I don’t want to get into the weeds but depending where you camp has a significant impact on what size panel/controller etc. you need to supply a given amount of power. This map shows the theoretical maximum amount of power one can produce from a 100% efficient solar system. In reality current design solar systems are rather inefficient. However using a given system you can see one would need twice the capacity or more in some areas of the US vs. the Southwest. Obviously the map is based on averages so one could expect fluctuations about the mean but for general system sizing the map could be helpful particularly when considering it on regionalized relative terms.
