[_ph_]

They aren't in the middle of nowhere, but usually quite a bit away from city centers, for safety reasons. Too far for a hot water line to be practical.

[cinntaile]

Up to 30km is no problem for water between 90-175 degrees celcius, so you reach plenty of cities.

https://doi.org/10.1016/j.apenergy.2018.02.080