Understanding US Power Outages – By Brian Potter

Summary

Modern civilization relies on electric power for almost everything, and even small disruptions to electric service are incredibly disruptive. Because of this, we demand a high level of reliability in electrical service. In 2023, the average US electricity customer was without power for only 366 minutes over the course of the year, equivalent to a service uptime of more than 99.9%. Other countries do even better: in 2021 the average German customer was without power for just over 12 minutes, an uptime of greater than 99.997%.Because reliable electrical service is so important, I wanted to better understand trends in US power outages. I partnered with Poweroutage.us, a service that provides live and historical power outage data for the US going back to 2017, on a county-by-county and utility-by-utility level. Their API not only gives live outage counts, but the "shape" of outages reported by the utilities. Poweroutage.us tracks approximately 94% of US electrical customers, letting us take a close look at power outage trends in the US.This dataset will let us understand broad trends in US power outages, but let’s first start at the bottom, and look at power outages in a couple of counties. Below are the last seven years of power outages for Cobb County, Georgia (where I live), and Los Angeles County, California (the most populous county in the US). The graphs show power outage minutes per week, where a power outage minute is one customer being without power for one minute.These graphs show two very important facts about power outages.The first is that power outages are heavily driven by a small number of extreme events. Very bad power outages will occur relatively infrequently, but can be hundreds of times worse than the typical week. In the week of October 26th 2020, Cobb County had a huge spike in power outages due to Hurricane Zeta: the 156 million outage minutes that week were about 300 times higher than average. Similarly, Los Angeles had a huge spike in power out...