This whole story referring to a solar superstorm effects on the electrical grid is total BS!!!
That facts stated are just plain WRONG.
The USGS knows nothing about the grid and probably doesn't have the funds to study it.
The USGS is in no way an authority on the electrical grid. Period.
The USGS does track geomagnetic disturbances including Solar activity and CME's (coronal mass ejections).
The authority of the US electrical grid and all operations are the Dept of Energy and NERC. The grid is broken down into many sections (for simplicity) and each section has an Reliability Coordinator (RC) who are responsible for studying and modelling the possible effects of these geomagnetic events (including solar storms). All electric companies must follow the rules and abide by the guidelines of their RC.
This has been studied for decades and is ongoing actively studied.
The geomagnetic danger areas are always the same due to properties in the earths crust.
The middle of the US is in very low danger of the effects of a solar storm.
The danger areas of these geomagnetic storms are always the same areas; the Northeast US and Canada, and Texas into Mexico. Possibly all of Canada.
The US is electrically tied strongly to Canada and we get a lot of megawatts from their large hydro plants.
We are also tied to Mexico, but that favors Mexico mostly.
The risk is to transformers, the storms cause large currents to flow from the Earth ground to the transformers cores. Can trip transformers offline due to relay protective devices, or do permanent damage to the power transformers core windings. Power transformer cores are tied to earth ground through a large copper cable.
Geomagnetic events can cause regional sections of the grid to de-energize due to transformers tripping.
All electrical transmission companies are notified days in advance and continually leading to a geomagnetic event.
The biggest threats are large solar flares.