Montana (US-MT)
Market Type: Deregulated (Retail Choice)
SSS Relevance: ⭐⭐⭐ High
Grid Carbon Intensity: See emissions section
SSS Factors: significant nuclear capacity, hydroelectric resources, no mandatory RPS, regulated market structure
1. Overview
Montana operates a partially deregulated electricity market where residential and small commercial customers are typically served by regulated, vertically integrated utilities, while retail choice is largely limited to large industrial consumers 1. The market is dominated by NorthWestern Energy, the state's largest utility, which is currently undergoing a proposed merger with Black Hills Energy as of late 2025 1. Other key participants include Montana-Dakota Utilities (MDU) and over 20 rural electric cooperatives 2. The state participates in the Western Energy Imbalance Market (EIM) to manage real-time supply and demand 1.
The generation mix is diverse, with renewable energy accounting for approximately 57% of in-state electricity generation in 2024, ranking Montana 10th in the U.S. for renewable share 3. This renewable mix is driven primarily by hydropower (33–41%) and wind (15–22%), followed by solar (~2%) 4. Despite the high renewable share, coal (37%) remains the single largest individual fuel source, though it is now outpaced by the combined total of renewables 5. Montana repealed its Renewable Portfolio Standard (RPS) in 2021 after exceeding the 15% requirement 6.
Regarding grid emissions, the U.S. Energy Information Administration (EIA) estimates Montana's 2024 carbon intensity at 969 lbs $CO_2$ per MWh, which is higher than the U.S. national average 7. This figure reflects the state's continued reliance on coal, despite significant retirements such as two units at the Colstrip plant in 2020 8. Current market trends include surging demand from data centers and a focus on grid reliability, with the 2026 Integrated Resource Plan (IRP) aiming to meet winter peak loads without relying on volatile market imports 9.
2. Market Structure
Montana's electric utility landscape is divided among investor-owned utilities (IOUs), cooperatives, and municipal entities. The state's largest utility is NorthWestern Energy, an IOU serving approximately 60% of the load and providing electricity and natural gas to the western two-thirds of the state 10. Other significant providers include Montana-Dakota Utilities (MDU) and Avista Utilities 10. The cooperative sector includes over 25 distribution cooperatives represented by the Montana Electric Cooperatives' Association (MECA), with Flathead Electric Cooperative being the largest 10. The state currently has only one municipal electric utility, the City of Troy Municipal Electric 1.
The market structure is characterized by a return to regulation following a period of deregulation. In 1997, the state passed Senate Bill 390 to implement deregulation, but market volatility between 2000 and 2007 led to "reregulation" in 2007 11. Currently, residential and small commercial customers do not have retail choice and must purchase power from their local regulated utility 11. Retail choice is restricted to large industrial customers with a load greater than 5 megawatts (MW), as well as customers who were grandfathered in as of October 2007 11.
Montana does not have a single, state-wide Independent System Operator (ISO) or Regional Transmission Organization (RTO). Instead, the grid is divided between two major regional organizations: the Midcontinent Independent System Operator (MISO) serves the eastern portion of the state, while the Southwest Power Pool (SPP) operates in parts of Montana, primarily through its Western Energy Imbalance Service (WEIS) 1. Much of western Montana remains outside a formal RTO, though utilities like NorthWestern Energy participate in energy imbalance markets to manage real-time power 1. Major physical infrastructure is owned by utilities and federal agencies, including the Western Area Power Administration (WAPA) and the Bonneville Power Administration (BPA) 1.
3. Clean Energy Policy
Renewable Portfolio Standard (RPS) Montana no longer maintains a Renewable Portfolio Standard (RPS) following the repeal of the Montana Renewable Power Production and Rural Economic Development Act in 2021 via House Bill 576 [1]. Prior to repeal, the state mandated that public utilities and competitive electricity suppliers obtain 15% of retail electricity sales from eligible renewable resources by 2015 [1]. The repeal was largely attributed to market saturation, as the state's existing energy mix from hydropower and wind already exceeded the 15% requirement [1].
Clean Energy Mandates and Goals The state lacks a current legislative "100% clean energy" mandate. However, Montana aims to achieve net greenhouse gas neutrality for average annual electric loads by 2035 and economy-wide net-zero emissions by 2050, goals established by executive order rather than statute [3]. The state's largest utility, NorthWestern Energy, has pledged to achieve net zero carbon emissions by 2050 and to acquire only non-carbon emitting generation resources after 2035 [3].
