Sidewalks are still flat on the ground, which is not great in much of the world (like Normandy) where sunlight comes in at an angle. You would still get some ge

Sidewalks are still flat on the ground, which is not great in much of the world (like Normandy) where sunlight comes in at an angle. You would still get some generation, but would it be worth it compared to cells mounted elsewhere at a better angle, with less need for hardening, and less accumulation of dirt? Doing this on the sidewalks would add a lot of costs and complications.