What are the problems with using corn ethanol for fuel?

Brian Westenhaus, over at New Energy and Fuel, has been telling me what a good product corn ethanol is. He is very familiar with raising corn for ethanol, and can see how the process has been improved in recent years. Now it takes hardly any petroleum and chemical inputs from the farmer in order to grow a crop if corn for ethanol. The process is very mechanized, so it does not take much labor either.

He has been having some discussions with Robert Rapier, who sees corn ethanol as being a problem, primarily because of its low energy return. I see some other issues with corn ethanol, relating primarily to its competition with food, and because of this, its tendency to raise the price of food. This is a problem for poor people around the world who cannot afford high-priced food. Another concern is that the amount of corn ethanol produced will tend to decline over time, rather than being a real help when we need it.

Let me explain the issues as I see them.

1. Not a good enough energy return.

This is the summary exhibit of a big corn ethanol study done at Berkeley in 2006 that expresses its results in several ways:

According to the Berkeley study, “Ethanol today” is a very efficient user of petroleum. Even back when this study was done, it used .04 mega joules (MJ) of petroleum for each MJ of ethanol produced. From what Brian is telling me, advances are working to make this ratio even better. So from this point of view, ethanol is very helpful.

The objection that is raised by Robert Rapier and others relates more to the total fossil fuels used in making ethanol. This is shown in two ways on the chart–as the ratio of fossil fuels to each MJ of ethanol produced (amounting to .774 for Ethanol Today), and as the reciprocal of this amount. This is the “Net Fossil Ratio” amounting to 1.30 for Ethanol Today. This latter ratio corresponds to what one sometimes sees referred to as Energy Return on Energy Invested, abbreviated as EROEI or EROI.

The objection that is made is that society needs, on average, a fairly high EROEI to operate, because the energy inputs measured in making this calculation are direct inputs (for example, energy of natural gas in running the ethanol plant, energy of natural gas in making fertilizer). Society as a whole needs a lot of indirect inputs as well, such as roads to take the ethanol to the plant, schools for the children of the ethanol workers, and clothing for the workers. We don’t know exactly how high an EROEI is needed on average to run society, but a reasonable approximation is about 5.0. If ethanol was only at 1.3 at the time of this study, even if it has improved somewhat, it is still almost certainly far below the 5.0.

The question is whether this comparison is fair–and different people would come to different conclusions. When we make electricity, we lose much of the energy value of the coal or natural gas in the conversion process. Similarly, if we build a gas-to-liquids plant for converting natural gas to liquid products, we use a fair amount of the energy from the gas in the process. A liquid fuel is more valuable than the gas, so this makes sense economically. Perhaps we should view making ethanol as partly a way of converting natural gas to a liquid. In this case, the relatively low ratio is not as much of an issue, especially if we have plenty of natural gas. If we don’t have plenty of natural gas, then shortages of natural gas get to be an issue as well.

We might also compare the EROEI of ethanol to the EROEI of alternative sources of additional liquid fuels for our vehicles. In this case, alternatives would most likely involve ramping up production from Canada’s oil sands. This would involve huge capital investment in plant and most likely considerable addition to pipeline capacity. The EROEI of this would also be low, perhaps 3.0 or less, when all of the pieces that need to be added to the system plus the expected operational inputs are considered. So it is not as if we have many good alternatives for ramping up liquid fuel production with EROEIs better than 5.0. What we have is a choice between less-than-perfect fuel sources.

2. Ethanol production uses resources that could be used for food production, and tends to raise food prices.

I think this is the big issue with ethanol production. When poor people around the world are spending 50% or more of their income on food to begin with, they really cannot afford higher prices for food, so higher food prices tend to cause hunger.

The real issue here is the fact that we live in a finite world, and are reaching limits in many different ways–including petroleum supplies, fresh water, arable land, food supply, and CO2 in the atmosphere. Using corn ethanol instead of petroleum for part of our fuel supply can help us substitute something that is not in short supply for something that is, and temporarily postpone a crisis that we might be reaching.

