Generators that run on natural gas are an alternative to generators that run on gasoline or diesel. The United States overall generation capacity is dominated by natural gas generators (43%) in 2019.
Natural gas generators are more cost-effective, more efficient to operate, and better for the environment than fossil fuel generators. Despite this, they aren’t as versatile as other generator types and won’t be the best choice for every application.
Find out about the different types of natural gas generators, how to calculate the size, and more by reading on.
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How do I choose between a natural gas generator and a diesel generator?
The first step when choosing a generator type is deciding what kind of power output you need. If you’re looking for a small amount of power, then a natural gas generator may be your best option. For larger amounts of power, a diesel generator will likely be a better fit.
A natural gas generator runs off natural gas, which can be found almost anywhere throughout the country. It’s also a cleaner source of energy than diesel generators, which require refined oil products generated from petroleum refineries.
A natural gas generator has its own advantages: it produces less noise pollution, requires no lubrication, and doesn’t have any moving parts. However, it does produce carbon dioxide emissions during operation.
Generators That Use Natural Gas
Natural gas generators fall into two main categories:
Standby
The use of standby generators is common in both residential and commercial applications. A natural gas generator is permanently installed and supplied with fuel by a local utility company in both cases. During power outages, the standby generator automatically kicks in. Standby generators are intended to run only for a limited amount of time during emergency situations, as operating them longer than recommended can lead to malfunctions and more frequent repairs.
Since natural gas pipes are underground and out of the elements, natural gas generators make an excellent choice for standby power. Outages are extremely rare with natural gas generators.
The good news is that homeowners and business owners can rely on having an unlimited supply of generator fuel that doesn’t “go bad” like diesel or have to be stored in tanks unless they live in an earthquake prone area.
Prime
The prime power generator is used when there is no local utility available, so the generated power is the only source of electricity. In most homes, the ability to quickly connect to a natural gas line isn’t available, and many homes lack a gas line altogether, so this type of natural gas generator is less common. Truck deliveries of natural gas are required without a natural gas hookup to a utility line.
In comparison to backup generators, prime power generators can run for much longer periods of time and handle much greater loads. Generators are typically transported on trailers or fifth wheels when they are needed on a job site.
Prime power generators are subsets of continuous power generators. As opposed to continuous generator sets, prime generators are designed to run continuously at variable loads for long periods of time.
The Uses Of Natural Gas Generators
Natural gas, or diesel, generators are routinely used in hospitals, nursing homes, and other large facilities that require a continuous power supply. The shelf life of gasoline is limited and it can be hard to find when you need it most – in an emergency.
It is also possible for propane tanks to become scarce during natural disasters. Companies looking to be more sustainable need an alternative to diesel generators, which are notorious air polluters.
Natural gas is also preferred by installers of residential standby generators for the same reason so that the homeowner does not have to cycle through gasoline regularly. It is actually not necessary for the homeowner to “add” fuel, it comes automatically over the utility line.
Natural Gas Generator Sizing
Let’s start by choosing the right generator size for your home. We discuss below portable generators that run on gasoline, propane, and/or natural gas.
The size of a generator depends on both the number of specific appliances and devices you need to power, as well as the size of your house. The following items are common:
- Refrigerator
- Central A/C
- Gas furnace
- Washer and dryer
- Microwave
- TVs and laptops
- Well pump
- Electric range
- Home security system
A generator’s kW rating determines how many items it can power; the higher the kW rating, the more items it can power. The product information will specify how many circuits you can power with a specific generator from a retailer like Generac.
You can then select only the items you want to power. An 11kW generator could power 16 circuits, while a 7.5kW generator could power eight. In homes with fewer than 16 circuits, you’ll have whole-house backup power.
In order to keep the appliances you want to be able to use power outage running during a power outage, you’ll probably need an electrician. In the latter case, the power usage will be higher, since some appliances consume more power when they are first turned on. You will need a generator that can meet the starting wattage requirement.
It is the same process when sizing a natural gas generator for industrial use: calculate your needs and ensure the generator is rated highly enough to handle the peak load.
Generators With Dual Fuels
In addition to running on natural gas, some generators can also run on propane, diesel, and gasoline. It is also known as a dual-fuel generator or a tri-fuel generator. In terms of portable generators, it’s difficult to find a natural gas-only model because finding a natural gas hookup on the road is difficult; dual-fuel and tri-fuel portable generators are more common. Dual-fuel industrial generators can also be used in the field when propane tanks are available.
