The Ideal Combination of Diesel Power and the Longer Running Times of Natural Gas

Gens Outside of a Large Business

Severe Weather. Human Error. Power Grid Vulnerability. Any one of these could leave thousands, even millions without power for days, sometimes weeks. You wisely installed a backup power system. If that system is based solely on diesel fuel, your power only stays on while the fuel lasts. With roads blocked and fuel being allocated solely to the most critical locations, your business could soon be plunged into the dark, waiting for power to be restored.

The solution is a Generac BI-FUEL™ generator. These inventive generators start on diesel fuel and add natural gas as load is applied, until the unit runs primarily on natural gas--offering dual fuel reliability. Statistics prove that natural gas lines are rarely affected during major disasters, so our BI-FUEL™ generators offer a continuous and reliable source of fuel, when you need it most.

BI-FUEL™ engines have been used in industrial applications for decades. However, the majority of those applications are third party, after-market conversions performed in the field. Generac offers fully integrated solutions that are the only EPA-compliant generators straight from the factory.

Business Benefits for Bi-Fuel™

Mitigate Risks with Redundant Fuel Options

Despite the perceived value of having diesel fuel on-site for reliability, power outages can damage infrastructure and make diesel refueling difficult or impossible. Generac BI-FUEL™ generators mitigate refueling issues by operating primarily on utility-supplied natural gas.

That means less diesel fuel is required on-site, and the diesel fuel that is available will last longer during an outage since running times are greatly extended. And, since the natural gas infrastructure tends not to be affected by the same conditions that lead to power outages, fuel reliability is improved.

The good news is that should something happen to interrupt the natural gas supply; Generac BI-FUEL™ generators can seamlessly run on 100% diesel fuel. You can end the debate between a natural gas vs. diesel generator.

Two Generac Industrial Power bi-fuel generators on a designated platform outside.

Lower Total Cost of Ownership


Because Generac BI-FUEL™ generators run primarily on natural gas, which costs less than diesel fuel—fuel costs are significantly reduced over the long term. And since less diesel fuel is required on-site, maintenance costs associated with the diesel fuel are also reduced.

Graphic charts comparing Bi-Fuel run-times and fuel savings.

Scalability as Part of a Modular Power System

Generac BI-FUEL™ generators can be configured as part of a paralleled solution; with our integrated Modular Power System (MPS), they can easily be combined with other Generac MPS diesel or gas generators, depending on your needs. 

This means you can add generators as your business and power requirements grow, without installing more power than you need at the start of the project. With multiple generators on call and critical loads prioritized, reliability is usually 99.999%—that doesn’t take into account the dual fuel sources. Each unit can also be taken out of service for maintenance without sacrificing critical backup power.

NEC and NFPA Code Compliance

Generac BI-FUEL™ generators meet the on-site fuel requirements for emergency systems as referenced in NEC 700 and NFPA 110. With less diesel fuel required to be stored on-site, permitting also becomes easier. We also know some indoor fuel installations may have severe storage tank capacity limits per NFPA or local codes—with our BI-FUEL™ generators difficult placements or space constraints become a viable option.

Environmentally Friendly to Support Green Missions

Many businesses are becoming “green” and the lower emissions and reduced carbon footprint of BI-FUEL™ generators help meet those requirements. But Generac goes beyond that as we are also committed to being environmentally responsible, in our manufacturing processes as well as the products that we provide to our customers.

Generac Industrial Bi-fuel generator being moved by a crane

Built to Last by an Industry Leader

Every fuel train component, every sensor, every actuator on the engine is specifically designed, engineered, and factory tested to work together optimally, efficiently, and backed by a full Generac factory warranty and product support.

Generac BI-FUEL™ Engines-Improving Power by Design

Our microprocessor controlled BI-FUEL™ diesel engine starts on diesel fuel and provides power from an air/natural gas mixture ignited by diesel injection and continuously monitored by the on board control. The diesel engine is equipped with a metering system that feeds natural gas into the incoming air supply.

The standard diesel injection system is used and the injector sprays diesel fuel into the cylinder at the correct time. The diesel fuel ignites and thus ignites the natural gas charge. Total power is derived from a combination of natural gas and diesel. The ratio of natural gas to diesel fuel is a function of several factors, including load and intake air temperature. The higher thermal efficiency of diesel engines and the lower cost of natural gas, along with low emission levels, combine to make the BI-FUEL™ engine a very economical choice.

Protection from the Elements

Generac manufactures its own generator enclosures to ensure each unit combines the highest level of durability with the latest engineering advancements in noise reduction, weather resistance, and streamlined design. In addition to our standard enclosures, we also offer high performance and extreme performance enclosures. 

Rugged Base Frames

Generac’s heavy-duty base frames ensure accurate alignment between the engine and alternator at all times. Oil and water drain points are situated for easy access. Vibration isolators contribute to smooth operation. Power cable stub-ups are positioned for easy installation.

PowerManager® Integrated Controls

PowerManager digital controls* let you monitor and control key elements of your generator system with the touch of a button or click of a mouse. Features like constant monitoring capabilities, adjustable parameters, and built-in protective alarms help provide the highest level of reliability.

*Available only on configured products.

Two Generac Industrial Power bi-fuel generators on a designated platform outside.

Sales, Design, Installation and Service Support

With more than 57 years of power generation experience, Generac has built a tool set for electrical engineers and contractors to simplify and save time sizing, specifying, or installing generators.

If you have questions about our BI-FUEL™ generators, single or paralleled, or just want to learn more, contact one of our Generac Industrial Power Distributors.

Our worldwide network has factory-trained and certified technicians with trusted expertise in system design, sizing, installation, commissioning, diagnostics, and repairs.