After the nano bots were released, then it leads end of the electricity age, how did that happened, scientifically ?
While there's a good deal of hand waving, the general idea was that they simply used the electricity themselves. That is to say, the nanobots consumed electricity, and they replicated enough that the population of nanobots was able to constantly absorb and use all the electricity being produced.
I realize this opens a lot of questions around how the nanobots kept themselves going once all the power was gone,but that's how the show explained it. I'll look for a transcript later.