Simultaneously washing and drying clothes while cooking a turkey in the oven, brussel sprouts in the toaster-oven, boiling water for tea, distracting the children with a computer or tv, doing some welding in the garage, and powering a bunch of Christmas lights. --- This is something that actually happened one year. It is much easier to use a big wire and a big breaker/fuse to the house than to have the power go out.