Revealing growing and disparate vulnerability in the U.S. power system: A spatiotemporal analysis of nationwide outages from 2014 to 2023

Power systems are increasingly challenged by a range of external and internal threats that undermine their reliability and resilience. Power system vulnerability, the proneness of the power system to disruptions, can be empirically characterized through the observable manifestations of power outages. However, existing research remains limited in spatial coverage, temporal scope, and analytical consistency, and lacks comprehensive, longitudinal, large-scale, and fine-grained analyses to capture the spatiotemporal dynamics of vulnerability. Recognizing this, we analyzed 179,053,397 county-level power outage records with a 15-minute interval across 3,022 US counties during 2014–2023. Applying a framework encompassing frequency, duration and intensity, we systematically assessed the dynamics of U.S. power system vulnerability. Results reveal an escalating trend over the past decade, with outages becoming more frequent, prolonged, and intense. Nationally, cumulative customer outage time reached 7.86 billion customer-hours, with a median of 0.64 million per-county over the past decade, underscoring significant service disruptions. Coastal regions, especially in California, Florida, and New Jersey, experienced more frequent and longer outages, while some inland areas exhibited higher outage intensity relative to their customer base. Moreover, we observed a strengthening association between social vulnerability and outage metrics over time, indicating that counties with higher social vulnerability experienced more severe and frequent outages, creating “dual-burden” regions where social disadvantage and infrastructural vulnerability compound each other. These findings provide a nationwide and longitudinal characterization of power system vulnerability in the U.S., offering empirical insights to inform practitioners in prioritizing investments for a more reliable, resilient and equitable energy infrastructure.