South Dakota power outages by utility

9 South Dakota utilities report outage minutes to EIA. The state median is 57 minutes a year; the range runs from 3 to 102.

Ranking by outage minutes

South Dakota, SAIDI without major event days, 2024; lower is better; 9 utilities.

Rank	South Dakota utility	Owner type	South Dakota home accounts	SAIDI min	Interruptions (SAIFI)	SAIDI with storms	South Dakota storm share	Price ¢/kWh
1	Watertown Municipal Utilities	Municipal	11,633	3	0.06	3	0%	9.30
2	City of Brookings	Municipal	10,544	11	0.14	11	0%	11.12
3	West River Electric Assn Inc	Cooperative	18,423	44	0.53	44	0%	14.25
4	Northern Electric Coop, Inc	Cooperative	5,757	50	0.67	50	0%	11.29
5	Black Hills Power, Inc.	Investor Owned	60,951	57	0.86	57	0%	14.37
6	NorthWestern Energy	Investor Owned	51,467	66	0.65	76	13%	12.56
7	Sioux Valley SW Elec Coop	Cooperative	22,213	71	1.01	71	0%	12.94
8	Rosebud Electric Coop Inc	Cooperative	4,856	95	0.76	112	15%	10.63
9	Black Hills Electric Coop, Inc	Cooperative	9,227	102	0.77	229	55%	14.76

South Dakota outage minutes by owner type

In South Dakota, 45% of 433,548 home accounts sit with the 9 qualifying utilities out of 15 in the file. South Dakota customer-weighted SAIDI is 57 minutes against a median of 57, and 1 of 9 South Dakota utilities exceed the U.S. median of 99. Counting major event days adds a median 0% to SAIDI.

South Dakota owner type	South Dakota utilities	South Dakota home accounts	South Dakota median SAIDI	South Dakota weighted SAIDI	South Dakota median SAIFI	South Dakota storm share	South Dakota median price ¢/kWh
Investor Owned	2	112,418	62	62	0.76	6%	13.47
Cooperative	5	60,476	71	67	0.76	0%	12.94
Municipal	2	22,177	7	7	0.10	0%	10.21

By owner type, Municipal utilities have the lowest median SAIDI in South Dakota (7 minutes, 2 of 9) and Cooperative the highest (71 minutes, 5 of 9).

South Dakota utilities that stand out

Why it stands out	South Dakota utility	South Dakota owner type	South Dakota accounts	South Dakota SAIDI min	South Dakota SAIDI rank	South Dakota SAIFI	South Dakota SAIDI with storms	South Dakota price ¢/kWh	South Dakota price rank
the most reliable	Watertown Municipal Utilities	Municipal	11,633	3	1 of 9	0.06	3	9.30	1 of 9
the least reliable	Black Hills Electric Coop, Inc	Cooperative	9,227	102	9 of 9	0.77	229	14.76	9 of 9
the largest	Black Hills Power, Inc.	Investor Owned	60,951	57	5 of 9	0.86	57	14.37	8 of 9
the one that slipped most	City of Brookings	Municipal	10,544	11	2 of 9	0.14	11	11.12	3 of 9

Does a higher price buy fewer outages?

Each dot is one of 9 South Dakota utilities.

South Dakota, 2024: first 8 of 9 rows

	Home price, cents per kWh	SAIDI, minutes a year
Watertown Municipal Utilities	9.30	3
City of Brookings	11.12	11
West River Electric Assn Inc	14.25	44
Northern Electric Coop, Inc	11.29	50
Black Hills Power, Inc.	14.37	57
NorthWestern Energy	12.56	66
Sioux Valley SW Elec Coop	12.94	71
Rosebud Electric Coop Inc	10.63	95

9 rows from EIA-861 survey.

CSV

South Dakota utilities, change in their own SAIDI

First to last year each utility reported, best change first.

Rank	South Dakota utility	South Dakota years	South Dakota SAIDI first	South Dakota SAIDI last	South Dakota change
1	Watertown Municipal Utilities	2017 to 2025	79	4	-95%
2	Sioux Valley SW Elec Coop	2015 to 2024	152	71	-53%
3	West River Electric Assn Inc	2019 to 2024	62	44	-29%
4	Black Hills Power, Inc.	2015 to 2024	80	57	-28%
5	NorthWestern Energy	2015 to 2025	93	82	-12%
6	Northern Electric Coop, Inc	2015 to 2025	68	65	-4%
7	Black Hills Electric Coop, Inc	2015 to 2025	96	120	+26%
8	City of Brookings	2021 to 2025	4	13	+224%

Analyst note

The worst South Dakota record, 102 minutes, ranks 40 of 40 among state worst cases. Of 9 South Dakota utilities with 1,000+ home accounts that report SAIDI, Watertown Municipal Utilities is lowest at 3 minutes a year and Black Hills Electric Coop, Inc highest at 102, a 31.3 to 1 spread. The state median is 57 minutes, -42% against the U.S. median reporter. Over each utility's own record, Watertown Municipal Utilities improved most (79 to 4 minutes, -95%, 2017 to 2025) and City of Brookings changed the other way (4 to 13, +224%); 6 of 8 fell. Home price and outage minutes line up at r = +0.51 across 9 South Dakota utilities: the pricier ones report more minutes. That is South Dakota's pattern, not a cause.

Questions on South Dakota outages

How bad is the worst South Dakota utility?

Black Hills Electric Coop, Inc reports 102 minutes, rank 40 of 40 among state worst cases.

Which South Dakota utility has the fewest outage minutes?

Watertown Municipal Utilities: 3 minutes a year, SAIDI without major events, 2024.

Which South Dakota utility has the most?

Black Hills Electric Coop, Inc: 102 minutes a year in 2024.

What is the typical SAIDI in South Dakota?

The median of 9 reporting utilities is 57 minutes, -42% on the U.S. median reporter.

Do cheaper South Dakota utilities have more outages?

Across 9 utilities r = +0.51, so the link is positive: higher price goes with more outage minutes.

How much of South Dakota outage time comes from storms?

At Black Hills Electric Coop, Inc 55% of all-event SAIDI is major event days.

How reliable is the largest South Dakota utility?

Black Hills Power, Inc. serves 60,951 home accounts and reports 57 minutes, rank 5 of 9; weighted by customers the state figure is 57.

Do South Dakota co-ops and investor-owned utilities differ?

3 owner types report in South Dakota: Municipal 2 utilities with 22,177 home accounts, Cooperative 5 utilities with 60,476 home accounts, Investor Owned 2 utilities with 112,418 home accounts.

What share of South Dakota home accounts do these utilities serve?

45% of 433,548 accounts, 9 of 15 utilities; 1 are above the U.S. median of 99 minutes.