The catch is that what seems to be plentiful at one point in time doesn’t always stay plentiful. At the time the decision was made to expand corn ethanol production, we seemed to have an excess of arable land, and corn prices were low. Using some corn for ethanol looked like it would help farmers, and also help increase fuel for our vehicles. There was also a belief that cellulosic ethanol production might be right around the corner, and could substitute, so there would not be as much pressure on food supplies.

Now the situation has changed. Food prices are much higher, and the number of people around the world with inadequate food supply is increasing. The ethanol we are using for our cars is much more in direct competition with the food people around the world are using, and the situation may very well get worse, if there are crop failures. Cellulosic ethanol is working much less well than hoped, and there are not any other approaches that look close to being commercial, although theoretically, in a few years, this could change.

If oil supply declines in the future, it is likely that the amount of food that can be produced around the world will decline, because the shorter petroleum supplies will interfere with mechanical planting and harvesting of crops, and with irrigation and herbicide and pesticide application. So as oil supplies drop, the conflict between food and fuel use of corn and of cropland can be expected to increase.

3. Concern about damage to the environment.

A closely related issue to (2) is the concern that the growing of corn in large quantities will cause damage to the environment and may make some of our shortages worse. For example, when corn is grown is grown “fencepost to fencepost,” there is concern that it may be planted in areas which are easily subject to erosion. We are already losing topsoil. This would tend to cause us to lose topsoil more quickly.

Also, water levels are dropping in quite a few aquifers, as a result of excessive water use. The Ogallala Aquifer in particular is dropping. If corn is grown where it needs to be irrigated, there is concern that it will make this situation worse.

As more and more of the earth’s surface is used for crops, less and less land is available for wild areas. This has an adverse effect on biodiversity. For example, bees and other pollinators may be adversely affected by not having a variety of food sources.

4. Requires subsidies or mandates to be salable in reasonable quantities.

At this point in time, corn ethanol is subject to both subsidies and mandates. Of course, oil gets its own forms of subsidies as well, so it is not easy to tell exactly how different costs are, when making a comparison.

Going forward, the assumption that has always been made is that petroleum costs would rise considerably, making alternatives more competitive. We really don’t know whether this will be the case. Food is a less discretionary item than fuel. If there are shortages of both food and fuel, people will buy food before fuel. So it may be that food prices will rise even more than fuel prices.

Natural gas prices are very low right now. The expectation is that these will need to rise, if shale gas producers are to make an adequate return on their investment. If natural gas becomes more expensive, this will put even more price pressure on corn ethanol.

5. The amount of ethanol produced may decrease, rather than increase, over time.

I mentioned above that the amount of food produced is likely to decrease over time, as the amount of petroleum available declines, because of the use of petroleum in the whole system. It seems to me that some of the same issues may spill over to ethanol production–governments will not be able to plan well enough to protect farmers from shortages. Also, there will be more pressure to move land from ethanol production into food production. Prices for food and ethanol will tend to rise, making it harder and harder for people to afford both fuel and food, so demand for fuel may decline.

As the amount of oil produced declines, the amount of ethanol that can be blended into gasoline as E-10 or E-15 decreases. So that portion of the ethanol market is likely to get smaller over time. E-85 has not caught on, in part because it tends to be expensive, and in part because there are not enough service stations selling it to make it reasonable for flex-fuel cars to be tuned to use E-85 in a more efficient manner. If there is pressure to use more and more land for food, I doubt the E-85 service station situation will get much better, so cars are likely to remain tuned to optimize mileage for gasoline, rather than ethanol. So I expect the proportion of E-85 sold will remain low, although we can debate this.

I also have a worry that many will think odd. Our financial system is very much tied in with all of our petroleum problems. I am afraid credit problems will become more and more of an issue, and ripple through the system. For example, farmers may not be able to get credit to buy new machinery, or even to buy seed for putting in the new crop. Because of this, production of corn, both for food and ethanol, may drop. Or your local electric utility may run into financial difficulties, and not be able to pay creditors or buy fuel. If there are electrical interruptions, this could affect ethanol production, even if the farmers are able to grow the corn.


