How reliable is the power in South Dakota?
South Dakota ranks 4th of 45 states without major events and 3rd with them (1st = fewest minutes), 68 below the U.S. 129 and 576 below the U.S. 662. Major events added 24 minutes, 28% of the with-events total. The figure covers 365,552 customers, 88% of the 415,372 EIA lists for South Dakota.
South Dakota with and without major events
minutes without power per customer, 2024, South Dakota and U.S.
- 62South Dakota, no major events
- 129U.S., no major events
- 86South Dakota, with major events
- 662U.S., with major events
| Measure | South Dakota without | South Dakota with | U.S. without | U.S. with |
|---|---|---|---|---|
| SAIDI, minutes per customer | 62 | 86 | 129 | 662 |
| SAIFI, interruptions per customer | 0.72 | 0.81 | 1.06 | 1.53 |
| CAIDI, minutes per interruption | 85 | 105 | 122 | 433 |
| Median utility, SAIDI minutes | 64 | 76 | — | — |
Which South Dakota utilities move the number
Northern States Power Co - Minnesota serves 29% of the customers in the South Dakota figure: 33% of lost customer-minutes with major events, 30% without. Without Northern States Power Co - Minnesota, the weighted figure would be 80 minutes with major events and 61 without, against 86 and 62.
- Northern States Power Co - Minnesota: 104,471 customers (29%), 64 min without and 100 with; 33% of lost minutes with major events, 30% without.
- NorthWestern Energy - (SD): 64,209 customers (18%), 66 min without and 76 with; 16% of lost minutes with major events, 19% without.
- Black Hills Power, Inc.: 73,846 customers (20%), 57 min without and 57 with; 14% of lost minutes with major events, 19% without.
All South Dakota utilities in the 2024 file
62 utilities in the 2024 EIA-861 files for South Dakota: 13 follow IEEE 1366, 1 uses another method, 48 filed no reliability figures. 14 are listed.
| Watertown Municipal Utilities | Municipal | IEEE 1366 | 14,404 | 3 | 3 | 0.06 | 0.06 | 0 | 1 of 9 | — |
|---|---|---|---|---|---|---|---|---|---|---|
| City of Brookings - (SD) | Municipal | IEEE 1366 | 12,252 | 11 | 11 | 0.14 | 0.14 | 0 | 2 of 9 | — |
| West River Electric Assn Inc | Cooperative | IEEE 1366 | 21,594 | 44 | 44 | 0.53 | 0.53 | 0 | 3 of 9 | — |
| Black Hills Power, Inc. | Investor Owned | IEEE 1366 | 73,846 | 57 | 57 | 0.86 | 0.86 | 0 | 4 of 9 | — |
| Northern States Power Co - Minnesota | Investor Owned | IEEE 1366 | 104,471 | 64 | 100 | 0.70 | 0.88 | 36 | 5 of 9 | — |
| NorthWestern Energy - (SD) | Investor Owned | IEEE 1366 | 64,209 | 66 | 76 | 0.65 | 0.70 | 13 | 6 of 9 | — |
| Otter Tail Power Co | Investor Owned | IEEE 1366 | 11,930 | 71 | 135 | 1.03 | 1.48 | 47 | 7 of 9 | — |
| Sioux Valley SW Elec Coop | Cooperative | IEEE 1366 | 24,475 | 71 | 71 | 1.01 | 1.01 | 0 | 8 of 9 | — |
| Black Hills Electric Coop, Inc | Cooperative | IEEE 1366 | 11,305 | 102 | 229 | 0.77 | 1.03 | 55 | 9 of 9 | — |
| Southeastern Electric Coop Inc - (SD) | Cooperative | Other method | 23,696 | 71 | 71 | — | — | — | Not ranked | other method, not comparable |
| Montana-Dakota Utilities Co | Investor Owned | IEEE 1366 | 9,258 | 148 | 154 | 1.41 | 1.44 | 4 | Not ranked | under 10,000 customers |
| Northern Electric Coop, Inc | Cooperative | IEEE 1366 | 6,888 | 50 | 50 | 0.67 | 0.67 | 0 | Not ranked | under 10,000 customers |
| Rosebud Electric Coop Inc | Cooperative | IEEE 1366 | 5,621 | 95 | 112 | 0.76 | 0.84 | 15 | Not ranked | under 10,000 customers |
| MidAmerican Energy Co | Investor Owned | IEEE 1366 | 5,299 | 42 | 428 | 0.57 | 1.19 | 90 | Not ranked | under 10,000 customers |
South Dakota utilities with no reliability figures
48 in the sales file, no SAIDI or SAIFI row; the 25 largest are listed.
