What solar costs in Montana
Berkeley Lab does not have enough reported installations in Montana to publish a reliable local price, so the figures below use the national median. Treat them as a starting point, not a quote.
The numbers
High electricity prices make solar pay faster, so a red figure in the third box is good news for a solar buyer and bad news every other month of the year.
Holding a quote above $30,000? Installers in Montana price the same system very differently. Two more bids is the cheapest way to find out where yours sits.
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What the roof makes month by month in Billings
A 3.4 to 1 swing across the year, which is steep. A system sized to cover your annual usage will run a large surplus in summer and leave you buying most of your winter power from the grid. Whether that works depends entirely on whether your utility banks the summer surplus for you.
Figures are for an 8 kW array at 20 degrees facing south, modelled from NSRDB radiation data at Billings.
What different sizes cost in Montana
| Size | Panels | Price | Output | Year one saving | Payback |
|---|---|---|---|---|---|
| 4 kW | 10 | $15,000 | 5,112 kWh | $766 | 16.7 years |
| 5 kW | 13 | $18,750 | 6,390 kWh | $958 | 16.7 years |
| 6 kW | 15 | $22,500 | 7,668 kWh | $1,149 | 16.7 years |
| 7 kW | 18 | $26,250 | 8,946 kWh | $1,341 | 16.7 years |
| 8 kWtypical | 20 | $30,000 | 10,224 kWh | $1,533 | 16.7 years |
| 10 kW | 25 | $37,500 | 12,780 kWh | $1,916 | 16.7 years |
| 12 kW | 30 | $45,000 | 15,336 kWh | $2,299 | 16.7 years |
| 15 kW | 38 | $56,250 | 19,170 kWh | $2,874 | 16.7 years |
| 20 kW | 50 | $75,000 | 25,560 kWh | $3,831 | 16.7 years |
Payback is the same at every size because this table holds the price per watt flat at the national median of $3.75: price and output both grow in step with the system, so their ratio does not change. Real quotes are not quite linear. Permitting, design and connection cost roughly the same on any roof, so a small system usually costs more per watt and a large one less, and pays back correspondingly later or sooner than shown.
Montana has too few reported installations for a local median, so the price is the national median of what households paid on host-owned systems installed in 2024-2025, compiled by Berkeley Lab. Local quotes can sit well above or below it.
8 programmes in Montana
The 30% federal credit ended for installations completed after 31 December 2025. These state, utility and local programmes are unaffected by that, and are now the only thing that reduces the price.
| Programme | Type | Run by | Reach | Updated |
|---|---|---|---|---|
| Corporate Property Tax Reduction for New/Expanded Generating Facilities | Property Tax Incentive | State | statewide | October 8, 2025 |
| Generation Facility Corporate Tax Exemptions | Property Tax Incentive | State | statewide | October 8, 2025 |
| Interconnection Standards | Interconnection | State | statewide | May 29, 2024 |
| Net Metering | Net Metering | State | statewide | March 30, 2026 |
| Renewable Energy Systems Exemption | Property Tax Incentive | State | statewide | October 8, 2025 |
| Yellowstone Valley Electric Cooperative - Solar Stock Watering System Rebate | Rebate Program | Utility | statewide | September 18, 2025 |
| Montana Solar and Wind Easements | Solar/Wind Access Policy | State | partial | January 13, 2026 |
| NorthWestern Energy - USB Renewable Energy Fund | Rebate Program | Utility | partial | September 18, 2025 |
Programme index from DSIRE, N.C. Clean Energy Technology Center, NC State University, licensed CC BY-SA 4.0. “Partial” means it reaches only some utilities or counties. A listed programme can still be closed or out of budget, so check its own page before counting on it.
How Montana ranks
Closest on payback: Arkansas (16.4 yrs), Idaho (16.7 yrs), West Virginia (16.9 yrs), Utah (17.0 yrs).
Solar in Montana, answered
How much do solar panels cost in Montana?
An 8 kW system in Montana, roughly 20 panels, costs about $30,000 before incentives. That is based on $3.75 per watt, the national median from Lawrence Berkeley National Laboratory for 2024-2025, because too few Montana installations are reported to publish a local figure. There is no longer a federal tax credit to subtract from that figure.
Is there still a 30% solar tax credit in Montana?
No. The federal Residential Clean Energy Credit under Internal Revenue Code section 25D was terminated by the One Big Beautiful Bill Act for expenditures made after 31 December 2025, and it did not step down first. A Montana homeowner buying a system with cash or a loan today receives no federal tax credit. Under a lease or power purchase agreement the credit survives as section 48E but belongs to the company that owns the equipment, not to the household. Montana still has 8 state, utility or local programmes covering rooftop solar.
How long do solar panels take to pay for themselves in Montana?
About 16.7 years in Montana. An 8 kW system costs roughly $30,000 and saves about $1,533 in its first year at the state's average residential rate of 14.99 cents per kilowatt-hour (EIA, July 2026). That calculation includes no federal tax credit, because the residential credit ended after 31 December 2025.
How much electricity does a solar panel produce in Montana?
Each kilowatt of panels in Montana produces about 1,278 kilowatt-hours a year, modelled at Billings facing south at a 20 degree tilt using NSRDB radiation data. An 8 kW system therefore makes roughly 10,224 kilowatt-hours a year. The national average is about 1,332 kilowatt-hours per kilowatt installed.
Is solar worth it in Montana?
It depends less on sunshine than on your electricity price. In Montana power costs 14.99 cents per kilowatt-hour (EIA, July 2026), which makes an 8 kW system pay for itself in about 16.7 years and clear roughly $19,011 over 25 years. Solar from your own roof works out at 12.5 cents per kilowatt-hour over its life, against 14.99 cents from the utility.
How many solar panels do I need in Montana?
A typical Montana installation is about 20 panels, which is 8 kW at the 400 watt module that is now standard and needs roughly 440 square feet of roof. To size it to your own use, divide your annual kilowatt-hours by 1,278, which is what each kilowatt of panels produces in Montana each year.
Do solar panels work in winter in Montana?
Yes, but output falls sharply. In Billings a kilowatt of panels makes about 161 kilowatt-hours in Jul and about 48 in Dec, a swing of 3.4 to 1 across the year. A system sized to cover your annual consumption will therefore run a surplus in summer and leave you buying power in winter, so how your utility settles that difference matters as much as the size of the array.
Three competing quotes beat any amount of comparing panel brands
Sales cost and margin are over a third of an installed price in Montana, and they are the part that competition removes. A single quote from whoever reached you first is how people end up in the top quarter of what their neighbours paid.
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Prices and rules change. We will tell you when they do
Berkeley Lab publishes installed prices once a year, the EIA updates electricity rates every month, and Congress changed the tax treatment of all of this in 2025. One email when something on this site actually changes, and nothing else.
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