It's very expensive, but when we moved to our rural retirement home we had a whole house generator installed. Three days after we moved in, a massive storm hit the area and shut our electricity off for seven days. Our generator ran flawlessly (we were lucky enough to have a natural gas line on our road). We shut it down when away from the house, and at night, and we had neighbors over to get water and take showers.

After that we never doubted our investment.