Solar panels in Boston: what they cost and what they make
A typical Boston home needs 13 solar panels. They would make about 6,957 kWh a year and cost $14k to $21k before incentives. At today's electricity prices they pay for themselves in about 7.3 yrs.
See panels on your own Boston roof
Type your address. You get your roof from above, the panels that fit, a month-by-month forecast and a battery test. No phone number.
What solar costs in Boston
At $3.00 a watt, the median price cash buyers pay nationally, a 5.5 kW system costs about $16,500. Quotes in Boston will usually fall between $13,750 and $20,625. Complex roofs, main-panel upgrades and financing push prices up.
The 30% federal tax credit no longer applies to systems homeowners buy. Massachusetts residential renewable energy credit: 15% up to $1,000. On this system that is worth about $1,000, and it is included below.
The number that decides whether solar pays in Boston is what your utility pays for the power you send back. Under full payback is about 7.3 yrs. Under net billing it is about 12.2 yrs, because only the ~42% of solar a typical home uses as it is made saves the full retail price.
Cash purchase, prices rising 2.5% a year, panels losing 0.5% a year, $25/kW a year for upkeep. No federal credit for homeowner-owned systems.
Every way to pay for a 5.5 kW system in Boston
Change any number →| Way to pay | Day one | Monthly payment | Monthly net, year 1 | Ahead after 25 years |
|---|---|---|---|---|
| Pay cash Full price on install day | $15,500 | $0 | +$163 | $48k |
| Credit-union loan 8% APR, 20 years, no dealer fee | $0 | $138 | +$25 | $31k |
| “1.99%” solar loan 1.99% APR, 25 years, 25% dealer fee | $0 | $87 | +$76 | $38k |
| Lease $150/mo, +2.9%/yr | $0 | $150 | +$25 | $2,300 |
| Power purchase (PPA) 25.6¢/kWh, +2.9%/yr | $0 | $148 | +$26 | $7,100 |
Under net metering, at 30.1¢/kWh rising 2.5% a year. The “1.99%” loan’s $4,125 dealer fee is included in its payments. Lease and PPA prices are typical offers, not quotes.
How much sunshine Boston gets
kWh per kW, 25° southJul is the best month for solar in Boston, and Dec the weakest: a Dec day makes 45% of a Jul day. A 6 kW system would make about 366 kWh in Dec and 821 kWh in Jul.
On June 21 the sun rises at 5:07 am and sets at 8:24 pm, 15 hours 17 minutes of daylight. On December 21 it is up from 7:10 am to 4:14 pm, just 9 hours 4 minutes.
Peak sun hours in Boston, month by month
| Month | Flat ground | Panels at 37° | kWh per kW |
|---|---|---|---|
| Jan | 1.8 | 3.2 | 74 |
| Feb | 2.6 | 4.0 | 86 |
| Mar | 3.7 | 4.7 | 116 |
| Apr | 4.8 | 5.2 | 125 |
| May | 5.4 | 5.1 | 131 |
| Jun | 5.8 | 5.2 | 128 |
| Jul | 6.0 | 5.6 | 137 |
| Aug | 5.4 | 5.5 | 131 |
| Sep | 4.3 | 5.2 | 117 |
| Oct | 2.8 | 4.1 | 94 |
| Nov | 2.0 | 3.4 | 74 |
| Dec | 1.5 | 2.7 | 61 |
| Year | 3.8 | 4.5 | 1,274 |
A peak sun hour is one hour of sunlight at 1,000 W per m². Why sites disagree.
The best angle and direction for panels in Boston
| Roof faces (6/12 pitch) | Output vs south | kWh per kW |
|---|---|---|
| South | 100% | 1,274 |
| Southeast | 95% | 1,210 |
| Southwest | 95% | 1,210 |
| East | 82% | 1,045 |
| West | 81% | 1,032 |
| North | 59% | 752 |
Face panels south and tilt them 37° for the most energy over a year. East and west roofs keep about 82% of that. A north-facing roof keeps 59%, which is rarely worth the money. Try other angles.
Where the sun goes over Boston
The noon sun is lower in winter, which is why the best winter tilt (63°) is steeper than the best summer tilt (12°).
Boston's homes
Boston has 283,374 households. 35.7% own their home, and 40,842 of those owners live in single-family houses, the kind of home that usually gets rooftop solar.
The median home here was built in 1947. Many roofs that age are due for replacement. Replace the roof first, then add solar: taking panels off and putting them back later costs thousands.
31.6% of homes heat with electricity and 56.4% with gas. If you switch to a heat pump or an electric car, plan for more panels or leave room on the roof.
Source: U.S. Census Bureau, American Community Survey 2020–2024 5-year estimates.
If the power goes out in Boston
Solar panels alone shut off in a blackout. Add a battery and they keep going. One Tesla Powerwall 3 (13.5 kWh) running a fridge, freezer, furnace fan, lights, Wi-Fi, TV and microwave (6.9 kWh a day):
Change the appliances, the battery and the weather in the battery calculator.
Questions people ask about solar in Boston
How much do solar panels cost in Boston?
A 5.5 kW system — enough for the average Massachusetts home — costs about $13,750 to $20,625 before incentives, based on $2.50–$3.75 per watt. Massachusetts's state tax credit takes off about $1,000. The 30% federal credit no longer applies to systems homeowners buy.
How many solar panels does a house in Boston need?
About 13 panels of 420 watts for a home using 570 kWh a month, the Massachusetts average. Each kilowatt of panels here makes about 1,274 kWh a year on a south-facing roof.
Is solar worth it in Boston?
Over 25 years, solar power here costs about 11.5¢ per kWh, against 30.1¢ from the grid today. Payback is about 7.3 yrs if your utility credits exported power at the full retail rate, and 12.2 yrs if it pays about 30% of retail.
How many peak sun hours does Boston get?
4.5 a day on panels tilted to 37°, and 3.8 on flat ground. The best month is Jul; the weakest is Dec.
What is the best angle for solar panels in Boston?
37° for the most energy over a year, facing south. 63° is best in winter and 12° in summer. On a normal pitched roof, anything within 15° of 37° gives you about 95% of the maximum.
How long would a home battery last in a Boston power outage?
A Tesla Powerwall 3 running a fridge, freezer, furnace fan, lights, Wi-Fi, TV and microwave (6.9 kWh a day) lasts about 43 hours with no sun. With 7 kW of solar to recharge it, it gets through a three-day outage even in overcast January.
Solar near Boston
| City | Miles | kWh per kW | Sun hours |
|---|---|---|---|
| Everett, MA | 5 | 1,292 | 4.5 |
| Quincy, MA | 5 | 1,302 | 4.5 |
| Somerville, MA | 6 | 1,292 | 4.5 |
| Cambridge, MA | 6 | 1,292 | 4.5 |
| Revere, MA | 6 | 1,293 | 4.5 |
Cities with the same sunshine as Boston
These far-away cities get almost exactly as much solar energy per panel.
- Aurora, IL 1,296 kWh per kW
- Kokomo, IN 1,298 kWh per kW
- Missoula, MT 1,295 kWh per kW
Snow: NASA records about 15 cm of snow on the ground here in an average January. Covered panels make little until it slides off, and these figures (like PVWatts') don't subtract that.
Sources: NASA POWER 2001–2020 monthly climatology (grid cell 43 km from Boston's Census point), our PV model (within 1.6% of NLR PVWatts® on average), U.S. EIA prices and use, U.S. Census 2025 population estimates and ACS 2020–2024. Estimates for an average home, not a site survey. How we calculate.