Maine pays about 25.0¢ per kilowatt-hour for residential electricity and receives about 4.2 kWh per square metre per day of sunlight — 6th and 41st respectively among the 50 states and DC tracked here. Those two numbers set the ceiling on what rooftop solar returns in Maine, and they point in opposite directions.
Where Maine sits against the rest of the country
Maine is 10.2¢/kWh above the median residential rate across this dataset (14.8¢/kWh) and 0.4 kWh/m²/day below the median insolation (4.6 kWh/m²/day). Under this site's standard assumptions, that combination puts Maine 6th of 51 for modeled payback speed, at 9.6 years against a dataset median of 13.5 years.
What actually drives payback in Maine
Maine is rate-led: upper half of the dataset for electricity price (6th), lower half for sunlight (41st). Swap Maine's sunlight for the dataset median and payback moves to 8.9 years (0.7 years of swing). Swap its electricity rate instead and payback moves to 15.1 years (5.5 years of swing). The rate swap is the larger of the two, so what a kilowatt-hour costs is the input deciding the outcome in Maine.
State incentives on record
Recorded for Maine: Net Energy Billing (NEB) with kWh credit option; Efficiency Maine programs; sales tax exemption.
No federal credit is applied above (Section 25D expired 31 December 2025), and export terms often matter more than the headline rate (net metering guide).
The modeled system, in numbers
At Maine's sunlight level a 7 kW array produces roughly 8,370 kWh a year, worth about $2,093 in first-year bill savings at 25.0¢/kWh against an assumed $22,400 installed cost. A ten-year payback at this sunlight level would require a residential rate of about 24.0¢/kWh, which Maine already exceeds.
States with comparable economics
Maine's closest analogues by modeled payback are Nevada (10.0 years), New Hampshire (10.1 years), New York (10.2 years). They arrive there from different rate and sunlight combinations, so their incentive rows are the useful comparison.
- Nevada — modeled payback 10.0 years
- New Hampshire — modeled payback 10.1 years
- New York — modeled payback 10.2 years