Grid reliability · 2024 · 43 reporting utilities

Power outages in Tennessee

The utilities that reported here serve 2,725,858 customers between them, not the whole state. Weighted by customer count, they averaged 2.8 hr without power in an ordinary year and 5.8 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 46% of the outage time Tennessee recorded once they are counted: 5.8 hr against 3.1 hr without them, a factor of 1.9×. 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 41 utilities that filed both figures of the 43 reporting here, 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 year2.8 hr11 of 51 jurisdictions, longest first · 42 filings

With major events5.8 hrStorms, ice, and fires included as filed · 42 filings

Interruptions a year1.8×Ordinary year; 2.3× with major events

The bill sideWhat solar offsetsRates and modelled output by utility

The utilities behind the average

Each of Tennessee’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 42 filings and the storm-inclusive average from 42 filings, out of 43 filings that published an outage figure at all. Those two sets are not the same utilities, so the two columns cannot be compared filer by filer. 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
Nashville Electric Service	452,888	87 min	filed, contradictory	1.0×
City of Memphis - (TN)	427,658	4.7 hr	5.5 hr	1.7×
Middle Tennessee E M C	346,813	42 min	49 min	0.9×
Knoxville Utilities Board	220,632	3.2 hr	5.9 hr	1.4×
Volunteer Electric Coop	128,556	7.3 hr	11 hr	5.0×
City of Clarksville - (TN)	85,314	99 min	3.4 hr	1.8×
Duck River Elec Member Corp	84,585	2.7 hr	4.6 hr	2.1×
Johnson City - (TN)	83,793	2.5 hr	11 hr	1.2×
Sevier County Electric System	62,436	3.8 hr	5.5 hr	2.1×
Appalachian Electric Coop	49,902	4.9 hr	15 hr	2.9×
Kingsport Power Co	49,555	2.7 hr	17 hr	1.2×
City of Greeneville - (TN)	40,451	2.1 hr	13 hr	1.8×
Gibson Electric Members Corp	39,835	2.3 hr	5.2 hr	2.4×
City of Dickson	39,146	4.8 hr	5.2 hr	3.3×
City of Jackson - (TN)	38,314	115 min	115 min	1.1×
Sequachee Valley Electric Coop	38,000	4.2 hr	5.0 hr	2.7×
Columbia Power System - (TN)	36,577	2.7 hr	2.9 hr	2.5×
Fort Loudoun Electric Coop	35,442	6.4 hr	7.9 hr	2.6×
City of Cleveland - (TN)	34,449	46 min	61 min	0.8×
City of Bristol - (TN)	34,327	86 min	9.1 hr	1.6×
Holston Electric Coop, Inc	32,442	3.3 hr	15 hr	2.3×
City of Clinton - (TN)	31,000	3.0 hr	4.4 hr	1.0×
Tri-County Elec Member Corp (TN)	28,886	5.2 hr	6.5 hr	3.8×
City of Gallatin - (TN)	26,511	52 min	2.7 hr	0.8×
Powell Valley Electric Coop	26,192	2.3 hr	8.3 hr	3.1×
City of LaFollette	22,994	4.6 hr	12 hr	4.2×
City of Paris - (TN)	22,766	5.1 hr	8.1 hr	4.5×
Maryville Utilities	22,271	62 min	79 min	0.5×
City of Fayetteville	19,575	2.6 hr	3.6 hr	2.0×
Plateau Electric Cooperative	18,207	67 min	95 min	3.5×
City of Morristown - (TN)	16,509	69 min	4.0 hr	1.2×
Mountain Electric Coop, Inc	16,262	2.8 hr	2.8 hr	2.9×
City of Rockwood - (TN)	15,267	3.1 hr	5.4 hr	1.8×
City of Pulaski - (TN)	15,089	2.5 hr	13 hr	2.5×
City of Dyersburg	11,985	16 min	26 min	0.2×
City of Shelbyville - (TN)	11,746	17 min	25 min	0.4×
Bolivar Energy Authority	11,449	111 min	5.6 hr	1.1×
Tullahoma Board-Public Utils	11,215	40 min	56 min	2.3×
City of Milan - (TN)	8,635	not reported	5.8 hr	not reported
McMinnville Electric System	8,284	16 min	31 min	0.2×
City of Winchester - (TN)	6,835	25 min	4.0 hr	0.3×
City of Lewisburg - (TN)	6,662	59 min	59 min	1.0×
City of Ripley - (TN)	6,403	49 min	89 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.