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A natural gas whole house generator is the only backup option with no fuel logistics at all. The unit connects to the same utility gas line feeding your furnace or water heater, so it runs for the duration of an outage - days or weeks - without anyone touching a tank. That is the whole pitch, and for most homeowners who go standby, it is decisive. Gasoline and propane portable owners trade that convenience for a fraction of the cost; see standby vs portable if you are still deciding.
How a gas standby install works
The generator sits on a concrete pad outside, connected to two systems: your gas line and your electrical panel through an automatic transfer switch. When grid power drops, the switch starts the unit and transfers the house load, usually within 10-30 seconds. When power returns, it switches back and shuts down. Nobody is home? It happens anyway. That automation is what you are paying for beyond the hardware.
Installation requires licensed gas and electrical trades and a permit in essentially every US jurisdiction - the details are in our installation guide. Realistic all-in cost for a 16-22kW unit lands between $10,000 and $14,000; the full cost breakdown explains each line.
The gas supply question nobody asks until quoting
Utility gas meters come sized to the house's existing appliances. Adding a 22kW generator can exceed the meter's capacity, and the fix - a larger meter or new supply line - costs $500 to $2,000 and is legitimately the installer's job to verify during quoting. If your bids differ by thousands, this line item is often why. One of our sourced buyer questions asks exactly this: will you need a natural gas upgrade for a whole house backup generator? Sometimes yes, and finding out before signing beats finding out during commissioning.
Fuel comparison in one paragraph
Natural gas: infinite runtime, no storage, cheapest per hour, requires a gas line you may not have. Propane: tank storage with an indefinite shelf life, works anywhere, slightly less power than gasoline in dual-fuel portables. Gasoline: cheapest hardware, worst storage behavior, hardest to source mid-outage. The propane guide covers the tank path; the comparison table in our generator guide lists dual-fuel portables.
What about "gas powered" portables?
Search intent splits here: "gas powered whole house generator" usually means either a standby on utility gas (above) or a big gasoline portable that can back up most of a house through a transfer switch. If you meant the portable: the 7,500-13,000W class from Champion, Westinghouse, and DuroMax does that job for $2,000-$3,500 installed with a switch, covered in the Champion guide. If you can say the word "generator" and "forever" in the same sentence with a straight face, you want the standby.
FAQ
How long can a natural gas generator run continuously? As long as the gas flows. Practically, standby units are rated for extended operation and need oil checks every few days of continuous running; a 22kW unit at half load burns roughly 100-200 cubic feet per hour.
Is natural gas cheaper than propane for generators? Usually yes per equivalent output, and you never pay for a tank. The gap narrows wherever gas utility rates spike.
Can a natural gas generator be converted to propane? Most standby units (Generac, Kohler, Briggs) are factory dual-fuel NG/LP and switch via a simple configuration during install - not an aftermarket project.
Do I need a permit? Yes for the install, both gas and electrical. Your installer handles it; a bid without a permit line is a red flag.