One issue that has come up recently is the fact that the US is now producing more corn ethanol than it can easily blend into its own supply, so we are exporting some of the corn ethanol. With this approach, the subsidy for corn ethanol is acting to keep the price down for countries importing the ethanol. We don’t know whether the corn ethanol would have been competitive with local products without the subsidy–presumably it would not have been, and local farmers would have been able to sell their ethanol instead. Our subsidy helps to put European producers of corn ethanol (to the extent any is produced in Europe) out of business.

I would imagine the dollar amounts involved are at this point relatively small. I suppose the issue is that “our” subsidy is going to help someone else. The theory is that if we are going to subsidize something, we should be subsidizing our own ethanol use, not someone else’s (although, in the end, it all goes to augment oil use), and both act to reduce our balance of trade problems. If Europe is really unhappy about this outcome, they will add a tariff, or otherwise restrict trade.

I am sure that there are other issues, for example, with corn ethanol’s impact on CO2 emissions and air quality, but I have not researched them adequately to address them. The points I have listed give at least a flavor of the objections I see.

About Gail Tverberg

My name is Gail Tverberg. I am an actuary interested in finite world issues - oil depletion, natural gas depletion, water shortages, and climate change. Oil limits look very different from what most expect, with high prices leading to recession, and low prices leading to financial problems for oil producers and for oil exporting countries. We are really dealing with a physics problem that affects many parts of the economy at once, including wages and the financial system. I try to look at the overall problem.
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21 Responses to What are the problems with using corn ethanol for fuel?

  1. Tim Auld says:

    All of these issues are endemic problems of large scale monoculture. Estimates for industrial agriculture are in the order of 10 units of energy consumed for 1 unit of food energy produced, for example. I would prefer to see attention focused on improved agricultural practice, as this would result in more efficient production in every respect. Productivity gains would naturally improve any fuel production (which has happened throughout the history in the form of dedicating an amount of production to feeding working animals).

    A straight forward example of boosting productivity by moving away from monoculture is alley farming. Useful trees are planted in rows perpendicular to the prevailing wind direction. Other crops and livestock can be raised between the rows. Yield from the inter-crop can be increased in the order of 30% by reduced wind effects, more than making up for the space lost to the trees. The trees become habitat for birds and predatory insects that further increase yield by reducing pest control costs. Livestock conversion rates are improved as wind chill is abated. The trees themselves can produce useful products – they may be thinned for poles, firewood and eventually timber.

    This is what permaculture is about. Using natural patterns to design systems that are extremely productive and in harmony with natural systems. An example of where ethanol production has been integrated with ecological design is the Samboja Lestari project in Borneo. Arenga palms are used as both a firebreak and for production of ethanol and palm sugar, providing income for locals.

  2. Owen says:

    Well, I didn’t want to take the matter too far afield from the ethanol perspective of the original article, but it all extrapolates.

    I am a former military officer. I can assure you that a “civil civil war” perspective does NOT extrapolate. Officers are very thoroughly trained before they are commissioned in the 7 days in May scenario. The US Air Force, Navy, Army and Marine officer corps is the finest and most integrity laden such ever to exist in the history of mankind. A military coup is not only out of the question, it will never allow the question to be asked. The lightest criticism of any administration’s strategy will generate a resignation by the officer in question.

    This is true with this president in times of ample military funding and it was true in the years just after the Soviets surrendered and there was funding draw down. The US military will never lead a coup.

    The US military will, however, take advantage of any orders to reduce competing oil demand. The US gets its imports via pipeline from Canada and fairly short runs across the Gulf. Only a few million bpd require long, vulnerable trips.

    Not so with China. The US submarine force could shut down China GDP growth within about week.

    • marty schoffstall says:

      I don’t remember the military being at issue in these postings. A civil civil war as defined by my friend is about the various “interests” say “social services” doing their best to eliminate (some) “educational funding” so that they can be “fully funded”. to date, they supported each other because there were tons of dollars to raise (appropriate) to fund everything.

      Interesting of late is the press is the realization that the long term support between the LABOR unions and the PUBLIC SERVICE unions is going away because the LABOR union membership/leadership realize that they are being asked to die on a giant hill of money that the PUBLIC SERVICE unions believe that is theirs no matter what.

