County annual report · FIPS 46051
2021 Grant County, SD Power Outage Report
In 2021, customers in Grant County, SD went without power for an average of 77.5 hours, a total of 242K customer-hours (South Dakota average 3.4 hours). That ranks 2nd worst of 61 South Dakota counties and 105th 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 Grant 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 | May 19, 2021 21:45 | May 19, 2021 22:00 | 15m | 1,490 | 373 |
| 2 | May 20, 2021 07:00 | May 26, 2021 16:15 | 6d 9h | 1,490 | 228K |
| 3 | September 4, 2021 07:00 | September 5, 2021 01:30 | 18h 30m | 577 | 11K |
| 4 | October 8, 2021 13:00 | October 8, 2021 15:30 | 2h 30m | 82 | 69 |
| 5 | October 6, 2021 19:15 | October 6, 2021 20:15 | 1h | 22 | 22 |
| 6 | November 8, 2021 20:15 | November 8, 2021 22:30 | 2h 15m | 18 | 41 |
| 7 | November 2, 2021 20:00 | November 3, 2021 13:15 | 17h 15m | 16 | 40 |
| 8 | August 29, 2021 01:00 | August 29, 2021 02:00 | 1h | 12 | 12 |
| 9 | April 6, 2021 14:15 | April 6, 2021 18:30 | 4h 15m | 11 | 47 |
| 10 | August 18, 2021 13:30 | August 18, 2021 21:15 | 7h 45m | 11 | 10 |
Outage episodes by size in 2021: 3 reached 100+ customers, 2 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 Grant 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 |
| H-D Electric Coop Inc | 2018 | 2.6 hrs | 1.52 | 1.6 hrs | 1.14 |
| 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 | - | - | - | - | - |
| City of Big Stone City - (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 ÷ 3,124 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. Grant County has data for 2019–2025.
Cite this report
MassOutage (massoutage.com), Grant 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/grant-county