Montana Clean Energy Guide

Montana runs one of the cleanest grids in the country almost by accident. Roughly 62% of its electricity is low-carbon, but the story is old dams and a fast-growing wind fleet rather than policy ambition: the state repealed its renewable standard in 2021 and still leans on coal for its single largest slice of generation. This guide covers the numbers, the siting fight in the east, and the data-center demand wave now reshaping NorthWestern Energy's planning.

The honest framing for utility-scale developers: Montana is a wind-and-hydro state with negligible utility-scale solar, no state renewable mandate, and permitting that lives almost entirely at the county level. That makes it a market where a good landowner relationship and a friendly county commission matter more than any statewide program, and where the biggest tailwind is not a clean-energy law but a surge of proposed data-center load looking for firm, cheap power.

A Clean Grid With No Clean-Energy Mandate

Montana's low-carbon share is real: roughly 62% of in-state electricity came from low-carbon sources over the rolling 12 months through March 2026, with hydropower at about 38% and wind at about 22%, and solar around 1 to 3%. Coal still supplies about a third of generation and remains the single largest fuel. Note the definitional split that trips people up — American Clean Power reports 24.10% of Montana's electricity from wind, solar, and storage (18th nationally), but that figure deliberately excludes hydropower, the state's biggest clean source. Both numbers are correct; they measure different things.

None of this rests on a mandate. Montana enacted a Renewable Portfolio Standard in 2005 through SB 415, requiring public utilities and competitive suppliers to source 15% of electricity from renewables by 2015. The state met and exceeded the target, then repealed the RPS in 2021 through HB 576. Today Montana has no RPS, no clean energy standard, and no binding statewide renewable or carbon-free goal. Development is driven by economics, federal incentives, and utility procurement rather than by state policy.

Net Metering, Solar Shares, and the 2025 Session

Net metering survives but with tight limits. Under Montana law (MCA 69-8-602), net metering is capped at 50 kW per installation for NorthWestern Energy customers, and aggregate or virtual net metering is not authorized for the two investor-owned utilities, NorthWestern Energy and Montana-Dakota Utilities. NorthWestern's prior attempt to end net metering and create a separate solar rate class was rejected by the Montana PSC. SB 188, the Montana Solar Shares Act, which would have created a community and shared-solar framework for 50 kW to 5 MW facilities, passed the Legislature in 2025 but was vetoed by Governor Gianforte on June 9, 2025.

The 2025 session (adjourned April 30, 2025) was consequential mostly on siting and environmental review. A suite of MEPA-narrowing bills (HB 270, HB 285, HB 291, HB 466, and SB 221) passed in response to the Held v. Montana climate ruling, limiting greenhouse-gas emissions analysis in environmental review, and SB 301 passed to empower the PSC to grant certificates for transmission construction. Tax bills that would have raised non-coal electrical-energy taxes to coal-severance levels (HB 326) or revised wind facility taxation (HB 915) failed, so no new statewide renewable tax incentive was enacted.

The Wind Fleet: Big, Real, and Almost All of It

Montana's operating utility-scale clean fleet is overwhelmingly wind. Cleanview counts roughly 2,147 MW across 23 operating wind farms; ACP puts wind, solar, and storage together at 2,398 MW (31st nationally). Utility-scale solar and storage remain thin: SEIA pegs total solar around 150 MW (roughly 45th nationally, about 1.7% of electricity), Montana had no utility-scale solar at all until 2017, and the state's first standalone battery project (about 75 MW) only broke ground in 2024. Cumulatively, clean-power projects represent about $5 billion invested, pay $20.6 million a year in state and local taxes and $19.7 million a year in land-lease payments to landowners, and can power roughly 700,000 homes.

Named Projects

• Clearwater Wind Energy Center (750 MW): Montana's largest, spanning Custer, Garfield, and Rosebud counties near Miles City and Forsyth. Developed by NextEra Energy Resources in four phases from 2022 to 2025, roughly $1 billion of investment across 269 turbines on about 150,000 acres, with Portland General Electric (311 MW procured, including a 208 MW owned facility via build-transfer) and Puget Sound Energy holding shares.
• Beaver Creek Wind Facility (248 MW): Puget Sound Energy project in Stillwater County, fully operational August 2025, 88 turbines, enough for roughly 83,000 homes.
• Pryor Mountain Wind Project (240 MW): PacifiCorp-owned and operated in Carbon County near Bridger, online since 2021 with 110 Vestas and 4 GE turbines. It was Montana's largest until Clearwater.
• NaturEner Glacier Wind Farm (210 MW): Across Toole and Glacier counties, roughly $500 million invested, first phase (106.5 MW) in late 2008 and expanded to 210 MW by 2009.
• NaturEner Rim Rock Energy Center (189 MW): Toole County, operating since December 2012.
• Judith Gap Wind Energy Center (135 MW): Invenergy project in Wheatland County, selling power to NorthWestern Energy, one of Montana's earliest large wind farms (online December 2005).

