The kind of outlet one sees for 240V is to keep you from plugging your 120V iPhone charger into it, not because it's any kind of limitation on the grid. You can have European-style (or Australian, or Vietnamese, or...) outlets in your U. S. house if you like, and pull 220V out of every outlet in your house, you'll just have to do a ton of rewiring. (Theoretically; if I've forgotten something, it's because I've never heard of anyone converting a U. S. house to use non-U. S. appliances.)