Photovoltaic Consultation: 45° Gable Roof North/South

With purely north-facing orientation in Saarland, that's about 3,700 kWh p.a. that can be additionally harvested (if that were the case for the OP). Now one can calculate for oneself what the possible yield is and whether it is worthwhile to feed in and/or consume 74,000 kWh over 20 years (heat pump, car, etc.).
Especially in the morning and evening due to the west/east sun, that already makes sense (storage is available anyway).

Yes, one can try to achieve a savings account return from that after a long time, which depends on whether the electronics hold up that long. You can calculate 30-40 years for modules, 12-25 years for inverters. Eventually the contactors wear out. Whether north-facing installation pays off depends on the consumption profile and it must not be a plan made by a pushy salesman.
To the OP:
For the offer with north roof orientation, I would check with which electronics the provider wants to install, especially how many MPPTs and in which voltage ranges they operate efficiently. I know enough offers with several orientations where the poor matching leads to a yield reduction of 30+%. You can fairly well substantiate this technically through the properties of the inverters used.

Thanks, I will keep that in mind. Currently, I am in discussions with companies for on-site appointments for concrete offers; when I have something, I will get back to you. At the moment, there are only "preliminary offers," without an on-site inspection you can't really rely on them. But maybe the rough values are still interesting. 1: 8 kWp, 8 kWh, 17k 2: 14.5 kWp, 10 kWh, 21k 3: 12 kWp, 11kWh, 21.4k I still owe a precise roof planning from my side, I will try to do it tomorrow. The differences in the installed capacity result from how much the windows etc. have already been considered or not by the companies.

On East and West, two modules should fit horizontally at the very bottom and above that, another one horizontally in the center. So that there are 3 modules per side/triangle. I can hardly estimate how wide it is at the height of the gutter.

A 10.5 kWp system (only South) with a 13.5 kWh storage for 20k€ with backup power is planned, otherwise I would have waived the storage due to economic efficiency. The storage costs about 9k€ and is therefore actually (without considering the backup power) very expensive and uneconomical.

Well then, congratulations. The satellite dish should definitely be removed from the roof! What do you use the substitute current for?