New model measures economic risks solar storms pose to US power grid

In 1967, a solar storm nearly led to World War III as U.S. leaders feared the Soviet Union was responsible for jamming early-warning radar systems. Despite averted catastrophe due to timely solar forecasts, space weather poses a continuing threat. Solar storms materialize when the sun ejects plasma and magnetic fields during coronal mass ejections, which subsequently interact with Earth's magnetic field and conductive materials, inducing geoelectric fields.

The resulting currents can destabilize power transmission through high-voltage transformers. Despite their potential for damage, quantifying the economic risks of geomagnetic storms has been challenging due to fragmented socioeconomic assessments. To address this gap, Oughton and colleagues have devised a new model that integrates physics, engineering, and economics to estimate the economic consequences of a 1-in-250-year geomagnetic storm in the United States.

When validated against measurements from the 2024 Gannon storm, the model accurately predicted the impact on electric substations and the power grid. According to the model, a 100-year storm may leave 3.5 million people and 91,000 businesses without power, leading to $1.22 billion in daily economic losses. Conversely, a 250-year storm, the most intense scenario considered, could impact up to 5 million Americans and more than 135,000 businesses, resulting in direct losses of about $980 million per day and total losses of $1.81 billion per day.

The research underscores the importance of investing in grid resilience to mitigate future storm-induced disruptions and highlights the need for further investigation into the cascading effects of geomagnetic storms on power systems during simultaneous extreme weather events.