MeterMath

Solar payback Maine

Solar panel payback in Maine

7.6 years for a typical home solar system in Maine to pay for itself, with no federal tax credit.

A 5.5 kW system sized for the average home here, which uses 527 kWh a month, costs about $15,400 at $2.80 per watt. It saves about $1,860 in its first year, and after 25 years it is $46,351 ahead. That is fast: the system has paid for itself with most of its 25 to 30 year life still to run.

¢/kWh
 
kWh
 
kW
 
$/W
2026 quotes average $2.60 to $3.00.
$
Rebates or state tax credits.
% of retail
 
Output, rate increases and upkeep
kWh/kW
 
%
The rest goes to the grid. Higher if you are home by day.
%
U.S. prices rose 5% in the past year.
%
$
Set to 0 if your inverter warranty runs 25 years.

How Maine compares

Maine ranks 2nd of 51 for solar payback, fastest first. The fastest is Hawaii at 5.9 years. At U.S. average figures, payback is 12.3 years.

Two things set payback: what each kWh is worth and how many the panels make. Maine ranks 3rd for electricity price, most expensive first, at 32.41¢/kWh, and 42nd for sunshine, at an estimated 1,200 kWh a year per kW of panels. Expensive power does the work here; sunshine is below the U.S. average of 1,350 kWh per kW.

The calculator assumes power sent to the grid earns 75% of the retail price, typical of net metering. Your utility's tariff sets the real rate, and a lower credit slows payback.

Solar pays back faster here than in any neighboring state; next is Massachusetts at 8.0 years.

StateElectricitySun, kWh/kWPayback
Maine32.41¢1,2007.6 yrs
Massachusetts30.49¢1,2008.0 yrs
New Hampshire26.60¢1,2009.1 yrs
Vermont23.75¢1,15010.4 yrs

More for Maine

What these numbers assume

  • A 5.5 kW system, sized to cover about 100% of a typical home's yearly use.
  • $2.80 per watt installed, paid in cash, with no state or local incentives entered.
  • No federal tax credit: Section 25D ended for systems placed in service after December 31, 2025.
  • Half the output used in the home as it is made; the rest credited at 75% of the retail price.
  • Electricity prices rising 3% a year, panels losing 0.5% of output a year, and a $2,000 inverter replacement in year 12.

Change any of them in the calculator above to match your own bills. The formulas are on the main solar payback calculator.

Sources

  • Electricity price: EIA Electric Power Monthly, Table 5.6.A (July 2026 data).
  • Household use: EIA 2025 retail sales divided by customers.
  • Installed cost: 2026 residential marketplace averages.
  • Output per kW: MeterMath estimate for a south-facing fixed roof system, rounded.
  • Export credit: MeterMath assumption for typical net metering.
  • Tax credit status: Public Law 119-21.