Balcony solar sounds brilliant and probably has clear ROI. Rooftop solar is an awkward middle between grid-scale solar and balcony solar. Rooftop solar might only make sense in developed countries through subsidies.
Actually, there's a lot of unsubsidized solar popping up in a lot of developing countries all over the middle east, Africa, etc. Anything from villas to shanty towns. Reason: local grids are unreliable and solar is affordable enough. Add some batteries and you are pretty much energy independent. Most of that solar goes on people's roofs.
The reason that's affordable there and requires subsidies in wealthier nations is all the nonsense the nanny states we live in come up with to over complicate things. You need certified this and that. Only people in possession of a special license can plug component A into component B, or strip some wires. And then there is the local grid monopoly that throws up all sorts of obstacles.
There's a way around this. Just buy some panels and batteries on amazon and wire up your shed, boat, cabin in the woods, etc. It's all plug and play. You don't need any permits, special skills, etc. And you end up with a system that can provide a couple of KW of power. Not that hard. There's nothing special about a rooftop. You might need a ladder to get there and you might want to take some safety precautions to avoid dropping off.