Alternative Fuel: Compressed Natural Gas 101

What is it? 

Compressed Natural Gas, known as CNG to some, is fuel that is made by compressing geologic natural gas to less than 1% of its volume at standard atmospheric pressure, then dispensed through natural gas fueling stations to natural gas vehicles. 

Fleet benefits

Aligned with the value proposition of alternative fuels, compressed natural gas provides environmental benefits sought after by leading corporations seeking emission reductions in either their scope 1 or scope 3 categories. Compressed natural gas provides up to 75% greenhouse gas (GHG) emission savings. New engine technology offered by Cummins-Westport has achieved California’s lowest smog-forming emissions standard through near-zero nitrous oxide (NOx) emissions.

On the economic front, compressed natural gas is known for low, stable fuel prices. Thanks to its environmental characteristics, compressed natural gas avoids taxation penalties placed on high-carbon fuels like diesel. Historically, compressed natural gas has also qualified for a per-gallon retroactive tax credit that further reduces fuel cost. Grant programs for both infrastructure and vehicles remain an option for fleets across the country. These grants work to further reduce the incremental costs associated with a transition to natural gas. 

Lastly, compressed natural gas is one of the most established alternative fuels and for this reason, is desired by fleets across market segments. Compressed natural gas, natural gas vehicle technology and fueling infrastructure is widely available, established and proven. 

• Natural gas vehicles have proven performance across a wide array of market applications and vehicle classes. Cummins-Westport is a leading natural gas engine manufacturer that works with a variety of tank packagers and truck manufacturers to offer natural gas vehicles. They’ve built upon the first generation of engines, overcoming issues that originate with any brand-new technology, through the release of their Near-Zero engine platform in 2018. Fleets are running natural gas vehicles in many applications: trucking, refuse, school and transit – to name a few. Check out all proven natural gas technologies tracked by the Alternative Fuels Data Center.

• Natural gas vehicles have the luxury of utilizing an established infrastructure of 1,000+ public and private fueling stations. Otherwise, companies can build their own fast-fill or time-fill fueling station at minimal investment. Time-fill fueling stations allow natural gas vehicles to refuel while the vehicle is parked, like overnight. This reduces driver time and costs that typically would be spent refueling. Newer, modular systems can be installed for fleets wanting onsite fueling to take up the space of a parking stall, while easily expanding as your fleet and fueling needs as they grow in the future.

Fleet considerations

Natural gas vehicle prices are more expensive than diesel or gasoline equivalents which is why federal and regional grant programs are so important. In many cases, these programs offset the incremental cost or significantly reduce it, but it is still a valid consideration. 

Maintenance is another consideration fleets must give thought to, well in advance of a conversion. Natural gas vehicles are easier and cleaner to maintain but have different maintenance intervals than diesel. If fleets choose to ignore manufacturer maintenance procedures, operating costs and performance deteriorate. If maintained according to specifications, maintenance costs compare to diesel and in some cases are lower. 

Compressed natural gas, although significantly cleaner than diesel and other alternatives from a lifecycle perspective, is still a fossil gas. If your sustainability initiatives revolve around decarbonization, you may be better considering renewable natural gas, a non-fossil fuel that leverages existing natural gas vehicle technology and infrastructure.

Bottom line

Compressed natural gas presents an immediate option for fleets to reduce transportation-related emissions. Vehicle technology is proven and infrastructure developed. Companies can obtain lifecycle emission benefits and obtain government financial support to do so. However, in regions without clean fuel incentives, the incremental cost of compressed natural gas and related natural gas vehicles may be challenging for fleets seeking the lowest cost fuel solution.