That's a question that most of the blind followers haven't thoroughly thought out that much.
Back in the early 80's NYC area had a hurricane just about like Sandy and we lost power in part of the house, which was weird, the outage lasted from Friday around noon until Sunday afternoon, but at least we still had some lights and could cook, the back of the house where the bedrooms were totally out, but I remember my mother saying, she's just about had it with these lights being out, etc, so I said, how are you gonna live after Armageddon when there won't be any electricity? . . . . no answer.