Is solar worth it in Maine?
A 7.0 kW rooftop system near Portland produces about 9,230 kWh a year. Priced against the 8 residential tariffs currently on file in Maine, payback runs from 8 years on the best of them to 48 on the worst.
Why the tariff matters more than the panels
Two households in Maine with identical roofs and identical systems can see paybacks 8 and 48 years apart, purely because they are on different tariffs. Solar produces at midday; households consume in the evening. Only 55% of what these panels make is used as it is made — the rest is exported, and what an exported kWh earns is set by the tariff and by state net metering rules, not by the hardware.
That is why the figures here are computed hour by hour against each real tariff rather than by taking a bill and assuming solar removes a share of it. How this is modeled →
Payback by tariff in Maine
7.0 kW system at $3.00/W, household using 1000 kWh a month, no incentives. A range means the export credit is not filed with the tariff and the outcome depends on net metering rules — 8 of 8 tariffs here belong to a utility that reports residential net metering.
| Utility | Tariff | Structure | Annual saving | Payback |
|---|---|---|---|---|
| Bangor Hydro-Electric Co | Rate A-4 Residential Service - Time of Use | Time-of-use | $1,441–$2,606 | 8–15y |
| Bangor Hydro-Electric Co | Rate A Residential Service | Flat | $1,334–$2,447 | 9–16y |
| Central Maine Power Co | A Residential Standard Offer Service (Bundled) | Tiered | $1,327–$2,385 | 9–16y |
| Central Maine Power Co | A-TOU Residential Service Time-of-Use | Time-of-use | $686–$2,251 | 9–31y |
| Central Maine Power Co | A-TOU-OPTS Residential Service - Optional Time-Of-Use (Super Saver) | Time-of-use | $1,029–$1,984 | 11–20y |
| Central Maine Power Co | A Residential Standard Offer Service | Tiered | $687–$1,210 | 17–31y |
| Central Maine Power Co | A-TOU Residential Service - Time-of-Use | Time-of-use | $46–$1,077 | 19–454y |
| Central Maine Power Co | A-TOU-OPTS Residential Service - Optional Time-Of-Use (Super Saver) | Time-of-use | $435–$893 | 24–48y |
Price it for your own usage and system size →
What would change this
Your roof. Production is modeled for Portland on a south-facing array at 20° tilt. Shading, orientation and pitch all move it, and solar resource varies within Maine itself.
Your usage pattern. A household at home during the day self-consumes more and exports less, which shortens payback wherever export credit is poor.
Rising rates. These figures hold today's prices flat. Electricity prices have been rising, and every rise shortens payback — so treat these as a conservative bound.
State and local incentives. Not included here, and in some states they are worth more than the federal credit was. Check your state energy office before deciding.