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EarthTalk®
From the Editors of E/The Environmental Magazine
Dear
EarthTalk: Where does ethanol as an automobile fuel fit into the
alternative energy mix? Is it better for the environment than
gasoline?
-- Donna Allgaier-Lamberti, Pullman, MI
Ethanol-a
biofuel derived from corn and other feedstocks-is already playing
a major role in helping to reduce emissions from many of the traditional
gasoline-powered cars on the road today. According to the U.S.
Department of Energy, nearly half of all the gasoline sold in
the U.S. contains up to 10 percent ethanol, which not only boosts
octane but also helps meet federally mandated air quality requirements.
By promoting more complete fuel combustion, this small amount
of ethanol mixed into gasoline reduces exhaust emissions of carbon
monoxide-a regulated pollutant linked to smog, acid rain, global
warming and other environmental problems-by as much as 30 percent
compared with pure gasoline.
Also,
a growing number of so-called "flex-fuel" vehicles now
available can run on either straight unleaded gasoline or so-called
E85, a mix of 85 percent ethanol and 15 percent gasoline. Ethanol
proponents underscore emissions savings, cost stability (ethanol
is distilled from domestically grown corn) and reduced reliance
on (foreign) oil as benefits of more drivers filling up their
tanks with E85 instead of gas.
But
even though some eight million flex-fuel vehicles are now on U.S.
roads, most of them are not near convenient ethanol refilling
stations and are therefore mostly running on regular gasoline.
(The U.S. Department of Energy website has a map-based listing
of E85 refueling stations across the country-most are in the Midwest's
"corn belt.") So while the capacity and perhaps demand
for a cleaner burning fuel is there, supplies have not kept pace-some
say because the federal government has subsidized ethanol producers
only and not the distributors and retailers who get the product
to customers.
But
this may change. In May 2009 President Obama signed a Presidential
Directive to advance research into biofuels like ethanol and expand
their use. The resulting Biofuels Interagency Working Group is
developing a plan to increase flex fuel vehicle use by making
E85 and other biofuels more available.
While
many environmental advocates view increasing ethanol use as a
promising development (if drivers would actually fill up with
it), others are not so sure. Cornell agriculture professor David
Pimentel argues that producing ethanol actually creates a net
energy loss. His research shows that a gallon of ethanol contains
77,000 BTUs of energy for engines to burn but requires 131,000
BTUs to process into usable fuel, not including additional BTUs
burned from fossil fuel sources to power the farm equipment to
grow the corn, and the barges, trains and trucks used to transport
it to refineries and ultimately fueling stations.
Pimentel
also says that powering a car for a single year on ethanol would
require 11 acres of corn, which could alternatively feed at least
seven people. If we step up our use of ethanol and begin putting
our farmers' yields into gas tanks instead of on dinner tables,
we could see a shortage of domestically grown food and higher
prices at the grocery store. To address this problem, biofuels
producers are researching alternative non-food feedstocks such
as algae, corn stalks, wood chips and switchgrass, though they
would still make use of arable land that could grow food for human
consumption.
CONTACTS: U.S. Department of Energy, www.energy.gov;
Argonne National Laboratory, www.anl.gov;
E85 Fueling Station Locations, www.afdc.energy.gov/afdc/ethanol/ethanol_locations.html.
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Magazine, P.O. Box 5098, Westport, CT 06881; earthtalk@emagazine.com.
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