I've always thought municipal hot water systems are a good idea. Maybe warming water in buffer tanks to supply to homes for hot water and heating writ large a few hours or days later is a feasible buffer?
Municipal hot water systems would suffer from significant heat losses in the piping between the heating plant and the houses, not to mention the huge infrastructure expense of running an extra set of hot water lines throughout a municipality.
What I was describing is more along the lines of dispatchable electric heat pump water heaters in houses. These type of water heaters are already available today, and we should be replacing every natural gas water heater with them.
I would totally be a huge infrastrucre cost. That said many water systems are due for overhauls in the coming years anyways.
However, heat loss is not a significant issue. These systems were installed in Scandinavian countries as well as in a lot of the Soviet Union, with heat losses of 9% and less achievable. This compares favorably with ~5% power losses in the grid. Water stores heat very very well.
The main advantage is that while yes it is a bit less efficient for waste electricity, it allows nuclear power plants, data centers, and other waste heat-producing industries to recuperate 80+% of heat losses, and crucially when heating is a big cost, thermal solar is about 3x more effective than photovoltaic.
This system would make it possible for 100% of heating carbon emissions to be eliminated, all the time, while at the same times allowing for buffer tanks to soak up excess electricity supply.
