ᐅ Placement of Solar Panels on a Southeast or Southwest Roof?

Hello, we need to decide where to place the solar thermal panels on our roof. There are two options: on the southeast side (red) or the southwest side (blue). The house is rotated about 23 degrees from the north-south axis on the plot. The roof is a cross-gable design. All roof slopes have a pitch of 25 degrees. Who has experience or can offer some advice? Best regards, Steffi33

We chose the east-facing roof. This was the decision of the architect, site manager, and heating technician.

If I remember correctly, I believe I read that a south-western orientation performs slightly better than a south-eastern orientation.

I just realized I have a misconception... the panels are each facing south (rotated 23 degrees toward the west)... so the question would rather be whether the south gable casts a longer shadow on the right (red) or left (blue) side (or at all)?

We have now decided on the "red" side. For us, the deciding factors were the shorter distance to the attic (as Olli mentioned above) and the feeling that this side is more "southern." Best regards, Steffi33.

Hello Steffi,

even if it is probably too late now:
If I were you, I would have also considered your usage patterns.
That means if you usually shower or bathe in the evening, you need the hot water THEN. In that case, heating in the evening would make sense.
If you tend to shower or bathe in the morning, the thermal system should ideally be active under load in the morning as well. However, if you shower very early in the morning (e.g., before work), this might not make much sense since the sun may not be high enough yet.