Do we need to invent anything? My understanding is that most of the grid in the US operates on 3 phase, and some buildings (including residential) already have

Do we need to invent anything? My understanding is that most of the grid in the US operates on 3 phase, and some buildings (including residential) already have a 3 phase supply to operate AC and industrial applications. All we are missing is for it to be standard to wire the 3 phase distribution throughout buildings to every outlet (preferably in a backwards compatible manner; in theory converting 3-phase to single phase is just a matter of ignoring a wire. I would assume that a) the grid can handle people doing this and b) doing this with out current 3-phase standard would result in our current single phase standard,