A new study has mapped what a powerful solar storm could mean for the United States' electricity network and economy, offering one of the clearest pictures yet of space weather risk.
Using a framework that combines physics, engineering, and economics, researchers estimated the impact of a 1-in-250-year geomagnetic event. The model was tested against measurements from the Tennessee Valley Authority during the 2024 Gannon storm, strengthening its real-world relevance.
The findings show that even a more moderate 100-year storm could leave about 3.5 million people and 91,000 businesses without power, with daily economic losses reaching $1.22 billion. In the most extreme scenario studied, a 250-year storm could affect up to 5 million Americans and more than 135,000 businesses, with total losses estimated at $1.81 billion per day.
Geomagnetic storms begin when the Sun releases plasma and magnetic fields during coronal mass ejections. When that energy reaches Earth, it can generate geoelectric currents that disrupt high-voltage transformers and strain grid operations. The study highlights that these effects are still not fully captured in many existing assessments.
Published in AGU Advances, the research offers a practical roadmap for strengthening grid resilience and improving preparedness for future space weather events. It also points to the value of studying how solar storms could interact with other extremes such as heat waves or hurricanes. The work suggests a future where smarter infrastructure planning helps societies stay connected under increasingly complex natural conditions.
