Montana pays about 12.3¢ per kilowatt-hour for residential electricity and receives about 4.5 kWh per square metre per day of sunlight — 46th and 28th respectively among the 50 states and DC tracked here. Those two numbers set the ceiling on what rooftop solar returns in Montana, and they point in the same direction.
Where Montana sits against the rest of the country
Montana is 2.5¢/kWh below the median residential rate across this dataset (14.8¢/kWh) and 0.1 kWh/m²/day below the median insolation (4.6 kWh/m²/day). Under this site's standard assumptions, that combination puts Montana 48th of 51 for modeled payback speed, at 16.6 years against a dataset median of 13.5 years.
What actually drives payback in Montana
Montana ranks in the lower half on both inputs — 46th for electricity price and 28th for sunlight. Swap Montana's sunlight for the dataset median and payback moves to 16.3 years (0.3 years of swing). Swap its electricity rate instead and payback moves to 14.3 years (2.4 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 Montana.
State incentives on record
Recorded for Montana: Alternative Energy System tax credit (up to $500 individual / $1,000 joint); property tax exemption for first 10 years; net metering retained.
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 Montana's sunlight level a 7 kW array produces roughly 8,968 kWh a year, worth about $1,103 in first-year bill savings at 12.3¢/kWh against an assumed $22,400 installed cost. A ten-year payback at this sunlight level would require a residential rate of about 22.4¢/kWh, which is 10.1¢ above what Montana households pay today.
States with comparable economics
Montana's closest analogues by modeled payback are Idaho (16.6 years), Kentucky (15.9 years), North Dakota (17.4 years). They arrive there from different rate and sunlight combinations, so their incentive rows are the useful comparison.
- Idaho — modeled payback 16.6 years
- Kentucky — modeled payback 15.9 years
- North Dakota — modeled payback 17.4 years