County annual report · FIPS 46109
2021 Roberts County, SD Power Outage Report
In 2021, customers in Roberts County, SD went without power for an average of 2.1 hours, a total of 8,626 customer-hours (South Dakota average 3.4 hours). That ranks 38th worst of 61 South Dakota counties and 2181st of 2,974 nationally.
Compared with SD, the US and 2020
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Roberts County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | April 28, 2021 21:15 | April 28, 2021 23:30 | 2h 15m | 1,096 | 2,421 |
| 2 | February 28, 2021 14:45 | February 28, 2021 15:00 | 15m | 974 | 244 |
| 3 | December 7, 2021 15:15 | December 7, 2021 20:45 | 5h 30m | 146 | 803 |
| 4 | March 25, 2021 11:30 | March 26, 2021 17:15 | 1d 5h | 145 | 366 |
| 5 | July 16, 2021 21:30 | July 16, 2021 22:45 | 1h 15m | 79 | 99 |
| 6 | July 24, 2021 05:00 | July 24, 2021 07:45 | 2h 45m | 31 | 85 |
| 7 | September 30, 2021 15:30 | September 30, 2021 16:45 | 1h 15m | 31 | 10 |
| 8 | April 30, 2021 15:15 | May 2, 2021 01:00 | 1d 9h | 26 | 878 |
| 9 | May 13, 2021 18:00 | May 17, 2021 16:15 | 3d 22h | 26 | 2,438 |
| 10 | April 2, 2021 19:45 | April 2, 2021 20:15 | 30m | 15 | 8 |
Outage episodes by size in 2021: 4 reached 100+ customers, 1 reached 1,000+ customers, 0 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Roberts County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| Otter Tail Power Co | 2021 | 86 min | 1.13 | 74 min | 1.09 |
| Whetstone Valley Elec Coop Inc | 2018 | 73 min | 0.64 | 42 min | 0.43 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Montana-Dakota Utilities Co | - | - | - | - | - |
| Codington-Clark Elec Coop, Inc | - | - | - | - | - |
| Traverse Electric Coop, Inc | - | - | - | - | - |
| Lake Region Electric Assn, Inc - (SD) | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 79% of South Dakota's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 4,096 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Roberts County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Roberts County, SD annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/south-dakota/roberts-county