A
new report out of MIT’s Laboratory
for Energy and the Environment is giving
pause to those looking to corn-based ethanol
to fill the widening gap between oil demand
and peak production. Written by Tiffany
Groode and John Heywood, and entitled “Ethanol:
A Look Ahead,” the report examines
the petroleum consumption, greenhouse emissions,
and land impacts of the ethanol industry.
The
study looks at the entire process of ethanol
production and all the additional variables
that enter into the production equation.
It specifically focuses on the concept of
net energy value, the difference between
the energy cost of production and the energy
value of the product. For corn-based
ethanol (corn being the only technically
feasible high-volume feedstock currently
being used for ethanol production), the
energy costs of growing the corn depend
on where the corn is grown. Corn grown
in poor soil requires additional fertilizer
and irrigation, which decreases the net
energy value of the ethanol.
According
to Groode, using corn grown in Iowa as a
feedstock for ethanol production gives the
fuel approximately the same energy efficiency
as gasoline, while growing the corn in Georgia,
where the soil isn't as good, causes the
net energy value of the ethanol to be less
than gasoline.
The
report also examines ethanol’s effect
on greenhouse gasses, which are approximately
equal to gasoline. While ethanol burns
more cleanly than gasoline when it is used,
the natural gas and electricity used in
the production processes offset these lower
emissions during use.
Currently,
the U.S. Government has set a goal of increasing
ethanol production seven fold by 2017.
However, if corn is the sole source of production,
Groode’s analysis of the land impact
seems to render these goals unattainable.
To meet the government goals, 75% of all
current corn production would need to be
dedicated exclusively to fuel.
In
the final analysis, Groode concludes that
while corn-based ethanol has significant
shortcomings as a complete long-term solution,
it does have some good points. From
an overall economic standpoint, corn-based
ethanol could serve to reduce dependency
on foreign oil, providing time for the development
of better alternatives. In addition,
corn-based ethanol could function as a stepping
stone to other forms of ethanol currently
being researched. |