Plug-In Solar in Montana
There's no plug-in solar law or bill in Montana. The Legislature only meets in odd-numbered years, so for now the utility's net metering and interconnection rules are what apply.
- No plug-in solar law in Montana yetNo bill yet
- Utility rules are in effect.No cap on plug-in watts.
- Cents: 14.1.Jan to Aug 2026: EIA's average residential price per kWh.
- $157 each year.An 800 W kit in Billings, with no utility solar fee added.
Connect in Montana only after your electric utility's approval. Pick an inverter that has a UL 1741 listing with anti-islanding, or a UL 3700 listing.
Montana's Rule Today
NorthWestern Energy, the largest utility, takes a Level 1 interconnection request for systems of up to 50 kW AC. That request requires equipment that a nationally recognized testing laboratory has listed as certified. You also pay a $200 processing fee that is non-refundable.
Net metering rules: Montana statute (MCA 69-8-103 plus 69-8-602) covers hydro, wind or solar systems up to 50 kW at the customer's premises. The utility must bill a minimum monthly fee equal to what other customers in that rate class pay. NorthWestern's annual settle-up sends unused kWh credits to the utility, and no payment comes back.
Savings from a Kit in Montana
In Billings, PVWatts estimates 1,388 kWh a year for every 1 kW of panels. Homes in Montana pay 14.1 cents for each kWh in 2026 so far. Results for an 800 W kit vary by placement:
| Where the panels go | kWh a year | Saved a year |
|---|---|---|
| Tilted south on a stand | 1,110 | $157 |
| Upright on a railing | 700 | $99 |
| Facing east or west | 888 | $126 |
Each Month in Billings
- Jan59
- Feb69
- Mar97
- Apr100
- May113
- Jun117
- Jul130
- Aug122
- Sep104
- Oct88
- Nov60
- Dec53
kWh that an 800 W kit makes, tilted south.
Kit Prices for Montana
| Kit | kWh a year | Saved a year | Pays back in | Price |
|---|---|---|---|---|
| US Solar Supplier 1180 W EZ1 Kit | 1,638 | $231 | 3.9 years | $899 |
| Bright Saver 360 W Balcony Kit | 500 | $71 | 5.9 years | $414 |
| EcoFlow STREAM 800 W Kit | 1,110 | $157 | 7.0 years | $1,099 |
Tilted south, all of it used at home. Compare all kits
Good to Know in Montana
- A plug-in solar warning came out in October 2026 from Missoula Electric Cooperative. It asks members to call before they connect a kit, and to compare Montana's lower-than-average retail rates with what a kit costs.
- Power is fairly cheap: residential customers paid an average of 12.66 cents/kWh in 2024. A plug-in kit saves less for each kWh than it would in high-cost states.
- Montana's large utilities have resisted new solar programs before. NorthWestern Energy, along with Montana-Dakota Utilities, opposed a community solar bill from 2025 (SB 188), vetoed by the governor on 13 Jun 2025.
Do You Rent or Have a Balcony?
Your landlord or HOA makes the mount decision, while your electric utility makes the hookup decision. Read about solar for balconies and solar for apartments.
Primary Utilities
- NorthWestern Energy
- Flathead Electric Cooperative
- Montana-Dakota Utilities
Next Steps for You in Montana
- Pick a size: a 400 W kit in Billings makes about 555 kWh a year; a 1,200 W kit makes about 1,666 kWh. Run yours.
- Raise the idea of a plug-in bill with your state lawmakers, following the lead of bills passed elsewhere.
Sources
- Montana Legislature home
- MCA 69-8-103, Definitions
- Utility net metering requirements, MCA 69-8-602
- Net Metering & Private Generation, NorthWestern Energy
- NorthWestern Energy Level 1 Small Generator Facility Interconnection Request
- Plug-In Solar: Know Before You Buy, Missoula Electric Cooperative
- Community solar bill vetoed by Gianforte, Montana Free Press
- EIA State Electricity Profile tables, Montana 2024
- Data from NREL PVWatts, Billings and EIA Table 5.6.B, 2026 price data
Check all the states at a glance, or a nearby state: Wyoming, Utah, Idaho.