The volume of renewable fuel used as the basis for calculating the percentage renewable fuel standards is fixed by CCA 211(o)(2)(B) for certain years (through 2012 for biomass-based diesel and 2022 for other renewable fuels), with volumes after those dates to be determined by EPA in accordance with considerations specified in the statute. However, for cellulosic biofuel EPA must annually project the anticipated volume of production for the coming year and, if the projection is less than the statutorily-prescribed volumes, provide for a corresponding downward adjustment of required volumes. EPA also has broad authority to waive any of the requirements under conditions specified in the Act. (See CAA 211(o)(7).
In general we treat the mandated volumes as ethanol-equivalent. Thus, if only ethanol were used, the actual physical gallons of renewable fuel used would exactly match the mandated volumes. Renewable fuels with energy content than ethanol will have Equivalence Values higher than 1.0, and thus one gallon of nonethanol renewable fuel will count as more than one gallon in the context of compliance with the standards. As a result, the physical volume of renewable fuel used to meet the RFS2 standards may be lower than the volume on which the standards were based.
The total actual volume of renewable fuel required may also vary from that used to set the standards if the projected volumes of gasoline and diesel used in the calculation of the standards differs from the actual volumes of gasoline and diesel produced in the U.S.