Editor's note: Response to our May 26 BushGreenwatch on the
potential of ethanol as one means of reducing America's fossil
fuel dependence was so substantial that a follow-up seemed
appropriate. Research and development (R&D) subsidies for
ethanol are one of the many issues in the energy bill being
debated in the Senate this week.
Corn-based ethanol
While corn-based ethanol production has drawn bipartisan support
in both the House and Senate -- and will likely receive far more
research and development (R&D) funding than other alternative
fuels -- scientists and environmentalists alike debate whether
this will actually improve U.S. energy efficiency, or is
basically a guise to provide subsidies for the corn industry.
Due to the complexity of the production process, the scientific
community is divided. Most say that corn-based ethanol does
contain more energy than it takes to produce it.
But some studies suggest that when all the energy needed to
produce corn-based ethanol is considered, it uses more energy
than the final product actually contains. [1] These studies
consider a variety of factors that others omit or calculate
differently, such as the amount of natural gas in nitrogen
fertilizer used on corn crops; the amount of energy necessary to
convert corn into ethanol; how much energy it might take to
remediate the environmental impacts of corn; and the amount of
diesel gasoline used by tractors to harvest corn. There is also
the question of how much energy is contained in waste products
that come from the production of corn-based ethanol.
Critics also note that the amount of natural gas used in the
corn-based ethanol production process does not significantly
reduce greenhouse gas emissions. Jeff Fiedler, a climate policy
specialist at the Natural Resources Defense Council (NRDC), says
greenhouse gas emissions from corn-based ethanol are only 15
percent lower than those from traditional gasoline. [2]
Cellulosic Ethanol
Cellulosic ethanol is a form favored by environmental groups due
to its minimal impact on the environment and substantial energy
efficiency benefits. Fiedler recently told Grist Magazine that
ethanol derived from switchgrass results in a 95 percent
reduction in greenhouse gases compared to refining and burning
gasoline. [3]
The environmental benefits of cellulosic ethanol go well beyond
emissions reductions, according to Nathanael Greene, author of
the NRDC report, "Growing Energy: How biofuels can help end
America's oil dependence." Whereas corn-based ethanol requires a
significant amount of fossil fuels to produce, Greene told
BushGreenwatch, "There is enough energy in switchgrass that the
plant could not only power the ethanol production process, but
also contain left-over electricity for export."
Nalin Shani, senior research assistant for the environment and
energy project at the Brookings Institution, adds that
"Cellulosic ethanol uses less water and fewer pesticides than
corn-based ethanol."
Sufficient financial support for cellulosic ethanol R&D could
make a meaningful inroad into reducing America's reliance on
foreign oil, says Greene. But while the potential exists, the
technology does not.
Hence more R&D dollars are needed. "Making cellulosic ethanol is
possible, but it can't be done economically until we develop
more advanced technology," says Greene. "The potential pay-off
compared to costs is enormous."
###
SOURCES:
[1] BushGreenwatch, May 26, 2005.
[2] "Growing Energy: How biofuels can help end America's oil
dependence," NRDC, Dec. 2004.
[3] "Mikey Likes it: Bush's Pick to head the USDA is a big
ethanol booster," Grist Magazine, Dec. 9, 2004.
