Maybe it's useful when trying to justify solar adoption. If you have control over some level of panel allocation, you could use something like this to explore w

Maybe it's useful when trying to justify solar adoption. If you have control over some level of panel allocation, you could use something like this to explore where you'd want to put panels first -- answering the question of where are you going to make the best economic case for solar panels. Then, once the top places are addressed, you can move onto the second tier of locations, then the third, etc... This could be helpful if you're in gov't and have some control over a pilot neighborhood project. Or a developer that wants to include solar on some homes/businesses and wants to know where it makes the most sense. You're right that this probably isn't too much better than qualitative reasoning about how sunny certain places are, but this is quantitative, so you can have a little more confidence in your qualitative assessment.