County annual report · FIPS 45019
2021 Charleston County, SC Power Outage Report
In 2021, customers in Charleston County, SC went without power for an average of 2.0 hours, a total of 466K customer-hours (South Carolina average 2.1 hours). That ranks 28th worst of 46 South Carolina counties and 2216th of 2,974 nationally.
Compared with SC, the US and 2020
Coverage line is EAGLE-I's share of South Carolina customers tracked each year.
Biggest outages in Charleston 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 | July 7, 2021 12:00 | July 9, 2021 07:30 | 1d 19h | 52,176 | 100K |
| 2 | July 28, 2021 18:30 | July 29, 2021 00:15 | 5h 45m | 11,080 | 12K |
| 3 | December 13, 2021 06:45 | December 13, 2021 11:45 | 5h | 5,410 | 16K |
| 4 | August 9, 2021 13:15 | August 10, 2021 06:45 | 17h 30m | 4,448 | 1,474 |
| 5 | July 31, 2021 03:45 | July 31, 2021 04:45 | 1h | 4,258 | 1,069 |
| 6 | January 9, 2021 01:30 | January 9, 2021 02:15 | 45m | 4,035 | 3,026 |
| 7 | March 12, 2021 14:30 | March 12, 2021 21:00 | 6h 30m | 3,938 | 2,111 |
| 8 | March 31, 2021 13:00 | April 1, 2021 21:45 | 1d 8h | 3,788 | 24K |
| 9 | May 3, 2021 08:45 | May 3, 2021 21:45 | 13h | 3,558 | 1,064 |
| 10 | July 19, 2021 12:15 | July 28, 2021 15:15 | 9d 3h | 3,413 | 44K |
Outage episodes by size in 2021: 160 reached 100+ customers, 35 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 Charleston 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 |
|---|---|---|---|---|---|
| Dominion Energy South Carolina, Inc | 2021 | 1.5 hrs | 1.10 | 79 min | 1.02 |
| Berkeley Electric Coop Inc | 2021 | 1.8 hrs | 1.16 | 1.6 hrs | 1.10 |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 99% of South Carolina's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 231,046 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. Charleston County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Charleston County, SC 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-carolina/charleston-county