What is a Dual Fuel Generator?

Generators have you covered. If you need power while away on a picnic or camping trip, just have your generator and enough fuel and you’re good to go. Most generators in the market though, run on a single type of fuel in their operation. However, there are generators that run on two different types of fuel, namely: bi-fuel generators and dual fuel generators. So what is a dual fuel generator?

Dual fuel generators are generators that use two different types of fuel. But how different is this from bi-fuel generators? Well, dual fuel generators run on a mixture of the two different fuels, whereas bi-fuel generators use two different fuels but run on one type of fuel at a time. More on this below, read on.

How does dual fuel generator work?

What is a Dual Fuel Generator?As stated above, a dual fuel generator works by combusting a mixture of two different fuels, to produce power.

But to give more context to this, here is a quick rundown on the historical developments that led to the development of the dual fuel generator.

Work on dual fuel generators began as early as the 19th Century. The reason for this was, different fuels have their own advantages and limitations, and by creating an engine that uses a mix of two fuels, the hope was to capitalize on these advantages and maybe reduce the limitations.

For instance, whereas natural gas burns cleaner, i.e. produces less soot/particulate if any at all, diesel produces soot and particulate upon combustion. However, natural gas has a high ignition temperature, whereas diesel has a low ignition temperature.

By first running the generator on diesel due to its low ignition point, natural gas can then be ignited by the high temperature from the burning diesel.

The most known pioneer in this development was Rudolph Diesel.

Are dual fuel generators worth it?

Yes, dual fuel generators are worth it.

Dual fuel generators let you capitalize on the benefits of two different fuel types while minimizing the limitations. Also, you get the flexibility of working with whichever fuel you have available, meaning you won’t lack power.

Also, since most dual fuel generators primarily run on diesel and natural gas, you are assured of the longevity of the dual fuel generator.

Low running costs, more flexibility, and more longevity for dual-fuel generators make it a worthy purchase.

Can dual fuel generators run on natural gas?

What is a Dual Fuel Generator?Yes, a dual fuel generator can run on natural gas.

Earlier prototypes and even current models of the dual fuel generator primarily run on a mixture of diesel and natural gas.

However, since gasoline and natural gas are not easily miscible, this combination is not used in dual fuel generators. Additionally, gasoline is also relatively more volatile, and storing it may present challenges.

Benefits of dual fuel generators

Improved efficiency

Most dual fuel generators run on a mixture of diesel and natural gas, with diesel being used during ignition, and once running, the dual fuel generator adds more natural gas to the engine.

Under optimum conditions, dual fuel generators operate using a 75% Natural gas and 25% diesel mix. And since natural gas burns for a longer period, and produces more power per unit, increased fuel efficiency can be observed in most cases, compared to single fuel or bi-fuel generators.

Lower running costs

With greater fuel efficiency, dual fuel generators can produce the same amount or even more power per unit, compared to single fuel generators. This translates to more savings to your pocket.

More options and flexibility

With a dual fuel generator, you’re always assured of power, even when there’s bad weather affecting mains electricity supply.

Power on demand

Regardless of the weather conditions, with a dual fuel generator you can always have power. Additionally, there are now portable dual fuel generators, so you can also have power wherever, be it a camping or hunting trip.

Improved engine/ generator life

Diesel engines are known to be generally durable, and last a long period of time provided they are routinely maintained. With an optimum fuel mix of 75% natural gas and 25% diesel, dual fuel generators release relatively less particulate/soot since fuel is efficiently burnt. This means such generators have less carbon build-up, which if left unchecked may affect an engine’s lifespan.

Faqs About Dual Fuel Generator

Are dual fuel generators any good?

Yes, dual fuel generators are good. With dual fuel generators, you can be assured of fuel efficiency, lower running costs, and be sure that your generator will serve you for a long time, since they are durable.

Can I use natural gas in a dual fuel generator?

Yes, you can use natural gas in a dual fuel generator. The first dual generator prototype used a mixture of diesel and natural gas.

However, you need to have both diesel and natural gas in the dual fuel generator for it to work, this is because diesel is needed for ignition since natural gas has a very high ignition temperature which is hard to achieve without a pilot fuel.

How long will a dual fuel generator run on propane?

What is a Dual Fuel Generator?How long a dual fuel generator runs on propane depends on the specific amount of electrical load it is imposed on. Additionally, the size of the generator’s engine determines how long the dual fuel generator runs on propane.

