Corn ethanol is inefficient and drives food prices higher

Corn ethanol has environmental, economic and social impacts that reach far beyond the gas tank. And by almost any analysis, those impacts make it a poor choice for fuel in the United States.

QUESTION: I read years ago that ethanol plants needed to be subsidized in order to make “ends meet.” Since then, how much has the efficiency of ethanol-producing technology improved? Is the industry now getting more energy out of the ethanol produced than put in? How dependent is this efficiency on the type of biofuel used (corn, grass, sugar cane)? Asked by Hector Raynal, El Paso, Texas

ANSWER: The United States loves corn. We use it for everything, from Coca-Cola sweetener to cow feed to “plastic” cup base. And we grow a lot of it: about 730 billion pounds in 2010*. On par with America’s love for corn is its oil addiction—and over the past 10 years we have combined these two great infatuations in the form of ethanol, a biofuel that can be mixed with gasoline to power cars and trucks. While the process of making corn ethanol involves simple fermentation and distillation—not unlike making whisky or vodka—the impacts of moving nearly 126 billion pounds of corn off the table and into the tank are enormous, and infinitely more complex.

Corn, like any plant, needs sunlight, soil and water to grow. In the United States, it gets myriad additional inputs: in 2005, farmers applied 10 billion pounds of nitrogen fertilizer to our nation’s corn, irrigated more than 80 percent of the cropland and sprayed about 170 million pounds of herbicides—and that’s while the plants were still in the field. Once the Little Red Hen is ready to harvest all of that corn, it needs to be picked, packaged and shipped off for processing and distribution.

Every step in that process requires energy. The question is, can we get more energy out of corn ethanol that we have to put in? This is the energy output ratio you’re asking about. If the Hen sends the corn to be made into biofuel, she will get about 1.3 units of biofuel energy out for every unit of fossil fuel energy in. And unfortunately, that’s the lowest energy ratio out there for biofuels. For comparison, Brazil—the world’s second largest biofuels producer after the United States—gets an output ratio of 2 from their sugar cane ethanol. Also, studies on net energy output of biofuels are convoluted and often hard to sift through: while some say it takes more energy to produce biofuels than the fuel provides, others say just the opposite. We’ll attempt to clarify the situation in the Nitty Gritty.

A bio-ethanol fuel manufacturing plant in the Midwestern United States. Select Committee on Energy Independence and Global Warming

While energy ratios give a valuable metric for comparison, judging the impacts of biofuels—and their ultimate value as a sustainable fuel source—is more complex than comparing energy outputs or piecing together lifecycle analyses. Corn ethanol has environmental, economic and social impacts that reach far beyond the gas tank. And by almost any analysis, those impacts make it a poor choice for fuel in the United States.

One such negative impact is diverting corn from food to fuel: the 14 million acres of corn we used for biofuels in 2008 could have fed 26 million cows to maturity, or have sustained as many as 100 million people for a year. Further, choosing to use that corn for fuel decreased the amount available as food on the international market and may have contributed to skyrocketing food prices and increasing deforestation rates in the Amazon.

So with all of the harmful side effects, why doesn’t the Red Hen just keep the corn on the table and out of the tank? Even characters in fables are susceptible to economic incentives, evidently. With the help of decades of farm subsidies keeping inputs cheap, a tariff on foreign ethanol, 40 percent of production costs being covered by tax dollars, and government mandates for production, sending corn to the tank earns famers a lot more money. Is that really our primary goal from an alternative fuel source? Almost certainly not, so lets look elsewhere for fuel and leave the corn for the cola and cows.

READ MORE: Life cycle assessments capture more of corn ethanol’s overarching impacts [Click through for the Nitty Gritty Answer].

