Power Outages in South Carolina: Duration, Frequency & Backup Planning
South Carolina had the highest all-event SAIDI in the 2024 EIA state table, making the gap between ordinary reliability and major-event exposure especially important.
Source: U.S. Energy Information Administration, Electric Power Annual Table 11.3.
52.3 hours
3,136.5 minutes of all-event SAIDI per average customer in 2024. Rank: #1 of 51 jurisdictions by duration.
2.37 events
Average non-momentary interruptions per customer. Rank: #8 by SAIFI.
1326 minutes
Average restoration duration per sustained interruption using EIA’s all-event CAIDI.
How much did major events change South Carolina’s 2024 result?
EIA publishes reliability both with all events and with major-event days excluded. We calculate the difference between those two SAIDI values.
Without major events, South Carolina’s SAIDI was about 2.0 hours. The all-event figure was 52.3 hours. This does not mean every household experienced that amount of downtime; SAIDI is a statewide utility-weighted average across reporting customers.
How South Carolina compared with the national total
South Carolina’s all-event SAIDI was 413% higher than the U.S. total of 611.3 minutes in the same EIA table.
Its SAIFI was 55% higher than the U.S. total of 1.521 sustained interruptions per customer.
National all-event CAIDI was 401.9 minutes per interruption versus 1326.3 minutes in South Carolina.
For resilience planning, South Carolina’s 2024 result argues for treating multi-day recharge as a separate requirement from ordinary short-outage battery sizing.
Do not size a battery from SAIDI alone
SAIDI is useful context, but it is not a recommended battery runtime. A home backup system should be sized from the loads you actually need, the outage duration you want to cover and the recharge paths you can depend on.
South Carolina reliability snapshot
“Without major events” values remove major-event days under the reporting utility’s applicable method.
| Metric | All events | Without major events | What it means |
|---|---|---|---|
| SAIDI | 3136.5 min | 117.8 min | Annual sustained-interruption minutes per average customer |
| SAIFI | 2.365 | 1.207 | Sustained interruptions per average customer |
| CAIDI | 1326.3 min | 97.6 min | Average restoration minutes per sustained interruption |
EIA reported customer coverage for South Carolina: 96.5%. EIA notes percentages may occasionally exceed 100% because reliability-meter counts and customer-count denominators come from different survey schedules.
What this report can tell you
It shows the statewide scale of sustained distribution interruptions in one calendar year, separates major-event and non-major-event reporting, and makes it easier to compare South Carolina with the national benchmark and other states.
It is useful for understanding why a backup plan needs both stored energy and a realistic recharge strategy.
What it cannot tell you
It cannot predict the next outage at a specific address. Utility territory, feeder design, vegetation, weather, local construction and restoration priorities can produce reliability very different from the statewide average.
Use the state reliability explorer to compare other states and the national study for methodology and full rankings.