      I remember the oath way back in my youth, it is a constitutional oath for officers. And while the success rate of using an “illegal order” defense under the UCMJ approaches zero, during Katrina it was used by various NG troops to not participate in firearm seizure. As the frayed Posse Comitatus Act is marginalized by the past several administrations my hope and prayer is that whatever might happen in the US is not settled by the US armed forces.

  3. Owen says:

    If the crash is inevitable, and you’re American, you want America to sustain casualties lower than those of other countries.

    It’s a disquieting reality that is military in origin, and make no mistake about it, an American government — ANY American government, is getting paid by the taxpayer to orchestrate precisely that. If they don’t, they are betraying their voters.

    In that context, there is an awkward perspective of accepting the inevitable and insisting that the US consume as much as it can, to deny China a chance to catch up.

    • schoff says:

      Reading between the lines Gail appears to be trying to navigate an ethical path of maintaining the maximum good for the maximum people, but I’m being fast and loose.

      However, I’d like to point out that there are some politicians that would not feel they betrayed their constituents by NOT submerging another nation to extend the US – they would think that highly doing so was highly unethical. I doubt that Gail would insist on that, nor would I or other readers in the US. My foreign travels especially in Africa working on projects that are self, family, and (US) community
      funded certainly make one appreciate the US but overall Western foolishness, in truth naked wickedness of many things.

      As for China I would argue that extending the consumerist culture of death is/was no gift to the Chinese. I think they have played this international economic game very adroitedly, and knowing some of the players there at the policy level I am not surprised, they are significantly smarter than their peers in the Reagan/Bush/Clinton/Bush administrations that I know. But as they are (mostly) American educated, they are no more wiser. They bought this hook line and sinker.

      I find it interesting as former/current socialists/communists that they chose
      consumerist capitalism (i’d differentiate that from classical capitalism) US style over say Swedish style socialism/capitalism.

      I am continually amazed that the chinese take FED
      printed pulp paper and hand the US
      the sweat of their citizens, nearly the last drops of their resources (coal, water, etc), and trash their country environmentally. If I was a conspiracy
      person I’d say this has to be the greatest conspiracy in the history of the planet.

      • Yes, I agree all of this is strange, and there are some who would feel a need to invade other countries. But it seems like the likely payback would be pretty small, and it would require paying out even more salaries for soldiers, etc. So I am not so certain it will happen. It may be more local skirmishes–one state against another, or fights over water rights (Colorado, for example).

        • schoff says:

          i’m hoping post iraq/afghanistan we’re done invading. I took owen’s “righteous” post (and that’s a good thing where I come from), as America’s subtle and not so subtle exploitation.

          I have a friend who calls the intra-America first stage of all of this as a “civil civil war”, and it has already started, now it is just about “money” (so they think).

  4. dan allen says:

    Gail wrote: “Using corn ethanol instead of petroleum for part of our fuel supply can help us substitute something that is not in short supply for something that is, and temporarily postpone a crisis that we might be reaching.”

    Gail, a common thread running through your writings seems to be that postponing the inevitable energy/economy crash would be a good thing. It’s come up before in your stance that we should take it easy on criticizing the huge energy corporations. But given that we will inevitably use this ‘extra’ time to merely increase our vulnerability to catastrophe(i.e. more CO2 emissions, higher population, more land degradation, more resource draw-down, etc), such a postponing seems suicidal to me. Do you really think we would do otherwise with this ‘extra’ time?

    • Realistically, a lot of us are not likely not to survive the shift from exponential growth to slow motion crash. At best, what we can hope for is to live a bit longer before the crash takes many of us. So I see holding off the crash, or not moving it ahead, as a reasonable objective. If I thought everyone (or a vast majority) could go sailing through, then a might take more of a position like other people.

      If nothing else, I would like people to think through what they are advocating. If you haven’t thought through what scenario you think might be ahead, then it is hard to put together a strategy to match the real issues that are likely ahead.

