Commercial fleets are increasingly moving toward alternative fuels to reduce their greenhouse gas emissions. Renewable natural gas (RNG) has enormous potential to help the transportation industry come closer to carbon neutrality. So, how do landfills play a role in this decarbonization journey?

Turning Landfill Waste into Renewable Natural Gas (RNG)    

How is it possible to obtain fuel from landfills ? It starts with organic waste, such as food scraps stacked and compacted in the landfills. The organic matter buried under other layers of trash then starts to rot without oxygen -- this is when anaerobic bacteria come to play. They break down the organic matter into smaller compounds, including CO2 and methane, and they end up collecting in specific cavities throughout the landfill.

The gas is then recovered and processed. When moisture, CO2, nitrogen and other impurities are removed, the result is nearly pure methane, which is known as Renewable Natural Gas (RNG). It can be used interchangeably with methane obtained from fossil resources and can sometimes be injected into the local natural gas distribution network. Cummins’ natural gas engines, for example, are fully compatible with RNG. 

California's approach offers a compelling example of how turning garbage into fuel can help decarbonize the transportation sector. In 2022, an impressive 97 percent of all on-road fuel used in natural gas vehicles in California was RNG. What are some of the main reasons for this incredibly high number? Supportive state policies and incentives for RNG production, like the Low Carbon Fuel Standards. Local governments’ demand for decarbonization also played a role in RNG’s increased growth.

The Benefits of Using Landfill-derived RNG In Commercial Vehicles 

Converting landfill waste into RNG presents an exciting opportunity to reduce carbon emissions in commercial transportation. In some cases, RNG from landfills can even have a negative carbon impact. Burning and releasing CO2 derived from captured and refined biogas reduces the contribution to global warming more than releasing methane directly into the atmosphere. This is because methane’s world warming potential ⁠— compared to CO2 ⁠⁠— is greater.

Waste management companies have established partnerships to obtain RNG directly from the landfills where they handle waste disposal. This creates a circular economy where waste becomes fuel, powering the trucks that collect and transport it. Besides having lower emissions, the garbage collection company can save money on fuel, and avoid exposure to fluctuations in diesel fuel prices. 

Landfill RNG has also been used to power transit buses. For instance, the city of Hamilton in Ontario, Canada is working to build a green transit fleet with buses powered by RNG derived from landfills. This not only helps reduce carbon emissions but also promotes cleaner air in urban environments. Major businesses including Amazon, UPS and Walmart have also begun to add RNG-powered vehicles to their delivery fleets.

RNG production can result in attractive business models for landfill operators. Not all landfills can accommodate a landfill gas collection system. According to the U.S. Environmental Protection Agency, slightly less than half of the 2,600 U.S. landfills accepting municipal waste could economically collect landfill gas. Of these, about half are currently producing RNG. This means that growing landfill RNG production still has a great deal of potential. As more landfills start harnessing the technology to produce RNG, this could stimulate local economies by creating jobs and reducing waste management costs. 

Cummins' L9N and X15N Natural Gas Engines: Reduced Emissions and Cost Savings

Cummins is at the forefront of decarbonizing the commercial transportation sector with its natural gas engines. The L9N and X15N are designed to leverage the potential of RNG. Utilizing RNG from landfills, these engines can achieve carbon negative emissions and help cut fuel costs. 

The Cummins L9N engine can help fleets dramatically reduce smog-forming nitrogen oxides (NOx) emissions by 90 percent – much lower than the EPA standard. It’s a great choice for buses and refuse trucks, delivering both reliable torque and horsepower while lowering emissions. 

The Cummins X15N offers powerful performance, efficiency and low emissions, making it an ideal fit for heavy-duty applications. In fact, Walmart is now incorporating the X15N in RNG-powered semi-trucks into its regional haul fleet at distribution centers. The X15N is designed to meet stringent EPA and California Air Resources Board (CARB) 2024 regulations while delivering impressive cost savings. Its optimized fuel system and reduced maintenance requirements can lower total cost of ownership. When compared to its predecessor, the ISX12N, the X15N offers significant design improvements. This makes the X15N a more appropriate choice for heavy-duty applications.

Capitalize on Financial Incentives for RNG Fuel Adoption

Through a series of financial incentives and government programs, fleets can capitalize on the benefits of RNG. One of the most substantial incentives comes from the Inflation Reduction Act (IRA) of 2022. The IRA provides significant tax benefits aimed at encouraging the use of cleaner energy sources, including RNG. Most notable is the multi-year extension of the Alternative Fuel Tax Credit (AFTC). This provision allows a $0.50 per gallon tax credit for natural gas used as transportation fuel, reducing operational costs for fleets converting to RNG. 

The IRA is helping businesses invest in alternative fuel refueling equipment with an increased fueling infrastructure credit of $100,000 per qualifying piece. This encourages businesses to deploy RNG-powered vehicles by reducing the cost of RNG refueling infrastructure, ensuring a smoother/easier transition to RNG.

These incentives make RNG a practical and cost-effective solution for decarbonizing commercial vehicle fleets. They align economic benefits with environmental responsibility, making it easier to switch to RNG for fleets.  

Cummins, with our range of natural gas engines designed for RNG, stands ready to support your business in making this transition. Contact your local Cummins sales office today to learn about partnering with us on RNG technology.