The term ‘Sun Belt’ may not be familiar to you, but you can infer where it originates from by its name. It is a term used in the United States to denote the area of the country located roughly under the 36th parallel. It is the part of the country which gets the most sun and with the hottest climate, as it covers the entirety of the southern border.
It’s a simple question, but when you think about it a bit, the answer may just elude you. You may assume it is done automatically, but to really know what the underlying mechanism is, you need to understand how, for example, solar parking lot lights actually work.