Right now, the electrical power I’m using to submit this entry as I watch television in my warm home is being supplied by my Generac Guardian 12kw generator. It’s been running continuously for more than 40 hours now since the latest ice storm left 250,000 people in Maine without power. I’ve had this unit for nearly ten years now, and it has reliably provided power whenever the grid fails, which can happen a few times a year in this pretty rural part of the country.

The exact model I have is a 04456-0 which is 10kw when used on Natural Gas or 12kw when used with LP (Liquified Petroleum) Gas. Ours sits on a small pad in the backyard hooked up to the same buried LP gas tank I use to heat the house, provide hot water, etc. Since the unit is air cooled, there’s no radiator or water pump to worry about. No fan belts. And very little maintenance. Essentially, you have a 5-year battery to replace and an oil change every six months. It “exercises” once a week for 20 minutes and will indicate if there is a problem. The most that’s ever gone wrong with it in all these years was a bad spark plug that I fixed in minutes. Mostly, you ignore it until the power goes out. I test mine in the fall or if I hear a big storm is coming; I do that by walking over to the master breaker switch from the power company and shutting it off. Like clockwork, 45 seconds later the house is lit back up as the generator is up and running.

Most importantly, this generator is automatic. As a volunteer firefighter, I wanted a unit that would start up and run automatically, since when we loose power there’s a good chance I’ll be too busy out on the fire trucks to go dragging a portable out of the garage and wiring it in.

Back about 10 years ago, this kind of permanently-installed generator was less common. The Generac line was really one of the first for consumers. At the time, automatic standby units were for businesses and public safety use. Big commercial units were simply out of the range for home use. My Guardian was purchased and installed professionally — including the transfer switch and wiring — for around $5500. I’m told they’re available for much less now. There are also other products out there — mostly higher-end ones like those from CAT — that are great, but still too expensive for the average rural homeowner.

Honda makes great portable generators, like the previously-reviewed EU Series, which is enough to keep the fridge or freezer cold, or switch over and run the furnace to keep the house warm, but they’re heavy, tricky to set up for many people, and don’t hold as much fuel. At 12kw, the Guardian can run my whole house as long as I don’t go crazy. The electric dryer and the air conditioner in my server room are not connected to breakers served by the generator, but everything else is. We’re careful not to use all the burners on the stove and the microwave and oven all at once, but otherwise, it’s just like being on the grid. The generator burns just under a gallon of LP gas per hour on a light to average load. With the tank I have, I can go several days if need be, which is plenty of time to arrange for a delivery of more fuel. During this blackout, my neighbors have even come over to cook and use the shower while their houses are still without power and they’re struggling to keep enough heat in to keep the pipes from bursting. I can’t think of a better testimonial than that.

My older model doesn’t have Generac’s new “True Power” feature that provides a cleaner power cycle for sensitive electronics, so I use battery backup units with AVR (automatic voltage regulation) on that gear. Newer Generac models provide this themselves. The one linked to below appears to be the newer version of mine in terms of size/market/capability, but it’s only $3k. Given that it includes the transfer switch, that’s a hell of a deal. For a cheapo 1 or 2 kw portable generator and transfer switch you’d pay around a thousand bucks.

— Andrew Pollack

12/22/08