Natural Gas vs Propane Generators: The Real Trade-offs
Natural gas vs propane for home standby generators: runtime, cost per hour, rural realities, and conversion.
The fuel question is usually answered by your address: if utility natural gas reaches your meter, use it; if not, propane. But the details matter for sizing, cost, and runtime, so here's the full picture.
Natural gas: the set-and-forget fuel
Connected to your existing gas service, a standby generator runs indefinitely at roughly $3 to $5 per hour under load. No tank, no deliveries, no refueling in an ice storm. The trade-off: slightly lower power output than the same engine on propane, and it's only an option where gas mains run.
Propane: rural independence
A 250 to 500 gallon tank runs a properly sized standby unit roughly 4 to 8 continuous days depending on load. Propane stores indefinitely and the engine makes slightly more power on it. Plan tank placement and delivery access at quote time, and keep the tank at least half full through storm season.
Dual-fuel and conversion
Most major standby units convert between the fuels with a factory kit, and DuroMax tri-fuel portables run gasoline, propane, or natural gas from one machine, which is the flexibility play for storm kits.
Quick Answers
Which is cheaper to run?
Natural gas, typically $3 to $5 per hour under generator load, with no tank costs. Propane costs more per BTU plus tank logistics, but it's the only automatic option beyond the gas mains.
How big a propane tank do I need?
500 gallons is the rural standard for whole-home standby: roughly a week of continuous runtime at typical loads. We size the tank with the generator so the math is done once.
Can I switch fuels later?
Usually yes, via a factory conversion kit installed by a licensed technician. Tell us if a fuel change is plausible (e.g., gas mains coming to your road) and we'll spec accordingly.