Natural Gas vs. Diesel Generators: Pros and Cons



Having a reliable generator is crucial towards your keeping your continued operations running smoothly and efficiently. The last thing you want for your facility, data center, or building is for a power outage to derail business as usual. Reliability can depend on your fuel choice for your emergency generator. 

Natural gas and diesel generators are the conventional means for generating power consistently. Still, you may be compelled to choose one over the other depending on cost, continued maintenance, environmental friendliness, and even the size you can reasonably accommodate.

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Natural Gas Generators

a valve for LP/NG generator

Natural gas generators are a reliable and frequent source of creating power. They are so commonly used that they accounted for 42% of the total operating electricity generating capacity in the US in 2016. Natural gas is a non-renewable resource obtained through the same methods used to extract oil, where a liquid is converted into a gas and produces power. These generators are preferred for continuous power generation but lets look at the pros and cons of natural gas versus its diesel counterpart for stationary standby use.


  • Natural gas generators are very cost-effective when it comes to operating and running as the cost of fuel is much cheaper than diesel fuel.
  • Greenhouse gas emissions are lower for natural gas than other fuel sources, and it is one of the cleanest fossil fuels in circulation. 
  • Natural gas is also far more available in metropolitan areas, so generators have better access to crucial pipelines. This readily available energy source is versatile and ensures storage costs are kept low since technically, you do not need to “store” anything. 


  • Although Natural Gas Generators are more cost-effective to operate, the fuel availability can be unreliable in areas that are prone to natural disasters. In California, for example, the pipeline gas utility will shut off service to areas that have been affected by an earthquake.
  • Natural Gas Generators are LESS cost-effective to purchase and install than Diesel Generators are.
  • Natural Gas generators are typically much larger than Diesel which can be a problem if the site has a limited footprint or available space for the install. 

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A natural gas generator is extremely efficient when the fuel source is uninterrupted. Being More affordable to operate than Diesel generators are, NG generators are a good choice for a prime power applications. Having said that, it would be best if you thought of the overall cost and the overall reliability when it comes to standby stationary applications. As for reliability, the operator may have a lack of control over the fuel source in certain areas and as such should plan for utility shutdowns and interruptions during natural disasters. Regarding the costs, just know that natural gas generators will carry a higher cost of ownership due to the cost of the generator and the increased expense of the installation. 


In the market for a used and refurbished generator for your company? Contact CI-GROUP with your questions!

Diesel Generators


These generators that run on diesel fuel are another popular choice for power generation in many areas of the world. A diesel generator is usually composed of two working parts, which are the engine and the electric generator. These generators are common in industries where back-up power is critical or where a continuously supplied source of fuel (like natural gas) is impossible or impractical, like on ships for example. They are also highly versatile and can be used in large and small spaces alike.

Diesel generators are commonly used in places where emergency power is critical to the operation. In the event of a utility power outage, it will be readily available for use. 


  • Diesel engines, despite their fuel being substantially more expensive than natural gas, are highly cost-effective. Diesel has a higher energy density, meaning that for equal amounts of gasoline, diesel provides more power. 
  • Because the fuel is stored on-site, natural disasters that would interrupt utilities and operators using natural gas generators, would not affect the diesel generators.
  • Diesel generators are much cheaper to buy than natural gas generators and they are less expensive to install.
  • Once you get into the larger sizes (above 200kw), Diesel generators have a smaller footprint that Natural gas generators.


  • As we’ve gone over already, a diesel generator is a LESS expensive option for power than a natural gas generator. Also, its maintenance costs are less than that of natural gas. However, the cost to run a diesel generator due to the cost of fuel is far more than that of a natural gas generator. Weighing both financial factors and knowing your application and anticipated usage is important when deciding whether to choose one over the other.
  • Diesel generators have higher emissions than natural gas generators.
  • Diesel fuel supply is limited to the tank size.

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Diesel generators are a great choice to power your site in almost any back-up power application. They are reliable, much more cost-effective to purchase and install, and they have a faster start-up time than Natural Gas Generators. Diesel won’t be affected by utility shutoffs during natural disasters when they are needed most. Having said that, Natural gas generators are much cheaper to operate in environments where prime power is needed. Due to the cheaper cost of fuel, you can expect to make the higher cost worthwhile when operating all the time. (Typically, a 2-year ROI but this varies based on usage). 

Are you ready to purchase a reliable new or used diesel or natural gas generator for your critical operations that fit your budget, and assess your needs? CI GROUP is here to help you find the perfect match!

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