RFA urges CARB to revise carbon intensity values under the LCFS
The Renewable Fuels Association is urging the California Air Resources Board to revise indirect land use change (ILUC) penalties assigned to certain biofuels under the state’s low carbon fuel standard (LCFS). In a letter RFA President and CEO Bob Dinneen sent to CARB Chairwoman Mary Nichols on Jan. 17, he notes that more than two years have passed since CARB adopted a resolution directing its staff to prepare amendments to revise the carbon intensity values of several biofuels, including corn ethanol, sugarcane ethanol and soy biodiesel.
Dinneen also addresses direct carbon intensity values in his letter. While several updates have been made to the model used by CARB to assign direct carbon intensity values to biofuels, CARB staff has continued to rely on outdated data. He points out that new peer-reviewed research has determined a carbon intensity value for corn ethanol that is 38 percent lower than the value estimated by CARB.
“Thus, I am writing to again encourage CARB to honor its commitments to expeditiously revise the ILUC penalty factor assessed against corn ethanol and to utilize the ‘best available science’ when determining direct [carbon intensity]values,” said Dinneen in the letter. “Revising the direct and indirect [carbon intensity] values for corn ethanol would be much more than a mere academic exercise; rather, a continued failure to update these [carbon intensity] values will jeopardize the ability of regulated parties to reasonably comply with the LCFS program’s increasingly rigid [carbon intensity] standards in 2013, 2014 and beyond.”
One study Dinneen points to was published by Michael Wang at Argonne National Laboratory, who created the GREET model used by CARB to determine carbon intensity values. That study determined the carbon intensity of average corn ethanol is 62 grams of CO2 equivalent per mega joule (g/MJ). However, CARB’s outdated data assigns a 99.4 g/MJ carbon intensity value to average Midwest corn ethanol.
Wang’s analysis found that relative to petroleum-based gasoline, corn ethanol could reduce greenhouse gas emission by 19 to 48 percent. The savings were even greater for ethanol made from sugarcane, corn stover, switchgrass, and miscanthus, which resulted in relative GHG savings of 40 to 62 percent, 90 to 103 percent, 77 to 97 percent, and 101 to 115 percent.