Blackouts, storms, floods, downed power lines... life without electricity is not only inconvenient, it can be unsafe and frustrating. Several years of severe weather around the country, as well as national jitters, have a growing number of homeowners purchasing standby generators for protection against power outages. Developed originally to bring electricity to rural America, power and light generators have revolutionized the way electricity is used. They have powered everything from communications systems for Admiral Byrd's Antarctic expedition to equipment at the Hoover Dam construction site. At the Silvas' new house, we've installed a natural-gas-powered, 11-kilowatt auxiliary electrical generator next to the new garage to provide power to meet the family's essential electrical needs. Depending on their power capacity, standby generators can power almost everything in your home—heat and lights, security system, well or sump pumps, refrigerator and freezer, water heater, air conditioner, medical support, television or computer for days or even weeks. Here's how they work: a residential standby generator system — a generator and an automatic transfer switch — monitors your utility power and immediately starts the generator during a power failure, even if you're not home. When power has been restored, the switch shuts down the generator and shifts your home back to utility power. The switch also tests the generator weekly to ensure it 's always in working order. Portable generators, a less expensive but more labor-intensive option, must be started manually, require monitoring, and need refueling with gasoline every few hours during use. They should not be operated in a basement or garage. Exhaust fumes, heat and noise, and the risk of fire or carbon monoxide poisoning require that they be used outdoors. All generators, whether portable or permanent, need to be well ventilated. Most residential standby generators are powered by natural gas or liquid propane, fuels that can be piped directly to the unit if you are already using either of them as fuel for your home. Generally a little larger than a central air-conditioning unit, generators are installed outside the house and enclosed in a housing that keeps them ventilated, quiet, and protected from the elements. Residential units range in power from 8.5 to 22 kilowatts, though 11 kilowatts is about all an average home will ever need. The Silvas' system, an 11-kilowatt generator and the automatic transfer switch, cost about $10,000 installed. Whether it's a temporary blackout or larger blowout, an emergency power generator can provide the insurance you need to rest easy in the 21st century.