Siting Is Local — and the East Is Fighting Back

Montana permits utility-scale wind and solar mainly at the county and city level, not through a state siting board. The Major Facility Siting Act, administered by DEQ, does not define wind or solar farms as facilities, so they are not automatically subject to state MFSA review; a developer may voluntarily petition DEQ. In practice, counties and cities use zoning, height limits, setbacks, noise standards, and building permits under the Montana Land Use Planning Act. DEQ still handles most environmental permits and, per HB 31 (2025), requires decommissioning plans and financial-assurance bonds for wind and solar.

Statewide, HB 939 (2025) set a baseline: a turbine may not be built if it is 500 feet or taller, or located less than 1,500 feet from an occupied residence, unless the property owner approves a shorter setback, and it adds deicing requirements. That was the moderate outcome. Eastern Montana legislators pushed harder bills — HB 389 would have imposed 3,000-foot road and 1.5-mile property-line setbacks, alongside SB 283 and SB 505 — and Scout Clean Energy testified that HB 389's setbacks would eliminate all but roughly 1% of its development area, calling it a de facto moratorium. Those bills failed; HB 939 passed instead.

The pressure is concentrated in the east and is largely framed around property rights and local zoning. Wibaux County adopted countywide zoning in response to the AES-linked Wibaux Wind Farm, with setbacks reported at 1,250 feet from property lines and 1.5 miles from residences. Dawson County drafted a countywide zoning plan addressing wind, partly in response to the proposed Glendive Wind project. And in November 2024, the Montana State Land Board tabled discussion of including state trust lands in NextEra's roughly 775 to 800 MW Glendive Wind project, spanning McCone, Prairie, and Dawson counties. Alongside Glendive, the pipeline includes NextEra's Haymaker Wind (about 315 MW in Wheatland and Meagher counties, construction targeted for 2026 and operation around 2028) and a proposed Wibaux Wind Farm — all contested rather than confirmed under construction.

For a live view of where projects are stalling and which counties are drafting restrictions, see our Montana opposition tracker.

Data Centers Are the Demand Story

The dominant emerging demand driver in Montana is data-center load, and it sits at the center of NorthWestern Energy's 2026 Montana Integrated Resource Plan (filed April 30, 2026). The IRP models three data-center scenarios — 150 MW, 650 MW, and 1,160 MW — against a current average daily peak load near 760 MW and a system peak around 1,300 MW. NorthWestern has signed letters of intent with three data-center developers for loads ranging from 150 MW to over 1,000 MW, and calls large-scale data centers the most significant anticipated source of load growth.

The constraints are physical and financial. The IRP flags severe transmission bottlenecks around Billings, Butte, and south of Great Falls, and projects a roughly 23 MW winter capacity shortfall in 2027 to 2028 that each new data center would accelerate. To allocate costs to big new loads, NorthWestern filed a Large New Load Service Tariff (Rule No. 24) on March 31, 2026. On the supply side, the utility says its portfolio became adequate for the first time on January 1, 2026, via the 175 MW Yellowstone County Generating Station (a gas plant near Laurel) and the acquisition of Avista's 222 MW Colstrip share — firm capacity, not clean, underscoring that Montana's near-term answer to load growth is not primarily new renewables.

Outlook

Montana's paradox is that it already has a clean grid and almost no policy pushing it cleaner. The upside for developers is a strong wind resource, cheap land, meaningful lease payments to landowners, and a data-center demand wave that will need firm and renewable supply for years. The downside is a permitting environment that has moved against wind in the exact eastern counties with the best resource, plus real transmission constraints that limit how much new generation can actually reach load.

Watch three things. First, whether the large proposed wind projects — Glendive, Haymaker, and Wibaux — can clear county zoning and the HB 939 baseline, since that determines whether Montana's wind fleet grows or stalls. Second, how NorthWestern resolves its data-center scenarios and transmission constraints in the 2026 IRP, which will shape procurement for the rest of the decade. Third, whether utility-scale solar and storage finally scale from their small base to pair with wind and firm up a grid that, for now, still leans on coal and gas to keep the lights on in winter.

Frequently Asked Questions