How reliable is the power in Wyoming?
Wyoming ranks 22nd of 45 states without major events and 10th with them (1st = fewest minutes), 25 below the U.S. 129 and 534 below the U.S. 662. Major events added 23 minutes, 18% of the with-events total. The figure covers 240,883 customers, 79% of the 305,607 EIA lists for Wyoming.
Wyoming with and without major events
minutes without power per customer, 2024, Wyoming and U.S.
- 105Wyoming, no major events
- 129U.S., no major events
- 128Wyoming, with major events
- 662U.S., with major events
| Measure | Wyoming without | Wyoming with | U.S. without | U.S. with |
|---|---|---|---|---|
| SAIDI, minutes per customer | 105 | 128 | 129 | 662 |
| SAIFI, interruptions per customer | 0.93 | 1.00 | 1.06 | 1.53 |
| CAIDI, minutes per interruption | 113 | 128 | 122 | 433 |
| Median utility, SAIDI minutes | 63 | 63 | — | — |
Which Wyoming utilities move the number
Powder River Energy Corp serves 11% of the customers in the Wyoming figure: 44% of lost customer-minutes with major events, 32% without. Without Powder River Energy Corp, the weighted figure would be 80 minutes with major events and 80 without, against 128 and 105.
- Powder River Energy Corp: 27,532 customers (11%), 295 min without and 496 with; 44% of lost minutes with major events, 32% without.
- PacifiCorp: 147,268 customers (61%), 92 min without and 92 with; 44% of lost minutes with major events, 54% without.
- Montana-Dakota Utilities Co: 18,970 customers (8%), 107 min without and 107 with; 7% of lost minutes with major events, 8% without.
All Wyoming utilities in the 2024 file
30 utilities in the 2024 EIA-861 files for Wyoming: 7 follow IEEE 1366, 1 uses another method, 22 filed no reliability figures. 8 are listed.
| Cheyenne Light Fuel & Power | Investor Owned | IEEE 1366 | 44,112 | 33 | 33 | 0.49 | 0.49 | 0 | 1 of 4 | — |
|---|---|---|---|---|---|---|---|---|---|---|
| PacifiCorp | Investor Owned | IEEE 1366 | 147,268 | 92 | 92 | 0.86 | 0.86 | 0 | 2 of 4 | — |
| Montana-Dakota Utilities Co | Investor Owned | IEEE 1366 | 18,970 | 107 | 107 | 0.67 | 0.67 | 0 | 3 of 4 | — |
| Powder River Energy Corp | Cooperative | IEEE 1366 | 27,532 | 295 | 496 | 2.24 | 2.88 | 41 | 4 of 4 | — |
| City of Gillette - (WY) | Municipal | Other method | 16,729 | 4 | — | 0.05 | — | — | Not ranked | other method, not comparable |
| High Plains Power Inc | Cooperative | IEEE 1366 | 13,979 | 312 | 312 | — | — | — | Not ranked | — |
| Black Hills Power, Inc. | Investor Owned | IEEE 1366 | 2,593 | 2 | 2 | 0.03 | 0.03 | 0 | Not ranked | under 10,000 customers |
| Fall River Rural Elec Coop Inc | Cooperative | IEEE 1366 | 408 | 16 | 16 | 0.11 | 0.11 | 0 | Not ranked | under 10,000 customers |
Wyoming utilities with no reliability figures
22 in the sales file, no SAIDI or SAIFI row.
| Utility | Type | Customers |
|---|---|---|
| Lower Valley Energy Inc | Cooperative | 29,101 |
| High West Energy, Inc | Cooperative | 6,958 |
| Yampa Valley Electric Assn Inc | Cooperative | 758 |
| NorthWestern Energy LLC - (MT) | Investor Owned | 683 |
| WAPA-- Western Area Power Administration | Federal | 5 |
| City of Powell - (WY) | Municipal | — |
| Town of Fort Laramie- (WY) | Municipal | — |
| Wyrulec Company | Cooperative | — |
| Niobrara Electric Assn, Inc | Cooperative | — |
| City of Torrington - (WY) | Municipal | — |
| Town of Lusk - (WY) | Municipal | — |
| Big Horn Rural Electric Co | Cooperative | — |
| City of Pine Bluffs - (WY) | Municipal | — |
| Garland Light & Power Company | Cooperative | — |
| Big Horn County Elec Coop, Inc | Cooperative | — |
| Municipal Energy Agency of NE | Not stated | — |
| City of Cody | Municipal | — |
| Bridger Valley Elec Assn, Inc | Cooperative | — |
| Beartooth Electric Coop, Inc | Cooperative | — |
| Southeast Electric Coop, Inc | Cooperative | — |
| Wheatland Rural Elec Assn, Inc | Cooperative | — |
| Carbon Power & Light, Inc | Cooperative | — |
The biggest Wyoming utilities against the U.S.
- PacifiCorp (investor owned, 47% of Wyoming customers in the file): SAIDI without major events 92 min, 37 below the U.S. 129; with major events 92 min against 662.
- Cheyenne Light Fuel & Power (investor owned, 15% of Wyoming customers in the file): SAIDI without major events 33 min, 96 below the U.S. 129; with major events 33 min against 662.
- Lower Valley Energy Inc (cooperative, 10% of Wyoming customers in the file): no reliability figures filed.
- Powder River Energy Corp (cooperative, 9% of Wyoming customers in the file): SAIDI without major events 295 min, 166 above the U.S. 129; with major events 496 min against 662.
- Montana-Dakota Utilities Co (investor owned, 6% of Wyoming customers in the file): SAIDI without major events 107 min, 22 below the U.S. 129; with major events 107 min against 662.
Wyoming by type of utility
Among Wyoming utilities that report under IEEE 1366, investor owned utilities average 80 minutes without major events and cooperative utilities 291.
| Type | Utilities | Customers | SAIDI without | Median utility | SAIDI with |
|---|---|---|---|---|---|
| Investor Owned | 4 | 212,943 | 80 | 63 | 80 |
| Cooperative | 2 | 27,940 | 291 | 156 | 489 |
Next to Wyoming in the ranking
Wyoming report card
Smart meters: 86% of residential meters, 5 utilities (U.S. 92%). Wyoming time-based rates: 3 of 7 utilities, 0.2% of residential customers enrolled (U.S. 10.6%). Wyoming efficiency spend: $28.9 per customer (U.S. $124.2). Demand response: 0 W per customer (U.S. 77). Wyoming net-metered systems: 10.8 per 1,000 customers. Rankings.
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8 Wyoming filings in EIA-861 2024 (retrieved 2026-10-01), 4 ranked utilities. Method and sources.
Questions
How many minutes without power did the average Wyoming customer have in 2024?
105 minutes without major events and 128 with them (7 IEEE 1366 utilities, customer-weighted).
Why do the two Wyoming numbers differ so much?
Major events add 23 of the 128 minutes (18%); Powder River Energy Corp supplies 44% of the with-events total.
Which Wyoming utility reported the fewest and the most minutes?
Among 4 utilities with 10,000+ customers: Cheyenne Light Fuel & Power 33 minutes without major events, and Powder River Energy Corp 295.
Which Wyoming utilities use which method?
7 follow IEEE 1366, 1 uses another method, 22 filed no reliability figures.