Buy a portable generator if your outages are occasional and you’re willing to manage cords, fuel, and loads; useful home-backup portables generally run roughly $700 to $1,500 at retail for the unit. Buy a standby generator if outages are frequent or long, you travel, or medical equipment depends on power; you’re paying thousands more for automatic, whole-home, hands-off backup.
That’s the real split: a portable is cheaper and flexible, but it needs a person to set it up and feed it fuel. A standby costs far more after professional installation, but it starts itself, transfers power by itself, and keeps running from natural gas or a large propane tank.
The decision in one table
Here’s the clean homeowner version. These figures use manufacturer-published specs for a large open-frame portable and a whole-home standby, plus the fuel and safety guidance covered in detail below.
| Factor | Portable generator | Standby generator |
|---|---|---|
| Cost class | Useful home-backup portables in the 7,500-12,000W class generally run roughly $700-$1,500 at retail for the unit. | Costs thousands more after professional installation, with price driven by pad, gas plumbing, electrical work, permits, and the home’s panel setup. |
| Watts | A large example like the Westinghouse WGen9500DF is rated 12,500 starting / 9,500 running watts on gasoline, and 11,200 / 8,500 on propane. | A Generac Guardian 22kW model 70432 is rated 22,000W on propane and 19,500W on natural gas, per Generac’s published spec. |
| Starts itself | No. You roll it out, connect it, start it, and manage the loads. | Yes. The automatic transfer switch starts the unit and switches circuits without you being home. |
| Fuel | Gasoline or propane, depending on the model. Gasoline needs rotation; untreated gasoline degrades in about 30 days per Honda’s guidance. | Natural gas from the home’s line, or propane from a large tank. |
| Runtime | The WGen9500DF runs about 7 hr at 50% load on a 20-lb propane tank, per Westinghouse’s published figure. | Natural gas can run indefinitely if the utility supply stays on. Propane runtime depends on tank size and load. |
| Noise | Open-frame portables in this class run about 72-74 dBA. Inverter portables can be 52-61 dBA but cost more per watt. | The Guardian 22kW is rated 67 dBA at its weekly self-test, per Generac’s spec sheet. |
| Install | Needs a safe connection plan: heavy cords to appliances, or an interlock kit/manual transfer switch installed at the panel. | Requires professional installation: concrete or composite pad, gas plumbing, electrical work, permits, and inspection. |
| Maintenance | You maintain the engine, keep fuel fresh, and store cords, covers, and propane or gasoline. | You still maintain the engine, but the unit is permanently connected and includes weekly exercise on many systems. |
If you want the shortest answer: buy the portable when budget matters most and you’ll be home to run it. Buy the standby when power loss is a serious household risk, not just an inconvenience.
What a portable really gets you
A portable generator gets you a lot of backup power for the money, but it does not give you a whole-home automatic system. You’re buying a machine you can roll out, fuel, start, and connect during an outage.
The Westinghouse WGen9500DF is a good worked example because it sits in the big home-backup portable class. Westinghouse lists it at 12,500 starting watts and 9,500 running watts on gasoline, or 11,200 starting watts and 8,500 running watts on propane. That is enough for a refrigerator, well pump, furnace fan, lights, electronics, and selected household loads if you manage what runs at the same time.
That last phrase matters: load management. A portable in this class can feel huge compared with a small campsite generator, but it still cannot pretend to be a fully automatic whole-home system. Big loads need planning, and you may have to choose between appliances instead of running everything like utility power never dropped.
The WGen9500DF also has remote start and a transfer-switch-ready L14-30R outlet, per Westinghouse’s published figures. That outlet matters because the clean way to feed selected house circuits is through an interlock kit or a manual transfer switch installed at the panel. If you’re shopping this wattage range, our guide to the best 12000 watt generator class will help you compare similar big portables.
Do not backfeed a house with a dryer cord. That is not a shortcut; it is a dangerous setup that can energize utility lines, hurt a lineworker, damage equipment, and leave your household without proper protection. A portable that powers house circuits needs a proper interlock kit or manual transfer switch installed at the panel.
The upside is flexibility. You can use a portable at home, at a jobsite, or with an RV if the setup matches the load. You also avoid the big permanent-installation bill that comes with standby power.
The downside is labor during the exact moment you least want it. You may be setting up in rain, wind, heat, or darkness, then checking fuel every few hours. If you’re away when the power fails, the portable does nothing until a person gets it running.
Check the Westinghouse WGen9500DF price on Amazon →
What a standby really gets you
A standby generator is the better answer when the outage plan has to work without you. It sits outside permanently, watches utility power, starts automatically, and transfers power through an automatic transfer switch.
The Generac Guardian 22kW, model 70432, is the clean example here. Generac’s published spec lists 22,000W on propane and 19,500W on natural gas. It also lists a 200-amp automatic transfer switch, Wi-Fi monitoring, True Power with less than 5% total harmonic distortion, a Wisconsin-built G-Force engine, and a 5-year limited warranty.
The automatic transfer switch is the heart of the standby difference. When utility power drops, the system starts the generator and switches the connected circuits by itself. When utility power comes back, the transfer switch moves the house back and the generator shuts down after its cycle.
