All states / Massachusetts
Solar in Massachusetts
At 29.61¢ per kWh and 1302 kWh of production per kW each year, a household paying $200 a month needs a 5.85 kW system. Paid in cash, it returns its $16,029 cost in 7.1 yr.
What we don't know yet
Two prices, two answers
Payback 7.1 yr — at competitive quoted prices ($2.91/W, EnergySage 2026): net cost $16,029, 25-year net $50,567.
Payback 9.5 yr — at typical reported prices ($3.90/W, LBNL 2023): net cost $21,822, 25-year net $44,774.
The gap is methodology, not staleness: the first what you get if you shop around for competitive quotes; the second what the average buyer actually paid, as recorded in permit and incentive data. Every table below uses quoted prices. Why we show both.
By monthly bill
| Your bill | Use / yr | System | Panels | Net cost | Payback | 25-yr net (cash) | Lease, year 1 |
|---|---|---|---|---|---|---|---|
| $100/mo | 3,566 kWh | 2.74 kW | 7 | $6,971 | 7.2 yr | $21,249 | $317 |
| $150/mo | 5,593 kWh | 4.3 kW | 11 | $11,500 | 7.1 yr | $35,908 | $497 |
| $200/mo | 7,619 kWh | 5.85 kW | 15 | $16,029 | 7.1 yr | $50,567 | $677 |
| $300/mo | 11,672 kWh | 8.96 kW | 23 | $25,087 | 7.1 yr | $79,883 | $1,037 |
Cash, loan or lease — at $200 a month
| How you pay | 25-year net | Upfront | Year 1 | Payback / cash flow | Federal credit to you |
|---|---|---|---|---|---|
| Cash | $50,567 | $16,029 | $2,106 | 7.1 yr | $0 |
| Loan $124/mo · 6.99% APR · 20 yr | $36,794 | $0 | $616 | immediate (+$616 in year 1) | $0 |
| Lease / PPA | $18,997 | $0 | $677 | immediate (+$677 in year 1) | $0 |
The 30% federal credit goes to the system owner, not to you. It is reflected in the rate you are offered. The owner claims it at 30% under IRC 48E.
The inputs, and where they came from
| Input | Value | Source |
|---|---|---|
| Residential electricity rate | 29.61¢/kWh | U.S. EIA API v2, electricity/retail-sales, residential sector, 2026-06 |
| Specific yield | 1302 kWh/kW/yr | NLR (formerly NREL) PVWatts v8 API, 1 kW reference system (city:boston-ma) |
| Installed cost | $2.91/W | EnergySage Marketplace real-quote average, as of Sep 2026; page updated 2026-08-28 · LBNL Tracking the Sun 2023 median: $3.9/W, reference only |
| Export compensation | full retail net metering · 100% | Full retail net metering — not yet verified against the tariff |
| Federal credit, purchase | 0% | IRC 25D (expired) |
| Federal credit, third-party owner | 30% | IRC 48E (Clean Electricity Investment Credit) |
| State incentives | $1,000 | Residential Renewable Energy Income Tax Credit (Schedule EC) (15%, up to $1,000) |
City-level production on file for: Boston. The figures above use Boston.