County annual report · FIPS 46103
2025 Pennington County, SD Power Outage Report
In 2025, customers in Pennington County, SD went without power for an average of 13.0 hours, a total of 883K customer-hours (South Dakota average 6.5 hours). That ranks 8th worst of 65 South Dakota counties and 601st of 3,000 nationally.
Compared with SD, the US and 2024
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Pennington County, 2025
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | November 13, 2025 19:45 | November 14, 2025 09:30 | 13h 45m | 41,253 | 135K |
| 2 | December 18, 2025 08:00 | January 1, 2026 00:00 | 13d 16h | 25,159 | 572K |
| 3 | December 17, 2025 19:45 | December 18, 2025 07:00 | 11h 15m | 1,810 | 7,899 |
| 4 | March 25, 2025 18:45 | March 26, 2025 22:00 | 1d 3h | 1,700 | 46K |
| 5 | November 3, 2025 14:45 | November 5, 2025 22:30 | 2d 7h | 1,516 | 1,468 |
| 6 | May 28, 2025 11:30 | June 2, 2025 02:15 | 4d 14h | 1,423 | 11K |
| 7 | February 24, 2025 18:45 | February 26, 2025 18:00 | 1d 23h | 1,303 | 25K |
| 8 | January 1, 2025 22:00 | January 6, 2025 17:15 | 4d 19h | 1,068 | 528 |
| 9 | September 26, 2025 01:15 | September 26, 2025 14:00 | 12h 45m | 1,053 | 1,291 |
| 10 | June 18, 2025 19:15 | July 3, 2025 18:45 | 14d 23h | 1,043 | 28K |
Outage episodes by size in 2025: 49 reached 100+ customers, 11 reached 1,000+ customers, 2 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 Pennington County reported on EIA Form 861 for 2025, 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 |
|---|---|---|---|---|---|
| Black Hills Power, Inc. | 2024 | 40 min | 0.70 | 40 min | 0.70 |
| Black Hills Electric Coop, Inc | 2024 | 3.8 hrs | 1.03 | 1.7 hrs | 0.77 |
| West River Electric Assn Inc | 2024 | 44 min | 0.53 | 44 min | 0.53 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Black Hills Energy | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about n/a of South Dakota's customers in 2025; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 68,130 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. Pennington County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Pennington County, SD annual power outage report, 2025, 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/2025/south-dakota/pennington-county