New carport: 2x heavy current, dimension empty conduit for photovoltaics?

15cm, so 150, sorry.

Thank you very much, I think 4mm² would really be the minimum and maybe, just to be safe, go up to 6...

If you have too much money and fear, then yes. For most 11kW boxes, a flexible cable with 6 is already the maximum that can be attached at all. 2.5 is sufficient—like in the kitchen for an 11kW stove/oven. 4 is already a considerable safety margin. 6 is a waste of money.

Don't forget the LAN cable for the wallbox.

Don't forget the LAN cable for the wallbox.

Is that really the case? The box would only be one wall away from the router... I think WLAN should work fine there... but what are actually the advantages of the wallbox having an internet connection? For vehicle updates?

If the wallbox has a WLAN module and WLAN is available on site, that also works. Since WLAN distribution often has its peculiarities, I am a fan of LAN. When you are just laying cables, LAN often just comes along easily. I would not connect the wallbox to the internet, but only to the home network. You can retrieve the charge status and statistics and make settings. Of course, it also depends on the type of wallbox.