Extreme weather has caused a ten-fold increase in large-scale power outages across the U.S. since the 1980s, according to a new study released by Climate Central on April 10. The average number of weather-related outages doubled in the past decade and comprised 80 percent of all power outages. The study defined weather-related outages by the following criteria: outages that last for at least one hour and are experienced by 50,000 or more customers; consists of a power interruption of at least 300 megawatts; or where the demand for electricity exceeds supply by at least 100 megawatts.
The study found that 147 million customers lost power due to weather extremes since 2003, often for more than an hour, with 15 million losing power on average every year. Since a customer is considered either a home or business, the actual number of people affected by weather-related power outages could be as much as half a billion over the past decade.
The top ten states most affected were Michigan, Texas, Ohio, Pennsylvania, Virginia, Maryland, North Carolina, California, Illinois and Indiana, where much of the electrical distribution networks are above ground and more susceptible to extreme weather. States west of Texas comprised only 10 percent of the total weather-related power outages.
The study was based on 28 years of power outage records from the U.S. Department of Energy’s Office of Electricity Delivery, as well as the North American Electric Reliability Council. The report shows that power outages from extreme weather predominantly result from damage to primary transmission lines and substations, as opposed to localized residential distribution networks.
Where variables such as outage reporting were examined in the analysis, Climate Central found that non-weather-related outages have remained relatively unchanged since 1984, while weather-related outages have doubled despite stricter reporting requirements since 2003. The study also found that such large-scale power outages occurred ten times more frequently each year in the 2000s than in the 1980s and early 1990s.
While the country’s aging energy infrastructure is becoming ever-more susceptible to weather extremes, the Climate Central study found that an increasing incidence of severe weather is the primary contributing factor. The report shows heavy downpours and strong winds have increased by 74 percent in the northeast and as much as 45 percent in the eastern Midwest since 1958.