Natural gas can be injected into your generator with the help of a conversion kit. Instructions are included in your kit, and you can easily find tutorials online. You can always hire a pipefitter if you’re not comfortable doing it yourself. An adapter between the carburetor and air cleaner can be installed easily with a good kit that does not require any adjustments to the frame.
The gas that escapes from a wellhead during drilling operations can also be used to power industrial-strength generators. In most cases, this gas is burned off, wasting valuable fuel and polluting the environment at the same time. Oil well pump jacks, man-camps, and other buildings can be powered by a generator using raw gas as fuel instead of diesel.
Also Read: Should I Use Generators Indoor Or Outdoor?
Can A Dual Fuel Generator Run On Natural Gas?
Yes, but it may not be practical. Most natural gas systems are designed to operate on a constant flow rate of about 2,000 cubic feet per minute (CFM).
If you were to inject natural gas into the intake manifold of a natural gas engine, it would cause the engine to shut down due to excessive pressure. This is why most natural gas engines are equipped with a regulator to control the amount of natural gas entering the system.
If you do decide to install a dual-fuel generator, make sure you get one that has a built-in regulator. Otherwise, you’ll have to purchase a separate regulator.
Natural Gas Conversion Kits
By using an adapter, it is possible to administer natural gas with this conversion kit. You can run your dual fuel generator on natural gas if you have low-pressure natural gas for your stoves, grills, and heaters. A governor regulator, a carburetor adapter, stud extensions, mounting bolts, fittings for the adapter, and a hose are included in this kit.
Adapters blend natural gas with air above carburetors. In essence, this kit is not a permanent conversion, but it works great and is a great adaptation. As the most popular conversion technique, it is also the least expensive and requires the least amount of labor.
Natural Gas Conversion Kit for Dual Fuel Generators
In order to avoid any accidents, you must use approved conversion kits and follow all safety precautions. In order to strengthen the entire process, it is crucial to use the right conversion kit.
Safety Alert!
Regulators are safety devices, so never ignore them. It has a vacuum valve inside that allows fuel to flow when there is sufficient suction on the outlet. Engines generate vacuums that pull in air and fuel as they whirl. The vacuum pressure opens the valve on the regulator, allowing fuel to pass through. Fuel flow would stop instantly if your engine shut down.
A step-by-step guide can be found here:
- Remove the air filter cover and filter.
- Remove the nuts that secure the air filter to the carburetor. If you have choke levers or pipes, remove them carefully.
- Make sure the stud extenders are firmly screwed on. Tighten them up with a pair of pliers.
- The carburetor is connected to the natural gas supply through the hose connected to the tank and the regulator. Once the tank is filled with natural gas, connect the hose to the regulator and the carburetor.
- The carburetor adapter should be placed over the stud extensions. Make sure the natural gas supply hose is tucked between the housing and the carburetor adapter when reinstalling the air cleaner.
- Tape or seal all fittings. Make sure you drill in the bolts with the utmost care so as not to damage the gas supply.
- Ensure that the generator is started and at operating temperature, that the gas supply is not excessive, and that the pressure is low.
Can propane be an alternate fuel source for a natural gas backup generator?
Propane is a great alternative to natural gas, but there are some important differences between the two fuels. Propane is much less expensive than natural gas, so you might consider using it as a backup fuel source. However, propane is heavier than natural gas, which means that it takes longer to burn. If you plan to use propane as a backup fuel source, you should choose a larger generator.
Is it better to run a generator on propane or gas?
It depends on what you need. If you want to run a small generator, then propane will work fine. But if you want to run a large generator, then natural gas is the way to go.
Is it cheaper to run a generator on gas or propane?
That depends on how much electricity you generate. If you don’t know how many kilowatt hours you produce each month, you won’t know whether it’s cheaper to run a generator with propane or natural gas.
Is it good to run a generator on propane?
Running a generator on propane is safe and easy. There are no harmful emissions, and propane burns cleanly. The only drawback is that propane is heavier than air, so you’ll have to keep your generator close to where you store your propane tank.
References
https://www.eia.gov/energyexplained/gasoline/
https://en.wikipedia.org/wiki/Liquefied_petroleum_gas
https://afdc.energy.gov/fuels/propane.html
