Montana solar calculator
Size a Montana home solar system from your electric bill — kW, panel count, roof area, true cost with no federal credit for 2026 installs, and payback.
Quick answer: At $0.151/kWh and 4.7 peak sun hours, a $200/month bill needs about 12.30 kW — 30 × 410 W panels covering ~60 m². Gross cost is ~$31,119 with no federal credit for systems installed after 2025, offsetting $2,400 a year for a ~13.0 year payback.
Your details
Ballpark, not gospel. Ballpark, not gospel. Sized at 78% real-world output with the Montana sun-hour average — confirm shading, roof angle and your utility's net-metering terms with a local installer before buying. The savings math values all generation at your retail rate; size to your annual usage and choose your settle-up month carefully, since unused credits reset to zero uncompensated.
The 30% credit ended — what changed
The residential clean energy credit (26 U.S.C. § 25D) gave homeowners a 30% credit on solar installed from 2022 through 2025. The July 2025 tax law ended it: no credit is available for property placed in service after December 31, 2025. That is why every figure on this page is ~30% higher than pre-2026 guides show. If your system went live by the end of 2025, tick the box above to see the credit applied; leased systems may still benefit because the leasing company claims the commercial credit. Source: IRS — Residential Clean Energy Credit.
Typical Montana system sizes by monthly bill
| Monthly bill | System size | Panels (410 W) | Net cost (no 2026 federal credit) | Payback |
|---|---|---|---|---|
| $100 | 6.15 kW | 15 | $15,560 | 13.0 years |
| $200 | 12.30 kW | 30 | $31,119 | 13.0 years |
| $300 | 18.04 kW | 44 | $45,641 | 12.7 years |
Computed at $0.151/kWh, 4.7 peak sun hours and $2.53/W installed, with no federal credit for 2026 installs. Run your exact bill above.
Solar in Montana: the details
Solar cost in Montana
Solar installs in Montana sit inside the national price band. The EnergySage marketplace averaged about $2.53 per watt installed in 2026, with market quotes typically landing $2.15–$2.91/W — inside the $2.50–$3.50/W national band. A typical ~12 kW Montana system grosses around $30,500 before any local utility incentive, with no federal credit for 2026 homeowner installs.
What moves the number: roof complexity, panel tier, and how competitive the quote market is in your metro. Get at least three quotes — spreads of $0.50/W between installers are common.
Export rules: getting paid for surplus power
Montana gives full 1-for-1 retail-rate net metering for systems up to 50 kW at NorthWestern Energy and Montana-Dakota Utilities.
The catch is the calendar: unused kWh credits reset to zero, uncompensated, in your customer-chosen annual settle-up month — and electric co-ops set their own terms.
Practical takeaway: for heating-heavy homes, April 1 usually beats October 1 as the settle-up month — summer surplus would otherwise vanish right before winter, when you'd use it most.
Montana solar incentives
Montana's headline incentive is a property-tax break:
Renewable-energy property-tax exemption — $20,000 of a home system's appraised value stays out of taxes for 10 years after installation. File Form AB-14 with the Department of Revenue to claim it.
No statewide rebate was found in 2026 sources; check DSIRE for utility programs.
Is solar worth it in Montana?
Verdict: marginal, but full net metering helps. A $200/month bill lands at a ~13.0-year payback at 2026 prices — not exciting, not disqualifying. Full 1:1 retail net metering is the tailwind; two levers help: size to your annual usage so credits don't strand, and pick your settle-up month (April 1 suits heating-heavy homes).
Questions people actually ask
Straight answers, no fluff. Then run your own numbers above.
How many solar panels do I need in Montana?
It follows your bill. At the Montana average of $0.151/kWh and 4.7 peak sun hours, a $200/month bill needs about a 12.30 kW system — roughly 30 × 410 W panels covering ~60 m² of roof.
What is the average cost of solar panels in Montana in 2026?
The EnergySage marketplace averaged about $2.53 per watt installed in 2026, with market quotes typically $2.15–$2.91/W — inside the $2.50–$3.50/W national band. A typical ~12 kW system grosses around $30,500, with no federal credit for 2026 homeowner installs.
Does Montana have net metering?
Yes — with a catch on the calendar. Montana gives full 1-for-1 retail-rate net metering for systems up to 50 kW at NorthWestern Energy and Montana-Dakota Utilities, but unused kWh credits reset to zero, uncompensated, in your customer-chosen annual settle-up month. For heating-heavy homes, April 1 usually beats October 1: summer credits would otherwise vanish right before winter. Electric co-ops set their own terms.
Does Montana offer any solar tax credit or rebate?
The headline incentive is a property-tax break: Montana's renewable-energy property-tax exemption keeps $20,000 of a home system's appraised value out of taxes for 10 years after installation — file Form AB-14 with the Department of Revenue.
Is the 30% federal solar tax credit still available?
Not for homeowner purchases anymore. The residential clean energy credit (26 U.S.C. § 25D) is not available for property placed in service after December 31, 2025, under the July 2025 tax law (Public Law 119-21). Systems installed by the end of 2025 can still claim 30%, and leased systems may still benefit because the leasing company claims the commercial credit instead. (Source: IRS — Residential Clean Energy Credit.)
Is solar worth it in Montana?
The calculator puts a $200/month bill at a ~13.0-year payback with no federal credit — marginal at 2026 prices, though full 1:1 retail net metering is a real tailwind. Two levers improve the picture: size to your annual usage so credits don't go to waste, and pick your true-up month carefully (April 1 suits heating-heavy homes).
Figures last checked October 2026. Sources: EIA Electric Power Monthly (July 2026: 15.14¢/kWh), NREL PVWatts/NSRDB (~4.7 peak sun hours), DSIRE, Montana Public Service Commission; IRS — Residential Clean Energy Credit.
More US solar calculators
Compare other states: Texas, Florida, California, Arizona, North Carolina, Michigan, Minnesota, Mississippi, Missouri, Nebraska, Nevada, New Hampshire, New Jersey. And the national US solar calculator for country averages.
Comparing quotes? The solar cost calculator breaks down cost per watt and the solar ROI calculator maps your payback year by year. Going deeper: installation cost guide, how net metering works, how much you can save with solar and the solar batteries guide.