      • dan allen says:

        My point is that, by all appearances, every second that elapses at our current rate of consumption diminishes the carrying capacity of the Earth. If this is true, delaying collapse results in MORE deaths, human & otherwise. There’s obviously a heapload of bad stuff coming — it just seems to me that the sooner it happens, the better chance we have of saving SOMETHING.

        • marty schoffstall says:

          I think a lot of Americans feel that way, in my experience those who exist in close fraternal and religious groups, they see the sufferings of their members (even in another continent) and non-members and simply want the reset button pushed.

          I remember reading SciFi back in the 70s that took the position that if you squandered all the resources of your planet and your civilization fell, you had to wait till tectonic movements exposed new mineral resources, don’t think that would work for petroleum.

          I’m reading “When Money Dies” and I was struck by the statement that every year people in the weimar republic would say “it can’t get any worse than this”, and then it did, year after year. I probably would have said the same thing last year in Swaziland, but now with no fuel for buses, no more $’s from SA, and higher food prices, 2011 is ramping up to be a greater nightmare.

        • It seems to me that we have temporarily had a special bonus with respect to the carrying capacity of the earth, in terms of fossil fuels. In the long run, the carrying capacity is determined by how much plant material will grow; how polluted the land, water, and air are; and what the climate is in various parts of the world (which is tied in with what plant material will grow). It also depends on whether carrying capacity is defined in such a way that continued degrading of the soil through farming is considered acceptable. See Long term agricultural overshoot.

          I think the true carrying capacity (without farming) is whatever it was in the hunter gatherer era, adjusted for pollution and climate impacts. That is tiny compared to today–100 million or less. If we allow farming, then perhaps it is one billion people, adjusted downward by the impacts of pollution and climate.

          Ideally, to limit the impact on pollution and climate, the world’s population would need to go to a sustainable level tomorrow. But that would mean the vast majority of us would have to die, essentially now. I don’t consider this a desirable outcome.

          Cycles in climates are such that we should have been approaching an ice age about now, if there had been no problems with CO2. We really don’t know how long we have until the next ice age, with or without climate change. So at best, we are helping a much smaller number of people than are alive today (probably lower than 100 million to 1 billion) for however many years it is until the next ice age. While it would be nice to help this group of people, I don’t see any good way of doing it.

          By the way, I don’t think left-over fossil fuels can be to any extent be used in the future. They require our current infrastructure for extraction, because the “easy to get” fuels are mostly gone. So “saving” them doesn’t seem to be particularly helpful.

  5. schoff says:

    As a motor fuel given the installed base of diesel engines on the farm I’m still pushing SVO, but I do wonder if again we should be looking elsewhere: distillation following fermentation is a solution for small engines (I prefer my chainsaw to a two man saw), and for range/stovetops. Good old white lightening is much simpler and multi-purpose
    than pursuing ethanol production.

    Time and again I run up against questions of, is this the right decision when the old policy, subsidy, titanic scale, etc. goes away?

  6. Bicycle Dave says:

    Reading the headline for the article, my initial reaction was to just ignore it – as I feel that almost any use of ethanol is a huge step in the wrong direction. The only exception I can see for ethanol or some type of bio-fuel is for farm use. Otherwise, this is a really a discouraging subject. However, I did read your essay and I believe you did a good job of laying out the issues.

    Aside from all the problems you detailed, my major concern is the perpetuation of the “car culture”. Personal motor vehicles are the primary cause of our PO, GW, and environmental issues (although coal fired power plants are strong contenders). I strongly believe that the US should be making every effort to change the personal transportation paradigm. Investment and support of the ethanol industry is a distraction that I believe history will view in very negative terms. This is just another indication of the fact that the great majority of folks simply don’t have a clue about the finite nature of our planet.

    I’m not going to attempt to substantiate my assertions about the insult to Earth from our car culture or offer transportation alternatives – I suspect I would be preaching to the choir on this blog. I really wonder how closely we are paralleling Jared Diamond’s description of the collapse of Easter Island?

  7. marty schoffstall says:

    Gail, great posting. I am biased towards thinking small but commutarian or in the new lingo a form of “collaborative consumption”. I am interested in what the farms, Amish and “English”, within a couple of miles could do in a Tainter world – some degree of collapse of our (overly) complex society.

