How reliable is the power in Montana?
Montana ranks 33rd of 45 states without major events and 26th with them (1st = fewest minutes), 23 above the U.S. 129 and 320 below the U.S. 662. Major events added 189 minutes, 55% of the with-events total. The figure covers 501,041 customers, 84% of the 598,677 EIA lists for Montana.
Montana with and without major events
minutes without power per customer, 2024, Montana and U.S.
- 152Montana, no major events
- 129U.S., no major events
- 342Montana, with major events
- 662U.S., with major events
| Measure | Montana without | Montana with | U.S. without | U.S. with |
|---|---|---|---|---|
| SAIDI, minutes per customer | 152 | 342 | 129 | 662 |
| SAIFI, interruptions per customer | 1.16 | 1.63 | 1.06 | 1.53 |
| CAIDI, minutes per interruption | 131 | 210 | 122 | 433 |
| Median utility, SAIDI minutes | 148 | 297 | — | — |
Which Montana utilities move the number
NorthWestern Energy LLC - (MT) serves 75% of the customers in the Montana figure: 51% of lost customer-minutes with major events, 58% without. Without NorthWestern Energy LLC - (MT), the weighted figure would be 669 minutes with major events and 256 without, against 342 and 152.
- NorthWestern Energy LLC - (MT): 376,392 customers (75%), 118 min without and 233 with; 51% of lost minutes with major events, 58% without.
- Flathead Electric Coop Inc: 78,834 customers (16%), 235 min without and 586 with; 27% of lost minutes with major events, 24% without.
- Missoula Electric Coop, Inc: 17,133 customers (3%), 506 min without and 1,606 with; 16% of lost minutes with major events, 11% without.
All Montana utilities in the 2024 file
36 utilities in the 2024 EIA-861 files for Montana: 6 follow IEEE 1366, 3 use another method, 27 filed no reliability figures. 9 are listed.
| NorthWestern Energy LLC - (MT) | Investor Owned | IEEE 1366 | 376,392 | 118 | 233 | 0.95 | 1.30 | 49 | 1 of 4 | — |
|---|---|---|---|---|---|---|---|---|---|---|
| Montana-Dakota Utilities Co | Investor Owned | IEEE 1366 | 26,559 | 177 | 360 | 1.39 | 1.95 | 51 | 2 of 4 | — |
| Flathead Electric Coop Inc | Cooperative | IEEE 1366 | 78,834 | 235 | 586 | 1.90 | 2.72 | 60 | 3 of 4 | — |
| Missoula Electric Coop, Inc | Cooperative | IEEE 1366 | 17,133 | 506 | 1,606 | 2.19 | 3.59 | 69 | 4 of 4 | — |
| Fergus Electric Coop, Inc | Cooperative | Other method | 7,038 | 444 | 1,239 | — | — | — | Not ranked | other method, not comparable; under 10,000 customers |
| Lower Yellowstone R E A, Inc | Cooperative | Other method | 5,228 | 88 | 88 | 0.88 | 0.88 | — | Not ranked | other method, not comparable; under 10,000 customers |
| Northern Lights, Inc | Cooperative | Other method | 4,287 | 267 | 352 | — | — | — | Not ranked | other method, not comparable; under 10,000 customers |
| Fall River Rural Elec Coop Inc | Cooperative | IEEE 1366 | 2,080 | 8 | 17 | 0.07 | 0.13 | 54 | Not ranked | under 10,000 customers |
| Black Hills Power, Inc. | Investor Owned | IEEE 1366 | 43 | 59 | 59 | 1.20 | 1.20 | 0 | Not ranked | under 10,000 customers |
Montana utilities with no reliability figures
27 in the sales file, no SAIDI or SAIFI row; the 25 largest are listed.
