Montana Solar Estimate

Montana

Solar in Lewistown, Montana

A south-facing roof in Lewistown makes about 1,222 kWh per kW each year, 3% below the Montana average; a typical home's net-zero system here is about 8.8 kW, costs as low as $21,669 installed, and pays back in about 13 years on NorthWestern Energy rates.

See the numbers for your Lewistown address

At a glance

Sunlight per kW
1,222
kWh a year, 3% below the Montana average
Typical system
8.8 kW
net zero for 900 kWh a month
Installed cost
as low as$21,669
up to $26,484
Payback
as low as10.8 yrs
10.8–14.5 yrs at 2.7%/yr

Typical gas-heated home, 900 kWh a month, best-case figures with the range shown. Sources.

Who sends your bill

At the center of Lewistown the service-territory layer shows NorthWestern Energy; Fergus Electric Cooperative serves parts of the surrounding area. Boundaries are coarse at town edges, so your bill is the final word; the utility finder checks any address.

What the sun does in Lewistown

  • A south-facing roof at a 30° pitch makes about 1,282 kWh per kW a year before snow and 1,222 after a 5% snow allowance, 3% below the Montana average.
  • July is the best month at about 163 kWh per kW; January the worst at about 38. Net metering carries the summer surplus into winter, which is why the net-zero size and your utility’s bank reset month both matter.
  • Roof direction and pitch change the yield by a quarter or more; the estimate reads your actual roof from satellite imagery and fills south-facing planes first.
  • Electric heat roughly doubles a January bill compared with July, so a winter bill from an electrically heated house is annualized with a Montana heating profile rather than multiplied by twelve.

A typical Lewistown home: 900 kWh a month, gas heat

Net-zero system
8.8 kW
1222 kWh per kW per year
Installed cost
as low as$21,669
up to $26,484
First-year savings
up to$1,795
at least $1,566
Payback
as low as10.8 yrs
10.8–14.5 yrs at 2.7%/yr

Valued at NorthWestern Energy rates (15.8¢/kWh energy); no federal credit for homes in 2026. Your roof, usage and heating change every number.

Figures use NorthWestern Energy, which gives the better payback of the utilities serving the Lewistown area (Fergus Electric Cooperative: about 18 years). Your bill says which one you are on.

Questions Lewistown homeowners ask

How much do solar panels cost in Lewistown?
For a gas-heated home using about 900 kWh a month, a net-zero system of about 8.8 kW costs roughly $21,669 to $26,484 installed at current Montana cash prices, before any incentive. Larger homes and electric heat need bigger systems; your address gives a real figure in about a minute.
How long does solar take to pay for itself in Lewistown?
About 10.8 to 14.5 years for that typical home on NorthWestern Energy rates, assuming electricity prices rise 2.7% a year. NorthWestern Energy's own rules (fixed charge, net-metering credits) are built in. Figures use NorthWestern Energy, which gives the better payback of the utilities serving the Lewistown area (Fergus Electric Cooperative: about 18 years). Your bill says which one you are on.
Which utility serves Lewistown?
At the city centre the service-territory layer shows NorthWestern Energy; Fergus Electric Cooperative serves parts of the surrounding area. Boundaries are coarse at town edges, so your bill is the final word.
Does solar work in Lewistown's winters?
Yes, with a seasonal shape: July makes about 163 kWh per kW and January about 38, after a 5% allowance for snow cover. Net metering banks summer surplus against winter use, which is why the net-zero size and the bank's reset month both matter.
What incentives apply in 2026?
The 30% homeowner credit (Section 25D) ended for systems completed after December 31, 2025. Business-owned systems, including ranches and rental property, still qualify for the 30% investment credit and bonus depreciation when placed in service by the end of 2027; tax-exempt owners receive the 30% as cash. No Montana state credit. Not tax advice.

On the map

Montana-Dakota UtilitiesLincoln Electric CooperativeLower Yellowstone Rural Electric CooperativeMarias River Electric CooperativeMcCone Electric CooperativeMid-Yellowstone Electric CooperativeMissoula Electric CooperativeNorVal Electric CooperativeBeartooth Electric CooperativePark Electric CooperativeBig Flat Electric CooperativeSheridan Electric CooperativeBig Horn County Electric CooperativeSoutheast Electric CooperativeSun River Electric CooperativeTongue River Electric CooperativeCity of Troy ElectricMission Valley PowerYellowstone Valley Electric CooperativeFergus Electric CooperativeVigilante Electric CooperativeRavalli Electric CooperativeFlathead Electric CooperativeGlacier Electric CooperativeHill County Electric CooperativeNorthWestern Energy
Lewistown (gold) and NorthWestern Energy service territory. Hover a region to see its utility.

Nearby: Big Timber, Havre, Laurel, Billings, Livingston, Red Lodge. All Montana cities.

Sources

Every figure on this page comes from the documents and models below, with the date each was produced or last checked.

  1. Sunlight and monthly production for Lewistown
    Effective October 31, 2026 · Checked October 31, 2026 · Read from the primary source
  2. NorthWestern Energy rates and net-metering rules (worked example)
    Effective October 15, 2026 · Checked November 1, 2026 · Read from the primary source
  3. Which utilities serve the area
    Checked October 31, 2026 · Read from the primary source
  4. Installed cost, savings and payback
    Checked November 1, 2026 · Read from the primary source

Spot an error? Email mtsolarestimate@gmail.com. How the estimate is built: methodology.

Your Lewistown address, your numbers

The estimate reads your roof, takes your real usage and applies your utility’s rules. About a minute, no contact details asked.