Hard Look at Gov. Pataki Ethanol Proposal

As expected, Gov. George Pataki's (R-NY) alternative fuel proposal  that I wrote about earlier in the week, is largely based on increasing ethanol production and availability. As I learned from Cornell Professor Pimentel's analysis of corn to ethanol, the Energy Return On Energy Invested (EROEI) is low (perhaps less than 1.0) and cannot be scaled to replace more than a fraction of transportation fuel. But the proposal has stirred earnest debate in New York about the efficacy of investing so much in ethanol with this NY Times article.

Gov. George E. Pataki wants to ... make ethanol and biodiesel, two controversial alternative fuels, available in the 27 service areas on the New York State Thruway and in 100 more stations throughout the state as early as this year, in a first small step toward reducing the state's petroleum consumption. The governor is also proposing incentives to bring refineries that produce ethanol into the state.

So, let's explore ethanol's place in New York's alternative energy basket.  

In energy production, this is all that matters. You don't want to waste energy trying to make less energy. Given how dependent our agriculture is on fossil fuels for fertilizer, equipment and how energy intensive it is to refine ethanol for burning, it's not surprising that the full EROEI calculation doesn't add up for ethanol:

Adding up the energy costs of corn production and its conversion to ethanol, 131,000 Btu are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 77,000 Btu. "Put another way," Pimentel said, "about 70 percent more energy is required to produce ethanol than the energy that actually is in ethanol. Every time you make 1 gallon of ethanol, there is a net energy loss of 54,000 Btu."(Pimentel)

So before we invest too much in ethanol production and distribution, let's make sure there is a positive EROEI. This probably means moving to a more organic method of farming, which would be a great thing, but this doesn't seem to be part of the proposal. Wouldn't it be a cruel hoax if by subsidizing ethanol production to move away from fossil fuels, we end up encouraging more intensive farming practices that require more fossil fuels?

Let's assume the first (and very important) hurdle of a positive EROEI of 2-5 is met. The next issue we would have to deal with is exactly how much fuel we could replace with corn ethanol:

If all the automobiles in the United States were fueled with 100 percent ethanol, a total of about 97 percent of U.S. land area would be needed to grow the corn feedstock. Corn would cover nearly the total land area of the United States. (Pimentel)

Which is impossible, plus we have to use some of that corn to eat too. Most of the corn produced in this country goes to feed livestock for meat production, so at best we could only replace perhaps a fraction of the gasoline demand and we'd all have to become vegetarians.

And from the NY Times, we learn that it's not like ethanol is really that "green" from a local air pollution/global warming perspective since carbon and other dangerous chemicals are still released into the atmosphere:

Peter Iwanowicz, a director of environmental health for the American Lung Association of New York, said the environmental benefits of the two fuels were mixed.

"Ethanol increases ozone formation, which is obviously harmful for people with lung disease, and biodiesel increases emissions of nitrogen oxide," he said.(NY Times)

Then we finally get at the political dimension to Pataki's ethanol idea, which goes beyond just having a Green Republican image:

Mr. Pataki has been criticized for promoting ethanol because it is made from corn grown in states that include Iowa, which he has been visiting recently to gauge support for a possible presidential run...Environmentalists have largely denounced making ethanol-capable vehicles, calling that a boondoggle intended for the agriculture lobby and Detroit. When automakers build cars and trucks that can use ethanol, called flex-fuel vehicles, they earn credits that make it easier to meet fuel-economy regulations, in turn giving them leeway to build more gas-guzzlers.

Now that's triangulation politics that even Clinton (Bill or Hill) would be proud to play. And at the end of all this it seems we will be using more fossil fuels than ever before.

A Better Way for NY: Niche Strategy for Cellulose Biofuels
This kind of examination is helpful because it redirects us to better ideas, like plug-in hybrids and biodiesel made from cellulose, instead of food that can be eaten:

...even the governor's advisers say that making ethanol from corn is a bad idea and that they prefer using wood or certain kinds of grass. The plan also includes incentives to help the state modify its hybrid-electric vehicles so that the cars can be plugged into stationary outlets to enable them to use even more electricity than fuel, a practice discouraged by the auto industry.

These aren't universal answers to replacing fossil fuels, but they can serve as incremental steps to a world that is better prepared for peak oil.

