CNG vs. LNG - What's the Difference? Which Is Best for Your Commercial Fleet?

CNG vs LNG

CNG vs. LNG - What's the Difference? Which Is Best for Your Commercial Fleet?

  1. What Is Compressed Natural Gas (CNG)?
  2. What Is Liquefied Natural Gas (LNG)?
  3. What Is the Difference Between CNG and LNG?
  4. Is CNG or LNG Right for Your Fleet?
  5. The Benefits of Switching Your Fleet to Natural Gas
  6. Find Your Fleet's Fueling Solution With Shipley Energy

Your fleet needs fuel to power through daily tasks and keep your business operating smoothly. Many fleet managers turn to diesel or gasoline fuels to fill this role. Though gasoline and diesel are a common choice among commercial fleets, many fleet managers are looking to fuel alternatives for their low cost, availability, and environmental benefits.

Regardless of whether you've considered alternative fuel, your fleet is always looking for ways to reduce costs and increase efficiency. Natural gas fuel may provide the edge you need to improve performance across the board. Your fleet can either utilize compressed or liquefied natural gas options. Each fuel type has unique qualities, and the type that works best for you depends on a variety of factors.

What Is Compressed Natural Gas (CNG)?

Compressed natural gas (CNG) is an alternative fuel made from natural gas. CNG is formed by compressing natural gas to less than 1% of its volume at standard atmospheric pressure. This compressed gas is stored in a vehicle in its gaseous state with a pressure of up to 3,600 pounds per square inch.

Like gasoline-powered vehicles, CNG vehicles use a spark-ignited internal combustion engine. CNG is stored in a fuel tank or cylinder until it is transferred to the engine intake manifold or combustion chamber. There, the pressure is reduced to work with the engine's fuel injection system, and the CNG is mixed with air. Spark plugs then ignite the CNG and air mixture to power the engine.

CNG vehicles have a similar fuel economy to gasoline vehicles measured on a gasoline gallon equivalent (GGE). One gallon of gasoline is equal to about 5.66 pounds of CNG.

What Is Liquefied Natural Gas (LNG)?

Liquefied Natural Gas

Liquefied natural gas (LNG) is a fuel alternative that utilizes natural gas in its liquid form. LNG production begins by purifying natural gas and super-cooling it to -260 degrees Fahrenheit. The purification and cooling transform the gas into a liquid, which is then cooled below its boiling point to remove extra compounds in the fuel. Once cooled, the remaining liquid consists of mostly methane and small amounts of other hydrocarbons.

LNG is stored in a cryogenic tank to maintain its super-cooled properties. In an LNG vehicle, cryogenic tanks in the front of the machine store the fuel until it's ready to be used. Like CNG vehicles, LNG vehicles use common spark-ignited combustion engines.

Because LNG is a liquid, it has an increased density and can store more energy by volume. One GGE is equal to 1.5 gallons of LNG.

What Is the Difference Between CNG and LNG?

Aside from the fact that CNG is a gas and LNG is a liquid, these fuels have various characteristics that set them apart. When comparing CNG versus LNG, you may find one fuel type works better for your fleet than the other. Here are some key differences to consider.

Application

The density of CNG and LNG makes them suitable for different vehicle types and applications. As a gas, CNG doesn't pack as much energy into its volume. However, CNG has a wider range of applications across light, medium, and heavy-duty vehicles.

LNG has an increased energy density, which makes it suitable for longer-range vehicles like Class 7 and 8 trucks. You can use LNG for more medium to heavy-duty applications.

Price

According to data from the U.S. Department of Energy, CNG and LNG have had relatively similar or lower costs as compared to gasoline and diesel since 2000.

Individually, CNG and LNG have slightly different price points:

  • CNG prices: Over the past two decades, CNG has been less expensive per GGE than gasoline, diesel, and LNG. Though CNG prices fluctuate like those of other fuels, they have fewer drastic spikes when compared to gasoline and diesel.
  • LNG prices: Because LNG has a more involved production and transportation process, its prices are typically higher than CNG prices. However, LNG has maintained consistent prices with gasoline and diesel fuels and has avoided major price spikes.

