Grid reliability · 2024 · 22 reporting utilities

Power outages in South Carolina

The utilities that reported here serve 2,777,406 customers between them, not the whole state. Weighted by customer count, they averaged 116 min without power in an ordinary year and 53 hr once major events are counted. Each figure comes only from the filers that published it, and the counts are below.

What it means

Why there are two numbers

Across the utilities that filed both figures, major events account for 96% of the outage time South Carolina recorded once they are counted: 53 hr against 116 min without them, a factor of 27.2×. Solar panels alone do not help during an outage, because a grid-tied array shuts down when the grid does, so riding through one is a battery question. This figure will not answer it: it is an annual average across a utility’s customers, not the length or the load of any single outage. What it does say is how much of the outage time here arrives with major events rather than on ordinary days.

The comparison is drawn from the 22 utilities that filed both figures, which is all of them, so both sides of the ratio describe the same set of customers. The two headline figures above are averaged over everyone who filed each one, so dividing them would not give this number.

Ordinary year116 min30 of 51 jurisdictions, longest first · 22 filings

With major events53 hrStorms, ice, and fires included as filed · 22 filings

Interruptions a year1.2×Ordinary year; 2.4× with major events

The bill sideWhat solar offsetsRates and modelled output by utility

The utilities behind the average

Each of South Carolina’s figures is a customer-weighted average of the filings that carried that metric, not of the table as a whole: the ordinary-year average is built from 22 filings and the storm-inclusive average from 22 filings, out of 22 filings that published an outage figure at all. Those are the same utilities on both sides. A utility that filed without publishing a metric, or whose two major-event variants contradicted each other, is absent from that metric rather than counted as zero.

Reported interruption metrics for 2024, largest utility first.
Utility	Customers	Ordinary year	With major events	Interruptions
Dominion Energy South Carolina, Inc	816,766	81 min	32 hr	1.2×
Duke Energy Carolinas, LLC	670,391	3.0 hr	130 hr	1.3×
South Carolina Public Service Authority	211,845	55 min	58 min	0.6×
Duke Energy Progress - (NC)	177,876	2.1 hr	4.4 hr	1.2×
Berkeley Electric Coop Inc	130,042	89 min	4.9 hr	0.9×
Horry Electric Coop Inc	95,676	108 min	2.2 hr	1.6×
Palmetto Electric Coop Inc	79,619	32 min	11 hr	0.7×
Blue Ridge Electric Coop Inc - (SC)	72,913	3.2 hr	88 hr	not reported
York Electric Coop Inc	71,302	89 min	16 hr	1.7×
Laurens Electric Coop, Inc	63,495	97 min	138 hr	1.1×
Mid-Carolina Electric Coop Inc	60,406	117 min	65 hr	1.6×
Aiken Electric Coop Inc	52,839	94 min	132 hr	not reported
Santee Electric Coop, Inc	44,910	2.5 hr	7.4 hr	not reported
City of Rock Hill - (SC)	40,379	90 min	10 hr	1.3×
MPD Electric Cooperative	38,491	90 min	3.5 hr	1.0×
Black River Electric Coop, Inc - (SC)	34,494	99 min	3.8 hr	1.3×
City of Orangeburg - (SC)	24,461	4.2 hr	12 hr	2.1×
Lynches River Elec Coop, Inc	22,362	2.7 hr	8.6 hr	1.9×
Edisto Electric Coop, Inc	21,317	4.9 hr	39 hr	not reported
Tri-County Electric Coop, Inc (SC)	18,466	2.9 hr	17 hr	2.3×
Easley Combined Utility System	17,416	94 min	12 hr	1.0×
Greenwood CPW	11,940	34 min	66 min	0.5×

What this page is not

It is a state average of utility filings, not a measurement at any address. Each filing is itself an average over a whole service territory, so a rural feeder and a downtown network arrive here as one number, and nothing in this dataset says how far an individual address sits from it. Nothing here predicts a future year either, and a single severe storm can move a utility’s figure by an order of magnitude.

The methodology page states the sources, the definitions, and the limits. Back to the Grid Reliability Index

Source: U.S. Energy Information Administration, Form EIA-861 reliability file, data year 2024, covering 2024-01-01 through 2024-12-31. The snapshot covers no later period.