I installed a 6500 watt Generac generator (runs on gas) back in late '99...yeah I got jittery before Y2K. I do have a gas water heater so that wasn't a concern. Being an electrician I did forego the transfer switch which is still a very good idea as it will automate the start up of the generator (if equpped). I can run my entire house, minus the central air off the unit. I don't regret for a minute having it. I have it parked in the corner of the garage and plugged into a 220 volt receptacle that feeds into a subpanel in the garage which subsequetly feeds the main panel in the house. I color coded all the non-essential breakers and have a main in the garage to put the system on line. I do have to flip the main in the house panel prior to putting the generator on line to keep from feeding back to the road. The only thing that I haven't done yet, but am really thinking is a good idea...a 220v indicator lamp on the line side of the main that will tell me when power is back up.