| Utility | Type | Customers |
|---|---|---|
| Yellowstone Valley Elec Co-op | Cooperative | 23,296 |
| USBIA-Mission Valley Power | Federal | 23,124 |
| Powder River Energy Corp | Cooperative | 172 |
| McKenzie Electric Coop Inc | Cooperative | 117 |
| Avista Corp | Investor Owned | 33 |
| WAPA-- Western Area Power Administration | Federal | 16 |
| Goldenwest Electric Coop, Inc | Cooperative | — |
| Grand Electric Coop, Inc | Cooperative | — |
| Park Electric Coop Inc | Cooperative | — |
| Mid-Yellowstone Elec Coop, Inc | Cooperative | — |
| Beartooth Electric Coop, Inc | Cooperative | — |
| Sun River Electric Coop, Inc | Cooperative | — |
| Sheridan Electric Coop, Inc | Cooperative | — |
| Big Horn Rural Electric Co | Cooperative | — |
| Glacier Electric Coop, Inc | Cooperative | — |
| Ravalli County Elec Coop, Inc | Cooperative | — |
| Marias River Electric Coop Inc | Cooperative | — |
| Big Horn County Elec Coop, Inc | Cooperative | — |
| Lincoln Electric Coop, Inc | Cooperative | — |
| NorVal Electric Cooperative, Inc | Cooperative | — |
| Tongue River Electric Coop Inc | Cooperative | — |
| Big Flat Electric Coop Inc | Cooperative | — |
| Hill County Electric Coop, Inc | Cooperative | — |
| Vigilante Electric Coop, Inc | Cooperative | — |
| McCone Electric Coop Inc | Cooperative | — |
The biggest Montana utilities against the U.S.
- NorthWestern Energy LLC - (MT) (investor owned, 69% of Montana customers in the file): SAIDI without major events 118 min, 11 below the U.S. 129; with major events 233 min against 662.
- Flathead Electric Coop Inc (cooperative, 13% of Montana customers in the file): SAIDI without major events 235 min, 106 above the U.S. 129; with major events 586 min against 662.
- Montana-Dakota Utilities Co (investor owned, 4% of Montana customers in the file): SAIDI without major events 177 min, 48 above the U.S. 129; with major events 360 min against 662.
- Yellowstone Valley Elec Co-op (cooperative, 4% of Montana customers in the file): no reliability figures filed.
- USBIA-Mission Valley Power (federal, 4% of Montana customers in the file): no reliability figures filed.
Montana by type of utility
Among Montana utilities that report under IEEE 1366, investor owned utilities average 122 minutes without major events and cooperative utilities 278.
| Type | Utilities | Customers | SAIDI without | Median utility | SAIDI with |
|---|---|---|---|---|---|
| Investor Owned | 3 | 402,994 | 122 | 118 | 242 |
| Cooperative | 3 | 98,047 | 278 | 235 | 753 |
Next to Montana in the ranking
Montana report card
Smart meters: 100% of residential meters, 3 utilities (U.S. 92%). Montana time-based rates: 2 of 6 utilities, 16.8% of residential customers enrolled (U.S. 10.6%). Montana efficiency spend: $22.0 per customer (U.S. $124.2). Demand response: 42 W per customer (U.S. 77). Montana net-metered systems: 17.6 per 1,000 customers. Rankings.
Is your Montana utility better or worse than the Montana median?
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- Montana utilities among the best and worst
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9 Montana filings in EIA-861 2024 (retrieved 2026-10-01), 4 ranked utilities. Method and sources.
Questions
How many minutes without power did the average Montana customer have in 2024?
152 minutes without major events and 342 with them (6 IEEE 1366 utilities, customer-weighted).
Why do the two Montana numbers differ so much?
Major events add 189 of the 342 minutes (55%); NorthWestern Energy LLC - (MT) supplies 51% of the with-events total.
Which Montana utility reported the fewest and the most minutes?
Among 4 utilities with 10,000+ customers: NorthWestern Energy LLC - (MT) 118 minutes without major events, and Missoula Electric Coop, Inc 506.
Which Montana utilities use which method?
6 follow IEEE 1366, 3 use another method, 27 filed no reliability figures.