Solar panels in Portland, ME
Roofs in Portland get about 1,386 hours of usable sunlight a year — less than 83% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.
Check your specific roof in Portland → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.
What a typical Portland solar system costs
A 23-panel system (9.2 kW) is about right for an average Portland home using 10,800 kWh a year. It would produce roughly 10,839 kWh annually and offset 100% of that usage.
| System | Size | kWh/yr | Net cost | Saves/yr | Payback |
|---|---|---|---|---|---|
| 8 panels | 3.2 kW | 3,770 | $6,384 | $935 | 6.8 yrs |
| 12 panels | 4.8 kW | 5,655 | $9,576 | $1,402 | 6.8 yrs |
| 16 panels | 6.4 kW | 7,540 | $12,768 | $1,870 | 6.8 yrs |
| 20 panels | 8 kW | 9,425 | $15,960 | $2,337 | 6.8 yrs |
| 26 panels | 10.4 kW | 12,252 | $20,748 | $2,768 | 7.5 yrs |
Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.
Why Portland gets 1,386 sun hours
That figure comes from Google's analysis of real rooftops across Portland — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Portland reaches about 1,501 hours, roughly 8% better than typical.
The numbers behind this page
| Typical usable sunlight | 1,386 hrs/yr |
|---|---|
| Unshaded roof | 1,501 hrs/yr |
| Electricity rate (Maine avg) | 24.8¢/kWh |
| Installed cost assumed | $2.85/W |
| Panel size assumed | 400 W |
| Federal tax credit | 30% |
| Typical household usage | 10,800 kWh/yr |
| Power used as generated | 35% |
| Paid for exported power | full retail (net metering) |
| Rooftops sampled here | 11 |
| Google imagery from | 2024 |
Nearby cities
Portland solar questions
How many solar panels do I need in Portland?
About 23 panels for an average home. Portland roofs get 1,386 usable sun hours a year, so each 400W panel produces roughly 471 kWh annually.
Is solar worth it in Portland?
At 24.8¢/kWh and 1,386 sun hours, a typical system pays for itself in about 6.8 years and returns roughly $48,666 over 25 years. That is a solid return.
How much do solar panels cost in Portland?
A 9.2 kW system costs about $26,220 before incentives and $18,354 after the 30% federal tax credit. Prices vary by installer, roof complexity and equipment.
Worth reading before you buy
Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Maine electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.