How Do Natural Gas Vehicles Work?

Natural gas vehicles (NGVs) use natural gas as an alternative fuel to traditional gasoline and diesel. These alternative fuel vehicles have been around since the 1930s but were overtaken by gasoline and diesel-powered vehicles. With the growing need for sustainable solutions, NGVs are experiencing a resurgence.

Today, the global presence of natural gas vehicles is over 23 million, while the United States has over 135,000 NGVs on its roads. This guide highlights how these alternative vehicles work, some of their benefits, challenges and available infrastructure.

How Natural Gas Vehicles Work

Natural gas vehicles work the same way gasoline vehicles do since they have spark ignition combustion engines. In these engines, fuel mixed with air enters the combustion chamber, where it’s compressed and ignited by a spark plug. Compressed natural gas (CNG), which is typically stored in a fuel cylinder at the back or under the vehicle, flows through a high-pressure fuel line into a pressure regulator that reduces the pressure to match the engine’s system before the fuel enters the combustion chamber.

Once ignited, the expansion of CNG inside the combustion chamber forces the piston to move, generating the torque needed for the vehicle to operate.

Types of Natural Gas Used

Natural gas is present in diverse forms. NGVs are designed to run on distinct versions of these gases. Here are the different types of natural gas and their uses in NGVs:

• Compressed natural gas (CNG): This gaseous fuel is composed mainly of methane and compressed to a high pressure of about 3,000 to 3,600 psi, making it less than 1% of its volume. CNG is the most preferred natural gas fuel for NGVs.
• Liquefied natural gas (LNG): This is natural gas cooled into liquid form at about minus 260 degrees Fahrenheit (minus 161.5 degrees Celsius). In this state, LNG offers higher energy density than CNG and is best suited for heavy-duty vehicles like long-distance trucks.
• Adsorbed natural gas (ANG): This is natural gas stored in a porous adsorbent system and is designed to counter the storage limitations of CNG and LNG.

Components of a Natural Gas Vehicle

Natural gas vehicles have various components that work together for the vehicle to operate. Here are the key components of NGVs:

• Fuel tank: Like gasoline or diesel tasks, these tanks store the vehicle’s fuel, which in this case is compressed natural gas.
• Fuel line: A tube, metallic or otherwise, that allows the flow of fuel from the fuel tank to the fuel system.
• Pressure regulator: A device directly below the fuel tank that lowers CNG pressure to a level compatible with the engine’s fuel injection system.
• Natural gas fuel filter: A filtration system that eliminates contaminants and byproducts from CNG to prevent damage or blockage inside the engine system.
• Fuel injection: A fuel system component responsible for injecting fuel into the combustion chamber.
• Internal combustion: Engine configuration where fuel is combined with air in a combustion chamber or intake manifold and ignited by a spark plug.
• Exhaust system: A system designed to flush exhaust gases from the engine through the tailpipe.
• Transmission: A medium that transmits power from the engine to the wheels.
• Electronic control module: A control unit that manages engine performance. It monitors and regulates fuel injection, ignition timing and other key engine processes. 
• Battery: Like other fuel-based vehicles, NGVs also have batteries that supply electricity to kick-start the engine and power other electronics.

Benefits of Natural Gas Vehicles

Natural gases, whether renewable or conventional, have unique qualities over gasoline and diesel. It’s these qualities that make up the benefits of NGVs such as:

Fuel Efficiency

Alternative fuels and energy efficiency are key when considering NGVs. While these vehicles are similar to their diesel and gasoline-powered counterparts in terms of power, speed and acceleration, they may offer better fuel economy. The reason is that CNG engines have a higher pump octane number compared to gasoline.

Environmental Impact

Natural gas is one of the cleanest fuels available, making NGVs better for the environment than diesel and gasoline vehicles. When fueling NVGs, these gases produce 20% fewer greenhouse emissions. Additionally, NVGs can’t release evaporative emissions since CNG fuel systems are sealed.

Cost Savings

Generally, NGVs are more cost-effective than vehicles powered by traditional fuel, and that is due to the low retail price and stability of natural gas. The U.S. has vast reserves of natural gas, allowing domestic price-setting and eliminating market fluctuations common with crude oil. As of October 2024, the retail price of CNG was lower than that of gasoline and diesel.

Challenges of Using NGVs

One of the attractive aspects of natural gas vehicles and their functioning is their great potential to reduce carbon emissions. However, NGVs have challenges holding back their adoption, such as:

• High upfront costs: NGVs are still more expensive upfront because their systems cost more to produce. The fuel tanks, for example, must be sturdy enough to support high-pressure gas, making its production costly.
• Limited fueling infrastructure: There are still few natural gas fueling stations across the nation, most of which are located in areas that service long-haul trucks.
• Performance issues: NGVs typically have a lower driving range than their crude oil counterparts due to the low energy density of natural gas.
• Limited driving range: Unlike large commercial trucks, smaller NGVs have small tanks, which limits driving range due to the need for refueling.

Infrastructure and Support for NGVs

The support and infrastructure for NGVs in the U.S. are increasing, and the aim is to promote their adoption and improve the nation’s energy and fuel conservation measures. Some of the strategies in place are increased availability of fueling Infrastructure and government incentives.

About 1,000 natural fueling stations are available to the public across the country. The majority of those offer CNG, with about 50 offering the alternative LNG. For business and fleet managers, the increased availability of reliable natural gas suppliers provides an opportunity to install small fueling equipment and source gas in bulk.

Several states have provided incentives, such as tax credits, rebates and vouchers for NGVs and infrastructure owners, to encourage the adoption of natural gas vehicles.

Adopting Natural Gas Vehicles for Your Business

If you’re wondering how to adopt NGVs for your business, consider these two factors:

• Fleet optimization: Converting your fleet to utilize natural gas has unique advantages that positively affect your bottom line. Qualities like fuel efficiency and the low cost of retail gas will help improve fleet performance while cutting down on fuel costs.
• Cost-benefit analysis: Purchasing NGVs or converting traditional vehicles to use natural gas is costly upfront. However, natural gas is often less expensive, and there are tax credits and incentives that contribute to a good return on investment (ROI).

Get Reliable CNG Supply From Meritus Gas Partners

NGVs are a step toward a more eco-friendly future, aligning with the global sustainability movement. Besides this critical aspect, NGVs are similar to diesel and gasoline-powered vehicles in terms of operation. That means switching to natural gas may offer more benefits than downsides to your business.

At Meritus Gas Partners, we partner with trusted gas suppliers nationwide. With the right gas supplier and installation of a private fueling facility, you’re unlikely to notice challenges related to fueling NGVs, ensuring optimal fleet performance. Contact Meritus Gas Partners for more information on CNG supply!