The good idea is to design the plant process such that they are able to atleast stop in a proper manner with your available minimum back up power it is good to provide UPS for very complicated system. and DG Sets for some big systems. And make a contract to some agency which is able to provide...
this is clear
red-machine breaker is close m/cis running without any fault
green-m/c breaker is open m/c has no load yet
this is standard practice in hydro power station