That hands-off behavior is what you’re paying for. If you travel, have an elderly parent at home, keep medical equipment powered, or cannot stop work every time the grid blinks, automatic backup is not a luxury feature. It is the feature.
The Guardian 16kW is the smaller whole-home entry in Generac’s lineup. The right size depends on the house, the fuel, and which loads you expect to carry. A good installer should ask about HVAC, well pumps, refrigerators, sump pumps, kitchen loads, and any medical or work equipment before recommending a unit.
Fuel logistics are also different. A natural-gas standby uses the home’s gas line, so it can run as long as that service remains available. A propane standby runs from a large propane tank, which means the tank size and refill access matter before storm season, not after the roads are blocked.
Generac’s published fuel-consumption spec for its 18-kW model gives a useful planning reference: 1.70 gal/hr of propane at 50% load and 3.02 gal/hr at 100% load. That is why multi-day propane standby backup is 250-gallon-tank territory, not a couple of grill bottles on the patio.
The tradeoff is that a standby is not a weekend plug-and-play purchase. It needs a concrete or composite pad, gas plumbing, electrical work, permits, and professional installation. Those pieces vary enough by home that a single web quote can mislead you fast.
Check the Generac Guardian 22kW price on Amazon →
Total cost honesty
The portable side is easy to frame. Useful home-backup portables in the 7,500-12,000W class generally sell for roughly $700 to $1,500 at retail for the generator itself. The product boxes on this page show live unit pricing, so use those for the current number rather than trusting any fixed price in an article.
That portable price does not automatically include the safest house connection. If you want to feed a panel instead of running cords to individual appliances, you need an interlock kit or manual transfer switch installed by someone who knows the panel and local rules. That added work is still usually far below the cost class of a permanently installed standby system, but it is not the same as buying only a generator and calling the job finished.
The standby side is where bad advice gets expensive. The generator is only part of the cost. The final installed system also depends on the pad, trenching or gas routing, meter or propane supply, electrical labor, automatic transfer switch setup, permits, and the condition of the existing panel.
That is why we do not recommend trusting a single installed-cost number from a search result. Get multiple installer quotes for your actual house, then compare what each quote includes. One bid may include gas plumbing and permits; another may leave those as separate line items.
For a broader money breakdown, read our guide on how much a generator costs. Use it to understand the cost buckets, then use local quotes to price the real job.
Runtime and fuel logistics
Runtime is where many portable buyers get surprised. A large dual-fuel portable can run strong loads, but it still runs on fuel you stored, carried, and connected. Westinghouse’s published figure for the WGen9500DF is about 7 hr at 50% load on a 20-lb propane tank.
A 20-lb propane tank is about 4.7 gallons equivalent. That’s handy for short outages and easy storage, but it is not a multi-day whole-house fuel plan. For long outages, you either need more cylinders, larger propane storage, gasoline rotation, or a standby tied to natural gas or a large propane tank.
Gasoline has the biggest storage headache. Honda’s guidance says untreated gasoline degrades in about 30 days, so a gas-only plan needs rotation and treatment discipline. Stale fuel during an outage is a common way to turn a good generator into dead weight.
Propane stores indefinitely, which is why dual-fuel portables are popular for backup. You can keep propane on hand without the same degradation clock as gasoline. The tradeoff is that propane output is usually lower than gasoline output on the same machine, as the WGen9500DF ratings show.
Natural gas is the easiest runtime setup when it is available and the utility service stays up. A standby connected to natural gas does not need you hauling fuel. It can keep running outage after outage without you watching tank levels in the same way.
Propane standby owners need to think like fuel planners. Generac’s 18-kW fuel-consumption figure of 1.70 gal/hr at 50% load and 3.02 gal/hr at 100% load shows how quickly heavy use can pull down a tank. If you’re leaning that direction, our propane generator guide will help you compare fuel tradeoffs before committing.
Noise and neighbors
Portable generators are usually louder because many are open-frame machines. In the useful home-backup class, expect about 72-74 dBA. That is tolerable for emergency power, but it is not something most neighbors want running close to a bedroom window all night.
The Generac Guardian 22kW is rated 67 dBA at its weekly self-test, per Generac’s spec sheet. That is quieter on paper than a typical big open-frame portable, though placement still matters. Sound bounces off fences, siding, and tight side yards.
Inverter portables can be much quieter, with published ranges around 52-61 dBA. The catch is cost per watt. If your priority is quiet power for a refrigerator, electronics, and a few essentials, an inverter portable can make sense; if your priority is running major home loads, you’ll pay more to get there.
Noise also affects how you operate during long outages. A portable may need to run close enough for cord reach but far enough for exhaust safety. A standby is permanently placed during installation, so the installer should consider windows, property lines, airflow, code requirements, and service access before the pad goes down.
Safety: the CO difference
Carbon monoxide is the killer risk with portable generators. Run a portable at least 20+ feet from the house, with the exhaust pointed away from doors, windows, vents, crawlspace openings, and garages. Do not run it in a garage, on a porch, in a shed, or under an overhang.
