotes hard to sanity-check, New York numbers are broadly transferable.

The export question worth asking your Massachusetts utility

Massachusetts credits exported power at the retail rate — full net metering — under 220 CMR 18.04, so a kilowatt-hour you send to the grid is worth the same as one you buy. That is the best case for solar economics, and it is why the payback above is what it is.

It is also the assumption most likely to change. Twenty-two states have already moved to net billing. If Massachusetts did the same on typical terms, this system would take about 15.5 years to pay back instead of 8.3 — 7.2 years’ difference from a policy change, with no change to the hardware. The households best placed for that day are the ones already storing their surplus, which is why what a home battery actually costs is worth knowing even while full retail holds.

⚠️ Treat this one as unconfirmed. Whether the 60% multiplier in 220 CMR 18.04 applies to residential behind-the-meter systems could not be resolved. Treat as unknown and confirm with your utility. We could not verify it against a primary source, so check directly with your utility before relying on the figure above.

One limit worth knowing: this reflects investor-owned, state-regulated utilities; Massachusetts’s municipal utilities and co-ops are exempt in most cases and set their own terms.

Massachusetts’s own solar tax credit, and what else is left

The 30% federal credit ended for systems completed after December 31, 2025, so it is $0 here as everywhere. What remains is state, utility and local — and it varies far more than the federal rule ever did.

Residential Energy Credit — 15% of system cost, capped at $1,000. Computed on net expenditure. Because net expenditure is defined after subtracting the federal credit (830 CMR 62.6.1), and the federal credit is now $0, the Massachusetts credit applies to the GROSS cost — so its effective value has gone UP since 2025. On the $23,280 system modeled above that is worth up to $1,000. The paperwork side of claiming it is walked through in our solar tax season checklist .

SMART 3.0 — $0.03/kWh for systems up to 25 kW, $0.06 for low-income, plus adders of $0.04 for storage, $0.05 for low-income property and $0.03 for building-mounted, over 20 years. Applications opened 1 January 2026; the DPU approved tariffs on 8 July 2026. This is paid on the electricity your system generates, separately from bill savings, so treat it as a range rather than a fixed line.

Tax exemptions

Sales tax is exempt (6.25% state rate), which keeps roughly $1,455 off the upfront cost of the system modeled here.

Property tax is exempt for 20 years, after which the added value becomes assessable.

How Massachusetts’s package stacks up against the other states’ credits, rebates and exemptions is laid out on the solar incentives hub .

Is solar worth it in Massachusetts at 30.5¢/kWh?

Massachusetts pays because power is expensive, not because it is sunny. A 1,250 kWh/kW year is ordinary; a 30.5¢ rate is not. Every kilowatt-hour you stop buying is simply worth a lot here.

A payback under ten years also changes the timing question: once the numbers clear this comfortably, waiting has a cost of its own, and when to buy solar prices that out.

Two numbers put that in context. At Massachusetts’s rate, the electricity an 8 kW system would produce is worth about $2,744 a year, so the system costs roughly 8.5 years of that output to buy outright — a simple division, before costs. The headline 8.3-year figure above is the full model: it additionally counts 2.5%/yr rate inflation, $150/yr of running costs and one inverter replacement, which is why the two differ slightly. And doing nothing is not free: 25 years of that same electricity, with rates rising at 2.5% a year, comes to about $93,729.

For a 15-year payback in Massachusetts — given its sunshine rather than a national average — the electricity rate would need to be about 17.6¢/kWh. Massachusetts is at 30.5¢, which is comfortably above that line.

Sources and method

• Electricity rate: U.S. Energy Information Administration, average price by state — EIA Table 5.6.A, July 2026 data (released Sep 2026). Rate shown is Massachusetts’s residential average.
• Production: PVGIS v5.2 with the PVGIS-NSRDB radiation database, 1,250 kWh/kW for a five-point cluster around Massachusetts’s largest metro, then the 90% real-roof factor; the assumptions, the ERA5 cross-check and the attribution are on the methodology page .
• Incentives: DSIRE — Database of State Incentives for Renewables & Efficiency, NC Clean Energy Technology Center. Verify current amounts and fund status before relying on them.
• Federal credit status: IRS, Residential Clean Energy Credit . See our 2026 energy tax credit guide .
• Payback model: shared with the solar savings calculator — 2.5%/yr utility inflation, 0.5%/yr degradation, federal credit $0.

Massachusetts’s rate (30.5¢, EIA Table 5.6.A, July 2026 data (released Sep 2026)), export regime, production factor, installed cost and programs were last verified on 25 September 2026; Massachusetts’s export credit resets on its tariff cycle and incentive budgets run out mid-year, so confirm current terms before acting. Not tax or financial advice.

Frequently asked questions

How we calculated this

Worked for Massachusetts: 8 kW × 1,000 × $2.91/W = $23,280 gross (federal credit $0, so net before state incentives); 9,000 kWh a year × the blended kWh value at 30.5¢ retail ≈ $2,744 year-1 saving; payback ≈ $23,280 ÷ $2,744 = 8.3 years with 2.5%/yr rate growth, 0.5%/yr degradation and one inverter replacement in the 25-year model.

Sources: U.S. Energy Information Administration (EIA) electricity rates · DSIRE incentive records · public IRS/OBBBA guidance. Figures are modeled estimates, not quotes or tax advice. See our methodology.

States with a comparable tariff picture

• Why is my electric bill so high? — Splits a bill jump into weather, rate and usage — with Massachusetts’s own EIA rate history built in.
• Heat pump crossover temperature — Cold-zone question: the outdoor temperature where gas beats a NEEP-listed heat pump at Massachusetts’s rates.
• Cost to heat a home in Massachusetts — Gas, propane, heating oil, heat pump and resistance per MMBtu at Massachusetts’s own EIA winter prices — the heating side of the same rate.
• Electricity rate tracker — Massachusetts’s last 24 months of EIA rates, charted against the US average.
• Find your rate by ZIP — Massachusetts averages hide utility gaps — look yours up from EIA-861 in three clicks.
• Net metering by state (2026 table) — Every state’s export regime with program, date and source — the rule behind Massachusetts’s payback.
• Solar panel cost in New York — Same export regime at 29.9¢/kWh and a 7.9-year payback — the closest tariff comparison to Massachusetts.
• Solar panel cost in Maine — Same export regime at 32.4¢/kWh and a 8.0-year payback — the closest tariff comparison to Massachusetts.
• Solar panel cost in Rhode Island — Same export regime at 28.3¢/kWh and a 8.5-year payback — the closest tariff comparison to Massachusetts.