South Carolina

What This State's Utility Data Tells You

South Carolina has 26 electric utilities reporting to the federal EIA Form 861 survey, of which 24 file full SAIDI and SAIFI reliability metrics. Together these providers serve approximately 2.0 million customer accounts, spanning investor-owned utilities (IOUs), member-owned rural cooperatives, and municipally-owned systems — each with different governance models, rate-setting processes, and reinvestment patterns that shape reliability outcomes on the ground.

The statewide average SAIDI — the mean number of minutes a typical customer spends without power each year — is 180.3 minutes across utilities with reporting data. That falls within the 120–180 minute national benchmark range, indicating performance typical of U.S. distribution utilities. The average SAIFI — the number of outage events per customer per year — is 1.60, meaning South Carolina customers statistically face about one interruption per year on average. Excluding major event days (hurricanes, ice storms, wildfires), the SAIDI figure drops to 131.6 minutes — the gap between that and the headline 180.3 shows how much weather, rather than day-to-day infrastructure, drives outage time in South Carolina.

Within South Carolina, reliability varies widely: the best-performing utility reports SAIDI of 33.8 minutes while the worst reports 453.3 minutes — a 13.4× spread that typically reflects the difference between dense urban distribution grids and long, rural feeder lines. This kind of within-state variation matters when you're deciding where to relocate, choosing between service territories, or comparing reliability against a home-insurance quote. All figures on this page come directly from EIA Form 861, the federal annual electric power industry survey — use the ranked table below to look up specific providers and review their multi-year SAIDI, SAIFI, and customer-count trends.

The U.S. Energy Information Administration publishes the EIA Form 861 dataset every June, covering all licensed electric distribution utilities across the United States. Each utility self-reports interruption duration and frequency under definitions standardized by IEEE Standard 1366; the agency cross-validates the submissions against retail-sales volume and customer counts before release. Major event days, typically severe weather, are reported in a separate column and excluded from the headline SAIDI and SAIFI to keep year-over-year reliability comparisons meaningful. Use these state-level averages as a starting point, then check each provider's underlying multi-year submission on the federal portal before drawing conclusions about a specific utility.