Standby for Power
A generator can provide days of emergency power. Here's how to choose the right one.
Synopsis: It could be because of a natural disaster. It could be due to a grid malfuntion. Sooner or later, you will have to deal with a loss of power from your utility. That’s when you’ll want to be able to turn to a backup power source: a standby generator. In this article, contributing editor Sean Groom tells you how to choose the right generator for your situation. Generators fall into three basic categories: small portable units; large portable generators; and standby generators, which are large backyard power plants. Generators produce from 5000w of electricity to 50kw, and prices range from around $1000 to $15,000. The article includes sidebars in the PDF below on switch options (manual or automatic) and how you can determine if installing a generator is a do-it-yourself project.
While I was writing this article, a tree branch fell on a power line about a half-mile from my house. The lights, refrigerator, and air conditioner shut off, and my laptop battery quickly gave up. On the plus side, my neighborhood was quiet.
With a permanently installed backup generator, my lights would only have flickered, and the neighborhood would have been a bit louder. Moreover, my family would have had dinner at home, the kids’ clothes might have been washed, and my editor would have gotten this article a day earlier.
Of course, things could have been far worse. It could have taken days instead of hours to restore power, and it could have been winter. Thoughts like that cause many homeowners to buy a backup generator, but what kind do they really need?
Generators come in lots of flavors: sleek and quiet Hondas that would fit in a suitcase, brutish-looking wheeled Generacs complete with a hoisting ring for craning around a job site, and permanently installed tractor-size Kohlers that automatically switch on the moment grid-supplied power fails.
These examples represent the three broad categories of generator sizes: small, portable types for running a limited number of items (up to 3000w); larger, wheeled models capable of running a job site or a house’s essential appliances (4000w to 17,500w); and large, permanently installed standby generators that can power a house’s essentials or provide whole-house backup (7000w to 100,000w).
Three emergency-power strategies
Plugging appliances and lights directly into a portable generator is the most basic power backup strategy. The advantage of a portable generator is that you can use it for construction projects and camping. When it’s used as a home backup generator, however, drawbacks outnumber benefits. It must be outside and away from windows (i.e., not in the garage). Also, running extension cords through the house (often in bad weather) is inconvenient and potentially dangerous, as is refueling a hot generator every few hours. Also, you’re limited in the number of items you can run both by the output rating of the generator and by the number of outlets. Finally, small fuel capacity means that you need to have a large quantity of gasoline on hand for anything but the briefest power interruption.
The next step in backup power relies on a larger portable generator typically a unit on wheels that energizes the house’s circuits through the service panel. This scenario requires a manual transfer switch to disconnect the service panel from the grid and to connect it to the generator, often via a permanently installed exterior inlet. While the generator’s output rating still limits the number of circuits you can power, these wheelbarrow-style portable units come in sizes large enough to power an HVAC system, critical appliances, and lights. With the transfer switch, you can manage the load by switching circuits on and off. Of course, you still have fueling issues, and maintenance routines include testing the engine monthly.
For more photos and information on which generator is best for you, click the View PDF button below.