Natural Gas vs. Propane Generators: Choosing the Right Fuel
If your home has natural gas service, natural gas is the preferred fuel for a standby generator. If natural gas is not available at your property, propane is the proven and reliable alternative. Both fuel types power the same generators, produce the same electricity, and deliver the same level of home protection. The fuel decision is almost always dictated by what infrastructure exists at your home rather than a fundamental advantage of one fuel over the other.
Natural Gas: The Advantages
Natural gas is delivered continuously through underground utility pipes, which provides several compelling benefits. There is no fuel tank to purchase, install, maintain, or refill. You never run out of fuel regardless of how long the outage lasts. There is no fuel degradation or storage concerns. Natural gas is typically the lowest-cost fuel option on a per-BTU basis. The fuel supply is independent of the power grid, so natural gas continues flowing during electrical outages.
For homeowners with existing natural gas service, the installation is straightforward. The installer runs a dedicated gas line from your meter to the generator (typically a 3/4-inch or 1-inch line, depending on generator size and distance). The gas company may need to verify that your meter can support the additional load. In some cases, a meter upgrade is required, which the gas company typically provides at minimal or no cost.
Natural Gas: The Considerations
Natural gas has a lower energy density than propane (approximately 1,030 BTU per cubic foot versus approximately 91,500 BTU per gallon for propane). This means generators produce slightly less maximum output on natural gas compared to the same unit running on propane. A generator rated at 22kW on propane may be rated at 19.5kW to 20kW on natural gas. For most homes, this slight reduction is insignificant because the generator is rarely running at absolute maximum capacity. However, if you are on the borderline between generator sizes, factor in the natural gas derate when making your selection.
Propane: The Advantages
Propane is available everywhere, including rural properties miles from the nearest gas main. It is stored in an above-ground or underground tank on your property, giving you complete control over your fuel supply. Propane has a higher energy density than natural gas, so generators produce their full rated output on propane. Propane does not degrade or expire in storage. A full tank is always ready to deliver full power regardless of when the last fill occurred. Propane generators can serve as a complete off-grid power solution when combined with a large enough storage tank.
Propane: The Considerations
Propane requires a storage tank, which adds $500 to $2,000+ to the installation cost depending on tank size (250, 500, or 1,000 gallons). The tank must be refilled periodically, and during widespread outages, propane delivery may be delayed due to high demand. Tank placement requires a level area with code-compliant setbacks from the house, property lines, and ignition sources. You must monitor fuel level and schedule refills, especially before storm seasons. Many propane companies offer automatic delivery programs that monitor usage and refill proactively.
What About Dual-Fuel Generators?
Some generator models are factory-configured to run on either natural gas or propane, with a fuel selector switch or connection port for each fuel type. If your property currently has propane but may get natural gas in the future, a dual-fuel model provides flexibility. Most Generac, Kohler, and Cummins residential generators are available in natural gas, propane, or dual-fuel configurations.
Which Should You Choose?
Choose natural gas if your home already has natural gas service, you want zero fuel maintenance, and you prefer unlimited runtime without monitoring a tank. Choose propane if natural gas is not available at your property, you prefer having a dedicated fuel reserve under your control, or you are in a rural area where natural gas service does not exist. Choose dual-fuel if you may switch fuel sources in the future or want maximum flexibility.
IB Lighting carries generators in natural gas, propane, and dual-fuel configurations from all major brands. Call (800) 674-9019 and tell us what fuel source is available at your property. We will recommend the right model. Browse our generator selection to compare fuel options.