There’s something funny to me about taking your experience with solar on a small sailboat and extrapolating this to a commercial ferry that would need a very large solar installation that’s funny to me. Something tells me the experience isn’t transferable.

The point isn’t to power the main drive, the point is to preserve energy used elsewhere on the ship.

My experience sailing and dealing with vessels from 30ft to 180ft give me a perspective that you probably don’t.

Providing solar panels along the roof would give the ship a few KWh of power that would otherwise be drawing from the main batteries. This would extend the range of the ship by 5-10%.