IOU · Montana · EIA 12825
NorthWestern Energy LLC - (MT)
IOU · Montana · 402K customers. According to the U.S. Energy Information Administration's EIA Form 861, reliability for 2023 shows SAIDI 103 minutes/customer.
Reliability verdict
NorthWestern Energy LLC - (MT) shows near-benchmark chronic reliability in 2023: 103 minutes SAIDI excluding major events across 402K customers.
- 103 min
- SAIDI 2023
- 0.93
- SAIFI 2023
- 103 min
- SAIDI ex-MED
- 402K
- Customers
Chronic reliability judged on SAIDI excluding major event days when reported (IEEE 1366). Source: EIA Form 861 · August 2026.
Signature read: mid-cohort SAIDI between the 96 and 258 minute tercile cuts.
What mid-pack NorthWestern Energy LLC - (MT) filings show
NorthWestern Energy LLC - (MT) is an investor-owned utility operating in Montana under EIA identifier 12825. It reports service to approximately 401,963 customer accounts and generated about $0.89 billion in annual electric revenue, with a service footprint spanning 242 ZIP codes. Investor ownership puts this utility under the regulatory authority of the state public utility commission, which reviews its rate requests and reliability record.
In 2023, the average NorthWestern Energy LLC - (MT) customer experienced 102.5 minutes of power interruptions, a measure known as SAIDI, or System Average Interruption Duration Index. That sits within the 120–180 minute national benchmark range, indicating performance typical of U.S. distribution utilities. SAIFI, the average number of outage events per customer, was 0.93 for the same period, so customers statistically faced roughly 1 distinct interruption that year. Excluding major event days (hurricanes, ice storms), SAIDI drops to 102.5 minutes, the gap between that figure and the headline 102.5 reveals how much weather, not day-to-day infrastructure, drove outages.
The EIA dataset includes 4 years of continuous reporting (2020–2023) for NorthWestern Energy LLC - (MT), which lets you see whether reliability is trending up or down rather than judging from a single snapshot. Over that window, SAIDI moved from 165.5 down to 102.5 minutes, a trend worth noting for anyone weighing capital investment outcomes.
Based on this utility's own EIA Form 861 reliability record -- baseline (major-event- excluded) outage duration, total outage duration, and outage frequency -- each benchmarked against every reporting utility nationwide. Not a measure of electricity rates or customer service, which this portal does not track.
103 min/year per customer
Power-out minutes per year (2023)
SAIDI by year (2020-2023)
Minutes per customer-year · EIA Form 861
Year-by-year SAIDI for NorthWestern Energy LLC - (MT) from the same EIA filings as the table below. Lower is better; major-event years can spike the headline figure.
NorthWestern Energy LLC - (MT) SAIDI trend
NorthWestern Energy LLC - (MT) vs the nationwide SAIDI distribution
Where this utility's headline SAIDI sits among every EIA Form 861 utility with a reported figure
103 Lower than most fewer outage minutes than 66% of 911 utilities
Utilities nationwide, banded by latest reported SAIDI (minutes)
Each bar is a band; taller bars hold more utilities. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source U.S. EIA Form 861 reliability filings · August 2026
Price vs. reliability
Where NorthWestern Energy LLC - (MT) sits on price vs. reliability
Among the 781 U.S. utilities large enough to report both revenue per customer and a recent outage record, NorthWestern Energy LLC - (MT) charges more per customer than 29% of them, and is more reliable (lower SAIDI) than 69% of them, placing it in the quadrant where it pays less while still being more reliable, the best-value quadrant. Revenue per customer and outage minutes are independent figures: paying more does not guarantee fewer outages.
Revenue per customer: $2,214/year · Latest SAIDI: 102.5 minutes/year.
SAIDI 2023 breakdown: 102.5 minutes
Reliability Trend (2020–2023)
| Year | SAIDI (min) | SAIDI nMED | SAIFI | Customers |
|---|---|---|---|---|
| 2020 | 165.5 | 120.2 | 1.134 | 374,593 |
| 2021 | 151.4 | 128.4 | 1.371 | 367,486 |
| 2022 | 132.1 | 118.6 | 1.142 | 362,953 |
| 2023 | 102.5 | 102.5 | 0.934 | 368,707 |
SAIDI nMED = SAIDI without major event days. Source: EIA Form 861.
Service Area
NorthWestern Energy LLC - (MT) serves 242 ZIP codes in Montana.
Frequently Asked Questions
How reliable is NorthWestern Energy LLC - (MT)?
NorthWestern Energy LLC - (MT) had a SAIDI of 102.5 minutes in 2023. Leaving aside major weather events, that figure sits close to the national average.
What type of utility is NorthWestern Energy LLC - (MT)?
NorthWestern Energy LLC - (MT) is classified as a IOU serving Montana.
How many customers does NorthWestern Energy LLC - (MT) serve?
NorthWestern Energy LLC - (MT) serves approximately 401,963 customers in Montana.
How has NorthWestern Energy LLC - (MT)'s reliability changed over time?
NorthWestern Energy LLC - (MT) has 4 years of reliability data (2020-2023). This utility's SAIDI has stayed fairly flat over the period. Review the trend table above for year-by-year detail.
Utility Profile
- Type
- IOU
- State
- Montana
- Customers
- 401,963
- Annual Revenue
- $0.89B
- EIA ID
- 12825
Explore
Utilities with similar EIA profiles
Two cross-state peer sets for NorthWestern Energy LLC - (MT). Same-state SAIDI neighbors stay in Read-with below; these neighborhoods are nearest other-state utilities with at least 10,000 reported customers.
Similar customer count
Nearest utilities by Form 861 customers (402K here), outside Montana.
Similar chronic SAIDI
Nearest utilities by latest SAIDI minutes (102.5 here), outside Montana, excluding the customer-peer set.
Source: U.S. Energy Information Administration Form 861 annual electric power industry survey · ZIP service territory: OpenEI. Disclaimer: informational only, not professional advice. See full disclaimer · methodology.