Just putting aside the plug-ins for the moment, here's my bio-fuel proposal for New York:

Step #1. Create more incentives for local farms to reduce their consumption of fossil fuels.

Step #2: Locally produce a biodiesel fuel (not ethanol) from excess cellulose or cooking oil waste (not usable food) with a positive EROEI. Create a complete system from farm to refining to sales outlet that is not highly dependent on fossil fuels.

Step #3. Target useful niches in the transportation system, like Buses and Trucks, which run on diesel only and can be easily adapted to biodiesel. These are highly efficient at moving people to work and products to market. More essential to the economy than a single occupancy vehicle, which could use ethanol.  

Step #4. Roll this new fuel out in the distribution chain of diesel outlets using only biodiesel supply trucks. Then set realistic targets to convert a significant percentage of over to locally produced biofuels.

This plan would spur more local organic farms and stimulate a local bio-fuel supply system that could operate relatively independent of fossil fuels. This system could keep the economy moving in an fuel crisis and it wouldn't be competing with all the single occupancy vehicles directly since they can't run on diesel.

If Gov. Pataki really wants to insulate the local economy from fossil fuel price fluctuations, then he should really think about the whole supply chain of how biomass becomes a fuel and focus on critical elements in the economy that we would want to prioritize in a fuel crisis.

Send him a note with your thoughts on ethanol and bio-diesel.

Please do not cite Prof. Pimentel regarding the corn to ethanol EROEI.  His work on this subject has been superceded by numerous other studies in recent years, and Pimentel is now discredited.  Numerous recent studies show EROEI greater than one for corn ethanol.  For cellulosic ethanol, which you mention in your posting, the ratio will be much greater than one, probably five or ten.

Ethanol is important for our energy future because it is the easiest fuel to substitute for gasoline for the 200 million existing gasoline-fueled vehicles in the USA.  Existing autos built since 1995 can operate on ethanol concentrations of 20% or more without modification, and the first retrofit kits have appeared in the market to support operation on even higher concentrations of ethanol.

Biodiesel is especially important for support of diesel-powered agricultural equipment, in order to insulate farmers from petroleum price spikes.

As someone who went to Cornell and has met Pimentel in person, I found his logic and data to be very compelling. As in all research areas, it all comes down to the methodology used and how many components in the whole chain of events get included from planting a seed to it getting pumped into a car.

But I'm game for more data on the subject. I just want to make sure we do the EROEI analysis before investing huge sums of money into that instead of electric plug-ins based on wind/solar/other. Or just simply investing in greater conservation.

What other studies would you recommend on the subject of ethanol EROEI using corn or cellulose based feedstock?

And I completely agree about ethanol powered farm equipment. We need a whole system that is fossil-fuel free, not just a system that uses lots of fossil fuels inputs and produces another type of liquid fuel output.

I'm with DonInVa on this.

There is a 2004 paper by Lynd & Wang of Dartmoth published in the Journal of Industrial Ecology (an MIT and Yale publication)showing EROEI for corn and cellulosic biomass in different types of process configurations.  To tie everybody in the paper was guest edited by an Iowa State University Engineering person.  They were very thorough in identifying the energy inputs from fertilizing the crop all the way through crop handling, enzyme treatment and cogeneration in the ethanol plants.  They show positive EROEI for most processes.  Yes, corn can result in negative EROEI if set up indcorrectly and yes cellulosic can be better in some configurations.  But corn and cellulosic are about equal if configuring ideally for the respective feedstock.  The key is you can't set up one type of operation and then change feedstock or process parameters. No one size fits all.  Physical plant construction is critical to positive EROEI.  Sounds a lot like refineries and sour crude issues we discuss here all the time.

There have been enormous strides made in industrial enzymes for ethanol production.  This has been led by Novo Nordisk but others are working hard in that area. The enzymes are required to lower the energy cost to breakdown the complex molecules into sugars that yeast can convert to ethanol.  As I posted earlier today there are also growing markets for the edible waste from the ethanol processors, particularly distillers grain from corn.  Not only have the EROEI been shown to be positive there are very strong economic incentives to cycle corn through ethanol plants before feeding animals.

The point of all this is that old data in the biofuels area is not to be trusted.  People are figuring out how to get positive EROEI in a sustainable way.  I sometimes wonder if the scrutiny applied to biofuels was used for petroleum from exploration to wells through refining to cleanup and waste disposal what the true EROEI would be.  Those considerations are typical for evaluating ethanol.

