You need at least a 205V socket.
No, there are quite a few PS that will handle a S7 from the COMMON 15A 110V socket. The real issue is the number of PCI-E connectors, not the power draw.
I suppose it's possible you could buy a very high end EGVA gold power supply and run it. The 1300 would be at max load so You'd want to go higher.
1210 watts quoted "at the wall" - an EVGA 1300 would have about 10% power reserve, even my favorite Seasonic X1250s have some power in reserve.
The issue is you need 9 PCI plugins 3 for each board over the standard 2 for the S5.
10. one for the controller board. I don't know of any PS that has 9 connectors though, 8 and 10 yes.
Or you could do what I'm tenatively planning to do, run 2 S7 on 3 PS (though I might finally break down and buy some used server PS/breakout boards instead, since I figure I'll be running THESE units for quite a while).