Portable Backup Power for Your House: Gas Generator + Interlock vs. Power Station (2026)

A whole-house standby install starts around $7,000 and climbs fast. If that number isn't happening this year, you have two real alternatives: a gas portable generator connected through a code-legal interlock, or a battery power station. Both get called "portable." They behave nothing alike, and most guides pick one and pretend the other doesn't exist.

Short version: the gas path runs $1,100-2,600 all-in and gives you unlimited runtime as long as you keep hauling fuel to it. The battery path runs roughly $2,000-7,300 and gives you silence and indoor operation with a hard energy ceiling. Every price below comes from manufacturer or retailer listings pulled August 2, 2026.

The two portable paths, priced side by side

Both paths end at the same place: your breaker panel. The hardware in front of it is where they split.

The rest of this guide prices each path honestly, including the parts vendors don't advertise: fuel logistics on the gas side, usable-versus-nameplate capacity on the battery side.

The gas portable path: a 9,500-watt unit plus an interlock

The workhorse class here is the open-frame dual-fuel portable in the 7.5-13 kW range, which retails between $700 and $1,700. The unit I'd anchor the math on is the Westinghouse WGen9500DF: 9,500 running watts and 12,500 peak on gasoline, 8,500/11,200 on propane, with a 6.6-gallon tank. MSRP is $1,249; it has sold as low as $824 (Amazon, December 2025). Champion's 10 kW-class dual-fuel (model 201284) sits in the same lane at Tractor Supply, listing between about $1,000 and $1,150 depending on promotions.

That buys the generator. It does not buy a legal way to power your house. For that you add an interlock — a sliding plate on the panel that makes it physically impossible to close the generator breaker while the main is on:

Add it up: generator plus interlock lands at $1,100-2,600 all-in. That's under a fifth of the cheapest whole-house standby install, and it backs up your actual circuits — furnace, well pump, fridge — through the panel, not through extension cords snaked under doors.

Never backfeed through a dryer outlet

This gets its own section because people keep doing it. The "suicide cord" — a male-to-male cable from the generator into a dryer or range outlet — is illegal everywhere, and the reason is not bureaucratic. With your main breaker closed, your generator backfeeds the utility lines, and the transformer outside steps your 240 volts up to distribution voltage. A line worker repairing what they believe is a dead line gets electrocuted by your generator. People die from this in real storms, which is why utilities and code enforcement treat it the way they do.

It also fails in the boring directions: the cord's exposed live prongs, no overload protection, and a grid-reconnection event that can wreck the generator. The interlock in the table above is the cheap, legal fix. There is no scenario where the suicide cord is the right call.

What 9,500 watts actually runs — and what it doesn't

A 9.5 kW portable is not a small whole-house generator. It's an essentials-plus machine, and the difference shows up in motor starting surges, not running watts.

Two notes on that table. First, the propane derate matters: on LP the same unit peaks at 11,200 W, so the central-AC start that was marginal on gasoline becomes a coin flip. Second, "manual everything" includes load management — you are the transfer switch's brain, turning off the water heater breaker before the AC tries to start.

The fuel math the spec sheet buries

Westinghouse's own runtime claims for the WGen9500DF: 12 hours at 25% load, 8 hours at 50%. That second number works out to about 0.83 gallons per hour at half load. Now make it concrete:

• A standard 5-gallon can lasts about 6 hours at half load.
• Around-the-clock running burns roughly 20 gallons per day.
• A three-day outage is on the order of 60 gallons — twelve can-trips to a gas station that may also be dark.

This is the real cost of "unlimited runtime": you are the fuel delivery system. It's also where dual-fuel earns its price. Gasoline stales in months without stabilizer and wants rotating; propane cylinders store indefinitely. Running the WGen9500DF on LP costs you the derate to 8,500 running watts, but a stack of full 20-pound cylinders in the shed is a far better resting state than 40 gallons of aging gasoline. My honest pattern: store propane for readiness, switch to gasoline if an outage stretches and stations reopen.

The power station path: silent, indoor, and energy-bounded

A home-scale power station is an inverter plus lithium battery that connects to the same panel hardware — a manual transfer switch or inlet at $400-1,500 installed, or a vendor smart panel. The three units I'd shortlist for 240V-capable home backup:

The wattage numbers look generator-competitive. The constraint is energy, and vendors make it easy to miss: they publish nameplate kWh, not usable kWh, and usable is what you get. Our calculator assumes 85% usable, and I'd hold every vendor to that discount until they publish otherwise.

Run the arithmetic on the F3800 Plus base unit: 3.84 kWh nameplate, call it ~3.3 kWh usable. That's fridge, lights, and internet for roughly 4-6 hours — an evening, not an outage. Add two expansion batteries and you're near 11.5 kWh nameplate, which covers an overnight comfortably. Getting to multi-day territory means either the full 26.9 kWh stack, solar input, or accepting that this tool is for short outages. The full battery-versus-generator decision, including solar recharge math, is in battery backup vs. generator.

One 2026-specific correction to older advice: the federal 25D tax credit expired December 31, 2025. There is no federal credit on home battery purchases in 2026, so price these at sticker.

What the battery path buys that no gas portable can: it sits inside, it makes no noise, the switchover is automatic or close to it, and it works at 2 a.m. in freezing rain without you leaving the bed. For short outages, that's most of what people actually want from backup power.

Which path fits — the same logic our calculator runs

I'll give you the decision tree straight, because it's the one the calculator encodes:

Minimize cost, tolerate manual operation → gas portable + interlock. $1,100-2,600 all-in, unlimited runtime, and you personally manage starting, cording, refueling, and load juggling — outdoors, in whatever weather caused the outage.

Short outages, noise limits, HOA, or no appetite for fuel cans → power station. More per usable kilowatt-hour, but silent, indoor, and near-automatic. Size the battery stack against your real outage length, not the marketing photo.

Frequent multi-day outages → neither. Twenty gallons of gasoline a day is not a lifestyle, and battery stacks big enough for day three cost standby money anyway. That profile points at a standby generator — start with the installed-cost guide and budget the ongoing maintenance while you're at it, because the purchase price is not the whole bill.