The honest comparison
| Portable (10–12 kW) | Standby (20 kW) | |
|---|---|---|
| Equipment | ~$1,200–$2,500 | ~$5,500–$7,000 |
| Installation | $500–$1,500 (inlet + interlock) | $4,000–$8,000 (ATS, gas, permits) |
| Starts itself? | No — you're outside in the storm | Yes, in ~10 seconds, even if you're away |
| Fuel | Gasoline: refuel every 8–12 hrs | Natural gas / propane: runs for days |
| Noise | 70–78 dB(A) — loud | 62–69 dB(A) — conversation level |
| Powers | Essentials via cords or inlet | Whole house through the panel |
| Maintenance | Oil, stabilizer, exercise monthly | Weekly self-test, annual service |
When portable wins
Outages are rare and short (under ~12 hours a year), you're comfortable running extension cords, and someone is always home to start it. A good dual-fuel portable with a manual transfer switch is genuinely capable — it's just manual.
When standby wins
You lose power for days at a time, travel, work from home, have medical equipment, a sump pump, or an electric well — anything where "someone goes outside and starts the generator" isn't an acceptable plan. Standby also adds resale value; portables don't.
Ready to size one? Use the kW size calculator, then see what installation really costs with thecost estimator.