Portable, Inverter, or Standby: Which Generator Type Fits Your Home
The three main backup generator types are portable conventional generators, portable inverter generators, and standby (whole-home) generators. Portable models are the cheapest and easiest to buy today but need to be set up and refueled by hand. Standby units cost far more and require professional installation, but they start automatically and can back up more of your home. The right choice comes down to your budget, how much of your home you need to power, and how much hands-on setup you’re willing to do during an outage.
This guide compares the three types side by side, walks through fuel storage safety and shelf life, and shows you how to estimate your own power needs before you shop.
The Three Generator Types Compared
Fossil-fuel generators for home backup come in two basic builds: smaller portable units for temporary use, and larger permanently installed units sized for whole-home power. Both portable and standby generators can run on gasoline, diesel, natural gas, or liquid propane, depending on the model.
- Portable conventional generators. These run the engine at a constant speed regardless of how much power you’re actually drawing. They’re the least expensive option upfront and widely available at hardware and home stores. You have to manually start them, plug appliances in with heavy-duty extension cords, and refuel them by hand throughout an outage.
- Portable inverter generators. These adjust engine speed to match the load you’re drawing, which means they typically burn less fuel per hour than a conventional portable running the same appliances. They also produce cleaner, more stable power, which matters for sensitive electronics. Inverter models are generally quieter than conventional portables, though exact noise levels vary by model and manufacturer.
- Standby (whole-home) generators. These are permanently installed outside the home, similar to a central air conditioning unit, and connect to your electrical panel through a transfer switch. When the grid goes down, a standby unit starts automatically and can power more of your home’s circuits than a portable unit typically can. Standby generators cost significantly more than portable models and require a licensed electrician for installation, in part because the transfer switch has to prevent backfeeding power into utility lines, which is dangerous to utility workers and illegal.
Generator Comparison at a Glance
- Cost: Portable conventional and inverter generators cost less upfront than standby units. Standby generators cost more before you even count professional installation.
- Setup during an outage: Portable units require you to move them outside, start them, and connect appliances by hand. Standby units start automatically with no action needed from you.
- Power capacity: Portable generators are sized to run a limited number of selected appliances or circuits. Standby generators are typically sized to cover more of a home’s electrical needs.
- Fuel source: Portable units commonly run on gasoline or propane; standby units commonly run on natural gas or propane, with diesel used in some larger installations.
- Installation: Portable generators need no professional installation to use with individual appliances, though connecting one to your home’s wiring safely still requires an electrician. Standby generators always require a licensed electrician for the transfer switch and hookup.
- Overload risk: Portable generators carry a greater risk of becoming overloaded or overheated if you connect too much at once, which can cause the generator to fail.
Fuel Storage Safety and Shelf Life
Whichever fuel you choose, how you store it affects both safety and how long it stays usable.
- Gasoline degrades over time and may need a fuel stabilizer added to the tank to prevent spoilage if it will sit for a while before use. Store it only in approved, sealed containers, away from the house and any ignition sources.
- Propane is stored under pressure in its own tank and does not degrade the way gasoline does, which is one reason some households prefer it for generators that may sit unused between outages.
- Dual-fuel generators are designed to run on more than one fuel type, most often gasoline and propane, which gives you a backup option if one fuel is hard to find during a widespread outage.
- Site any fuel storage tank outdoors, safely away from the home, in a quantity that matches your household’s expected usage and how long you might realistically be without power.
Generator Safety Comes First
Generator exhaust contains carbon monoxide (CO), a gas you cannot see or smell that can incapacitate or kill a person within minutes. This applies to portable and standby generators alike.
- Never run a generator indoors, in a garage, basement, crawlspace, or shed, even with doors, windows, or fans open.
- Operate portable generators outside only, at least 20 feet from the home, with the exhaust pointed away from windows, doors, and vents.
- Install battery-operated or battery-backup carbon monoxide alarms on every level of your home and outside sleeping areas, and test them monthly.
- Never connect a generator directly to your home’s wiring without a properly installed transfer switch from a licensed electrician. Backfeeding power into utility lines this way can electrocute utility workers and is illegal.
- Turn off and let a generator cool before refueling it. Never refuel a hot or running generator.
If you already own a well pump, sump pump, furnace blower, or other equipment with a motor, review our companion guide on backup power load calculation for the full step-by-step process, including how to identify running watts versus starting-watt surges.
How to Calculate Your Actual Power Needs
Before you buy any generator, add up how many watts your household actually needs. This keeps you from overspending on capacity you’ll never use, or undersizing a unit that trips or stalls when a compressor kicks on.
- List what you want to run. Walk through your home and write down every appliance or device you’d realistically want powered during an outage: refrigerator, a few lights, phone chargers, a well pump, medical equipment, and so on.
- Find each device’s running watts. Check the nameplate or spec label on the device itself, usually on the back or bottom, or the owner’s manual. Appliance and equipment labels indicate their power requirements.
- Add up your running watts. This total is your baseline continuous load, the amount of power you need just to keep everything running once it’s already on.
- Add the single largest starting-watt surge. Motor- and compressor-driven appliances, like a refrigerator, freezer, or well pump, draw an extra burst of power for a second or two when they first switch on. Find the highest starting-watt figure among your motor-driven devices and add just that one number on top of your running-watt total.
- Make sure your generator exceeds this total. Your generator needs to produce more power than what your connected devices will draw, including that initial startup surge. Turn all devices off before connecting them to the generator, then switch them on one at a time once the generator is running.
If you can’t work out your power needs on your own, ask an electrician for help, especially before any permanent connection to your home’s electrical panel.
Frequently Asked Questions
Is a portable or standby generator better for a home?
It depends on your budget and how much of your home you need to power. Portable generators cost less and work well for running a handful of essential items by hand. Standby generators cost more and require professional installation, but they start automatically and typically cover more of a home’s electrical needs. Permanently installed, stationary generators are generally better suited than portable units for ongoing whole-home backup power.
What’s the difference between a conventional and an inverter generator?
A conventional portable generator runs its engine at a constant speed no matter the load, while an inverter generator adjusts engine speed to match demand. That typically makes inverter models more fuel-efficient and quieter, and they produce cleaner power that’s safer for sensitive electronics.
Can I store gasoline for my generator long-term?
Gasoline degrades over time and may need a fuel stabilizer if it will sit for a while before use. Store it only in approved containers, outdoors, away from the home and any ignition source, and rotate your supply periodically rather than letting it sit indefinitely.
How far from my house does a generator need to be?
Portable generators should run outside only, at least 20 feet from your home, with the exhaust directed away from windows, doors, and vents, to keep carbon monoxide from building up indoors.
Educational Disclaimer
This article is for general educational purposes only and does not constitute electrical, engineering, or safety certification advice. Wattage figures, fuel requirements, and specifications vary by manufacturer, model, and age; always confirm exact figures using your own device’s nameplate or the manufacturer’s documentation. Any permanent connection between a generator and your home’s electrical wiring should be designed and installed by a licensed electrician in accordance with local code. For more on building a full home power plan, see our guide to off-grid power basics, and pair your backup power plan with our food and water storage guide so refrigerated supplies stay protected during an outage. If you’re just getting started with preparedness overall, our prepping for beginners guide covers the broader picture this fits into.