Sunday, June 18, 2006

Nonrenewable renewables: The hidden life of biofuels

The farm fields are again sprouting with their recently planted corn and soybeans, and those verdant fields, once reserved for growing food, are increasingly devoted to what people are now calling renewable fuels. Those fuels, ethanol from corn and biodiesel from soybean oil, are touted as the path to energy independence and clean air and as an answer to global warming. How innocuous and wholesome these fuels must seem: They come from things we eat; the smell of biodiesel is no more offensive than that of french fry oil; ethanol is nothing more than the same alcohol we find in all alcoholic drinks; and the carbon dioxide which both fuels release into the atmosphere gets reabsorbed by the following year's planting.

That, anyway, is the extent of the story one might get from recent coverage of the biofuels boom. But are these fuels really the renewable wonders they seem? That may hinge on what people mean by renewable. If they mean that for a limited time the crops from which liquid biofuels are made can be repeatedly grown, harvested and processed to make biofuels, then they are perhaps in a very narrow sense correct. If what they mean by renewable is sustainable, then they are just plain wrong. Biofuels produced the way we are producing them today are not even close to sustainable. In truth, the current production methods for biofuels are more like mining operations than farming operations. That calls into question whether such fuels can deliver the benefits which are now being so incessantly trumpeted in the news media.

To understand why this is so, we have to go beyond the fleeting glimpses of farm fields that we get from our cars--glimpses that for many of us form the sum total of our knowledge of farming. If one were to stand across from a field of corn or soybeans for an entire season, one would, in most cases, witness the following: plowing done with a tractor, planting using large mechanical planters, the spraying of herbicides and pesticides, the application of fertilizers, irrigation (in some cases), and harvesting done by large machinery. In fact, one would see that all of the heavy field work is done by petroleum-powered machines.

This style of industrial farming involves huge petroleum and natural gas inputs to fuel the machinery; to make and apply the herbicides, pesticides and fertilizers; and to irrigate and harvest the crops. Many people don't know that oil is the basis for most herbicides and pesticides and that natural gas is the basis for most of the world's nitrogen fertilizers. (Nitrogen fertilizers are used heavily on corn, but not on soybeans which produce their own nitrogen.) Both oil and natural gas are finite resources; their use to help grow crops for fuel can in no way be called sustainable. In effect, we are mining finite hydrocarbons to grow crops for biofuels.

In addition, industrial farming causes soil erosion on a horrific scale. A recent study shows that soil in the United States is eroding at a rate that is 10 times faster than the rate at which it is being replenished. The numbers are worse in places such as India and China where the erosion rates are 30 to 40 times faster than the rate of replenishment. And, while many areas of the United States get ample rainfall, others require irrigation to be productive. That leads to another problem: overpumping. David Pimentel, one of the world's leading researchers on biofuels, pointed out in a recent study that "[i]n some Western U. S. irrigated corn acreage, for instance, in some regions of Arizona, groundwater is being pumped 10 times faster than the natural recharge of aquifers." This can hardly be termed a sustainable practice.

But, even where there is plenty of water to pump, irrigation can cause salt to build up in the soil rendering it useless for crops. In all, close to 50 million acres of farmland worldwide are lost to soil erosion and salinity each year. In effect, we are mining the soil and the acquifers of the world to produce crops.

But, we have yet to discuss the processing of crops for liquid biofuels. Here, the news is no better. First, of course, there is the diesel or gasoline burned to transport crops from the fields and grain elevators to the production facilities. More fuel is burned to transport the finished fuels from the production facilities to the service stations. The production facilities themselves run on a combination of electricity, natural gas and/or coal. In fact, the high price of natural gas has led ethanol producers to build new plants that will use coal for energy and heat. Electricity isn't exactly clean, either. It has to come from a generating plant that almost always uses either coal, natural gas or uranium to produce it. What this means is that the reputation that ethanol and biodiesel have for being "clean fuels" is rapidly being tarnished. The extensive use of fossil fuel energy to produce liquid biofuels can in no way be construed as renewable. Again, we are simply mining finite resources to run the production facilities.

