Standby Generator vs. Portable Generator: What North Shore Homes Actually Need

A standby generator turns itself on within seconds of a ComEd outage and can run your whole house for as long as the outage lasts. A portable generator costs a lot less, but someone has to be home to roll it outside, fill the tank, and plug things in. After the July 2026 storms knocked out power to nearly 300,000 ComEd customers across the region, plenty of North Shore homeowners found out the hard way which one actually works when nobody is home to run it.

Both machines make electricity. That is where the similarity ends. This guide breaks down what each one can power, what each one costs, and which homes actually need the automatic, whole house option instead of the cheaper backup plan.

What Is the Real Difference Between a Standby and a Portable Generator?

Short answer: A standby generator is bolted to a pad outside your house, wired into your electrical panel, and runs on natural gas or propane. It starts on its own the moment ComEd power drops. A portable generator is a gas powered machine you store in the garage, roll outside, and start by hand, and it needs a person there to run it.

Nicor and North Shore Gas already run a gas line to most North Shore homes, and that existing service is what makes standby generators practical here. The generator taps into that line, so fuel never runs out as long as the gas keeps flowing. A portable generator runs on gasoline from a can, which means somebody has to keep buying and storing fuel, and running out at 2 a.m. during a snowstorm is a real problem. If you are deciding between a natural gas hookup and a propane tank for your standby unit, our natural gas vs. propane generator guide breaks down the cost difference.

An automatic transfer switch is the other piece people miss. Standby systems come with one built in, and it safely switches your house between ComEd power and generator power in about 10 seconds. Connect a portable generator the wrong way, without a transfer switch, and you risk backfeeding electricity into the ComEd grid, which can injure a lineworker repairing the very line that knocked out your power. Our transfer switch installation page covers how that piece works and why it matters even if you stick with a portable unit.

How Much Power Does Each One Actually Deliver?

Short answer: A portable generator built for home backup puts out 5,000 to 10,000 watts, enough for a sump pump, a refrigerator, some lights, and a few outlets. A standby generator runs 10,000 to 30,000 watts, or 10 to 30 kW, enough to add central air conditioning, the furnace blower, and the whole kitchen at once.

If you already know a standby unit is the right call, our generator sizing guide breaks that 10 to 30 kW range down by square footage and appliance load, so you land on an exact number instead of a range.

The gap matters most in a finished North Shore basement. A sump pump alone can pull 800 to 1,050 watts to run and spike to 1,300 or even 4,100 watts just to start. Add a refrigerator, a few lamps, and a phone charger, and a mid size portable is already close to its limit. Central air conditioning, which needs 3,000 to 4,000 watts on its own, usually will not fit on the same circuit anymore.

A portable generator can usually carry the top three rows on that table at the same time, if you size it right and stagger what turns on. It almost never has enough headroom left for central air. That is the appliance that pushes most North Shore families from a portable unit toward a standby system, especially in July, when a multi-day outage and 90 degree heat show up together.

What Happens When the Storm Hits While You're at Work?

Short answer: A standby generator does not care whether you are home. A portable generator is useless until a person gets to it, and that gap is what decides which one actually protects your house.

Picture a weekday storm rolling through while you are at your desk in the Loop. Your standby generator senses the outage, runs a safety check, and is powering your sump pump, fridge, and Wi-Fi before your train even leaves Ogilvie. A portable generator just sits in the garage. Nobody is home to roll it outside, fuel it, and plug in the right cords. By the time you get back to Wilmette or Glenview that evening, a storm sewer backup could already have found your basement.

This is not a rare scenario. Most weekday outages start during business hours, and most North Shore households have two working adults, kids in school, or both. A generator that requires a person on site to work is a generator that fails exactly when your house is least protected.

Portable generators also come with real setup work every single time: rolling the unit at least 20 feet from the house, running heavy duty cords, checking the oil, and refueling every 8 to 12 hours depending on the load. A standby system skips every one of those steps automatically. You can check current outage status any time on the ComEd outage map, but the map cannot start your generator for you.

How Do the Costs Compare, Upfront and Over Time?

Short answer: A portable generator runs $500 to $3,000. A standby generator installed on the North Shore runs $8,000 to $18,000. The price gap is real, but so is the gap in what each one protects.