When you switch to CNG or LNG, you won't have to worry about increased fuel costs. On the contrary, you'll likely enjoy decreased or unchanged fuel costs.

Fueling

CNG and LNG have different fueling methods and requirements based on their composition. CNG offers fueling options that are similar to traditional gasoline or diesel fueling.

There are two types of CNG fueling stations available:

  • Fast-fill stations: Fast-fill stations receive natural gas from a pipeline, compress it onsite, and move it to storage vessels. These stations allow consumers to fill a car or light-duty vehicle quickly with the help of a special dispenser.
  • Time-fill stations: Time-fill stations deliver CNG at a lower pressure than a fast-fill setup and do not use storage vessels. These stations use large compressors to fuel vehicles over a longer period compared to fast-fill stations. A time-fill station is ideal for commercial vehicle fleets to use for overnight fueling.

LNG has some unique fueling requirements because it is super-cooled. Trained personnel must wear protective clothing, face shields, and gloves when handling LNG. In contrast to CNG, LNG has a fuel time similar to diesel.

Fueling

To accommodate these requirements, there are two types of LNG fueling stations available:

  • Containerized stations: Containerized stations utilize storage tanks, dispensing equipment, metering, and containment to create an LNG fueling station for your fleet.
  • Permanent stations: A permanent station has the same features as a containerized station with an increased storage capacity. These stations can be customized to fit your fleet's needs for greater convenience.

Is CNG or LNG Right for Your Fleet?

Both CNG and LNG offer benefits over traditional gas and diesel options. When weighing the benefits of compressed natural gas versus liquefied natural gas, your fleet's needs will play a deciding role.

Consider your answers to the following questions to help determine what fuel type may be best for your fleet:

  • What fuel type and vehicles are available? If you're planning to purchase new vehicles when you convert to natural gas fuel, you may choose CNG or LNG based on the types of vehicles that are available for your industry. For example, there may be more CNG vehicle options for waste haulers, dump trucks, delivery trucks, transit and school buses, pickup trucks, and cargo vans. There may be more LNG options for Class 7 and 8 long haul tractors, marine vessels, and heavy-duty mine haul trucks. Beyond industry factors, your location may have more CNG or LNG fueling infrastructure. Be sure to base your decision on what is convenient and available for your industry and location.
  • What type of driving range do you need? If your fleet drives shorter distances between refuels, you could choose either CNG or LNG. CNG may give a slight advantage in price, which could benefit you long-term. If your fleet consistently travels long distances, LNG will give you more miles with each fill-up. You may even be able to add an extra LNG tank to your vehicle for extended trips.
  • What type of fueling system works best for you? CNG fueling doesn't require special training or equipment, but it may take longer to complete based on your vehicles. LNG requires special fueling clothing and training, but it doesn't take as long to complete. If you need a more typical gas station experience, CNG may work better for your fleet. If long-range capabilities are more important than avoiding additional fuel training, LNG may work best for you. If you currently receive mobile fueling, you may be able to pick between CNG and LNG based on their convenience in other areas.
  • What is your budget? If you have a higher budget and plan to purchase new vehicles, you can likely choose between CNG and LNG based on industry and vehicle availability. If you want to stick to a lower budget, you may be able to convert your existing gasoline or diesel vehicles to use CNG or LNG fuel. These conversions provide an affordable solution to allow you to switch fuel types as long as you follow the necessary emissions and safety regulations. You may opt for CNG or LNG based on the conversion kits available for your vehicles and the price for each.

Altogether, your natural gas fuel choice should be as convenient and practical as possible. You know your fleet best. Keep your vehicles, work, and local natural gas offerings in mind to make the best choice.

The Benefits of Switching Your Fleet to Natural Gas

Considering CNG versus LNG for your commercial fleet is an important, win-win decision. Both natural gas fuels offer a host of benefits for your fleet, business, and the environment. Here are some of the things you can expect when you switch to natural gas.