The obvious question for newcomers to the biofuels debate is why biofuels themselves aren't used to run the production plants. The answer is troublingly simple: Under present methods of agriculture and processing, liquid biofuels are energy losers. Their production uses more energy in the form of fossil fuels than the finished biofuels contain. In fact, the entire biofuel regime is not only unsustainable, but a huge boondoggle which only exists because of large government subsidies. Absent those subsidies, no one would make liquid biofuels in commercial quantities.

Perhaps, you say, technology will improve, and we will eventually get more energy from biofuels than we expend to make them. No one can predict the future. But it is worth keeping in mind that the energy profit ratio--the amount of energy we get back from petroleum, natural gas and coal for each unit we expend extracting, processing and transporting them--ranges from 10 to 1 to 20 to 1. Biofuels are currently below 1 to 1 in their return. In other words, they are energy negative. Even if their energy profit ratio were to improve to say, 2 to 1 or 3 to 1, we would still find ourselves living in a very low-energy world if we had to rely on biofuels alone.

But, it is doubtful that, even in this best-case scenario, biofuels would do very much to help us. First, there isn't enough arable land to make much of a dent in the liquid fuels market. Perhaps even more important, food and fuel are already beginning to compete with one another and that has serious implications for most of the world's population which is poor. Some 3.7 billion people are currently considered malnourished. The last thing they need is higher food prices.

So, next time you pass by those fields of corn and soy, think of what you don't see; think of the hidden life of biofuels. Don't get bamboozled by the cynical public relations ploys of the biofuels producers; their only goal, after all, is to get you to support their lucrative subsidies. And, don't get taken in either by the wishful thinking of well-intentioned biofuels advocates; unfortunately, some may lead you to believe that life in the future will look pretty much like life in the recent past if we commit to biofuels.

Liquid biofuels are not renewable under any reasonable definition that also means sustainable. And, far from helping us kick our fossil fuel habit, the production of biofuels is only making our addiction worse.

(This article was based in part on papers published by David Pimentel and Tad Patzek. If you would like copies of those papers, email Kurt Cobb at


will in duluth,mn area said...

I am totally agreement with you in your tone and criticism of biofuels.
Having said that, I want to point out that, by everything I read, Patzek and Pimental's studies sure appear to have been widely discredited. (see my next post)
Even though you posting is probably 95 or 99% accurate, people will see Patzek/Pimental and say, oh, well that part's proven I can ignore all of Kurt's worries, they must be wrong too.

will in duluth,mn area said...

Folks, I know some of the sources below are biased, but I think the vast concensus is that Patzek/Pimental's studie(s) are flawed and wrong. Its sad, because its a distraction from the big picture that Kurt illustrates in most of his article.. i.e. that biofuels aren't sustainable. I think biofuels should continue to be criticised, questioned and pointed out as not-a-solution, but patzek/pimental shouldnt be used.




(from the energy blog,, a guy who is writing on ..what he views are possible solutions(?) to peak oil)

February 01, 2006
New Ethanol Study

A new report by UC Berkley analyzes six studies of the energy efficiency of ethanol, adjusted all of the studies to consistent system boundaries for comparison and based on the current state of ethanol production recalculated the values for corn ethanol and used a "realistic scenario" conditions to calculate the energy to produce cellulosic ethanol from switchgrass. The study found that the net energy ratio (energy out/energy in) is 1.2 for ethanol produced from corn and 8.3 for cellulosic ethanol produced from switchgrass.
The reports that they found erroneous were one by Patzek and and one by Pimental and Patzek.

