Study Backs Ethanol as Gasoline Substitute About one out of every 40 cars and trucks in the United States can now run on a commercial mix of gasoline and ethanol, mostly made from corn. And the federal government is backing the renewable fuel industry. But does ethanol really reduce dependence on fossil fuels?
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Study Backs Ethanol as Gasoline Substitute

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Study Backs Ethanol as Gasoline Substitute

Study Backs Ethanol as Gasoline Substitute

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This is ALL THINGS CONSIDERED from NPR News, I'm Melissa Block.


NPR's Christopher Joyce has the latest on a stubborn debate.

CHRISTOPHER JOYCE: The CITGO gas station on West Street in Annapolis is one of four stations in Maryland that sells E85 fuel, 85 percent ethanol and 15 percent gas. Manager Juan Kang (ph) says the regular gas pumps get a lot more use than his single ethanol pump.

JUAN KANG: We sell regular gasoline 1,500 gallon a day. This is 20 gallon a day.

JOYCE: But Kang says when gas prices were high last year, ten times as many people bought ethanol. The question is, did that switch reduce America's consumption of oil and other polluting fossil fuels? Well, that depends on how you add up the amount of energy needed to make ethanol.

DANIEL KAMMEN: Do you include the lunch that the farm workers eat as an energy input?

JOYCE: That's Daniel Kammen, physicist and energy expert at the University of California at Berkeley.

KAMMEN: Do you include the energy to build the factory to build the tractors? You can spend a lot of time on stuff which is sort of secondary. Part of this is really a quibble over numbers. But it does boil down to a really critical thing, and that is do we do better from a national security perspective, from an energy perspective than from a greenhouse gas and global warming perspective by burning gasoline or by growing a bio-fuel and putting that in our tank?

JOYCE: Kammen and colleagues at Berkeley think we do. His team reviewed the main studies on ethanol and energy, updated the figures, and tried to standardize the energy inputs, things like the energy needed to make fertilizer or electricity and anything else you need to either refine gasoline or ferment ethanol. Their result?

KAMMEN: We found unequivocally that it does not take more energy than you get out of the amount of ethanol, so that it's a net good if you're going to grow ethanol and use it.

DAVID PIMENTEL: It's another typical pro-ethanol paper.

JOYCE: That's David Pimentel, an agriculture scientist at Cornell University. He is, to say the least, skeptical of the Berkeley team's research, which directly challenges his own conclusion that making ethanol takes way more energy than you get out of it.

PIMENTEL: They criticize us for including the energy for the labor, that is the farm labor who's working on the farm. They deleted that. They also deleted a major input that is the farm machinery.

JOYCE: Pimentel says when you include all the important sources of energy needed to grow the corn and make the ethanol, he lists 14 of them, you find that it takes 70 percent more energy to make a gallon of ethanol than you get out of it. Since much of that energy comes from oil or coal, he says ethanol's not a good alternative. Pimentel adds that ethanol does make a lot of money for companies that grow corn. Daniel Kammen of Berkeley disagrees with Pimentel's numbers, but acknowledges that the positive energy benefit he sees in corn-based ethanol is modest.

KAMMEN: It's not a massive savings. It's not like you put in 10 percent energy and you get out 100 percent. We find that it is somewhat better than gasoline, but it's not a home run.

JOYCE: Christopher Joyce, NPR News.

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