Do severe storms affect air quality in high-population urban centers? Evidence from extreme weather events in Texas

We construct a high-frequency, hourly panel of generation and emissions for the universe of power-generating units in ERCOT, matched to plant-specific attributes, daily pollution concentration readings from the population of outdoor ambient monitors, and combined with quasi-experimental variation from all officially declared severe storm episodes in Texas over 2020–2024. Controlling for hour-of-day and day-of-week relative to storm timing, severe storms lead to substantial and persistent declines in generation from wind and solar facilities. These intermittent generation disruptions are mitigated by increases in output from coal and natural gas plants via sharp spikes in electricity prices and further amplified by elevated electricity demand during storm periods. Such energy mix reallocation results in statistically and economically significant increases in urban NO2 and PM2.5 pollution concentrations, with plant-level emissions of NOx and SO2 increasing by over 50% at fossil-fueled plants located in or near Texas’s major metro areas during hour-day periods when storm impacts are most acute.