@knud i think you have the same dimension mismatch because lots of people live in flats in a 3D fashion, but roofs are 2D

not to mention the nightmare of arranging access to hundreds of roofs compared to a single farm

i must admit i haven't seen any hard numbers on this, it just seemed obvious to me that installing and maintaining loads of solar in an empty field would be cheaper than doing a couple of panels across each of hundreds of houses. autoconsumption might change that

@benjamingeer