Germany is struggling to get people on-board with a green energy movement that involves banning high footprint domestic heating systems (e.g. gas boilers)-- thus forcing people to migrate to heat pumps. A low-income family who was interviewed said it would cost €45k to install a heat pump in their terraced home in Bremen.
That price tag sounds unreal. I am baffled. What’s going on here? I guess I would assume an old terraced German home would likely have wall radiators that circulate hot water. Is the problem that a heat pump can’t generate enough heat to bring water to ~60°C, which would then force them to add a forced-air ducting infrastructure? Any guesses?
(note the link goes to a BBC program that looks unrelated, but at the end of the show they switch to this issue in Germany. I’m not sure if that show is accessible… I see no download link but that could be a browser issue)
The issue is that the original radiators were sized to move the necessary n kW into the room with a water temperature of 60C. If you drop the water temperature to say 45-50C, you’re only going to get roughly two-thirds of the heat transfer. The other third needs to be made up somewhere else - additional heating or better insulation.
As you said, running continously is the ideal point for heat pumps. And for a continous load most radiators are big enough. In Germany they were scaled so they could heat up the rooms pretty quickly and then idle for time. Since thats not the goal with a heatpump we can use the idle time to even out the lower peak capabilities. You loose the ability to quickly adapt the room temperture, but with outdoor temperature probes connected to the heatpump this istn an issue. I am in the process of retrofitting my home to a heatpump and that what the engineer told me at least.
A bigger issue seems to be the single-pipe heating vs. two-pipe heating systems, but those are not the majority in germany and should be phased out anyway because they are so inefficient.