Pimentel released a new study last March, which again showed that biodiesel is not energy-positive.

Personally, I think biodiesel has a place - as fuel for planes, say - but cannot replace gasoline for cars.  Post-peak, we are going to have trouble growing enough food for the current population of the U.S.  Biofuel will be a luxury.

I have spent a great deal of time looking at the energy costs of ethanol and biodiesel.  To this day the only energy analysis that appears in the peer reviewed literature is Pimentel's analysis.  
Pimental and Patzek have taken a stand - researchers funded by pro-ethanol groups have taken theirs as well- the countervailing studies show a slightly positive EROI for corn-ethanol. But so what? Even at a VERY generous 2-1, what are we supposed to do 5 years after peak with 5% decline rates? Gross up the worlds energy balance sheet and use 1/2 of the annual fossil fuels to create 2x of ethanol, meanwhile displacing most of the food crops of the planet?

I agree that celluslosic ethanol has its place, as does sugar cane and a few of the biodiesels, but all of these solutions only go so far, and leave me with the following impressions:
1)The latent power in crude oil compared to alternatives is awesome. Until I really dug into this research and looked at the scale of alternatives, I didnt internalize how ginormous our energy subsidy really is...

  1. Politics will ensure that persuasive, influential people will succeed in society pursuing large scale energy alternatives that are bottoms up profitable (at least at first) but are net long term losers for the planet. Research is the only thing that can prevent this - but look at the research on something as simple as ethanol - no one can even agree on the basic framework on what to use as inputs

  2. Increasingly, tradeoffs between energy, food and the environment will take place, and I fear society will value them in that order, for better or worse.

  3. the only long term solution is on the demand side. Change our own HRoEI (Happiness Returned on Energy Invested)
Amen on the HROEI! As an example, a nice game of chess with a friend can be just as entertaining as a Playstation! (perhaps more mentally stimulating too!)

Yes Pimentel has been discredited: by the Ethanol Lobby, but not yet by science.
The US gasoline consumption is 9.5 million barrels / day, 9.5 * 365 * 42 = about 145 billion gallons annually. The US annual corn crop harvest is 10 billion bushels. 10 * 2.5 = 25 billion gallons of ethanol. Ethanol yield is about 2.5 gallons per bushel. 25 / 145 = about 17% If we used the entire annual corn crop to produce ethanol, 10% could be used for gasohol while the other 7% would be consumed by increased demand before the new ethanol plants came on line.
In addition to corn I have been looking at some numbers on soybeans and potatoes.
The US harvests about 2.5 billion bushels of soybeans annually, and about 23 million tons of potatoes. Potatoes yield about 25-30 gallons of ethanol/ton or 688 million gallons of ethanol about .5% of our gas consumption.
There has been much talk about bio-diesel from soybeans. The only numbers I can find are that soybeans yield about 9.5 to 10 pounds of oil/bushel. How much bio-diesel will 10 pounds of soybean oil yield?? 1.5 Gallons max, that would make 3.75 billion gallons of bio-diesel. Our annual distillate consumption is 4.5*365*42=69 billion gallons. Soybean bio-diesel would only supply 5.4% of our distillate needs. 3.75/69=.0543.
There is another problem with bio-diesel. Currently an average to excellent soybean yield is about 50 bushels/acre. At $6.00 a bushel that is a $300 annual/acre crop, However at best it will yield about 75 gallons of oil and 60 gallons of bio-diesel. That means with zero capitol and processing expense, the bio-diesel has a crop cost alone of $5.00 per gallon.
I understand that Minnesota has enacted a 2% bio-diesel law that requires nearly all diesel fuel to be blended with 2% bio-diesel. Now I don't know how much nearly is, but here is a web-site to explain it further.
Here is a web-site of oil yield for oil-bearing crops.