Put a battery-powered CO alarm inside the house. The First Alert CO400 is the one we link here because it is battery-powered, uses an electrochemical sensor, and carries a 5-year warranty. That alarm is not a substitute for safe placement, but it is a necessary backup layer.
Distance matters even when you think the wind is helping. Wind can shift, and exhaust can pool around openings. For more placement detail, read our guide to generator distance from the house before you run any portable during an outage.
Standby units are safer in normal use because they sit outside permanently with exhaust engineered away from openings. That does not mean they are zero-risk or maintenance-free. It means the installation is designed around outdoor exhaust, proper clearances, fuel connection, and automatic operation instead of a homeowner improvising in bad weather.
The other major safety issue is electrical connection. Cords to appliances are simple, but house-panel backup must use an interlock kit or manual transfer switch for a portable. A standby uses an automatic transfer switch, which isolates generator power from utility power as part of the system.
First Alert CO400 Carbon Monoxide (CO) Detector, Battery Operated Alarm, 1-Pack
Check the First Alert CO400 alarm price on Amazon →
Which one is right for you
Occasional-outage suburbanite
Buy a portable generator and add a proper interlock kit or manual transfer switch if you want to power selected circuits. This is the best fit if outages are occasional, someone is usually home, and you’re comfortable managing fuel and loads.
A big dual-fuel portable gives you enough muscle for a refrigerator, furnace fan, well pump, lights, electronics, and similar essentials with load management. Keep propane or fresh gasoline ready, store your cords where you can find them, and practice the startup process before storm season.
Hurricane-alley homeowner or work-from-home household
Buy the standby if outages are frequent, long, or costly. If the house has medical equipment, remote work gear, sump pumps, refrigeration needs, or family members who cannot safely handle setup, automatic backup earns its keep.
This is also the better fit if you leave town often. A portable cannot save a freezer or power a medical load while nobody is there to roll it out. If storms are your main risk, compare broader storm-ready options in our best generators for hurricane guide.
Renter or tight-budget buyer
Buy a portable, and consider a quieter inverter portable if your loads are modest. You may not be allowed to install a standby system or modify the electrical panel, so focus on safe cord use, CO placement, and realistic essentials.
A renter’s plan should be simple: refrigerator, small electronics, lights, and maybe a fan or other critical device, depending on the generator. Do not try to power the rental panel with a homemade cord. If you cannot install proper transfer gear, use cords directly to appliances and follow the 20+ foot CO rule.
Bottom line
For most budget-conscious homeowners with occasional outages, a large portable generator plus safe connection gear is the better buy. It costs far less, can cover the essentials, and gives you flexibility if you’re willing to manage fuel and loads.
For frequent outages, long storm seasons, travel, medical equipment, or true hands-off backup, buy the standby. The extra money pays for automatic transfer, higher whole-home capability, better fuel logistics, and a system that works even when nobody is home.
Whichever way you go, plan for maintenance before the next outage. Our guide on how long a generator lasts explains what affects service life and why neglected fuel and maintenance shorten it fast.
Frequently asked questions
Is a standby generator worth it over a portable?
Yes, if outages are frequent, long, or dangerous for your household. A standby costs thousands more after professional installation, but it starts itself, transfers power automatically, and can run from natural gas or a large propane tank. A portable is the better value for occasional outages if you can manage cords, fuel, and loads.
Can a portable generator power a whole house?
A large portable can power selected house loads, not everything like utility power. A model such as the Westinghouse WGen9500DF is rated 12,500 starting / 9,500 running watts on gasoline, which can cover essentials like a fridge, well pump, furnace fan, lights, and electronics with load management. Big appliances may need to be staggered.
How much does standby installation cost?
Standby installation typically adds thousands of dollars, but the real number depends on the home. Pad work, gas plumbing, electrical work, permits, panel condition, and transfer switch setup all change the quote. Get multiple local installer quotes and compare what each one includes.
Can I plug a portable generator into my house?
Only through a properly installed interlock kit or manual transfer switch at the panel. Never use a dryer-cord backfeed or any homemade backfeed setup. If you do not have transfer gear, run heavy-duty cords directly to appliances and keep the generator outside.
How long can each run continuously?
A portable runs until its tank or cylinder needs refueling; the WGen9500DF is listed at about 7 hr at 50% load on a 20-lb propane tank. A natural-gas standby can run indefinitely as long as gas service remains available. A propane standby can run for days with a large tank, but fuel use is load-dependent; Generac lists its 18-kW model at 1.70 gal/hr at 50% load and 3.02 gal/hr at 100%.
Are standby generators quieter?
Usually, yes compared with big open-frame portables. Open-frame portables in this class run about 72-74 dBA, while the Generac Guardian 22kW is rated 67 dBA at its weekly self-test. Inverter portables can be quieter at 52-61 dBA, but they cost more per watt.
What size standby generator do I need?
It depends on the loads you want to run, the fuel type, and your panel setup. Generac’s Guardian 16kW is the smaller whole-home entry, while the Guardian 22kW is rated 22,000W on propane and 19,500W on natural gas. Have an installer size the system around HVAC, well pump, sump pump, refrigerators, medical equipment, and work needs.
