I finally got around to watching some of the trailers and now see there is a "sciency" reason for the blackout, not a supernatural one. I also didn't realize originally that this series is set 15 years after the lights went out.

It looks like the show's main character is the daughter of the man who knew why everything shut down and a fair bit of the plot seems like it will revolve around the secret of why this happened and, potentially, how to fix things (e.g., in the trailer you see the dad hiding something in a locket before the lights go out, then hands it off 15 years later before his death).

All that said, it looks like it could be a fun show but, in my opinion at least, is one of those shows that requires a healthy dose of suspended disbelief; for example, one of the interviews mentioned that even batteries stopped working.