Here is a more efficient method of consuming corn. 15% water in shell corn contains 7000 btu's of energy per pound, and 15% shell corn weighs 56 Lbs per bushel. That is 392,000 Btu's per Bushel. At $2.00 per bushel that is $5.10 per million Btu's. Then I checked kerosene it's about the same as distillate. 6.819 Lbs per gallon and 19,810 Btu's per pound or 135,000 Btu's per gallon, or 7.4 gallons per Million Btu's. At $1.76 per gallon that is $13.00 per million Btu's. NG spot today was about $10.00 per million Btu's. Now according to the USDA a bushel of 15% corn should yield 2.68 gallons of ethanol,and ethanol contains 14,000 Btu's per pound and weighs 6.59 Lbs per gallon. That means that a bushel of corn will yield 247,000 Btu's, so you see you lose 145,000 Btu's in the ethanol process, however the leftover mash is used for cattle feed. I don't know the efficiency of a corn burning stove versus a gas or fuel oil furnace, however it is certainly more efficient than using it to produce ethanol, as a significant amount of energy is used in the conversion process. Corn burner web sites.

How much food value does ddg have after 65% of the energy has been removed?

The natural choice for your last proposal is wood, not corn. If you include the 10x higher transportation costs per BTU for corn in the equation you will abandon it rather quickly.
How much transport costs are their for a farmer that has no wood on his property but has thousands of bushels of corn molding outside beside his full grain bins. For the farmer Its a lot cheaper than propane or wood.
Agreed, but this limits the fuel application just to the farmers and to the people that leave nearby. The vast majority of people live in cities and for them it will be hard to work.
At least in NYC, all we would need is some electricity for the trains, biodiesel for the buses and everyone else could walk, bike or skate. We don't use 1/3 the gas that suburban folks do.
I think you miss the energy needed to supply such a huge city with almost anything it consumes. With this plus the air travel included New York would be much closer to the average per capita energy consumption than it looks from first sight.
I believe you ignored the value from the soymeal crop that would be available to sell to determine your actual crop cost for your biodiesel analysis.....I think the soymeal is  nearly the same dollar value as the BO after crushing.....although the market goes back and forth from meal shortages to BO shortages a bit
Do you think the soy meal will pay the capitol costs of the oil extraction and bio-diesel conversion processes? Plus blending and transportation costs.
at current prices a bushel of soybeans yields about $4.25  in soymeal value and about $2.50 in soyoil value
Probably the best single document analyzing the EROEI of corn ethanol is "The Energy Balance of Corn Ethanol: An Update", which was published by the USDA in 2002.

One of the authors of that report, Michael Wang, spoke on this subject several times in various places in 2005, and he has made a PDF of his slides available.  I call your attention to his slide 16, and particularly the  red line connecting two red dots on the right side.  Wang is saying here that his modelling program, GREET, can reproduce Prof. Pimentel's results for corn ethanol energy balance, if he uses the same assumptions as Pimentel, but that the upper red dot (positive energy) results if Pimentel's assumptions are corrected.  Notice all of the other blue dots in the upper (positive) part of the graph.  Those are all the other studies, which agree with each other, and which agree with Pimentel if his assumptions are corrected.  The corrections needed are summarized in the last paragraph on p.11 of the "Update" report cited above.

Co-products and combined cycles are the key in this business (and Pimentel largely ignores them).  For example, a few months ago I saw a press release about a new ethanol refinery operation to be established in Colorado in conjunction with a feedlot.  The corn will be processed to ethanol in the usual fashion, and the DDGS [Dry Distillers Grain Solids] which remain after the starch is processed will be fed to the cattle.  The manure will be composted, and the methane will be collected to fuel the still of the ethanol refinery.  The press release implied that the methane will be sufficient for the distillation, with no fossil fuel needed.  I ask you: what is the EROEI of this combined process?!?  It is very high, probably something like five or ten.  There are many other such examples.   Dupont has developed a process to produce their new polymer Sorona from corn starch, and now they are working on a cellulosic ethanol process so that they can use the rest of the corn plant.  Most cellulosic ethanol processes are going to be able to avoid using fossil fuels because they will fire the stills with the leftover lignin component of the plants (and may even sell excess energy as electricity). That is why you will see assertions that the EROEI of cellulosic ethanol will be much higher than that of current conventional ethanol refineries.

Thanks, I greatly appreciate your flagging that presentation. It really shows how creating a whole system around the ethanol / biodiesel production process can be made to be more efficient and return a positive EROEI. It also shows how starch/celluose is a more efficient feedstock for ethanol production.

If I'm not mistaken the key difference is that Pimentel's assumptions include fixed or "non-operating" energy costs of equipment, etc. I can accept fossil fuels being used as an initial energy "endowment" that helps create a system that could support itself over time and even ultimately serve to replenish fixed asset needs of the production system.

