"Oops, I think we may have underestimated the power of nuclear tests in space... 🤦‍♂️ #StarfishPrime" - President John F. Kennedy

Jul 09, 1962 - Starfish Prime tests the effects of a nuclear test at orbital altitudes.
https://en.wikipedia.org/wiki/Starfish_Prime

@topher depends...

There is "blind load compensation" at grid level, (similar to any modern - PFC-based PC Power Supply...) and at worst a grid operator will do #LoadShedding like #Eskom does in South Africa all the time to prevent #Brownouts or even do "#SupplyShedding" to prevent "#WhiteOut" aka. Overvoltage / Overcurrent scenarios like German grid operators do all tge time because there's way too much renewable energy at noon and not enough infrastructure to redirect it to consumers so at 240V & 50,5Hz they'll remotely disconnect the rectifiers of #SolarPanels and reject accepting said power into the grid.

Unless you pull a #NEMP like #StarfishPrime which has ]way more EMR by the thousands]( https://en.m.wikipedia.org/wiki/Starfish_Prime ), you won't see any reaction at ppwer grid controllers at all...