Plug-In Solar in Montana — Status: unclear
Is Plug-In Solar Legal in Montana?
No dedicated statewide plug-in solar law is identified in our tracker for Montana. That does not automatically permit or prohibit every configuration: grid-connected, zero-export, and electrically isolated off-grid systems can be treated differently. Before installing or connecting equipment, confirm current utility or interconnection rules, local code or permit requirements, property or lease conditions, outlet and electrical suitability, and the equipment listing and manufacturer instructions.
Last Updated: March 2026
Key Information
| Average Electricity Rate | 12.1¢/kWh |
| Estimated Annual Savings | $150/year |
| TOU Rate Spread | 3¢/kWh |
| Peak Sun Hours/Day | 4.7 |
| Retail Choice | none |
What You Can Do
No specific plug-in solar law. Traditional rooftop solar available. NorthWestern Energy offers net metering.
What You Can't Do (Yet)
Utilities require interconnection agreements for grid-tied systems.
Available Rebates & Incentives
Montana offers a personal income tax deduction for residential solar installations (up to $500/year). Net metering available through NorthWestern Energy. The federal 30% ITC (Section 25D) expired December 31, 2025.
Incentive Program Links
- DSIRE — Montana Solar Incentives — Full list of Montana state and utility solar incentive programs, including the income tax deduction.
Demographics (US Census 2023)
| Population | 1,137,233 |
| Total Households | 462,887 |
| Owner-Occupied | 320,318 |
| Renter-Occupied | 142,569 |
| Single-Family Homes | 371,522 |
| Apartment Units (5+) | 29,199 |
| Median Household Income | $70,170 |
| Median Home Value | $375,800 |
Solar Resource Data (NREL PVWatts)
| Peak Sun Hours/Day | 4.68 |
| Optimal Tilt Angle | 20° |
| Optimal Azimuth | 180 degrees (Due South) |
| Est. Annual kWh (800W system) | 1079 kWh |
| Best Solar Months | April–September |
Major Utilities
| Utility | Customers | Net Metering |
|---|---|---|
| NorthWestern Energy | ~380000 customers | Yes |
| Montana-Dakota Utilities | ~40000 customers | Yes |
| Montana Electric Cooperatives | ~150000 customers | Yes |
Explore Your Next Steps in Montana
Use these tools and guides alongside the state-specific rules above to evaluate your space, potential savings, and the right connection approach.
- Compare every state — Return to the national tracker to compare enacted laws, pending bills, and unclear jurisdictions.
- Check your MT setup readiness — Review placement, outlet, property, and state-rule questions before choosing equipment.
- Estimate savings in Montana — Use your location and setup assumptions to estimate bill savings and storage value.
- Understand off-grid and grid-connected use — Separate truly off-grid or portable solar from equipment that connects to a building circuit or utility grid.