Our 2026 Illinois generator cost guide breaks the standby number down line by line, including the unit, the gas line, the electrical work, and North Shore village permit fees. Running cost matters too. A standby unit burns about $30 to $60 in natural gas for a full day of outage coverage, based on current Nicor Gas supply rates. A portable generator's gasoline usually costs less per hour, but you have to be awake, present, and willing to keep it fed for the outage to actually count.

Which One Is Safer to Run?

Short answer: Both machines can produce deadly carbon monoxide, but portable generators cause far more injuries because they get placed too close to the house under stress, in the middle of a storm.

The Consumer Product Safety Commission recommends running a portable generator at least 20 feet from your home, with the exhaust pointed away from windows, doors, and vents. A 2026 CPSC safety bulletin pushes that guidance further, urging 25 feet where possible. Never run a portable generator in a garage, on a porch, or in a carport, even with the door open. Carbon monoxide builds up fast in those spaces, and open doors do not clear it quickly enough.

Standby generators avoid most of this risk because a licensed installer sets the unit's placement once, following manufacturer and code requirements for clearance from windows, doors, and vents, and it never has to be moved or restarted by hand during a storm. That is one reason installers pull an electrical and gas permit before setting the unit, the same permits our cost guide covers in its permit section. Our Illinois generator permit guide explains step by step what those permits involve.

Which One Actually Fits Your North Shore Home?

Short answer: A portable generator can be enough for a house with a simple sump pump, no medical equipment, and an owner who is reliably home during storms. Most other North Shore homes outgrow that setup fast.

A portable generator makes sense if your budget is tight, your outages are short, and somebody is almost always around to run it. It is a reasonable stopgap for a starter home or a second property that sits empty most weekdays.

A standby generator makes more sense if any of these describe your household: a finished basement with a sump pump, anyone who works from home, medical equipment that cannot lose power, or a habit of traveling during storm season. Add central air conditioning to that list every summer, since a portable unit rarely has the headroom to carry it. A standby unit can also pay off in ways a portable never will. See our guide on whether a whole house generator is worth it for the home value, insurance discount, and flood damage numbers behind that math.

Plenty of North Shore families start with a portable unit, then upgrade after one bad outage shows them what it could not cover. If you want the full picture on why outages here run long in the first place, our explainer on North Shore ComEd outages covers the tree canopy, aging lines, and lake effect weather behind it. And if a storm is rolling in right now, our ComEd outage map guide shows you how to check restoration status and report an outage in your area. Ready to go standby? Our Generac vs. Briggs & Stratton comparison breaks down warranty, price, and natural gas differences between the two brands.

Frequently Asked Questions

Can a portable generator run a sump pump and a refrigerator at the same time?

Yes, in most cases. A sump pump needs 800 to 1,050 running watts and a refrigerator needs 350 to 800 watts, so a 3,500 to 4,500 watt portable generator can usually carry both along with a few lights and a phone charger.

How long can a portable generator run before it needs more gas?

Most portable generators run 8 to 12 hours on a full tank under a moderate load. A multi-day outage, like the one that hit nearly 300,000 ComEd customers over the July 2026 holiday weekend, means refueling every few hours around the clock.

Do I need an electrician to set up a portable generator?

You do not need one to run appliances with extension cords, but you do need a licensed electrician to install an inlet box and manual transfer switch if you want to power your home's wiring directly. Skipping that step and backfeeding through an outlet risks injuring ComEd line crews and voiding your homeowner's insurance.

What size standby generator replaces a typical portable setup?

Most North Shore homes between 1,500 and 2,500 square feet need a 16 to 20 kW standby unit to cover what a portable generator cannot, mainly central air conditioning and the full kitchen. Larger homes from 2,500 to 4,000 square feet typically need 22 to 26 kW.

Can I use a portable generator if my natural gas service is also out?

Yes. A gasoline powered portable generator does not depend on Nicor or North Shore Gas service, so it can still run electronics, lights, and pumps even if your gas is interrupted. A natural gas standby generator cannot run without gas service, though gas outages are much less common than electric ones.

Is it safe to run a portable generator during a thunderstorm?

Keep it under a dry, open sided cover if it is raining, never under a tarp that traps exhaust, and keep it at least 20 feet from the house with the exhaust pointed away from windows and doors. If lightning is active, wait until it passes before you go outside to start it.

Whichever option fits your home today, the goal is the same: power that keeps running when the North Shore's trees, lines, and lake effect weather knock ComEd's grid down again. Fill out the form to get a real quote on standby or portable backup power from one licensed and insured local electrician.