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.