While transformers themselves may have low impedance, it’s the connectivity and expanse of the grid system that makes them vulnerable during geomagnetic disturbances. The longer the conductive path, the more susceptible the system is to GICs, regardless of the impedance characteristics of individual components like transformers.
An X500-level solar flare would be many times more powerful than the Carrington event and could wreak havoc on our electrical infrastructure. Given our increasing reliance on electricity for everything from communications to transportation, the societal impact would be significant.
Hence, the idea of a Strategic Transformer Reserve isn’t just about preparing for solar storms; it’s a multi-hazard approach that also considers other threats like cyber-attacks, terrorism, or even conventional warfare.
The key question remains: do the potential catastrophic consequences justify the financial and logistical costs of maintaining a transformer reserve? From a risk-assessment standpoint, considering the dire impacts of a severe solar event or other threats, investment in a transformer reserve could be seen as a rational and scientifically justified precaution.
Particularly when the lead time to manufacture such equipment is in the order of years. A grid outage of that duration would be biblically catastrophic: without electricity, we have no water, no gasoline, no communications. We’d survive, but the suffering is not something it seems wise to consider an acceptable cost. Especially at a time of enhanced geopolitical competition, the effect of a storm whose severest effects would likely be localized to the sun-facing hemisphere, seems important not to underestimate.
I think it would be great if, instead of countries merely having arms races, they had preparedness races. I guess for us ape-brained humans, tribalism feels more compelling than a threat you can’t bite the face off.