That, and the issues of how to grow food, distribute it, and preserve it.
Most cities, and likely most suburbs out to about 20 miles from the cities would be toast (there would be _massive_ attrition of ferals due to defensive gunfire + dilution to to increasing radial distribution from the center of the city).
Well, the old ones would. Current diesel vehicles are full of asinine electronics that would shut them down too.
("improvements" forced on us by the green weenies)
I don’t think the primary danger is to generating capacity, but to the giant transformers on the distribution grid.
As you may be aware, each of these takes about two years to manufacture, are made only OUTSIDE the U.S. The total world manufacturing capacity is about 10 per year.
So if a substantial portion of the 200 or so in the American grid are fried, there will be no possibility of repairing or replacing them before utter disaster takes place.