Global transformer overheating from geomagnetic storms

TL;DR

This paper develops a global risk assessment framework for geomagnetic storms causing transformer overheating and long-term power outages, integrating models of geoelectric fields, transformer thermal behavior, and regional conductivity.

Contribution

It introduces a comprehensive, multidisciplinary model to estimate the probability and impact of severe geomagnetic storms on global power infrastructure.

Findings

A 1 in 10,000 year storm could cause 1% of Europe and North America to experience long-term outages.

The model estimates the risk of transformer overheating and widespread power loss globally.

Assumes 33% spare capacity in high-voltage transformers for risk calculation.

Abstract

Geomagnetic storms occurring due to sustained, high-speed solar winds are known to induce currents in power distribution networks. These geomagnetically induced currents (GICs) can cause high voltage transformers (HVT) to overheat, thus resulting in a catastrophic electricity loss event (CELE). Since significant portions of infrastructures around the world rely heavily on access to electric power, it is essential to estimate the risks associated with GICs on a global scale. We assemble multiple methodologies across various scientific disciplines to develop a framework assessing the probability of a severe geomagnetic storm causing a long-term, widespread power outage. Our model incorporates thermal models of HVT tie bar hot spots, historical geoelectric field estimates, and a global conductivity model to estimate the risk of long-term power outage for regions between -70 degrees and 80 degrees geomagnetic latitude due to transformer overheating failure. Assuming a uniform 33% HVT spare capacity, our analysis indicates that a 1 in 10,000 year storm would result in approximately 1% of the population in Europe and North America experiencing a long-term (months to years) electricity loss.