...is district heating with waste heat, perhaps enhanced by the use of heat pumps to pump heat out of the cooling lines.
Here's some recent examples of operable systems now under expansion, and proposed systems:
China starts building long-distance nuclear heating pipeline.
Construction has begun of a 23-kilometre-long pipe that will transport nuclear-generated heat from the Haiyang nuclear power plant in China's Shandong province to a wider area, State Power Investment Corp (SPIC) announced. The plant started providing district heat to the surrounding area in November 2020...
HTR-PM heating project commissioned
The nuclear heating project of the demonstration High Temperature Gas-Cooled Reactor-Pebble-bed Module (HTR-PM) at the Shidaowan site in China's Shandong province has been connected to the heating grid and put into operation, China Huaneng announced...
Dukovany to Brno hot water heating supply pipeline takes step forward
Czech nuclear power operator ČEZ and municipal heating company Teplárny Brno have signed agreements relating to a 42-kilometre pipeline from the Dukovany nuclear power plant that aims to benefit 250,000 people in the city of Brno...
Systems of this type have operated in Romania, at the Cernovoda reactors, and I believe in the former Soviet Union, they may do so still.
This can - and should - be an element of process intensification. Since the thermodynamic efficiency of a system is a function of the ratio between the ratio cold reservoir and the high temperature reservoir in such a way that the colder the former is, the higher the efficiency, this is a win-win. I note that the working fluid need not be water, although in all current systems it is. The hydrogenation of CO
2 to give DME is exothermic, and the liquefaction of DME can result in temperatures much higher than the boiling point of water. Thus DME can be an excellent heat transfer tool for exploiting a system in which thermochemical hydrogen is generated and electricity is a side product.
In a sustainable world these types of things would be common; we may never have a sustainable world, but one is certainly feasible.
Where electricity is produced by combustion of dangerous natural gas, which dominates most grids in the United States, electric heating is extremely inefficient compared to just burning the dangerous natural gas in a home furnace and thus generates more carbon.