What countermeasures exist to mitigate solarstorm damage to power grids?

"Mitigating this threat could be as simple as outfitting vulnerable transformers with capacitors":

https://www.wired.com/story/sun-storm-end-civilization/

I was thinking about this the other day: a huge solar storm that can wipe out the power grid in continental United States will also wipe out literally every tech company. Google, Apple, Microsoft, social networking companies, none would exist.

On the other hand, companies like Walmart, Costco, Corteva, etc. would still survive and possibly thrive. Amazon would probably end up opening physical stores.

Noticing that one is coming and disconnecting the transformers from the transmission lines (which become long antenas) may be a way...