All states · Montana
Updated October 2026 · ranks 33 of 50
Only under favorable conditions
6 kW system · $17,640 after incentives · $1,209 returned in year one
0 yrs25 yrs
At 15.0 years the outcome depends more on individual circumstances than on the state average. It shortens appreciably with above-average consumption, an unshaded south-facing roof, or an installed price below $2.94 a watt, and lengthens with the opposite.
The answer depends on the individual property rather than the state average. At 15.0 years, shading or below-average consumption can move the outcome materially in either direction.
The case modeled here approximates an average Montana household on the state average rate of 15.0¢, with an unshaded roof and no financing: $17,640 of capital, $1,209 returned in the first year, and break-even near year 15.0. Above-average consumption, a south-facing roof or a competitive installed price shorten that period; shading, a loan carrying a dealer fee, or a sale within six years lengthen it. Exports earn 15.0¢, close to the retail rate, so daytime occupancy makes little difference to the result.
At 15.0¢ per kilowatt-hour, electricity in Montana costs 9% less than the United States average of 16.5¢. Inexpensive grid power lowers household bills but weakens solar economics, since each kilowatt-hour generated displaces a cheap one.
A 6 kW array in Montana generates approximately 8,063 kWh a year, above the national median. Irradiance is the one input that no change in policy can remove.
Montana operates full-retail net metering. Each exported kilowatt-hour is credited at the same 15.0¢ charged for consumption, so the grid functions as storage and there is no penalty for generating more than is consumed during daylight hours. This is the principal reason payback here is shorter than in states with comparable irradiance.
Montana offers no state rebate or tax credit at present, so the installed price of $17,640 stands. With Section 25D expired there is no federal credit to deduct either, the first year in over a decade in which that has been the case.
A 6 kW system, the size typical of Montana households, costs approximately $17,640 installed at $2.94 a watt before deductions. No deduction applies in Montana: there is no state rebate, no state tax credit, and no federal credit following the expiry of Section 25D on 31 December 2025. Prices vary with roof complexity, equipment selection and local installer demand; quotes $0.40 a watt either side of this figure are common. Smaller systems cost more per watt and larger ones less, although sizing beyond on-site consumption is not penalized, since exports earn 15.0¢.
| System size | 6 kW |
|---|---|
| Annual production | 8,063 kWh |
| Installed cost | $17,640 |
| Incentives | none |
| Net cost | $17,640 |
| Electricity rate | 15.0¢ / kWh |
| Export credit | 15.0¢ / kWh |
| Year-one saving | $1,209 |
| Break-even | 15.0 years |
| 25-year gain | $18,014 |
Of the 50 states published here, Montana ranks 33rd for how quickly a bought system repays itself. Fastest right now: Hawaii, New York, Illinois, Massachusetts. Slowest: South Dakota, Louisiana, North Dakota, Tennessee. Compare them all on the map.
Solar economics change at state lines rather than at county lines, because the export tariff and the netting period do. These states share a border with Montana, and the figure each produces on the same assumptions.
About $17,640 installed for a 6 kW system at $2.94 a watt. No deduction applies in Montana: no state rebate, no state credit, and no federal credit following the expiry of Section 25D. Larger systems are not penalized here, since exports earn the full 15.0¢.
Only under favorable conditions. A 6 kW system breaks even in 15.0 years on the assumptions used here, following the expiry of the 30% federal tax credit on 31 December 2025.
Approximately $1,209 in the first year on a 8,063 kWh system, rising thereafter as Montana electricity rates increase. Exports are valued the same as self-consumption at 15.0¢, so the figure holds regardless of daytime occupancy.
A 6 kW array is about 14 modules at 430 W and generates 8,063 kWh a year here, which covers a household using roughly that much. Sizing above on-site use is not penalized here, since exports earn 15.0¢. The sizing calculator works it out from a bill.
Only under favorable conditions. The retail rate here is 15.0¢ against a national average of 16.5¢, exports earn 15.0¢, and a 6 kW system breaks even in 15.0 years. What separates Montana from states with similar sunshine is the rate and the export tariff, not the weather.
Montana operates full-retail net metering.
Generation is taken from NREL PVWatts v8 for the largest metropolitan area in Montana, south-facing at 20°. The retail rate is from the EIA and the export credit from the state's net metering rule. The break-even figure incorporates 0.5% annual panel degradation, 3% annual electricity price growth, $150 a year in maintenance and an inverter replacement in year 12. The federal credit is set to $0 — Section 25D expired 31 December 2025. Credits accumulate across the year, so close to 95% of generation is valued at the full retail rate. Full method and sources. Privacy. Export terms checked against the state source in August 2026.
These are estimates for comparison between states, not quotations. Roof orientation, shading, consumption pattern and installer pricing all affect the result. At least three written quotations are advisable before purchase.