To what extent can existing ethanol refineries be refitted to switch to a cellulosic process?
The USDA can hardly be considered an unbiased source.  I have looked at that and a lot of other publications from pro biodiesel and ethanol believers.  However, if they really believe what they say, then publish their findings in a peer reviewed journal.  They don't, so I think they are not yet credible.
Wet distillers grain has better feed value than whole kernel corn.  Moistures is not that much different than whole corn.   Higher protein and oil content and better digestability.  A ton of distillers grain demands a much higher price as part of a feed ration than ground corn.  So the waste stream actually has more value ton for ton than the raw material.  Granted you don't get the same tons out as in but ALL of the waste stream can be sold.
> The manure will be composted, and the methane will be collected to fuel the still of the ethanol refinery.

The right kind of idea but it can be even better. Methane is an exelent wehicle fuel, its used for all city busses and a lot of cars in my home town.

Use another heat source, preferably one hot enough to make steam for a turbine to also get some electricity. Keeping with the theme it could be biomass. If it is hot enough to give a large electricity surplus use some of it to electrolyze water into oxygen and hydrogen and add 8% hydrogen to the methane.

I noted that the biomethane-fed distilleries neglected cogeneration a while back.
A combined plant is being built right now in Norrköping in Sweden.

There is already a small 50 000 m3/year ethanol plant that get a lot of its process heat from combined heat and electricity district heating plant burning mostly forest biomass.  The ethanol plant will probably get its capacity doubled in a year or two.

One methane fermentation stage is being built right now and will have a production of an equivalent to 7 m3 of liquid fuel per day to be increased to 11 m3 per day, 4000 m3/ year.

I do not know how large a percentage goes to the methane plant. I am trying to get figures to find out what this means for the total EROEI.

Hm. Looking at p. 12 of the PDF-of-slides, I see that most of the fossil energy used to produce ethanol appears to be non-petroleum.

Looking at p. 4, I see energy inputs of natural gas, LPG, electricity, and coal.

p. 6 says that ethanol has a lower energy quality than gasoline. I assume NG and LPG have higher energy quality. And of course, electricity is highest of all.

The production of 100 BTU of corn ethanol consumes 73 BTU of fossils. That already sounds nearly pointless. But consider this: It will be consuming either liquid fuels, or gas (a higher-quality fuel), or coal-fired electricity. I have to wonder whether the claimed greenhouse gas reductions (pp. 14, 15, 19) from ethanol were assuming the electricity would be gas-fired?

p. 6 also says that 100 BTU of cellulose ethanol costs only 9.6 BTU of fossil. Someone wrote above that corn and cellulose could be made equivalent? Doesn't look likely.

Take a look at p. 20. In 2004, 12% of US corn was used to produce 1.7% of the gasoline-plus-ethanol energy used in 2003. So if we used 100% of US corn, we'd be able to replace... a whopping 14% of our 2003-level gasoline consumption.

I look at this presentation, and I see a massive case against corn ethanol!

I also see a case for cellulose ethanol. As confirmed on p. 22. If cellulose really has an EROEI of 10, it seems perhaps worth working on. But I think anyone citing this presentation as support for corn ethanol needs to do a little more arithmetic or become a little less partisan.

If that includes the authors of the report, so be it.


most of the fossil energy used to produce ethanol appears to be non-petroleum.
Unless the input is from something which is not competing with oil (e.g. fertilizer made from otherwise-stranded natural gas), this isn't true.  LPG is a byproduct of gas and oil production.

The biggest improvement that could be made is to use spent steam from steam turbine generators to run the distilleries.  This would have a small efficiency hit on the generators, but nearly eliminate the use of fuel for distillation.

Well, look at the cited page: it lists very different numbers for fossil than for petroleum. It's not my conclusion--just my observation from their numbers.


Easier still-

Eliminate cattle/hogs from the equation- 7 to 1 grain to meat on cattle, 3 to 1 on hogs.  Compare to 2 to 1 grain conversion with poultry and 1 to 1 with catfish.

Essentially, the world is experiencing an overpopulation in farm animals. Between 1950 and 1994, global meat production increased nearly fourfold, rising faster than the human population. During this period, production rates jumped from 18 kg/person to 35.4 kg/person (Brown and Kane 1994; FAO 1997). The combined weight of the world's 15 billion farm animals now surpasses that of the human population by more than a factor of 1.5 (Table 1).

