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Helios Solar Storm Scenario

The study of solar eruptive phenomena has progressed over the centuries from scholarly recordings of astronomical events, such as sunspots, to advanced modelling of how solar activity may drive geophysical planetary responses, e.g., geomagnetic disturbances. However, there is still a great deal of uncertainty around the potential economic impacts of extreme space weather on modern society. 


In this report, we provide a catastrophe scenario for a US-wide power system collapse that is caused by an extreme space weather event affected Earth: the Helios Solar Storm scenario. 

This scenario is a stress test for managers and policy-makers. Stress tests are important for understanding risk exposure across a spectrum of extreme systemic shocks such as those proposed in the Cambridge Taxonomy of Threats, which encompasses a dozen major classes of catastrophes. A suite of scenarios can be used as a basis for calibrating an organisation’s inherent risk, vulnerability and resilience. 

  • The damage distributions resulting from the extreme space weather event in the standard scenario (S1) show a quarter of US EHV transformers tripped off-line with only 5% suffering any form of damage. 
  • The loss of these assets leads to a power outage initially affecting 90 million US citizens. The majority of those affected have power restored relatively quickly, with only 5% of the total US population being disconnected for more than three days. 
  • The US states most directly affected are Illinois and New York with direct losses from suspended economic activity of roughly $30 billion each in S1. 
  • The total indirect US supply chain shock is similar in size to the direct shock. International supply chain shocks, stemming from both upstream via US imports and downstream via US exports, are estimated to be roughly quarter the size of the overall direct US shock. 
  • At the industry sector level, US Manufacturing has both the greatest direct and indirect shocks, with indirect shocks having a roughly equal split between those that have been induced upstream and those induced downstream. 
  • China, Canada and Mexico, as the three largest trade partners of the US, collectively account for about a third of all indirect international supply chain impacts.