Portable Generators for Home Backup

Running watts and starting watts

Every generator is sold on two numbers and buyers routinely read the wrong one. Running watts — sometimes “rated watts” — is what the machine sustains indefinitely. That is the number that matters. Peak, starting or surge watts is what it can supply for a few seconds while a motor spins up. It is always the larger figure, so it is always the one on the box.

A generator advertised as “12,500 watts” is very often a 9,500-watt machine. Neither figure is dishonest; the marketing simply leads with the flattering one. Size your house against running watts and treat the surge headroom as insurance for the moment the well pump and the fridge start together.

Conventional, inverter, dual fuel

Conventional generators run the engine at a fixed 3,600rpm to hold 60Hz, whatever the load. They are cheap per watt, loud, and their output is a rougher approximation of a sine wave — fine for a fridge or a heater, less ideal for a laptop.

Inverter generators produce AC, rectify it to DC, and synthesize a clean sine wave back out. That lets the engine throttle down when the load is light, which is why they are dramatically quieter and more frugal at partial load. Honda's EU2200i publishes 48–57dB(A) depending on load; a conventional open-frame machine of similar output sits nearer 70dB. Every 10dB is roughly a doubling of perceived loudness, so that gap is not a detail.

Dual fuel runs on gasoline or propane. Propane typically yields 10–15% less power — Westinghouse publishes 5,300 running watts on gasoline against 4,800 on propane for the same WGen5300DF — but it stores indefinitely, does not gum a carburetor, and is available when every gas station within thirty miles has no power to run its pumps. In an actual regional outage that last point is the one that matters.

What it costs to run, not to buy

This is the arithmetic the category almost never publishes. A mid-sized generator burns somewhere around 0.75 gallons an hour at half load. At the EIA's reported average of $4.071 a gallon for regular gasoline in the week ending 31 August 2026, that is about $3.05 an hour, or roughly $73 a day running continuously.

Three days of that is $220 in fuel, on top of the machine. It is also about eighteen gallons — more than most households store, and more than six trips to a five-gallon can. Knowing that number before the storm is the difference between a plan and a purchase. The full fuel arithmetic is here.

How you connect it matters more than which one you buy

Extension cords through a window are how most people start, and for a fridge and a couple of lamps that is legitimate. Anything hard-wired — a furnace, a well pump, a sump pump — needs a transfer switch or an interlock kit.

What you must never do is backfeed: plugging a generator into a wall outlet with a double-male cord to energize the house circuits. It sends power back up the utility line at lethal voltage, it can kill the lineworker restoring your street, and it is illegal essentially everywhere. A transfer switch exists specifically to make that impossible.

The part that actually kills people

Carbon monoxide from portable generators kills people in the United States every year, and the pattern is depressingly consistent: the machine was in a garage, on a porch, in a basement, or under a window, during or after a storm. CO is colorless and odorless and the early symptoms — headache, nausea, confusion — are indistinguishable from being tired and cold, which is exactly how you feel on the second day of an outage.

Run it outdoors, at least twenty feet from the house, with the exhaust pointed away from every door, window and vent. Fit a working CO alarm on every level of the house before storm season, not during it. The full safety guide is here and it is not optional reading.