jafant
If you live far outside of a U.S. city or rural area(s), then, you will not require one.
I'm not sure why you think this. There are many variables in AC power, including how well the utility maintains its system. Living in a rural area is no guarantee of clean power. In farming communities, equipment used by farmers (such as milking machines) can be as much of an influencing factor as manufacturing equipment in urban areas.