supposed benefit of centralized boiling of water - heat captured can be used as power source, probably cheaper to boil in one central location than everybody all over town boils water when they need to drink etc.
But evidently I'm wrong in that supposition?
Use a heat pump to boil the water with efficient transferred heat (instead of higher energy generated heat), and some kind of heat recapture from the steam.
The heat used to boil the water could largely be extracted from the steam, to increase efficiency, and speed up condensation.
If this could be done with a small unit, it would be a nice upgrade over the common end-point on-demand hot water heater.
Any temperature water from just under boiling hot, through regular "cold"/room, down to chilled, based on heat recapture level. Always clean.
But I can see I got multiple down votes for this supposition already.
You'd almost need to set up an entirely separate distribution system for it to be more efficient than doing it in the home.