"alexy" wrote in message
A power failure plunges you into darkness and you
slip against the still spinning blade in the dark.

Your fault. You mean you didn't install a backup power supply on your
lighting?

Aren't you reaching a bit? I know the technology exists for backup power
supplies, but honestly, how many people do you know who have set it up. A
computer, electronic equipment, ok, but general house or workshop lighting?