LNG vs. Diesel and Propane as a Commercial Fuel

Diesel generators have earned and maintained a longstanding reputation for being a power generation workhorse, but can be bulky, noisy, smelly and overall unreliable. However, with the recent discoveries of large U.S. natural gas deposits, new natural gas engines are starting to topple diesel’s dominance, as well as many propane options. Natural gas generators are quieter, cleaner and more efficient than either type. Further, natural gas is becoming increasingly popular as it can now be safely and conveniently transported as liquefied product for use in commercial and industrial operations.

The benefits of using liquefied natural gas (LNG) versus diesel for fuel are also clear: Natural gas burns significantly cleaner; produces lower emissions of sulfur, nitrogen and carbon dioxide into the atmosphere; and lacks the strong, distinguishing diesel odor. These benefits present LNG as a sleek and increasingly popular diesel conversion alternative.

Read on to learn how switching from diesel or propane to LNG using today’s advanced technology can lower operational and capital expenses over a system’s lifetime when compared to traditional diesel generators.

• Reliability and cleanliness: Compared to diesel, natural gas generators have a more limited power output, meaning they generally cannot match the wattage of a diesel counterpart. However, when you install multiple natural gas generators together in a parallel configuration, not only can they produce a comparable or even greater amount of power, they also offer flexibility, scalability and numerous additional benefits, as detailed below:
  
  
• Easier permitting: Natural gas is a clean burning fuel that does not require excessive testing or permitting. The high level of emissions produced by diesel generators often increases the difficulty in procuring an air-quality permit.
  
  
• Reliable fuel supply: Since Crowley’s fleet of ISO tanks, used for LNG transportation, are largely secure and always available to consumers, customers can use natural gas for months and years, even during a disaster or crisis. For diesel generators, the fuel supply typically ends after three days. And during a crisis, fuel deliveries are often delayed or non-existent.
  
  
• Low maintenance: For diesel generators, the required low sulfur diesel gas system needs to be re-conditioned or polished every four to six months to ensure impurities don’t impact fuel flow. This is not an issue with natural gas. And if a customer uses propane, which is a less desirable fuel for generators, the derating of the engine leads to equivalent maintenance costs of diesel generators. (In most islands and countries outside of North America the standard is not HD5 propane, but a mix of propane, butane, pentane and sometimes ethane, which can have harmful effects on the engine over time – unlike natural gas.)
  
  
• Cost-effective engines: Automotive-style, spark-ignited engines are readily available in high volumes, making them more economical than similarly sized diesel and propane engines. Oftentimes, industrial operators will convert a natural gas engine to run on HD5 propane, which isn’t ideal due to the derating of the engine.
  
  
• Eco-friendliness: Many enterprises want to operate in the most eco-friendly way possible, so as to be considered a “green” company. Natural gas is the cleanest-burning fossil fuel available because it produces the fewest emissions and therefore has a much smaller carbon footprint. Natural gas generators also avoid the fuel containment, spillage and environmental concerns associated with storing diesel fuel. It also eliminates the safety issues of propane in the event of leakage or spill, because propane is heavier than air and does not dissipate easily or quickly.
  
  
• Safety: Natural gas generators also avoid the fuel containment, spillage and environmental concerns associated with storing diesel fuel. It also eliminates the safety issues of propane in the event of leakage or spill, which is heavier than air and does not dissipate easily or quickly. LNG is also not flammable when in a liquid, transportable state – unlike diesel and propane.
  
  
• Lower overall cost: Natural gas technology has become much more accessible and affordable. In fact, many natural gas generators now offer a significantly lower total cost of ownership (TCO) than their diesel and highly derated propane counterparts. LNG technology enhancements have created efficiencies that translate to cost savings in nearly every aspect of the product lifecycle, as explained below:
  
  
• Investment and installation cost: LNG generators often require two paralleled lower-kW generators as compared to one larger-kW diesel generator. However, the capital investment to acquire two smaller generators instead of one larger generator – which can be up to 45 percent bigger – is similar. And installing two generators means operators gain greater support from the supplier, which offsets the initial costs; incur less expensive installation costs, as the lighter equipment is easier to transport and place on job sites; and installation is less complicated and faster.
  
  
• Fuel cost: In the U.S., the cost of natural gas trends significantly lower than that of diesel. According to the U.S. Department of Energy’s April 2017 Alternative Fuel Price Report, the national average price between January and October 2017 for LNG was $16 /MMBTU. The average price of propane for over that time period was $18/MMBTU – 12.5 percent higher. During that same time, diesel prices were nine percent higher than LNG. While fuel prices are always subject to change, LNG is generally the more economical option of the three.

Is an LNG Conversion Right for Your Business? Talk to One of Our Experts.
Ready to learn more about switching to gas? If you’re a business or commercial operator in the Southeastern U.S. or Alaska, the Caribbean or Central America, Crowley can answer your questions and help you decide whether LNG conversion is the right fuel solution for your enterprise.