The EPA's Renewable Fuel Standard Rulemaking for 2018 -- Still a Push

The statute for the Renewable Fuels Standards (RFS) required the U.S. Environmental Protection Agency (EPA) to establish volume requirements for four categories of biofuels for each year from 2008 through 2022: cellulosic biofuel, biomass-based diesel, total advanced biofuel (which includes biomass-based diesel), and renewable fuel (referred to as conventional ethanol here). The difference between the total advanced mandate and the total of the cellulosic and biodiesel mandate is referred to as the undifferentiated advanced mandate and can be satisfied by a combination of qualified advanced biofuels. Conventional biofuels is generally assumed to be corn-based ethanol but this is actually not explicitly required by the RFS legislation. Instead, corn-based ethanol has been the cheapest alternative for this category that also meets the environmental requirements of the RFS. In addition, the conventional portion of the mandate can also be satisfied with discretionary blending of advanced biofuels, so one can refer to the conventional mandate as an implied mandate. We refer to this implied mandate as the conventional ethanol mandate in order to be consistent with the most common term for this particular RFS mandate. Cellulosic biofuels have been in very limited supply, so the EPA has written down the cellulosic mandate to very low levels relative to statutory levels each year. The total advanced biofuel mandate has also been written down in conjunction with the write down in the cellulosic mandate. The biodiesel mandate was established as a minimum of one billion gallons per year from 2012 through 2022, with larger amounts subject to EPA approval.