People ask me this at cookouts, at the hardware store, in the middle of a service call while I’m bolting down a transfer switch. “Marcus, do I really need the big unit, or can I just grab a portable and call it a day?” Fair question. The honest answer is that both are good tools, and picking wrong costs you either money you didn’t need to spend or comfort you’ll wish you had at 2 a.m. in an ice storm.
I spent twelve years pulling wire and installing backup power before I started writing about it. I’ve watched a family run their whole holiday off a $700 portable, and I’ve watched a guy spend $12,000 on a standby unit he barely needed. So let me walk you through the standby vs portable generator decision the way I’d explain it if we were leaning on your fence.
No jargon. Just watts, dollars, hours, and a few stories.
Key takeaways
- Portables cost $400 to $1,500 and cover the essentials; standby units run $4,000 to $12,000 installed and power the whole house automatically.
- A standby generator starts itself within seconds of an outage. A portable needs you outside, in the weather, hauling and refueling it.
- Carbon monoxide from portables kills people every year. Placement and a real transfer setup are non-negotiable.
- Match the machine to your outages: a few short ones a year leans portable; frequent or long ones leans standby.
The short version of standby vs portable generator
Think of it as convenience and capacity on one side, price and simplicity on the other.
A portable is a gas-powered engine on wheels. You roll it out, start it, and run cords or feed a small circuit. A standby generator is a permanently installed machine wired to your electrical panel that kicks on by itself, usually on natural gas or propane.
One asks something of you every single outage. The other asks nothing after install day.
What each one actually costs you
Portable generators
A solid portable runs $400 to $1,500. A quiet inverter model in the 3,000 to 4,000-watt range lands around $900. Add a good transfer switch or an interlock kit and a proper inlet, and you’re looking at another $300 to $700 in parts plus a couple hours of an electrician’s time.
Fuel is the recurring cost. A 5,000-watt portable burns roughly 0.75 gallons of gas an hour under moderate load, so a 24-hour stretch can eat 15 to 18 gallons. During a bad storm, when every gas station within twenty miles is dark, that fuel is the hard part.
Standby generators
Here’s where the number jumps. A whole-house standby unit, installed, typically runs $4,000 to $12,000 depending on size and site work. A 22kW unit that comfortably covers most homes tends to land in the $8,000 to $11,000 range with the pad, gas line, and transfer switch included.
That price scares people off, and I get it. But spread over the fifteen-plus years these units last, and against the fuel-station panic of a portable, it reads differently. If you want the full breakdown, our complete guide to whole-house standby generators lays out every line item.
Runtime and fuel: the part nobody thinks about until hour 30
This is where the two really split apart.
A portable holds maybe 4 to 8 gallons of gas, which buys you 8 to 12 hours before you’re standing in the driveway with a jerrican and a flashlight. You do that again. And again. Gasoline also goes stale in a few months, so the can in your garage from last summer may not even fire the engine.
A standby unit runs off your natural gas line indefinitely, or off a big propane tank for days. On a job last winter, a client’s 20kW ran nine days straight on utility gas without anyone touching it. If long outages are your worry, read up on how long a standby generator can run nonstop before you decide.
Never run a portable generator in a garage, shed, or within 20 feet of a window or vent. Carbon monoxide is odorless and it kills fast. The CPSC has documented hundreds of generator-related deaths, almost all from running the unit too close to living space.
Effort and comfort when the lights go out
A mistake I see all the time: folks buy a portable, then discover they hate operating it. Rain, cold, a dead flashlight, a pull cord that won’t catch on the third yank. Meanwhile the standby crowd doesn’t even wake up.
Standby units run a self-test every week and switch over automatically in about 10 to 30 seconds. You might notice the lights blink. That’s it.
With a portable, you’re the transfer switch. You’re the fuel delivery. You’re the guy in the storm. For a healthy adult during a rare, short outage, fine. For an older homeowner, or a house that loses power six times a winter, that adds up.
Which one fits your situation
Run yourself through this quick list before you spend a dime.
- You lose power less than three times a year, briefly? A portable likely covers it.
- You mainly want the fridge, a few lights, and phones alive? Portable, 3,000 to 5,000 watts.
- You have well water, medical equipment, or a sump pump you can’t lose? Lean standby.
- Outages in your area routinely last a full day or more? Standby, hands down.
- Nobody home is able or willing to fuel a machine in bad weather? Standby.
- Tight budget and you’re handy and mobile? Portable, done right, is honest value.
Sizing matters for both. Guess low and you’ll trip the unit; guess high and you overpaid. Our walkthrough on how to size a generator for your home keeps you out of both ditches, and if you’re leaning portable, the beginner guide to portable generators for home backup covers the setup properly.
The head-to-head, side by side
| Factor | Portable | Standby |
|---|---|---|
| Typical cost | $400 to $1,500 | $4,000 to $12,000 installed |
| Power output | 3kW to 8kW | 10kW to 26kW |
| Starts automatically | No | Yes, in seconds |
| Fuel | Gasoline, refill every 8 to 12 hrs | Natural gas or propane |
| Runtime | Hours, then refuel | Days, or indefinitely on gas |
| Lifespan | 10 to 12 years, seasonal use | 15 to 30 years |
| Install work | Inlet and interlock | Pad, gas line, transfer switch, permit |
A word on where the machine sits
Both types have placement rules, and they’re not suggestions. Portables need distance from the house and clear airflow. Standby units need a level pad and legal clearance from windows, doors, and property lines.
Before you order anything, check generator setback and placement rules and, for a permanent install, the concrete pad requirements. Getting this wrong means a failed inspection or, worse, a dangerous install. For general outage prep, the guidance at Ready.gov’s power outage page and the CPSC carbon monoxide center are worth ten minutes of your time.
Whichever way you go, buy and install carbon monoxide alarms with battery backup on every level of your home. They’re $25 and they’ve saved more lives than I can count.
What I’d tell my own brother
If money is tight and outages are rare and short, buy a quality portable, wire in a proper interlock, and keep fresh fuel with a stabilizer. Done right, that’s a smart setup that’ll serve you for years.
If you lose power often, run a well or sump or medical gear, or you simply don’t want to think about it again, save up for a standby. The peace of mind is real, and so is the resale bump.
Your next step is dead simple: count how many outages you had last year and how long they lasted. That number, more than any spec sheet, tells you which side of this you belong on. Then size it right and put it in legally.
