That website is not science, its a promotion of a book of fiction. The author has a PHD in history, he claims a level of expertise that he does not appear to actually hold. His book is full of inaccuracies about how EMP would affect various electronic and electrical systems and he's a fear monger on the subject. Isn't he the ding dong who co-wrote some other pseudo-science books and articles with Newt Gringrich? I suggest finding links to useful analysis by professional engineers and physicists.