On average, U.S. electricity customers experienced approximately five and one-half hours of electricity interruptions in 2022, almost two hours less than in 2021, according to our recently released Annual Electric Power Industry Report. The annual decline was driven by fewer major events in 2022 compared with 2021.
Since 2013, the average duration of electricity interruptions each year has remained consistently around two hours after excluding major events. Major events that cause power interruptions include weather, interference from vegetation near power lines, and utility practices. We measure U.S. electric utility reliability using two indexes:
We measure the impact these major events have on electricity reliability by comparing the SAIDI and SAIFI values of the affected states with the U.S. average (5.6 hours of outages and 1.4 outages per customer). In 2022, the United States had 18 weather-related disasters that exceeded $1 billion dollars in damages per event. Notable major events include the following:
Customers in Florida, West Virginia, Maine, Vermont, and New Hampshire experienced the most interrupted power in 2022, ranging from an average of 10.3 hours in New Hampshire to 19.1 hours in Florida. Nationwide, electricity customers in the District of Columbia, Delaware, Rhode Island, Nebraska, and Iowa had the shortest total electricity interruptions in 2022, ranging from an average of 34 minutes in the District of Columbia to 85 minutes in Iowa.
A higher average frequency of outages, unlike average duration, tends to be associated more with non-major events. Nationwide, Alaska had the most power interruptions per customer (3.5 interruptions on average), followed by Tennessee, Maine, West Virginia, and Vermont, all of which are heavily forested states. Power interruptions resulting from falling tree branches are common, especially because of winter ice and snowstorms that weigh down tree limbs and power lines. The District of Columbia had both the shortest outages and the fewest number of interruptions per customer.
Principal contributor: Alex Gorski