Constitutional Requirements Following the 2024 Held v. Montana Supreme Court ruling, the state is constitutionally mandated to consider greenhouse gas (GHG) emissions when permitting fossil fuel projects. The court determined that policies prohibiting the consideration of climate impacts violate the state constitution's guarantee of a "clean and healthful environment" [2].
Incentives and Programs Despite the repeal of the RPS, several incentives remain:
- Net Metering: Utilities must allow small-scale renewable systems (under 50 kW) to receive billing credits for excess energy returned to the grid [2].
- Property Tax Exemptions: Exemptions are available for buildings using renewable energy (up to $20,000 for residential) and for new generating facilities under 1 MW for their first five years [2].
- Financing: The Alternative Energy Revolving Loan Program offers low-interest loans up to $40,000 for residential solar and efficiency upgrades [3].
4. Utility Landscape
Montana's electricity market is served by a mix of investor-owned utilities (IOUs), cooperatives, and municipal entities. The state's generation profile relies heavily on hydroelectric facilities, which are described as the "backbone" of the system [1].
Investor-Owned Utilities (IOUs) The primary IOUs are NorthWestern Energy and Montana-Dakota Utilities (MDU), both for-profit entities regulated by the Montana Public Service Commission (PSC) [3].
- NorthWestern Energy: The largest utility in the state, serving approximately 60% of the load and more than 413,400 electric customers across the western two-thirds of Montana. It owns 11 hydro facilities [1].
- Montana-Dakota Utilities (MDU): An IOU primarily serving customers in eastern Montana [1].
Cooperatives Cooperatives play a significant role in the state's utility landscape, with 29 co-ops serving about 30% of the state's load [1]. The Montana Electric Cooperatives’ Association (MECA) represents 25 distribution cooperatives and three generation and transmission (G&T) cooperatives, serving over 250,000 people across all 56 counties [2].
- Flathead Electric Cooperative: The largest member-owned electric cooperative in the state [1].
- Wholesale Providers: Distribution cooperatives often purchase power from wholesale entities such as the Central Montana Electric Power Cooperative and the Upper Missouri Power Cooperative [2].
Municipal and Tribal Utilities Electric services are also provided by public and tribal entities. While major cities like Bozeman, Billings, and Helena are typically served by NorthWestern Energy, some municipalities operate their own utilities, such as the City of Troy [2]. Mission Valley Power, operated by the Confederated Salish and Kootenai Tribes, is a notable Tribal utility [1].
Recent Developments
- Merger: In August 2025, NorthWestern Energy announced a multibillion-dollar merger with Black Hills Corporation. If approved, the combined entity will serve customers across eight states [1].
- Acquisitions: NorthWestern Energy recently moved to acquire Energy West Montana, a natural gas provider serving approximately 33,000 customers [1].
5. SSS-Eligible Resources
No specific SSS-eligible resources identified. See section notes.
6. EAC/REC Registry Infrastructure
Montana utilizes the Western Renewable Energy Generation Information System (WREGIS) as its primary registry for tracking and verifying Energy Attribute Certificates (EACs), commonly referred to as Renewable Energy Certificates (RECs). As the independent, central registry for the Western Interconnection, WREGIS issues unique serial numbers for every megawatt-hour (MWh) of renewable energy generated to prevent double-counting 1212.
Compliance and Oversight The Montana Public Service Commission (PSC) is responsible for verifying RECs used for compliance with the state's renewable energy standards 12. To substantiate renewable energy claims and reduce Scope 2 emissions under frameworks like the Greenhouse Gas Protocol, RECs are tracked from issuance through retirement. Once used to meet regulatory mandates or voluntary sustainability goals, RECs are "retired" within the registry 1213.
Alternative Registries While WREGIS is the standard for the region, generators not tied specifically to the Western Interconnection may utilize other systems. These include:
- North American Renewables Registry (NAR): A national registry used for voluntary market transactions 12.
- CleanCounts (formerly M-RETS): A flexible registry accepting projects regardless of geographic location 12.
Third-Party Certification Many voluntary REC purchases in Montana are verified by Green-e® Energy to ensure rigorous consumer protection and environmental integrity standards are met 1413.
7. Grid Emissions
Section pending — data collection incomplete.
References
Sources & Last Updated
Research Date: 2026-03-10
Data Sources: EIA, EPA eGRID, state regulatory filings, SerpAPI research aggregation
This page was generated using automated research and may contain inaccuracies. Verify critical data with primary sources.