 

The Benefits of Switching Your Fleet to Natural Gas

 

Steady Fleet Performance

Getting adequate power and performance from your vehicles is non-negotiable. No matter the industry, you need to know that your equipment will deliver day after day. Rest assured that, with natural gas vehicles (NGVs), you won't sacrifice your fleet's performance. According to the U.S. Department of Energy, NGVs have similar power, acceleration, and cruising speed capabilities when compared to gasoline and diesel vehicles.

Though CNG and LNG don't provide as much driving range as most gasoline or diesel vehicles, your natural gas fuel choice can mitigate this discrepancy. If a long range is important for your vehicles, you can choose LNG vehicles and add extra storage tanks to maintain the range you need.

Lower Emissions

One key benefit of switching your fleet to natural gas is lowering your overall emissions. When it comes to tailpipe emissions, NGVs have comparable levels to newer gasoline and diesel vehicles. This is because all new vehicles are equipped with emission control systems that must comply with emissions standards.

Not all gasoline and diesel fleet vehicles are new and emission-friendly. According to NGV America, medium- and heavy-duty vehicles are the number one source of smog. Replacing your vehicles with NGVs can cut down on EPA criteria pollutants, especially nitrogen oxide. Overall, light-duty vehicles running on conventional natural gas can reduce lifecycle greenhouse gas emissions by 15%. And because CNG fuel systems are completely sealed, they produce no evaporative emissions.

If your business or customer base champions environmental causes, switching to natural gas fuel sends a clear message.

Natural Gas Availability & Economy

As a resource, natural gas is abundant and readily available in the U.S., especially when compared to the petroleum used to make gasoline and diesel. With natural gas recovery operations in 33 states, the United States is the number one producer of natural gas in the world. The large supply of natural gas in the U.S. keeps CNG and LNG prices low and stable. While gasoline and diesel prices fluctuate based on the global crude oil market, natural gas remains relatively unaffected.

Natural gas also supports the U.S. economy. When you use domestically produced fuel, you contribute to the American economy and help employ American workers. NGVs further diversify fleet fueling, which can reduce the impact of international fuel supply disruptions. Altogether, natural gas fuels are a secure source of energy with a variety of economic benefits.

Overall Savings

Whether you plan to purchase NGVs or convert your current fleet, you may be concerned about the upfront investment required to switch to natural gas. According to NGV America, your investment will offer returns relatively quickly. With lower fuel and maintenance costs, your NGV may offer a speedy 18- to 24-month payback.

NGVs may experience lower maintenance costs when compared to diesel-fueled vehicles because they do not include:

  • A diesel particulate filter
  • Diesel particulate filter regeneration or waste disposal
  • Selective catalytic reduction
  • Diesel emission fluid

In addition to lower maintenance costs, natural gas fuel costs are more affordable. This is due in part to the commodity cost associated with natural gas versus diesel:

  • Natural gas: Commodity, distribution, and processing costs come together to determine what you pay at the pump. Natural gas's commodity costs account for 23% of its price. This small share helps to reduce price fluctuations and keep natural gas costs steady.
  • Diesel: Commodity costs account for 60% of diesel's price. This leaves a much higher margin for price fluctuation based on global supply and demand.

In more ways than one, choosing natural gas for your fleet could provide substantial savings. Whether you're deploying delivery vans or operating heavy construction equipment, natural gas could transform your fleet into an economical and environmentally-friendly asset.

Find Your Fleet's Fueling Solution With Shipley Energy

At Shipley Energy, we're committed to providing efficient commercial natural gas and fleet fueling solutions that benefit your business. Our services don't stop at mere energy delivery, though. With over 85 years of experience, we're here to help you develop effective energy procurement strategies for your business. Our team will work with you to analyze your needs and reduce costs where possible.

As energy professionals, we care about providing cutting-edge, reliable solutions for our customers. As a local, family-owned business, we also care about cultivating relationships and partnering with businesses to find innovative and effective energy solutions.

For more information about our offerings for your fleet and business, contact us online today.

Fleet Fueling Solutions from Shipely Energy