A surprising (but still tiny) number of US houses also can have three-phase brought out to them by the electric utility. Some utilities will charge you upfront for stringing it up and lighting up the wires, but another surprising number of utilities will just amortize it from the monthly cost of service.

It's still rare enough you have to ask ahead of time if you want it for any building you get into, but in some major metro areas it has gone from "you have got to be joking" to "sure, let me check on that".

Now if only I can find a reliable, durable three-phase solar inverter...