    So I think about disintermediation, getting rid of the incredible supply chain of corn,
    and entire industries involved including industrial facilities, gas pipelines etc to make ethanol.

    Is it possible to use a different feedstock to power my communities that can be a marginal business today but grow more efficient as
    things tatter and the various implicit subsidies go away. So I move in my thinking to Soybeans and SVO.

    With a tiny amount of diesel I can start my tractor, heat the SVO in another tank and run my John Deere, my diesel F250, and my diesel genset when i have to weld or want ice for a mint julep in the middle of winter (realistically hot applejack in the winter). The technology for making SVO? A press.

    In fact i’ve seen complete “systems” on a trailer so that I could tow this around to the various farms in an organized rotation of soybeans. My soybean mash is high in protein, I didn’t have to use inorganic fertilizer to juice my nitrogen, etc.

    Am I missing something?

    • I think you are right, in that vegetable oil is much easier to produce than ethanol. There can be problems in using fuels that are not exactly chemically equivalent to the fuel your car was made for, but I don’t know how big a problem this would be. Robert Rapier would probably know more about this issue. I think the big issue tends to be gelling in winter, if it is cold out. But producing a little vegetable oil on your own farm would seem to be a worthwhile activity.

      • schoff says:

        the gelling is generally dealt with by starting the engine with normal diesel, using a heating coil to bring the 2nd (SVO) tank to the right temp/viscosity and then switching with a valve. that is what you do in the winter. i’ve been running an experiment in using old diesel, i’m upto 11 years of running it through various diesel engines.

  8. Hi Gail,

    I just thought I’d point out that using corn for fuel does not eliminate the use of that corn for food, the site you linked surprisingly didn’t list this in his article either.

    I mentioned last time that 95% of the corn grown is not directly consumed by humans., 40% of the corn grown is fed to animals and we in turn eat the eggs, milk and steaks from the animals. But when corn is distilled to produce alcohol (ethanol) only a portion of the carbohydrates are removed. All the leftovers, called “distillers grains” are still a very good high energy feed – 10% fat, 25% protein and 50% carbs. In fact since the feed has been “cooked” the protein may even be more digestible and the lower concentration of carbs doesn’t interfere as much with the normal digestion of roughage as compared to ground “raw” corn.

    Where the real energy problem comes in, however, is getting what is essentially corn soup – distillers grains are 80% water, from the distillery to the animals. You can dry it at great heat energy expense or you can feed it as is at great transportation energy expense (it is very perishable in the “wet” form).

    But the biggest problem I see with ethanol as fuel, is that corn prices are linked more and more closely with fossil fuel prices, which are not only increasing but becoming increasingly volatile. This is problem in that there is a long lead time bringing a beef steer or a dairy cow to market. The rancher and dairyman work in terms of years to adjust their supply as opposed to a farmer who still has months to make a decision on what to plant this year. The run up in beef and dairy prices recently is a direct result of the big jump in feed prices 3 years ago, which caused dairymen and ranchers to reduce herd size. Now, just when prices are getting back to the profitable range, we see corn rising again, approaching the record levels of 2008.

    The problem with ethanol is it’s hurrying us toward a time when there will be no small farms and ranches, they just don’t have the capital and access to credit to survive. We will then certainly be at the mercy of too big to fail.

    • You make some good points. I knew about the distillers grains. But when part of the corn is used for ethanol, there is still more corn grown than if it were only used to feed animals.

      I think the issue of the volatility in fossil fuel prices now affecting food to a greater extent is important. There is always a food/ fuel price tie, but the more connections there are, the worse it gets. And the tie can go both ways–a drought can affect fuel prices as well as food prices. I think this is related to the finite world issue, and the fact that we are making more and more substitutes to make up for shortages.

      It seems to me that access to credit it is one of the things that may be problematic in the near future. If this is the case, large farmers too will have problems.

      • marty schoffstall says:

        Another point on distillers grain, is that it is not a one for one substitute for unprocessed corn, there is a maximum percentage of substitution for mammals including differences between say cattle and dairy cows.

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