Portable or standby generator — which one do I need?
The same wattage costs 10× more installed. Here's what the extra money actually buys, and the decision rule that settles it for your house.
Side by side
| Portable (inverter / dual-fuel) | Standby (whole-house) | |
|---|---|---|
| Price | $400–1,500 (unit); +$400–900 transfer switch install | $5,000–15,000 installed, permit included |
| Typical capacity | 2,000–9,000 W | 10,000–26,000 W |
| Start | Manual — go outside, pull/press, plug in cords | Automatic within ~10 seconds, self-weekly test |
| Fuel | Gas (5-gal cans), propane, or dual; 8–14 h per tank at half load | Natural gas — unlimited runtime; LP tank option |
| Noise | Inverter: 50–60 dB; open-frame: 70+ dB | 58–70 dB, enclosure-muffled, often quieter at load than open-frame portable |
| What runs | Whatever you plug in, or circuits through the transfer switch | Everything wired to the panel, incl. 3–5 ton central AC |
| Portable to RV / job site | Yes — the same unit goes camping | No — permanently mounted on a pad |
| Maintenance | Oil changes you perform; store fuel with stabilizer | Annual service visit (~$200–500/yr); dealer handles it |
Portable wins when…
Outages are short and occasional. A 4,500 W dual-fuel portable keeps the 1/2 HP well pump, fridge, furnace, and lights up for the cost of a pizza dinner — and a multi-day refill stops at the gas station, not the dealer. You camp or work remotely. One 2,200 W inverter covers the tailgate, the campsite, and the outage. Budget is the constraint. Even with a 6–8 circuit transfer switch, the whole portable path lands under $2,500 installed.
Standby wins when…
You're not always home. Freezers, sump pumps, and security don't wait for you to come back and pull a cord. Outages run multi-day (ice storms, hurricanes): natural gas means zero refueling trips, and the generator carries central AC that no portable setup economically covers. The house is large or all-electric — a 14–26 kW standby is the only practical way to run a heat pump plus well pump plus everything else. Our whole-house sizing guide walks the load list, and the transfer switch guide covers the portable-side wiring.
The middle path most homeowners actually take
A 4,500–7,500 W portable + an installed 6–10 circuit manual transfer switch (~$400–900 in labor) is the 80% answer: it powers the well pump, fridge, furnace, sump, kitchen circuits, and a window AC — safely, without extension cords through the door — for under a third of standby cost. Step up to standby later if outages get longer or you add central AC. Run your exact list through the generator size calculator to size the portable correctly first — the #1 mistake is buying a 2,000 W unit and discovering the well pump won't start.
FAQ
Can I install a standby generator myself?
The pad and the unit, sometimes; the gas line, transfer switch, and permit almost never — most jurisdictions require a licensed installer, and manufacturers condition warranty coverage on dealer installation. Budget the install at $2,500–5,000 on top of the unit.
Do I still want a battery bank alongside a generator?
For short outages, batteries cover the gap silently before the generator even starts, and carry low-draw loads (fridge, internet) overnight without running the engine. The battery bank sizer sizes that layer; the generator then only runs for heavy, multi-day loads.
The portable path starts with one dual-fuel inverter big enough for the well pump surge.