Natural Gas

In the face of mounting climate change concerns, the transportation industry has been urged to shift away from conventional fossil fuels. Among the plethora of alternative energy sources, natural gas, specifically Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG), has emerged as a promising option for commercial fleet vehicles due to its potential to reduce emissions and improve energy security.

GHG Emissions and Natural Gas

Natural gas is composed primarily of methane, which, when burned, produces less carbon dioxide (CO2) per unit of energy compared to gasoline or diesel. It is estimated that the use of natural gas in vehicles can reduce CO2 emissions by approximately 15-20% compared to gasoline and diesel on a well-to-wheel basis. Expressing this reduction in terms of GGE, one GGE of natural gas emits about 0.68 kg of CO2, compared to one GGE of gasoline, which emits about 0.88 kg of CO2.

Economic Implications

  • Fuel Cost: Natural gas has been cheaper than gasoline or diesel on an energy-equivalent basis, making it a cost-effective choice for high-mileage commercial fleets.
  • Conversion and Maintenance: Although conversion to natural gas engines requires upfront investment, these costs are often offset by lower operating costs due to cheaper fuel prices and less engine wear, which results in lower maintenance costs.
  • Energy Security: As a substantial amount of natural gas is domestically sourced, its use can reduce dependency on foreign oil, helping to stabilize fuel prices and enhance energy security.


Environmental Impact

While natural gas does contribute to reducing CO2 emissions, other environmental considerations must be made:

  • Methane Slip: The release of unburned methane during refueling or from the tailpipe, known as methane slip, is a significant concern due to methane's high global warming potential. However, advancements in natural gas technologies are increasingly mitigating this issue.
  • Lifecycle Emissions: From extraction to use, the lifecycle emissions of natural gas must also be considered. While natural gas does reduce tailpipe emissions, fugitive emissions during extraction and transport could offset these benefits. Ongoing technological advancements aim to minimize these emissions, enhancing the environmental profile of natural gas.


Social Impact

  • Public Health: Reduced emissions from natural gas vehicles can lead to improved local air quality, with potential benefits for public health.
  • Job Creation: The transition to natural gas could stimulate job growth in the natural gas industry, which includes extraction, transportation, and conversion.



Natural gas is often seen as a 'transition fuel' towards a more sustainable energy future. It offers a cleaner-burning option in the short term, helping to bridge the gap as technologies for renewable and zero-emission fuels continue to develop. However, it should be noted that natural gas is still a finite resource, and efforts must be made to optimize its use and minimize its environmental impact.

Forecasting the Growth Rate

The growth of natural gas as a commercial fleet vehicle fuel is influenced by several factors. Increased awareness of climate change, tightening emissions standards, economic benefits, and technological advancements all contribute to its growth. However, challenges such as high conversion costs, infrastructure development, and competition from other alternative fuels may moderate this growth. Given these factors, it is anticipated that the use of natural gas in commercial fleet vehicles will continue to grow, although the rate may vary based on changes in the aforementioned factors.


In conclusion, natural gas represents a significant step forward in the pursuit of sustainable and economically viable alternatives to conventional fossil fuels for commercial fleet vehicles. While there are still challenges to be addressed, particularly in terms of methane slip and lifecycle emissions, the ongoing advancements in technology and changes in policy and societal perspectives point towards a future where natural gas plays an increasingly prominent role in commercial transportation.