Tom and Ray Magliozzi, who host of the popular NPR program Car Talk as "Click and Clack", address the controversial issue of ethanol efficacy. According to a listener's letter,131,000 British thermal units (BTU) are needed to produce a gallon of ethanol. However, that gallon only produces 77,000 BTU of energy. The listener wonders if the 54,000 BTU shortfall per gallon is truly cost-effective compared to gasoline.The Magliozzi's first point out the difficulty of calculating what constitutes the elements in producing the fuel. Scientists agree that the energy to plant the corn and processing it into starch should be in the equation. They disagree, though, if the energy to manufacture the tractor used in processing corn should be included as well. Also, converting corn into ethanol creates various bi-products such as corn oil. When the energy producing such products are entered into the equation, the shortfall vanishes. Tom also reminds readers that the equation only considers corn as the source of ethanol. Sugar cane, which can also be converted into the fuel and is more energy efficient, can wildly change the figures.
You can listen to Car Talk here.
[Source: The Sun News via Myrtle Beach Online, picture by Singer]












1. I've read the "do you include the energy it took to make the tractor which harvests the corn?" arguement before. Seems to me you only include it if you included the energy it took to make the supertanker and pipelines to transport the oil in the oil comparison calculation. I mean, compare apples to apples.
If the calculation of how many BTUs it took to make a gallon of gasoline includes such things, include them in the calculation for ethanol. It doesn't seem that hard to me. Why such a hangup?
Next are they going to calculate how much energy it took to make the Wheaties the farm workers ate for breakfast in the calculation? You could go on seemingly forever with factors. Do you add in the energy it took to manufacture the batteries which are in the ground-penetrating RADAR which the oil explorers used in trying to locate the oil field in the oil calculation?
Posted at 12:42PM on Jul 10th 2006 by 1985 Gripen