First of all, the Hawaii power grid was not knocked out. It was affected unexpectedly by the high altitude test. It only takes a few minutes to view the youtube video about the test. You might find it interesting background.
Read post 96 and also this peer reviewed paper: http://arxiv.org/ftp/physics/papers/0307/0307127.pdf
While wikipedia is not a technical reference, take a look there under EMP.
What is it you are trying to find or prove/disprove?
You stated that it 'screwed up the Hawaii power grid'.
My point is that it did NOT. Thank you for now acknowledging this and providing an informative link.
"The Hawaiian Electric Company reported no breakdown of power lines nor opening of circuit breakers, nor is there any indication from any source that such things occurred."