By Greg Roche, VP of Sustainability at Clean Energy Fuels
Trucking companies, and the shippers that hire trucking companies, are making bold commitments to cut their carbon footprint — such as becoming net zero by 2030. After the commitments are made, the hard work begins — hard work because achieving net zero or better requires more than operational improvements.
New business practices and cost-effective alternative technologies are needed to move beyond even the cleanest diesel platform. Renewable natural gas (RNG) has emerged as the leading pathway for low-carbon, clean air trucking. There are three compelling reasons why RNG is helping sustainable companies decarbonize their transportation today.
RNG is the lowest carbon transportation fuel available
RNG is derived from organic material found in green waste, food waste, landfills, sewage treatment and livestock manure. These organic wastes naturally decompose into methane. Methane that leaks into the atmosphere is a potent short-lived climate pollutant and greenhouse gas. Rather than releasing into the atmosphere, methane can be captured and converted into a drop-in replacement fuel for conventional natural gas.
When used for vehicle fueling, RNG reduces carbon twofold: first by capturing methane that would escape into the atmosphere and second by replacing high-carbon diesel fuel, another short-lived climate pollutant (i.e., black carbon). The California Air Resources Board monitors the life cycle of carbon emissions of fuels from cradle to grave. The chart below shows the carbon intensity of traditional fossil fuels and low-carbon alternative fuels. RNG produced from dairy manure has carbon emissions that are over 500% cleaner than diesel fuel. RNG has the potential to be negative carbon-intensive, which is a game changer. Replacing just 25% of a fleet’s diesel trucks with negative carbon-intensive RNG from dairy manure can reduce a fleet’s carbon emissions by 100%.
RNG is already in widespread use throughout North America today. RNG is not a bridge fuel, as more RNG supply is rapidly entering the market. A study by the University of California at Davis and the Lawrence Livermore National Lab found that the 3 billion gallons of diesel fuel used in California each year could be replaced by California-produced RNG. A study by the American Gas Foundation found that RNG supplies can reach between 10 billion and 35 billion gallons of fuel per year. RNG is a destination fuel that can power clean CNG trucks today and hydrogen or electric trucks when those technologies eventually mature.
RNG trucks improve the air we breathe
Many areas of the U.S. have harmful air, and diesel trucks play an oversized role in local air pollution. The greater Southern California area, California’s Central Valley, Houston, Dallas, Salt Lake City and other metro areas share this air pollution problem. Air pollution contributes to respiratory, cardio and other illnesses. Studies have linked local air pollution to susceptibility to COVID-19, Alzheimer’s disease and cancer. Diesel trucks emit high amounts of local air pollutants such as oxides of nitrogen (NOx) and diesel particulate matter. Diesel particulate matter is classified as a toxic air contaminant and is composed of carcinogenic compounds. Trucks powered by RNG have 90% lower NOx emissions than a new diesel truck and over 98% lower NOx emissions than many of the diesel trucks in use today. RNG-powered trucks have zero emissions when it comes to carcinogenic diesel particulate matter.
Much attention is given to alternative technologies that do not emit through a tailpipe. However, there is more to this story than just what happens at the tailpipe. RNG trucks are so clean that emissions of local air pollutants are about the same as a battery electric truck charged by the power grid because the grid is often powered by natural gas, coal and other fossil sources.
RNG trucks save money
RNG fuel costs less than diesel fuel. Fuel savings are particularly amplified today with skyrocketing diesel prices. RNG prices are also less volatile than petroleum fuel. RNG trucks have a maintenance benefit due to a simpler emissions control system. RNG trucks have a passive catalytic converter emissions control system, similar to a car. The catalytic converter requires no maintenance, unlike a diesel truck with a complex diesel particulate filter and selective catalytic reduction, essentially a roving chemistry set. The diesel emissions control system becomes less effective and requires higher and more expensive maintenance as the truck ages. The higher RNG truck purchase cost is quickly offset by fuel savings and lower maintenance and upkeep compared to a diesel truck.
RNG trucks have great economics compared to other emerging clean technologies. The cost of these emerging technologies is 200% to 300% more expensive than RNG trucks. These emerging technologies have far more expensive charging or fueling infrastructure costs than RNG fueling. An RNG truck at one-half to one-third the cost of other technologies has better carbon reduction and equivalent air quality benefits.
Leaders are taking action today
Climate pollution and air pollution are problems that exist today, not far in the future. While it is noteworthy for companies to make aspirational goals to achieve net-zero carbon emissions in the future, RNG trucks offer the ability to achieve net zero immediately. RNG truck technology has been proven and perfected over the past 14 years. RNG engines are mass produced by Cummins. RNG trucks are mass produced by Freightliner, Peterbilt, Kenworth, Volvo and Mack. RNG fueling infrastructure is available throughout North America and is rapidly expanding. Clean Energy alone has over 560 fueling locations at customer sites and at retail locations.
Companies like Amazon, UPS, Waste Management, Saia, Estes and TTSI are deploying thousands of RNG trucks today. What do these sustainability-leading companies know? RNG is the lowest carbon fuel available and offers an affordable alternative to diesel today that is proven and scalable.