I installed a Generac 14KW with full auto transferswitch and natural gas hookup earlier this year. It wasn't cheap, but it powers everything; the well pump, sump, AC, lights, TVs, computer, garage, fridge, etc. When the power goes out, it starts up and restores power within 20 seconds. I've run it for nearly 72 hours in two seperate events already this year without fail. It has saved me quite a bundle in ruined food and hotel fees!