| Utility | Type | Customers |
|---|---|---|
| Central Electric Coop, Inc - (SD) | Cooperative | 7,351 |
| City of Pierre - (SD) | Municipal | 7,327 |
| Dakota Energy Coop Inc | Cooperative | 3,638 |
| City of Madison - (SD) | Municipal | 3,322 |
| Nebraska Public Power District | Political Subdivision | 1,280 |
| City of Volga - (SD) | Municipal | 1,266 |
| WAPA-- Western Area Power Administration | Federal | 22 |
| Winner Municipal Utility | Municipal | — |
| City of Beresford | Municipal | — |
| City of Aurora - (SD) | Municipal | — |
| Charles Mix Electric Assn, Inc | Cooperative | — |
| Lake Region Electric Assn, Inc - (SD) | Cooperative | — |
| City of Parker - (SD) | Municipal | — |
| Moreau-Grand Electric Coop Inc | Cooperative | — |
| Southeast Electric Coop, Inc | Cooperative | — |
| City of Colman - (SD) | Municipal | — |
| East River Elec Pwr Coop, Inc | Not stated | — |
| Clay-Union Electric Corp | Cooperative | — |
| Codington-Clark Elec Coop, Inc | Cooperative | — |
| Bon Homme Yankton El Assn, Inc | Cooperative | — |
| Cam Wal Electric Coop, Inc | Cooperative | — |
| Oahe Electric Coop Inc | Cooperative | — |
| City of Elk Point | Municipal | — |
| City of Sioux Falls - (SD) | Municipal | — |
| Grand Electric Coop, Inc | Cooperative | — |
The biggest South Dakota utilities against the U.S.
- Northern States Power Co - Minnesota (investor owned, 25% of South Dakota customers in the file): SAIDI without major events 64 min, 66 below the U.S. 129; with major events 100 min against 662.
- Black Hills Power, Inc. (investor owned, 18% of South Dakota customers in the file): SAIDI without major events 57 min, 72 below the U.S. 129; with major events 57 min against 662.
- NorthWestern Energy - (SD) (investor owned, 16% of South Dakota customers in the file): SAIDI without major events 66 min, 63 below the U.S. 129; with major events 76 min against 662.
- Sioux Valley SW Elec Coop (cooperative, 6% of South Dakota customers in the file): SAIDI without major events 71 min, 58 below the U.S. 129; with major events 71 min against 662.
- Southeastern Electric Coop Inc - (SD) (cooperative, 6% of South Dakota customers in the file): reports on another method, not compared with the U.S. figure.
South Dakota by type of utility
Among South Dakota utilities that report under IEEE 1366, municipal utilities average 7 minutes without major events and cooperative utilities 68.
| Type | Utilities | Customers | SAIDI without | Median utility | SAIDI with |
|---|---|---|---|---|---|
| Investor Owned | 6 | 269,013 | 65 | 65 | 92 |
| Cooperative | 5 | 69,883 | 68 | 71 | 89 |
| Municipal | 2 | 26,656 | 7 | 7 | 7 |
Next to South Dakota in the ranking
South Dakota report card
Smart meters: 87% of residential meters, 8 utilities (U.S. 92%). South Dakota time-based rates: 3 of 8 utilities, 0.2% of residential customers enrolled (U.S. 10.6%). South Dakota efficiency spend: $43.8 per customer (U.S. $124.2). Demand response: 351 W per customer (U.S. 77). South Dakota net-metered systems: 1.3 per 1,000 customers. Rankings.
Is your South Dakota utility better or worse than the South Dakota median?
- Loading.
More
- South Dakota against all states
- South Dakota utilities among the best and worst
- South Dakota utility reliability and price by company
- South Dakota major outage reports from the Department of Energy
- South Dakota electricity prices
- South Dakota help with your bill
14 South Dakota filings in EIA-861 2024 (retrieved 2026-10-01), 9 ranked utilities. Method and sources.
Questions
How many minutes without power did the average South Dakota customer have in 2024?
62 minutes without major events and 86 with them (13 IEEE 1366 utilities, customer-weighted).
Why do the two South Dakota numbers differ so much?
Major events add 24 of the 86 minutes (28%); Northern States Power Co - Minnesota supplies 33% of the with-events total.
Which South Dakota utility reported the fewest and the most minutes?
Among 9 utilities with 10,000+ customers: Watertown Municipal Utilities 3 minutes without major events, and Black Hills Electric Coop, Inc 102.
Which South Dakota utilities use which method?
13 follow IEEE 1366, 1 uses another method, 48 filed no reliability figures.