Arkansas, if livestock/poultry included, produces the same waste stream as 22 million people(Guv Bill Clinton quote,IMHO).


With cattle in feedlots, it takes roughly 7 kilograms of grain to produce a 1-kilogram gain in live weight. Growth of feedlots is now minimal. For pork, the figure is close to 4 kilograms per kilogram of weight gain, for poultry it is just over 2, and for herbivorous species of farmed fish, such as carp, tilapia, and catfish, it is less than 2.

BTW-same article-In areas that produce grain, particularly those that double-crop grains, such as winter wheat and corn in east-central China, there are large amounts of crop residues--either straw from wheat or rice or the stalks from corn--that can be fed to cattle. Cattle, being ruminants, can easily convert crop residues into protein, leaving the manure to fertilize fields. The amount of beef now produced in this manner in the east-central provinces greatly exceeds that being produced on rangelands in the overgrazed northwest.

As China has already realized, the most efficient way to recycle biomass is thru digestive organs eg. mouths.

Don, thanks for the comments and links. That was VERY helpful.

It seems to me that the process of getting to a higher ERoEI depends on some tenuous links. Perhaps the most unseen is the quality of feed given to the cattle. If the quality is poor, then poor cattle result. Market value would be less and perhaps no one would consume the cattle. The positive ERoEI could break down there.

Again, Thanks!

I liked the sound of this coming out of SUNY-ESF in Syracuse.

This would fall more under the category of cogeneration.  Ethanol extracted in the manufacturing process and from woody biomass (there is no shortage of "brush" in upstate NY).  I don't think that we should encourage susidized farming of soybeans and corn just to produce ethanol, but perhaps as techniques to extract ethanol from byproducts of manufacturing and food production are expanded, we could maximize our energy production within the state.

Bio fuel has been subsidized for quite a few years, certainly in the early/mid nineties, when OPEC controlled the price to around $25/b. Now oil is $60/b, begging the questions a) why is a subsidy needed now, and b) at what price of oil will the subsidy no longer be required? $100/b? 200$/b? Higher? Why not have a sunset provision, such that a) as price rises, the subsidy is reduced, and b), at a believable price the subsidy will end?
The subsidies tell something. If biofuels are now more expensive than oil, let us say, for instance, by 50%, they will be more expensive than oil also when the oil prices rise. This is because the oil and other energy inputs will be more expensive, too. Farmers costs are rising already now. Biofuels are not used even in those poorer countries where imported gasoline is very expensive. Brazil makes ethanol as a side-product of sugar production, but this is an exception, not a model for everyone.

Besides, wood, cellulose, corn and other materials for biofuels have competing uses, which may have higher energy efficiency than making biofuels. For instance, it is more efficient to burn wood for heating or using it as building material, substituting for energy-intensive cement.

The European war-time experience tells, that in an emergency situation, when oil imports are blocked, wood, coal, lignite, peat and oil shales have been used for making synthetic fuels, never farm products. An energy crisis is usually accompanied by hunger.

It is especially dumb to start talking about using biofuels in a situation when it would be relatively easy to cut the oil consumption by 10% or more by gasoline taxes, for instance. This would reduce directly the oil dependence. Building a biofuel system for the same effect will consume a lot of energy for the infrastructure and, in fact, increase net energy consumption, at least in the beginning.

I think biofuels should not have to compete with essential food production. Ethanol should mainly come from cellulose not starch while diesel should come from Fischer Tropsch treatment of other bio-waste, not fat and vegetable oils. Byproducts such as electricity cogeneration should be emphasised. Secondly biofuels should be seen as an extender of other energy resources. One of those resources will be conservation or using less. To continue with some degree of  business-as-usual, biofuels could be blended with fossil fuels and complemented by cleanly generated grid electricity, as with a flex fuel plugin hybrid car. The transition won't be easy.    
I've listened to a lecture from David Blume from Permaculture.com regarding ethanol and food vs fuel.  Basically most of the grains we grow are fed to cattle.  We can feed cattle with what's left over from ethanol production (called dried distiler's grains DDGs).  DDG is said to make animals fatter, qucker.  So much for food vs fuel.

Regarding EROEI.  The problem here is that we use a lot of fossil fuels to grow our food.  Forget driving-- the larger problem is not being able to eat.  Don't forget that refining oil into gas also takes quite a bit of energy.  

