Air heat pump or use gas and solar?

There are four options for the solarkollektoren. See attachment. In my view, flat collectors are not an option at all, even though they are cheaper.

I wouldn't necessarily place them on the street side either, so actually only one variant remains.

Addendum:

On this oriented plan, you can see the street side at the bottom left and the other option at the bottom right....

Racking looks like shit, that much is clear. Do they want to rack because it would be more effective or because it "has to" be done to meet the requirements? I would choose the inefficient but visually appealing way and just write off the crap. The alternatives will cost you more. Or you install an air-water heat pump with the known pros/cons.

I will definitely not install an air-water heat pump. Why should I do that if a ground-source heat pump also works?

I might call the building authority on Monday and ask for an exemption to forgo solar.

Whether you have to mount it on a frame because it "must" be done or because it is more effective, I need to inquire about that. Mounting on a frame is out of the question. Especially since the installer also says that when it storms, these things often come loose from their anchors.

I suspect that even if unmounted flat-plate collectors were possible, the whole thing would still be less economical than using the more expensive tube collectors. I think it will come down to the tube collector solution. It looks like what I initially thought. Lying flat on the roof. Interesting how much more expensive they are.

Wasn't the brine heat pump ridiculously expensive for you? I'd rather spend the few thousand on visually acceptable solar collectors instead of taking a brine heat pump at a horror price. Or, priced in the middle of both solutions, pellets. You don't need solar for that, and you need a flue with gas anyway.

And why are the flat ones not an option? Just let them add it on and then the matter is settled.