First of all I hope this report, by an independent organization, will once and for all put to rest the controversy as to whether the net energy value is positive or negative. My support of ethanol for fuel is reinforced by this report. I see some disruptive times in switching from corn ethanol to cellulosic ethanol which is required to both conserve energy and to produce enough ethanol without compromising our food supplies. It is also true that it is more efficient to burn the feedstock in a CHP (combined heat and power) generator and use the electricity to power EV's and plug-ins. This possibly presents another difficult transition in that, at the present time and for the next 15-25 years, our vehicle fleet will be primarily dependent on liquid fuels and we will need all the ethanol we can produce in order to help keep the price of fuels under control. Our ethanol production capacity is rapidly ramping up to help meet this need and possibly could supply 20% of our liquid fuels by 2020. By that time gasoline will no doubt cost over $5.00 per gallon compared to less that $3.00 (more likely $2.25) per gallon for ethanol (in 2005 dollars).

(a commenter at this website said...)
Alan, your piece raises some good issues, but is far from comprehensive or up to date. A recent study by Dan Kammen and his colleagues, also at UC Berkeley, disected the many studies on the energy balance of ethanol. He concluded that most previous studies were not well done b/c of faulty assumptions. He concludes that corn-based ethanol has a slightly positive energy balance, and that it's carbon emissions benefits are dubious. He also stated, supporting President Bush's point about cellulosic ethanol in his SOTU speech, that cellulosic ethanol has a far better energy balance and far better carbon emissions benefits. Cellulosic ethanol is not commercially produced yet, because it's more expensive, but that's changing rapidly. The study is dicussed at

Corzine said Pimentel and Patzek are the only researchers since 1995 who have found ethanol to have a negative energy balance. In fact, the nine other energy balance studies conducted since 1995 all found net energy gains of at least 25 percent. (and...) Patzek was a longtime employee of Shell Oil Company and founder of the UC Oil Consortium, which has counted BP, Chevron USA, Mobil USA, Shell and Unocal among its members. Patzek also is a member of the Society of Petroleum Engineers, making his ethanol energy balance analysis hardly impartial, Corzine said. (and...)
"In terms of finer details, Pimentel and Patzek use old data, improper data, and their methods of data analysis are wrong. For example, they don't give proper energy credits to dried distillers grain, a coproduct of ethanol production" Dale said. "There is an internationally accepted standard method of doing such life cycle studies. Drs. Pimentel and Patzek don't come close to meeting the standards. Their studies don't meet the International Standards Organization test of transparency-they don't clearly state where their data comes from nor do they clearly state their assumptions. They cite themselves rather than independent sources for important data all the time.
And they don't submit their work for verification in recognized, peer-reviewed life cycle journals.


Kammen proves Ethanol's positive balance


More Ethanol criticism from I-SIS
(I-SIS issued a press release(15 Mar 2006) claiming that cellulosic ethanol (CE) is neither sustainable nor environmentally benign.)

Anonymous said...

Here is the URL

to a short article by Nicholas E. Hollis, in which the author states that the production of ethanol from corn requires low cost corn. When the cost of a bushel of corn (56 pounds of corn at 15% moisture) rises above a certain level, the ethanol plants become uneconomical to operate.

Iowan said...

A fascinating site for biofuels is
Handbook of Energy Crops
. There are many crops which might be more suitable for biofuel than corn and beans. One possibility is sorghum:

From the Handbooks entry on sorghum bicolor:

"Sorghums are high on the priority list of energy crops. The genus Sorghum includes grain sorghums noted for their ability to grow in dry climates and to manufacture starch efficiently. Sweet sorghums noted for their high yields of directly fermentable stalk sugars and their ability to grow anywhere that corn or soybeans grow, and sweet-stemmed grain sorghums which are crosses of grain sorghum with sweet sorghum and which combine the characteristics of the two types. Sorghum-based ethanol has a favorable energy input-output ratio. Because the stalk residues can be used for fuel and sorghums require less fertilizer than does corn. The directly fermentable sugars in the stalk present a challenge in that they are unstable compared with starch. Whether sweet sorghum and sweet-stemmed grain sorghum can become viable energy crops will depend on solving this serious seasonality problem. Processing facilities must be large enough to handle the entire crop in a matter of weeks, and the conversion to ethanol or other energy products must be spread out over a sufficient time period to keep unit capital investment low."

Of course, the problem of scalability and ERoEI must be addressed with any biofuel crop.