Regulation of Fuels and Fuel Additives: Renewable Fuel Standard ...

limit this program solely to a straight volume measurement of gallons in the context of
the RFS program for certain specified circumstances.
The Act is unclear as to whether a straight gallon measurement is required in
circumstances other than those specified by Congress. We believe the Act can and
should be interpreted to allow the use of Equivalence Values in those circumstances.
First, this is consistent with the way Congress treated the various specific circumstances
noted above, and thus is basically a continuation of that process. Second, EPA does not
believe that providing such an Equivalence Value for this small volume of renewable fuel
will interfere in any way with meeting the total national volume goals for usage of
renewable fuel. We are proposing to use an Equivalence Value of 1.0 for ethanol other
than cellulosic biomass or waste derived ethanol, and we expect that there will only be
very limited additional situations where an Equivalence Value other than 1.0 is used. As
a result, this approach is a reasonable way for the RFS program to ensure that the total
volume of renewable fuels will be used as required under the Act.
b. Energy Content And Renewable Content As The Basis For Equivalence
Values
We believe it is appropriate to base the Equivalence Value assigned to a particular
renewable fuel on the degree to which the renewable fuel supplants the petroleum content
of fuel used in a motor vehicle. This is consistent with the Act's definition of renewable
fuel, which refers to the degree to which it is directly used to replace or reduce the
quantity of fossil fuel present in a fuel mixture used to operate a motor vehicle. The
degree to which the fossil fuel is replaced is best represented by its relative energy
content. To appropriately account for the different energy contents of different
renewable fuels as well as the fact that some renewable fuels actually contain some nonrenewable
content, we propose to calculate Equivalence Values using both the renewable
content of a renewable fuel and its energy content. This section describes our proposal
for calculating the Equivalence Values.
In order to take the energy content of a renewable fuel into account when
calculating the Equivalence Values, we must identify an appropriate point of reference.
Ethanol would be a reasonable point of reference as it is currently the most prominent
renewable fuel in the transportation sector, and it is likely that the authors of the Act saw
ethanol as the primary means through which the required volumes would be met in at
least the first years of the RFS program. By comparing every renewable fuel to ethanol
on an equivalent energy content basis, each renewable fuel could be assigned an
Equivalence Value that precisely accounts for the amount of petroleum in motor vehicle
fuel that is reduced or replaced by that renewable fuel in comparison to ethanol. To the
degree that corn-based ethanol continues to dominate the pool of renewable fuel, this
approach would allow actual volumes of renewable fuel to be consistent with the
volumes required by the Act while still allowing some renewable fuels to be attributed a
higher value in terms of RFS compliance to the extent that they have a higher energy
content than ethanol.
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