Renewable Identification Numbers (RIN) and Renewable Volume Obligations (RVO) are the mechanisms the EPA uses to implement the RFS program. RVOs are the targets for each refiner or importer of petroleum-based gasoline or diesel fuel, while RINs allow for flexibility in how each of them may choose to comply. Each year, EPA issues RFS rulemakings calling for increasing volumes of renewable fuels.
The volumes for the four RFS targets (cellulosic, biodiesel, advanced, and total) are assigned to the obligated parties—refiners and importers of gasoline and diesel fuels—by way of RVO percentages. The RVOs are calculated by dividing each RFS target by the total estimated supply of nonrenewable gasoline and diesel fuel in each year. There are four separate RVOs that represent the four different RFS targets. For 2013, the four proposed RVO targets are:
The RVOs are applied to each obligated party's actual supply of gasoline and diesel fuel to determine its specific renewable fuel obligation for that calendar year. Obligated parties must cover their RVOs by surrendering RINs within 60 days after the end of each calendar year.