Which is more efficient/economical 110 volt 60 cycle or 220 volt 50 cycle in residences?

Well, it depends on where you want to live. It's not like you have a choice in the matter.

To answer your question, neither is any more efficient.

Regarding electrical usage, or billing for power, which is watt-hour, neither is more or less efficient.

Using 220 volt, allows wire size to be smaller, thus initial labor and material costs are less.


May I ask why do you think you have a choice of hertz?