Actually you don't need 50 KW.. I powered the important systems in my house with less than 5KW (About 2KW less in fact) A 5hp motor (Well 6 with loss) could do the job. I do not know what the generator capacity is in that hybrid or if it can. I think the Chevy Volt is a generator/battery/motor system but most of the hybrids are battery/motor/motor from what I know (But than my knowledge is limited).
I have often considered an all electric, with something like a Honda or Yahama 3000-5000 watt inverter generator on board ... This would, in fact, power my house when I had one (I think I measured about 1700 watts per leg, or 3400 total, so the 5,000 models could easily handle it, NO central Air, No Dryer, and we cook with gas. But those are your limits.)