Occasionally someone builds a house "off the grid." They put a bunch of solar panels on the roof and never connect to an electric company. These folks all use DC in their homes. Why do you suppose that is?

Answer 1

It is not quite true using dc in the homes. Sometimes that is true, but more often the dc is converted by a dc-AC converter, then used.

Why? Sometimes it is cost, sometimes it is "religious", sometimes it is related to political beliefs, in the end, they think it is a good idea.