Its a thumb rule of sort! https://globalsolaratlas.info/ https://globalsolaratlas.info/ The red area in the map is the most productive part for Solar and Oran

Its a thumb rule of sort! https://globalsolaratlas.info/ https://globalsolaratlas.info/ The red area in the map is the most productive part for Solar and Orange is partially good. Solar is very geographically dependent, also high altitude is good, that is why Tibet/Colorado is in dark red. Precipitation is a problem for Solar, that is why Florida is OK but not great place for it.