It’s merely a matter of time. The earth will be hit with a big solar flare and cme. Then we’ll find out how the electrical grid responds.
Some say this storm from 2012 would have done great damage, had it hit earth.
Near Miss: The Solar Superstorm of July 2012
July 23, 2014: If an asteroid big enough to knock modern civilization back to the 18th century appeared out of deep space and buzzed the Earth-Moon system, the near-miss would be instant worldwide headline news.

A ScienceCast video recounts the near-miss of a solar superstorm in July 2012.
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Two years ago, Earth experienced a close shave just as perilous, but most newspapers didn't mention it. The "impactor" was an extreme solar storm, the most powerful in as much as 150+ years.
"If it had hit, we would still be picking up the pieces," says Daniel Baker of the University of Colorado.
A similar storm today could have a catastrophic effect. According to a study by the National Academy of Sciences, the total economic impact could exceed $2 trillion or 20 times greater than the costs of a Hurricane Katrina. Multi-ton transformers damaged by such a storm might take years to repair.
"In my view the July 2012 storm was in all respects at least as strong as the 1859 Carrington event," says Baker. "The only difference is, it missed."
In February 2014, physicist Pete Riley of Predictive Science Inc. published a paper in Space Weather entitled "On the probability of occurrence of extreme space weather events." In it, he analyzed records of solar storms going back 50+ years. By extrapolating the frequency of ordinary storms to the extreme, he calculated the odds that a Carrington-class storm would hit Earth in the next ten years.
The answer: 12%.
In their Dec. 2013 paper, Baker et al. estimated Dst for the July 2012 storm. "
If that CME had hit Earth, the resulting geomagnetic storm would have registered a Dst of -1200, comparable to the Carrington Event and twice as bad as the March 1989 Quebec blackout."
Near Miss: The Solar Superstorm of July 2012 | Science Mission Directorate