Natural gas
If your home has natural gas service with enough meter and pipe capacity, a natural gas generator is the most convenient: no tank to fill, no deliveries. The limits are line capacity and the rare chance that pipeline supply is interrupted. Larger generators need much more gas flow than many existing meters supply, so we check before recommending a unit.
Propane
Propane (liquid propane, or LP) stores on your property in a tank. It does not depend on a pipeline, stores for years and burns cleanly. The tradeoff is tank size, placement and delivery. A larger tank gives longer run time. Many rural properties and homes without gas service choose propane.
Diesel
Diesel is common for large commercial and industrial generators because of power density and on-site storage. It needs containment, fuel-quality management and periodic testing. It is less common for homes.
Run time and storage
Run time depends on load, fuel and tank size. Use our Runtime and Fuel Calculator for a planning estimate. For a long outage, a propane tank sized for several days or a gas supply that stays on is the key.
Dual-fuel flexibility
Many Generac generators can run on natural gas or LP, and the Generac XG Series lets you select the fuel at the controller. That can simplify later changes.
Use natural gas if the supply is sized for it, propane if it is not, and diesel only where the load or the code calls for it.
