Is ethanol really the alternative fuel of the future?

yellowethanol.jpg Corn on the cob could be the new Texas tea.  Credit: Kary Nieuwenhuis

When President Bush confessed in his recent State of the Union address that “America is addicted to oil,” he finally caught up to General Motors, BP and other industry leaders that have been racing to provide a sustainable alternative to petroleum, in an attempt to reach for the green dollar.

Corn-based ethanol fuel appears to be on the immediate horizon, making yellow the new black. But for all its chic advertising— specifically, GM’s “Live Green, Go Yellow” campaign—and government endorsements, ethanol may not actually be a sustainable fuel after all.

In 2005, David Pimentel, a life scientist at Cornell University who served on the Energy Research Advisory Board to the secretary of energy from 1979 to 1983, did the math to figure out exactly what the cost would be for the US to face its oil habit head-on. According to his results, squeezing ethanol from corn is akin to a trip to the methadone clinic—not a long-term solution.

“[Corn-derived ethanol] collects too little energy for all the investments of energy we have to use to produce it,” said Pimentel.

Using figures from 2001, Pimentel concluded that powering the average US car for one year on E85—a fuel consisting of 15% corn-derived ethanol and 85% gasoline—would require 11 acres of farmland, an amount of land that could host enough crops to feed seven people for one year.

If that seems like comparing apples to oranges (or fuel for cars to fuel for people), Pimentel offers the following calculation from his 2005 research: The energy required to produce one gallon of ethanol is about 131,000 BTUs. One gallon of ethanol can supply about 93,000 BTUs of energy, which means 29% (or 28,000 BTUs) of the energy used to produce the fuel is lost, along with the food sacrificed to use the land.

The energy is lost in the manufacturing of the fuel, which includes costs like powering farming machines, making fertilizer and pesticides, transporting the crop to an ethanol refinery and, of course, running an ethanol refinery. Many of these operations are made possible thanks to gasoline fuel.

According to the Department of Energy 3.4 billion gallons of ethanol were produced in 2004, accounting for just one percent of automobile fuel used. That one percent of fuel, according to Pimentel, required 14% of the country’s total corn crops.

Furthermore, Pimentel added, cultivating corn consumes the most pesticides, causes the most nitrogen-based fertilizer run-off and causes the most soil erosion of any other crop in the US.

So, rather than turning to mixtures of gasoline and corn ethanol like E85, Pimentel’s suggestion for a greener fuel is converting coal into gasoline. The abundance of coal in America will cut back our dependence on foreign oil and cause fewer environmental problems than corn, according to Pimentel.

“I’m not saying you wouldn’t have problems with coal,” he said, “but they would be less [than with corn].”

Naturally, some scientists dispute Pimentel’s findings, and disagree with his plan to abandon ethanol altogether. A research team led by Alexander Farrell, assistant professor of energy and resources at the University of California Berkeley, released in January, performed a comprehensive analysis of six studies that they considered to be representative of the current literature on corn-based ethanol. Their assessment suggests that, contrary to Pimentel’s 2005 study, there is a positive energy output in ethanol production.

Farrell sites bad methodology for the two studies that showed a negative output: one being Pimentel’s, the other, a 2004 study by another Berkeley researcher, Tad Patzek.

“They use either obsolete data or data that is so poorly documented that we cannot tell what the quality of it is,” said Farrell. “But [the conclusion] is really different with other data we can find, and for that reason, suspect.”

One of the key reasons that the efficiency of corn ethanol is in question right now is because only the easily accessible sugars in the kernel are used for fuel. This process is almost the same as what moonshiners have done for centuries: break down the sugar in the starch to get a fuel (for both drinking or driving, but not at the same time).

For scientists like Farrell, ethanol’s stock is on the rise because of recent technical breakthroughs. Advances in two areas, farming and biotechnology, mean bigger crops and a better energy output for ethanol.

New farming techniques are improving the sustainability of land for growing large crops of corn. Meanwhile, biotech innovations may be able to boost the total energy output of ethanol fuel. For instance, efficient enzymes will soon be able to break down the fibrous cellulose of more robust plant material, which will make it possible to use a range of vegetation to produce ethanol.

“In order to produce ethanol that is really green, really environmentally friendly, we are almost certainly going to require cellulosic technology,” said Farrell.
By employing cellulosic methods, the whole plant—kernel, cob and stalk—could be used to make ethanol fuel, vastly expanding the efficiency of corn-based ethanol, he said. Better yet, Farrell added, we might give up the yellow fad forever and find better crops like willow trees, which can be grown in marginal areas where corn cannot be planted.

From the sound of the State of the Union address, it appears the Bush administration agrees with Farrell, and they are putting their money behind their perspective.

“We’ll also fund additional research in cutting-edge methods of producing ethanol, not just from corn, but from wood chips and stalks or switch grass,” Bush said, during his January 31st speech.

Perhaps green fuel is the greener alternative.

Originally published March 17, 2006


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