Average US Household Experiences Six Hours of Power Interruptions Annually

The U.S. Energy Information Administration (EIA) released statistics revealing that the average U.S. household experienced nearly six hours (5.8 hours to be exact) of power interruptions in 2018 (the most recent annual statistics available).  Although this is a bit of a good news / bad news story, personally this is a higher number than I would like to see.

Annual Trends for U.S. Power Interruptions

I see this as a good news / bad news scenario because of how the 2018 data compares to recent historical trends.  Specifically, although the average number of interruption hours in 2018 declined from nearly eight hours in 2017, the number is still substantially higher than the average for the four years from 2013 to 2016.  Generally, the annual average was 4 hours or less during each of these four years, which makes the 2018 total about 45% higher and the 2017 average seem like an anomaly. 

As you know, the frequency and severity of power interruptions varies across the 3,000 electric systems in the U.S. based on many factors.  For example, in 2018, South Dakota households experienced 1.5 hours of interruptions whereas North Carolina households suffered through a whopping 30 hours of interruptions, mainly due to Hurricane Florence and Hurricane Michael.  To help flatten out this geographic variability, the EIA calculates the System Average Interruption Duration Index (SAIDI) metric, which is the total time an average customer experiences an interruption lasting longer than 5 minutes. 

Interestingly, the duration of service interruptions that do not involve a weather event is relatively flat over the past 6 years (about 2 hours per year), so the total number of interruption hours is essentially driven by the number of weather events that occur during a year.  Based on the data, there were more service-interrupting weather events like hurricanes and forest fires in 2017 and 2018 compared to the previous 4 years.

So, what does this mean from an emergency preparedness perspective?  In my opinion, the relative increase in weather events requires an even greater focus on emergency planning to maximize reliability and minimize restoration times.  And thanks to climate change, I’d expect this weather volatility to increase over time.  So, don’t let up and let’s keep fighting the good fight so that we can consistently deliver maximum value and service quality to our customers.