Major impacts of weather events on the electrical power delivery system in the United States

Abstract

Weather events are a major source of disruptions to the electrical power grid. This study examines the occurrence and variability of major weather-related electrical power disruptions by utilizing multiple datasets. Our results show that weather is responsible for 50% of all events and 83% of customers affected by them. Thunderstorms are responsible for 47% of weather-related events, while winter storms and tropical cyclones contribute 31.5% and 19.5%, respectively. The median restoration cost for utilities during major storms was ∼$12 million, with a median restoration time of 117.5 h (∼5 days). Tropical storms had the highest median number of customers affected, followed by thunderstorms and winter storms. Fewer mutual aid crews are utilized for thunderstorms than tropical or winter storms. The unique challenges that electrical utilities face from weather events are highlighted with case studies of Hurricane Harvey in Texas (2017), a 2011 snowstorm in the Mid-Atlantic, and severe thunderstorms in Alabama in 2011. We conclude by demonstrating that variations in the number of outage events (r = 0.79) and customers affected (r = 0.65) are primarily controlled by the number of storms. Weather-related power outages continue to be an important cause of power disruptions despite investments in storm outage prediction models and system hardening.