Care Must Be Taken to Curb Methane Leaks, Says EDF
Natural gas-fueled trucks can provide an immediate greenhouse gas emissions and hence climate benefit – if care is taken to curb methane emissions both from the trucks themselves and more importantly from the supply chain, says a new report from the Environmental Defense Fund. Vehicle efficiency is important too, EDF says.
“Our range of results indicates that these fuel switches have the potential to produce climate benefits on all time frames, but combinations of significant well-to-wheels methane emissions reductions and natural gas vehicle efficiency improvements would be required,” states an abstract of Influence of Methane Emissions and Vehicle Efficiency on the Climate Implications of Heavy-Duty Natural Gas Trucks by EDF senior economic analyst Jonathan Camuzeaux and colleagues.
UPS pledged this month to operate certain of its over-the-road trucks in California on biomethane, aka RNG – renewable natural gas – to the tune of about 1.5 million equivalent gallons per year (F&F, May 5). RNG was not addressed in today’s EDF report. Agility Fuel Systems photo
The study was released today in Environmental Science & Technology, a publication of ACS, the American Chemical Society.
“Policymakers wishing to address climate change should use caution before promoting fuel switching to natural gas,” states the study. “Fleet owners and policymakers should continue to evaluate data.”
“The new study finds there are indeed pathways for heavy duty natural gas vehicles to achieve climate benefits, provided methane emissions across the value chain are reduced both upstream and at the vehicle level,” Camuzeaux said in a blog post this morning.
“Upstream emissions issues have to be addressed,” says another expert observer with ties to the environmental community. “This is not a controversial statement,” he told F&F in an email. “We all know that these improvements are necessary.”
‘Climate Benefits from Day One’
While the study warns of “damages to the climate for several decades” – up to 90 years for spark-ignition engines – “It is possible for natural gas trucks to provide climate benefits from day one,” says Jason Mathers, a senior manager in EDF’s corporate partners program.
EDF’s Jonathan Camuzeaux
Three things are necessary: reduced emissions from the natural gas supply chain, reduced emissions from the trucks themselves (both including boiloff losses related to liquefied natural gas) and improved truck efficiency, he told F&F.
“The time to get ahead of this question is now, before this industry hits a major growth spurt,” Mathers says in an EDF blog post. “Reducing methane leaks upstream of the vehicles themselves will determine whether a shift in fuels will have a cost or a benefit for the climate.”
NGVAmerica Is Not Wholly Pleased
NGVAmerica noted today that it is working with EDF and academic partners on a soon-to-be published “Pump to Wheels Methane Leakage” study promising “to end speculation about actual in-use methane leaks from natural gas stations and vehicles.”
NGVAmerica also cited a Washington State University study finding that upgrades in metering and regulating stations, changes in pipeline materials, better instruments for detecting pipeline leaks and regulatory changes have led to methane emissions that are from 36% to 70% lower than earlier U.S. EPA estimates.
“It’s confusing that the Environmental Defense Fund has chosen to conduct and release another study, outside of the cooperative work already underway,” association president Matt Godlewski said in a statement today.
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Source: EDF with Fleets & Fuels follow-up