Home standby generators basics

Home standby generators are hardwired into your house’s electrical system. In combination with another piece of hardware called a transfer switch, the generator will automatically start when the power goes out, and you won’t be without electricity for more than a minute or so.

Almost all home standby generators get their fuel from city gas or propane lines. The primary advantage of this is that no fuel storage is required – the generator is simply connected to your utility lines and draws fuel when it needs to. The choice between gas and propane is based solely on which is available in your area, there’s no real advantage to either.

Sizing a home standby generator
To choose a generator, you’ll need to know you requirements for both voltage and wattage. Voltage is a measure of the “pressure” of an electric current, while wattage is more like the “volume” of electricity being created. When choosing a home standby generator, you’ll need to know the specific voltage your home uses, then you can pick the model that supplies enough wattage for everything you’ll be running.

In the U.S., almost all homes have 120/240v service, meaning they have two 120v circuits. The two are combined to provide 240v for power-hungry appliances such as electric ranges, clothes dryers, central air conditioning, and water pumps.

Wattage requirements increase with each additional appliance you want the generator to power. The best way to get the right size home standby generator is to have an electrician measure the amount of power your essential appliances draw.  Home standby generators start around 7,000 watts (7 kW) and can easily be as large as several hundred kW.