Is Your Generator Ready for an Extended Outage?

Standby vs. portable: what's the difference?

A standby (whole-house) generator is permanently installed outside the home, connected to the home's electrical system through a transfer switch, and typically fueled by a utility natural gas line or a propane tank. It is designed to start when grid power fails. A portable generator is moved into position when needed, usually runs on gasoline (some models also accept propane), and powers selected appliances through heavy-duty extension cords or, if properly installed, a transfer switch.

The practical differences are fuel logistics, how much of the house is covered, and how much you have to do in the middle of a storm. A portable generator means refueling by hand and placing it safely outdoors every time. A standby generator removes most of that work but depends on its fuel supply, its installation and its upkeep. Either way, sizing should start from the essential-loads inventory described in our power outage guide.

Carbon monoxide: the non-negotiable rules

The CDC reports that more than 400 Americans die each year from unintentional carbon monoxide poisoning not linked to fires. CPSC identifies portable generators as one of the leading causes of post-storm CO deaths. The rules below come directly from CPSC, CDC and Ready.gov guidance.

• Never run a portable generator inside a home, garage, basement, crawlspace, shed or other enclosed area, even with doors or windows open (CPSC).
• Operate it outdoors only, at least 20 feet from the home, with exhaust directed away from windows, doors and vents (CPSC, CDC).
• Install CO alarms (battery-operated or with battery backup) on every level and outside sleeping areas; interconnected alarms are best. Test them monthly (CPSC).
• Consider portable generators with a CO shut-off feature; CPSC notes models certified to PGMA G300-2023 and UL 2201-2023 include CO safety technologies.
• Know the symptoms: headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion. People who are asleep can die before symptoms appear (CDC). If an alarm sounds, get outside and call 911 (CPSC).
• Using fans will not prevent CO build-up in the home (FEMA).

Transfer switches and why backfeeding is dangerous

Plugging a generator into household wiring without the proper equipment is dangerous. FEMA explains that hooking a generator directly into your home's power supply can send a surge to outside power lines and potentially injure or electrocute an unaware utility line worker, and that it bypasses some built-in household circuit protection. Ready.gov's evacuation guidance likewise warns against connecting a generator to your home's electrical system.

FEMA's recommendation is to have a qualified electrician install the appropriate equipment in accordance with local electrical codes, or ask your utility company to install an appropriate power transfer switch. Without a transfer switch, connect appliances to a portable generator using heavy-duty extension cords (FEMA, Ready.gov).

Fuel: the hidden weak point

Every generator is only as reliable as its fuel. For gasoline and other portable fuels, FEMA advises storing fuel outside living areas in properly labeled, non-glass safety containers, away from fuel-burning appliances, and turning off and cooling the generator before refueling. Ready.gov notes that gas stations may be closed during emergencies and unable to pump gas during power outages, so a plan that depends on buying fuel mid-outage is fragile.

Can a natural gas generator run during an extended outage? Generally, yes, as long as gas keeps flowing to your meter, which is why piped natural gas is a popular standby fuel. But it is not guaranteed. The U.S. Energy Information Administration documented that extreme cold in February 2021 caused the largest monthly decline in U.S. natural gas production on record, down 8.1 billion cubic feet per day (7%) from January, largely due to well freeze-offs. EIA also reported that Winter Storms Elliott (December 2022) and Heather (January 2024) disrupted weekly production. Production disruptions do not automatically mean homes lose service, but they show the supply chain has limits in severe weather.

Practical steps: ask your gas utility how it prioritizes residential service in an emergency, confirm your meter and line are sized for the generator plus your furnace and other gas appliances (your installer can check this), and keep a small, safely stored backup option for the truly essential loads if your medical or heating needs demand it. Propane users should understand how long their tank lasts at the generator's rated fuel consumption, using the figure in the owner's manual.

Maintenance: follow the manual, not a rule of thumb

Maintenance intervals vary by manufacturer, model, fuel and how much the unit runs. We deliberately do not publish generic oil-change or exercise-cycle intervals. CPSC's guidance is to regularly check and maintain generators to ensure they work properly and to read and follow all labels, instructions and warnings in the owner's manual.

• Find your owner's manual (most are available from the manufacturer by model number) and put the maintenance schedule in your calendar.
• Keep a record of service visits and any warning lights or fault codes.
• Keep the generator dry and protected from rain and flooding; touching a wet generator can cause electrical shock (Ready.gov). Follow the manufacturer's instructions for wet weather (CPSC).
• Keep the area around a standby unit clear as specified by the manufacturer and local code.
• Test your CO and smoke alarms monthly, regardless of generator type (CPSC).