Dual Fuel Generators: Flexibility When It Matters Most
A dual fuel generator operates on two different fuel sources, giving you the flexibility to use whichever fuel is available, affordable, or most convenient for your situation. For standby generators, dual fuel means natural gas and propane (LP). For portable generators, it means gasoline and propane. Tri-fuel models (available from Firman and others) add natural gas as a third option. Here is why dual fuel capability matters and how it works.
How Dual Fuel Works
A dual fuel generator has a fuel system designed to accept two different fuel inputs. For standby generators, the fuel type is selected during installation. A certified technician configures the generator for either natural gas or propane based on your available fuel supply. If your situation changes (for example, if you add a natural gas line to a home that previously only had propane), the generator can be reconfigured by a technician.
For portable generators, a fuel selector switch or valve lets you choose between gasoline and propane before starting the engine. You can switch fuel types between runs, though you cannot switch while the engine is running. This flexibility means you can use gasoline when it is available and switch to propane when gas stations are closed during widespread outages.
Why Dual Fuel Matters for Standby Generators
Every Generac Guardian, Kohler residential, and Cummins Quiet Connect generator sold at IB Lighting is a dual fuel unit. This means the same generator works for homes with natural gas service (connected to the utility gas meter) and homes without natural gas (connected to an on-site propane tank). If you move from a home with natural gas to one with propane, or vice versa, the generator can be reconfigured rather than replaced. Dual fuel also provides insurance against rare natural gas supply disruptions by allowing a propane tank to serve as a backup fuel source.
Why Dual Fuel Matters for Portable Generators
For portable generators, dual fuel capability is a significant practical advantage during extended outages. Gasoline becomes scarce during widespread power events as gas stations lose power, deliveries are disrupted, and demand surges. Propane, stored in readily available 20-pound grill tanks or larger cylinders, provides an alternative fuel source that does not degrade, is easy to store long-term, and is available at many retail locations even during outages. A dual fuel portable lets you start on gasoline and switch to propane when gas runs low, or vice versa.
Performance Differences Between Fuels
Generators typically produce slightly more power on propane than on natural gas (approximately 5% to 10% more output on LP). This is because propane has a higher energy density per volume than natural gas. However, natural gas is typically less expensive to operate per hour and is delivered continuously without tank refills. On portable generators, gasoline produces the highest output, with propane output approximately 10% to 15% lower. These differences are modest and do not significantly affect practical performance for residential backup.
Is Dual Fuel Worth It?
For standby generators, dual fuel is standard on virtually all current residential models. You get it automatically. There is no upcharge to avoid. For portable generators, dual fuel models cost $50 to $150 more than gasoline-only equivalents. This premium is worth it for the fuel flexibility alone. During a multi-day outage when gasoline is unavailable, the ability to switch to propane can be the difference between having power and sitting in the dark.
IB Lighting carries dual fuel standby generators from Generac, Kohler, Cummins, and Briggs & Stratton, plus dual fuel and tri-fuel portable generators from Champion, Firman, and DuroMax. Browse all generators in our online shop or call (800) 674-9019 for recommendations.