August 13, 2007
Key issues for the NGV industry have been addressed in the final versions of the UC Berkeley–UC Davis team’s Low Carbon Fuel Standard (LCFS) reports, and the Coalition is now seeking a more thorough analysis of diesel fuel in heavy-duty applications.
The final version of Part 1 of the report, the technical analysis, provides the correct global warming intensity (GWI) score for CNG (68); in earlier versions, the number was 13 points higher (lower is better) because of a calculation error. The final version of Part 2 of the report, the policy analysis, eliminates an earlier proposal that alternative fuels be required to achieve 10 percent carbon content reductions, just like petroleum fuels, even if they start with lower carbon intensity. Instead, it recommends that all fuels be held to the same standard—for fuels used in light-duty vehicles, that would be the carbon reduction target for California gasoline.
Another of the policy report’s 22 recommendations is that differences in the efficiency of gasoline and diesel engines should be accounted for, and diesel fuel for heavy- and light-duty uses should be treated differently. The study’s authors want to recognize the potential greenhouse gas reductions from light-duty diesel vehicles that meet California emissions standards, but prevent fuel providers from meeting the LCFS simply by selling more diesel fuel.
That’s a wise move, but there’s more work to be done, says Coalition President Mike Eaves. “The authors recognize that to really address the intent of the executive order, they need to address diesel separately from gasoline. But while they’ve done an extensive analysis of gasoline, they haven’t gotten very far with diesel and its applications in heavy-duty vehicles.
“The problem,” he says, “is that the potential for carbon intensity reductions is much muddier on the heavy-duty side. It’s not like the light-duty market, where the OEMs specify efficiency for every one of their products; a given heavy-duty engine can go into a wide variety of vehicles and have different fuel economies in each one.”
But untangling that thicket is crucial. “There should be a sense of urgency because there are viable fuels that can help reduce greenhouse gas emissions from heavy-duty vehicles right now,” Eaves says. “Plus, that’s where our industry is going to be generating credits.”
Courtesy of California Natural Gas Vehicle Coalition.