> 45C is low but not unworkable for a district heating loop,
*55C is on the output, read article first pls
Main problem is that it wouldn't work with buildings designed for higher heating temperature so it is limited to new builds. And it is not limited just to replacing heaters, hot water system is also designed to work with higher temperatures so heat exchanger used would have to be significantly larger
Another one is that load is not constant on both sides and not exactly something that can be increased on demand (unless you're fine with burning cycles just to electrically heat, but that's massively inefficient)
> Main problem is that it wouldn't work with buildings designed for higher heating temperature so it is limited to new builds.
That's no longer the case with modern, multi-stage high temperature heat pumps [1]. These consume more electricity, yes, but still achieve far better efficiency than straight burning fuel or resistive heaters.
[1] https://www.buderus.de/de/waermepumpe/hochtemperatur
I guess technically you could put heat pump at destination but that significantly eats into "free heat" part
And that is why existing installations put the heat pump to production side and then just pipe the high temperature water to district heating network.