What causes electrical outages?

September 3, 2024

From American Public Power Association (APPA); Published July 11, 2024

According to data submitted by more than 320 public power utilities to the American Public Power Association’s eReliability Tracker, more than 5.3 million customers were affected by 73,694 sustained outages in 2023. Understanding the causes of these outages helps public power utilities identify and prioritize areas for improvement to retain their reliability edge.

Top 10 causes of outages in 2023:

Tree
Equipment
Squirrel
Unknown
Storm
Weather
Other Wildlife
Equipment Replacement (planned)
Electrical Failure
Bird

Across all regions, public power customers experienced, on average, less than one sustained outage per year, and over an hour less total outage time than customers of other utility types.

Squirrels may be a more common cause of outages, but utility personnel in Groton, SD recently had to remove a racoon from system infrastructure. The critter caused a total of seven electrical blinks in the town of 1,376 before it was removed. Photo/story courtesy Paul Kosel, Groton Daily Independent.

The Biggest Reliability Villains, by Region

No data for Region 10, which includes the five U.S. territories

Region	Top Outage Cause	Outages by Top Cause	Percent of Outages
Region 1	Electrical Failure	220	10.4%
Region 2	Storm	1,492	24.5%
Region 3	Squirrels	1,036	19.2%
Region 4	Equipment	691	8.6%
Region 5	Equipment	2,051	16.8%
Region 6	Storm	502	22.2%
Region 7	Trees	4,436	14.8%
Region 8	Equipment Replacement (planned)	387	14.5%
Region 9	Equipment	841	18.3%

When Outages Occur

The summer months see the highest volume of outages, with nearly 35% of outages occurring in June-August.

eReliability Tracker

The eReliability Tracker is an affordable, easy-to-use mobile-friendly web-based service that provides public power utilities with an effective way to collect, categorize, and summarize outage information. Users can run in system reports to view a monthly snapshot of their utility’s reliability performance, identify problem areas and common outage causes, and calculate IEEE 1366 reliability indices.

Analyzing distribution system reliability is critically important for all utilities, especially those in public power, whose customers are their owners. However, the funding available for many public power utilities to spend on sophisticated software systems is insufficient to keep up with the evolving set of industry leading practices.

The eReliability Tracker provides an easy-to-use software that meets the needs of public power utilities without over complicating electronic outage tracking. A one-year subscription to the tracker costs $325 for APPA members, including Heartland Energy customers.

If you are interested in the tracker, APPA would be happy to set up a webinar to host a walk through of the system. Walkthroughs are normally under an hour in time, and APPA usually provides the option to test the tracker for two weeks if there is still an expressed interest.

If you are interested in a walkthrough, please email Reliability@PublicPower.org.