Top: RNG fueling station. Photo courtesy of Clean Energy Fuels
State of Sustainable Fleets is an annual evaluation of the clean commercial transportation market, conducted by TRC Companies, Inc. Now in its fifth year, the annual Market Brief provides historic data and analysis on leading sustainable technologies for fleets — including electrification, renewable natural gas (RNG) and renewable diesel — and significant developments from the past year on the markets for these technologies. “Five years has demonstrated the central role of innovation that is yet another signal that clean technology is a new reality for fleets,” states the Brief. “Enormous investment by producers has been funneled into a new renewable diesel (RD) market that is expected to follow a path laid by renewable natural gas (RNG): saturate the California market, move to other states with low-carbon fuel programs, and expand nationally. Both RNG and RD are “drop-in” solutions for fleets with compressed natural gas (CNG) and diesel vehicles, respectively, that use familiar fueling architectures and promise greenhouse gas (GHG) and other emissions reductions without much change to fleet behavior.”
According to the Market Brief, RNG production continued to grow in 2023 with over 150 new facilities coming online to meet the rising demand from fleets seeking improved sustainability without sacrificing economic viability. “This growth helped sustain competitive retail prices even as the average retail price of conventional natural gas rose to $3.04 due to geopolitical factors, averaging 50% less expensive than diesel on a dollar per diesel gallon equivalent (DGE) basis,” notes the Brief. “Carbon credit markets in several states including California helped ensure diesel price parity or better for the renewable version in those states. Fleet demand for natural gas, particularly RNG, grew for the third consecutive year although at a more moderate pace. The average natural gas vehicle (NGV) fleet used RNG for 70% of its fueling needs by volume in 2023, according to the annual survey, up from 46% the prior year. However, use is becoming more concentrated with the number of fleets operating NGVs that use RNG dropping below 50% for the first time in several years. RNG’s increasingly negative carbon intensity (CI) continued to secure its value to fleets that used it in 2023 when it attained an average CI of -119 gCO2e/MJ, a more than 20% improvement over 2022’s figures.” The report adds that the majority of new NGV deliveries were made to fleets in refuse (33%) and general freight (29%) vocations, “where demand is expected to grow in the coming years.”
