People hardly realize (or straight up don't realize) that once you're in the tropics even the notions of summer and winter start to get fuzzy. Consider: if you're on the equator then you can go from "summer" to "winter" in only a few steps. Obviously, near the equator solar is a no brainer.
And of course the opposite is true, once you're inside the arctic circle solar is basically pointless because there literally is a period of no sun lasting anywhere from several days to several months. Of course not too many people live inside the arctic circle so it's not too much of an issue.
Even between these extremes though, the usability varies a lot.