 

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6 Comments

  1. says: Larry Johnson

    Wow, Apparently SAGE doesnm’t even make an effort to use any facts but just writes what ever supports the preexisting opinion. I have never seen an article with so many inaccuracies. 80% of our corn irrigated? That is off by a factor of eight! Increasing deforestation in the Amaazon? Totally unrelated; Amazon deforestation has been going down since 2003 while ethanol production has increased by a factor of five.

    SAGE is Stanford students? God, help guide us into the future!!

  2. says: CD Lee

    Only about 10% of the entire U.S. corn crop is irrigated. Perhaps the 80% reflects California. As for corn prices and food: the farmer receives about $0.04 for every dollar spent on a box of corn flakes. Overall, farm receipts are about 11% of the total food bill. Rising corn prices have little overall impact on food prices.The the United States (and the United Kingdom) enjoy the lowest food prices, based on expendable income, in the world. Rising corn prices pose a bigger challenge for the cattle farmer than someone buying corn flakes.

    Depending on the year, only about 5% of the U.S. corn crop goes into human consumption. This includes all the corn flakes, tortilla chips, cornbread, and corn syrup. The remaining 95% or so feeds cattle, hogs, poultry and fish; while some is exported to other countries and some is converted into fuel ethanol.

    Corn is the most logical crop to use for fuel production in the U.S. at this point. As a country, we have been growing, harvesting, shipping, storing, feeding and processing corn for decades. The addition of ethanol facilities into the system was an easy transition. Corn also makes transitioning to other forms of biofuel an easier process. Sugar cane is more efficient at producing ethanol, but as a country we cannot grow very much sugar cane. Although, perhaps someday we will. Until sugar cane, or some other crop, can be grown on as many acres and produce as much ethanol, corn is the most logical option.

  3. says: Brian

    Another glaring fact left out of this post is that corn used for ethanol is not taken off the table. You’ve completely ingnored dried distillers grains (DDGs). DDGs are the by-product of ethanol production. What does one do with DDGs. Well, for the most part they are feed to cattle which puts that corn right back into the food supply. DDGs make a great feed because what’s left after the production of ethanol is nutrient and energy rich and the part of the kernel that isn’t easily digestible has been stripped out.

    That being said corn ethanol will more than likely not remain as the standard raw material for ethanol production. This is still a young industry and second generation production methods are scaling up to go online. Cellulosic ethanol should take the place of grain ethanol, and then we have algae gearing up to be a big game changer.

  4. says: Francis Patrick

    Corn makes a better feedstock for ethanol than sugar cane due to the numerous by products such as dried distillers grains, corn oil, corn syrup,etc. There are no by products with sugar cane, it’s either ethanol or sugar. That’s the reason why Brazil has a shortage of ethanol and is now importing American corn ethanol and corn ethanol is replacing sugar cane ethanol on the international markets. With the co products corn is probably the best feedstock for ethanol.

  5. says: Gina Lappe

    Thank you all for your comments, they do a great job of showing just how complicated an issue corn ethanol really is. But I will defend that using corn for ethanol fuel is a bad idea – for food prices, for energy, and for the environment.

    While it is true that the US has an existing infrastructure for corn production that makes the fuel jump a relatively easy one, that does not mean that 1) our system for growing corn is a good one, or 2) we somehow become isolated from the global market.

    With regards to 1, it takes a lot of energy, water, and chemicals to grow corn in the US and adding more demand to that market will increase our already excessive use of these resources. My Nitty Gritty response tells a more complete story, every SAGE column has such an in-depth analysis; we are Stanford students. If you are still not satisfied, check out USDA, where I got all my numbers.

    For 2, simple supply and demand tells us that if we add additional demand to the market – fuel demand for corn – the price will go up. This price increase will impact every participant in the corn market, not just people buying corn flakes. For example, when corn prices go up markets start looking elsewhere for cheaper inputs, like soy for animal feed. Soy is a quickly expanding crop in Brazil with cropland taking over cerrado and rainforest alike.

    The issue is complicated, but the answer is clear. We need to be looking elsewhere for ways to fuel our fleet.

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