The energy transition is pushing natural gas vehicles (NGV) aside for battery electric vehicles (EV), according to new research.

“The State of Sustainable Fleets 2021,” issued in late May by consultancy Gladstein, Neandross and Associates, said imminent climate change priorities make EVs the ultimate solution. The report was sponsored by transportation fueling, manufacturing and leasing firms, with perspective from the University of California (UC), Davis and the Institute of Transportation Studies.

According to UC Davis, many fleet operators have adopted “low-pollution technologies such as natural gas and propane, which are significantly more affordable” than zero-emission vehicles. “However, the urgency to meet climate change goals and the fact that these clean drivetrains or efficiency improvements alone cannot do so are pushing regulations to favor zero tailpipe emission technologies.”

Diesel and gasoline vehicles “face increasingly stringent regulatory initiatives, including sales bans, and growing emission reduction expectations from sustainability-oriented customers and the public,” researchers said. However, compressed natural gas (CNG) NGVs lead the alternative vehicle market for fleets, “with fueling infrastructure available nationwide and commercial NGV sales across a wide range of applications and platforms.” 

Hydrogen fuel cell EV technology “remains expensive and available in only very limited production,” but models for transit and over-the-road markets have doubled in the past year. 

Government support is essential to developing alternative fuel markets, said researchers. As a result of government support, alternative transportation technologies have become more accessible and cost-effective, according to the authors.

Meanwhile, in California, 92% of all NGVs last year used renewable natural gas (RNG), and the California Air Resources Board has determined the NGVs achieved carbon negativity. The carbon intensity of the RNG used in CNG form has continued to decline, according to NGVAmerica and the RNG Coalition. 

NGVAmerica President Dan Gage said this is a first for California fleets, emphasizing that “verified data” means the trucks and buses leave “zero-carbon footprint while virtually eliminating criteria pollutant emissions that contribute to asthma, heart disease and poor air quality.”

Separately, Portland, OR-based utility NW Natural said early results look promising for a hybrid natural gas-electric heavy-duty tractor truck. The Cascadia day cab tractor tested is using Hyliion Holdings Corp.’s electric drivetrain. The tests were conducted as part of a vehicle loan program for three fleet operators seeking alternatives to diesel.

Hyliion’s powertrain to boost performance of CNG vehicles provided enough power to pull more than 100,000 pounds uphill with performance comparable to diesels, according to NW Natural’s Chris Kroeker, business development segment manager.

NW Natural expanded the truck program last year for fleet operators to validate natural gas vehicle technology.