Choosing the Best Home Generator for Your Emergency Needs
Let’s suppose that it’s a hot summer evening and your family is relaxing at home. The air conditioning is flowing happily, your kids are playing video games, your spouse is watching TV, and you are working on the computer. Suddenly, there’s a bright flash of lightning and a clap of thunder. Off in the distance, you hear a deep, muffled boom that shakes the house.
Your lights go out. The air conditioning stops. The video game and TV go black, and your computer shuts down.
You’ve heard this kind of boom before. That was when your whole neighborhood had no power for two days. Hmm… Didn’t you and your spouse plan to discuss buying a home generator at that time?
Having a home generator to kick in when the electricity from the grid fails can be more than a convenience. In some cases, depending on location, time of year, and even medical need, a power outage can be dangerous. However, most homeowners hesitate to install one because they don’t understand how a home generator system works, what fuel options are available, and how to choose one that fits their electricity needs during a power failure.
Looks like you’ve come to the right place.
How a Home Generator Works
Home generators are situated outside the home because they generate electicity by burning fuel (gasoline, diesel, propane, or natural gas). A large capacity generator mounted on concrete pads is called a “standby generator”. Smaller home units that can be carried or mounted on wheels are referred to as “portable”. Solar-powered (and other alternative) battery-back-up systems are also available – and while the initial price per watt tends to be more expensive, they use no fuel and can also be used to reduce your regular electric bill. Also, DC current generators tend to be smaller and (depending on the manufacturer) less expensive than AC portable generators; however, they are mostly used for mobile homes and back-up battery chargers for solar and wind systems.
Basically, electrical output from a home generator runs through a power cable into your home’s electrical panel as soon as the home’s power mains (the electric lines from the grid) are turned off. Because the amount of current is dangerous, you need to install a transfer switch to do this safely. The transfer switch turns off the connection to the grid and then connects to the generator. Likewise, it can be switched back to the grid once power returns. Transfer switches come in manual and automatic configurations, and they are mounted near your electrical service panel (or fuse box).
Standby generators almost always come with automatic transfer switches as part of the package. This means that the switch can sense voltage loss in the grid line, automatically signal the standby generator to start, and then switch over to output from the generator until it senses that grid voltage has returned to normal. Most families that choose standby generators are looking for systems that can seamlessly shoulder their power needs in the event of a power failure.
Portable generators do not usually come transfer switches so these must be purchased. Transfer switches for portable generators should be rated to handle the generator’s surge and running wattage (we’ll get to this later). Most purchasers of portable systems are looking for an inexpensive system that will only be used to power home necessities such as furnace/AC, sump pumps, well pumps, and a few lights. While less expensive, the drawback here is that most portable systems don’t switch on automatically. You have to bring out, connect, and start up the portable generator yourself. You’ll also need to be sure:
- The generator has a grounded connection
- It is kept in a dry location outside your home
- The generator has a sufficient fuel supply
- It is also located a safe distance from your home so exhaust gases are not drawn into your home
- Never operate a generator inside your home or garage or any confined or enclosed space due to carbon monoxide exhaust
Note this last caution in particular. According to a report in the New York Times, “One unintended consequence is the growing number of people — dozens a year — who die from carbon monoxide poisoning because they ran their portable generators in enclosed spaces without enough ventilation for the exhaust.”
Newer standby generators mainly burn natural gas or propane, though a few models burn diesel fuel. For natural gas and propane, fuel is fed from a pipeline (or from a very large propane tank). Standby generators can run for days at a time and match the normal power-demands of the home. Portable generators are available in a variety of fuel types including natural gas, propane, diesel, and gasoline. Naturally, when you are considering a home generator, you need to consider how fuel price and storage convenience will affect your usage of the generator as well as estimating its operating and maintenance costs. Your climate is another consideration, since some generator engines can become troublesome in extreme cold or heat.
How Much Power?
When deciding on a home generator, you should know just what you want to keep running during a power failure. Start by making a list of those things you want to be able to power. Remember, too, that some things like electric motors, TVs, and other electronics use extra power when powering up. This is known as “surge wattage“. For example, a ceiling fan may be rated at 75 watts while it’s running. But, when it is first turned on it uses a half-second long surge of 150 watts to begin spinning. While that might not sound important, consider what happens if you have an air conditioning system, a refrigerator, two ceiling fans, and a TV getting turned on at the same time. That momentary surge wattage could jump as high as 8,000 to 10,000 watts or more. If your home generator and transfer switch here are only rated for handling 5,000 watts, you’re going to have lots of angry words in the dark.
Bear in mind the capacity of your generator system because you may not be able to use all your appliances at the same time. Nevertheless, some people sometimes think they can squeeze just a little bit more electricity out of their generator. Portable generators fail more frequently from being overloaded. For this reason, Energy.gov advises:
Make sure your generator produces more power than will be drawn by the electrical devices you connect to the generator, including the initial surge when it is turned on. Ensure all electrical devices are turned off before you connect them to a generator. Once the generator is running, switch devices on one by one. Shut them down again before switching back to your utility service.
Now that you’ve got the basic information, start looking around at different types of home generators. Consumer Reports offers good, up-to-date recommendations based on size, price, and reliability. Some utilities, such as Centerpoint in Texas , offer rebates on home generators through a participating dealer. After all, the more you learn about home generators, the more empowered you’ll be — and a lot less in the dark.
New York National Guard with Portable Generator image courtesy of The National Guard.