In 1859 the world was hit by an EMP from a massive solar flare, called the Carrington Event. From a comment by Sampenny in the original article.
The Carrington event was a direct hit of a solar-generated EMP, and it destroyed some portion of the very primitive electronics of the time: the telegraph that connected batteries through a coding key to an electrical line stretching across the country-side. The electrostatic disturbances lasted more than a day, and the most obvious effects were the aurora borealis shining around the world. A few years ago the earth missed an equivalent event by just a couple of days of orbit, only now our entire society depends on electronics that fries when subjected to the kind of EM fields that will enter our grids when such as event does occur
More recently in March 1989 we had a geomagnetic storm which caused a massive blackout in Quebec. It was repaired in 9 hours, but a more massive widespread storm could take months.