County annual report · FIPS 46103
2018 Pennington County, SD Power Outage Report
In 2018, customers in Pennington County, SD went without power for an average of 1.5 hours, a total of 99K customer-hours (South Dakota average 1.1 hours). That ranks 5th worst of 30 South Dakota counties and 2105th of 2,798 nationally.
Compared with SD, the US and 2017
Coverage line is EAGLE-I's share of South Dakota customers tracked each year.
Biggest outages in Pennington County, 2018
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 8, 2018 20:45 | May 24, 2018 23:15 | 16d 2h | 4,963 | 38K |
| 2 | October 8, 2018 04:15 | October 8, 2018 05:30 | 1h 15m | 4,021 | 5,026 |
| 3 | December 26, 2018 13:45 | December 26, 2018 15:00 | 1h 15m | 2,695 | 2,695 |
| 4 | September 24, 2018 15:15 | September 24, 2018 19:00 | 3h 45m | 1,794 | 4,914 |
| 5 | June 22, 2018 07:00 | June 25, 2018 14:15 | 3d 7h | 1,619 | 906 |
| 6 | April 11, 2018 10:45 | April 13, 2018 12:45 | 2d 2h | 1,202 | 1,476 |
| 7 | October 19, 2018 07:15 | October 23, 2018 21:30 | 4d 14h | 956 | 909 |
| 8 | March 3, 2018 16:15 | March 6, 2018 01:00 | 2d 8h | 779 | 2,424 |
| 9 | September 19, 2018 18:30 | September 21, 2018 21:30 | 2d 3h | 741 | 2,534 |
| 10 | October 25, 2018 15:00 | October 25, 2018 16:30 | 1h 30m | 601 | 386 |
Outage episodes by size in 2018: 36 reached 100+ customers, 6 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 Pennington County reported on EIA Form 861 for 2018, 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. | 2018 | 3.8 hrs | 1.21 | 3.7 hrs | 1.17 |
| Black Hills Electric Coop, Inc | 2018 | 68 min | 0.92 | 68 min | 0.92 |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| Black Hills Energy | - | - | - | - | - |
| West River Electric Assn Inc | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 46% of South Dakota's customers in 2018; 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, 2018, 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/2018/south-dakota/pennington-county