Ask the Energy Expert
Are you shopping for a generator?
By Tyler Nickell, Assistant Engineer
Q. I'm thinking about getting a generator in case of an ice storm. Can you help me decide what kind to buy?
A. Many home-owners ask this question when snow and icy
weather could be in the forecast. Several factors and questions should be considered and answered before you make a purchase like this, to ensure a safe and positive experience. These include what type of generator to purchase, where to purchase, the kW capacity of the generator, necessary maintenance, and various safety concerns with generator installation and operation.
Should you decide to purchase a generator, consider how you want to use it.
Portable Generators: Smaller, more affordable models are usually referred to as “portable” generators and are available at Lowe's, Home Depot, and local hardware stores. These units will most likely not run an entire home, but will allow a refrigerator, space heater, and some other necessary appliances to function. All items used with a portable generator must be plugged directly into the unit, which should be placed outdoors to mitigate CO exposure.
Standby Generators: Larger units, known as “standby” generators, are most likely only available from electrical supply stores. They are installed so that they automatically turn on when a loss of power is detected through an Automatic Transfer Switch (ATS). Many use natural gas or propane and require no refueling by the homeowner, making the fuel sources easier to handle.
Q. How can I determine the size I need?
A. The generator you consider buying should have adequate kilowatt (kW) capacity for your home. Many portable generators average 5.5kW-8kW with models up to 17.5kW available. (Some generators state capacity in Watts; 1 kW = 1,000 Watts).
Larger portable models may be capable of running the most necessary appliances in your house, but keep in mind that they rely on a fuel tank you must refill. Unless you have more fuel on hand, they have only limited run time. They range in cost from about $1,000 to $3,000 per unit.
Standby generators are usually larger, ranging from 10kW-45kW or more. Most run on liquid propane (LP) or natural gas. Prices range from $3,000 to $16,000 or more.
The load chart shown here can give you some idea of the kW capacity different appliances require to start and to run.
Also keep in mind, as motor loads of the AC/Heat Pump units indicate, the capacity needed to start those units is larger than the running capacity. This must be accounted for when purchasing a generator — particularly a standby generator that automatically restores power to the home.
Q. Are generators difficult to install and maintain?
A. Standby generators should ideally be installed by licensed electricians, but in all cases, Cuivre River must insist that installations meet the National Electric Code to provide safe operation not only for the homeowner but also for our linemen. Improperly installed generator units (generators that don’t use the proper type of transfer switch, or that are hooked up incorrectly) may result in a “backfeed” situation where the generator is supplying power not only to the home but to the primary line outside the home. This can result in serious injury or worse for our linemen or other people in the area that may purposefully or accidentally come into contact with downed powerlines. A good suggestion is to always notify your electric supplier if you are purchasing and installing a backup generator of any design.
Typical maintenance for a generator would include:
Starting the generator on a monthly basis to check its operability,
Monitoring fuel and oil levels for the motor at these times, and
Storing fuel in an appropriate manner, keeping in mind that gasoline loses some energy potential over time, making it less effective as a fuel source.
In all cases, we advise you to check with your electrician and/or the manufacturer of the equipment you will power with the generator to ensure you have the appropriate capacity to run the items you choose.
Also, remember to stagger the start-up of items on the generator, beginning with the largest items (such as AC/Heat) first.
Q. Can I use a generator to power my big screen HDTV.
A. If you are planning to use a generator as the power source for sensitive electronics, such as a TV or computer, make sure the generator has automatic voltage regulation of at least +/- 10%. Sensitive home electronics, which are often expensive to replace, can fail quickly if low or high engine RPMs result in poor voltage.
Find more information at these helpful websites:
For generator safety and general information, contact the Safety Coordinator, ext. 232 or 4733.
For load sizing information, contact the Engineering Department, ext. 392.