That is how it has to be done. It doesn't triple anything actually. On a floor circuit breaker lighting panel you have two hots in the breaker panel and a hot feed as well from the generator with a transfer switch that runs off the utility as well when power is available. You are actually running 3 phase service to all breaker panels and taping each phase for lighting and outlet circuits. Simply cut off every third breaker and you cut a third of the light load. Again make certain it is not the emergency power circuits.
We used to keep a third of the lights off anyway as it was too bright. That left us a spare to turn on when doing repairs on the other circuits. All modern hospitals are wired this way and actually it saves on wire and operation cost doing it this way. A bit technical but cheaper. I'm a retired Maintenance Mechanic and was an electrician and HVAC Mechanic in health care facilities.
All hospital floors are wired three hot conductors per breaker box and you still can only put so many lights per breaker anyway. For every two hot conductors of different phases you use one neutral which carries the load unbalance thus saving the cost of one wire. The same on the electrical outlets.
Now if they want to cut their heat load as well to make cooling cheaper close all curtains facing the sun :>} A significant drop.
Good, interesting reply. Thanks, i learned something new today.
Its not the issue what the best and quickest way to do something might be.
There are unions involved. Where there are unions, there is OT, needed or not.