I'll also add that switching to 240V would give us lower line losses everywhere on the grid (saving energy). Just think of all the power wasted in house wiring

I'll also add that switching to 240V would give us lower line losses everywhere on the grid (saving energy). Just think of all the power wasted in house wiring multiplied by millions of households. For an illustration, get out your vacuum cleaner, and vacuum your house. Now that it's been running for a while, grab the power cord: it's rather warm, isn't it? The power also went through your wiring in your walls, through your panel, and up to the transformer for your house, at that voltage. (Even worse, since the US has 120V split-phase power, it was probably unbalanced, leading to even greater line losses.) Doubling the voltage to your vacuum cleaner would mean you'd only waste 1/4 as much energy in the form of heat due to wiring losses, assuming the vacuum has the same-sized motor. Of course, suddenly switching everyone to 240V would also mean millions of vacuum cleaners and toasters going into the landfill, so that wouldn't exactly be environmentally-friendly either.