Generally, a 20-Pound dual fuel generator when filled with propane should run for about 4 to 8 hours. However, this may differ depending on the quality of propane, size of the generator’s engine, or even the load imposed on the generator.

Which is cheaper to run, propane or gas generator?

A gas generator is cheaper to run compared to a propane generator.

Whereas propane costs relatively less per unit compared to gasoline, the energy output from gasoline is comparatively more than propane. A unit of gasoline produces 27% more power compared to a similar unit of propane.

Hence, it takes more units of propane to produce the same amount of power produced by a unit of gasoline, thus more costs when running a propane generator.

Is it better to run a dual fuel generator on gas or propane?

This depends. It is better to run a dual fuel generator on propane if you’re mostly concerned with eco-friendly power solutions. Similarly, if you’re more concerned with costs and fuel efficiency, a dual generator running on gas would be appropriate.

Another plus for the dual fuel generator running on propane is propane does not degrade and can be stored for longer periods compared to gas, which can degrade in less than a year. Also, gas produces more heat and sound upon combustion compared to propane, meaning extra costs towards sound proofing and ventilation for the generator.

Does Generac make a portable dual fuel generator?

No, Generac does not make portable dual fuel generators. Instead, Generac makes bi-fuel generators like the Generac BI-FUEL generator, which ignites diesel first, and after running for a while and as the electric load increases, it adds and combusts natural gas.

Does Honda make dual fuel generators?

Yes, Honda makes dual fuel generators like the SG7000AA dual fuel generator which uses a Honda GX390 OHV engine.

Are propane generators quitter than gasoline?

Yes, propane generators are quitter than gasoline generators. Noise levels for propane generators generally falls between 40-80 decibels, depending on size as well as the electrical load imposed on the generator.

The reason why propane generators are quitter, mostly lies with manufacturer designs. Most manufacturers producing propane generators factor in inbuilt inverters in their design which makes propane generators quitter. Most generators in the market rely on an alternator which means the engine noise when the generator is running is constant irrespective of electric load.

With inbuilt inverters, noise produced by the generator’s engine changes according to the electrical load imposed on the generator.

Another point to note is that, engines in propane generators are relatively less strained than gas or diesel powered engines, and thus emit less noise; however, this results in reduced fuel efficiency for the propane generators.

How many watts do I need to power my house?

To power your house, you will need approximately 5000 to 7500 watts. This amount is in the case where you’re powering basic appliances in your house like: television, lights, refrigerator, air conditioner and maybe a sump pump.

If you need to run more appliances in your house, or for a bigger house, you may need more watts than this.

Does Briggs and Stratton make a dual fuel generator?

Yes, Briggs and Stratton make dual fuel generators like the GCL5000B LPG Dual fuel generator, which uses LPG and petrol/gasoline.

How do you hook up a dual fuel generator?

First consult with laws in your jurisdiction whether you can hook up a dual fuel generator on your own to a propane tank or natural gas, or if you’re required to have it done by a professional.

Here’s how you hook up a dual fuel generator:

Step 1: Install a transfer switch, and connect your dual fuel generator to your home’s power circuit. Preferably, hire an electrician to do this.

Step 2: Place the dual fuel generator at least 20 feet from your house. This should be done on a relatively level surface. You’ll also need to build a small shelter to protect your dual fuel generator from extreme weather.

Step 3: Add engine oil as well as gas or diesel to the dual fuel generator, and start the generator.


Dual fuel generators are definitely a must have utility for anyone seeking alternative power sources, either when off the grid, or as a backup when conventional power fails.

Before you invest in a dual fuel generator, take time to think through the options, and make the best choice based on cost efficiency, eco-friendliness, or even preferences or laws on noise.

Additionally, once you have settled on a particular model, ask if the dealer can help you hook up your dual fuel generator. If they don’t offer such services, you can enlist the services of a professional, or if it’s allowed by your jurisdiction’s laws, hook up the dual fuel generator yourself.

All the best.

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About Steve Stuart

Steve Stuart is an electrical engineer who developed interest on generators during his school years. After school, he became a generator enthusiast. This is after encountering power supply problems at the area of residence where he lived. Power would be on and off and so food would go bad and the room heater would go off especially during winter. After trying the different generator brands for several years, Steve now provides information on the available brands and products in the market today. Based on his experience, he gives the do’s and the don’ts when it comes to generator use.

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