Regarding polution.  Don't forget that plants use carbon dioxide.  Under Kyoto, ethanol should get some credits for this fact.

While ethanol won't ever replace gasoline, we should still strive to develop this resource.  We need fuel.  We should get it wherever we can-- especially when it's local and home grown.

"We need fuel." No, the Americans don't need more fuel. The US consumes more oil per capita than anyone else, double the amount we use in Europe. The US need conservation, not biofuels.
The US needs both biofuels and conservation.
Several comments on the thoughts above, and for background realize I am a farmer from Kansas, who found his way here b/c it increasingly looks like farming is becoming an "energy" business as well as a food business.

  1.  Ethanol will NOT replace gasoline anytime soon.. Will it be part of the solution?  I think it can be, but has been noted above, anything close to 100% replacement looks completly out of the question

  2.  Pimentel's numbers: Peer reviewed or not, he makes a lot of "worst case" assumptions.  For example, I think his average corn yield is around 110 bushel of corn per acre, where trendline corn yield is much closer to 140

  3.  When looking at energy inputs for corn, always keep in mind that there is certianly some flexibility in those and given an economic incentive, farmers will respond by reducing energy expenses.. Couple of examples -- if fuel reaches a new price point, no-till or minimum-till farming will grow, reducing fuel use.  Also, and some may find this hard to belive, but a fair amount of irrigated corn acres waste LOTS of energy b/c the cost to use and pump the water is less than the management expense of trying to figure out how to do it more efficently.  So if you double the cost of energy to the American farmer, you will lower his energy use and probably maintain close to the same level of production -- giving a much better energy balance.

  4.  Yes, ethanol is still subsidized, to the tune of 51 cents per gallon, but the returns to ethanol production are HUGE at the moment.  One example, the plant closest to me, a small one and not known as being exceptionally well managed, returned $3 for every $2.50 investment last year alone!  Yea, that's correct, a better than 100% return in a single year, that should explain the tremendous interest in ethanol at the moment, and you can take away the government subsidy and even at today's gas prices ethanol is quite profitable.

  5. To the "but we will run out of food crowd".  Tell that too a farmer who saw cash corn prices at harvest time this year at $1.30 per bushel... lower than at any time in many, many years, not even considering inflation.

Ethanol is far from perfect, but the technology continues to mature, and I believe it can serve a useful place in the energy equation.
  1. Re: Pimental - We SHOULD have a worst case analysis - todays worst case may be tomorrows best case - what if the Oglala acquifer runs dry and water is the limiting factor in the midwest and weve built 15% of our transportation scheme around ethanol? No corn in that year...What if there are pests and we are running short of pesticides due to nat gas shortages etc? I dont think Pimentals numbers are all that unrealistic -conservative maybe but in the ballpark.

  2. this conversation should really be about what EROEI threshhold should be a minimum to accept projects for using what oil we have left on a large scale - 2-1 wont cut it. 5-1? 7-1?

  3. I amend my prior statement to this: increasingly there will be choices made between energy, food, WATER, and the environment.
All of your points highlight how important conservation of water, oil, soil, etc is to our future. What's the EROEI of a HUMMER?
you finally bought one?
You should have gotten together with some folks in Maine.  Wood pellets are going for $180+ ton there because of shortages, while you're getting under $47/ton by my numbers.  If you and some of your friends had sent a barge of shelled corn down there for blending with wood pellets you could all have made a bundle.
Couldn't send a barge of corn anywhere this year due to the Mississippi river backup due to hurricanes.  One reason prices are so low.  There are mountains of corn on the ground around elevators in Iowa.  With no way to get rid of it for months into the future.  A lot will mold before used.  Is this a good use of our "Food"?  Farmers see ethanol as a hedge against price swings that are out of their control.
Maybe you could have sent it via one of the Lake Michigan ports and down the St. Lawrence seaway.  No hurricane backups there!
Can you burn moldy corn? Or (ugh) feed it into ethanol fermenters?

On a related topic, here's an observation on the psychology of alternative energy. The idea of taking perfectly edible corn and shoving it into a woodstove or boiler does not feel good to me. It feels almost immoral--people are starving, etc. But here's the weird part: using corn to make ethanol, and then burning the ethanol, feels much better--it's clever, high-tech, progressive, productive...

If others have the same set of reactions, that might help to explain the completely irrational push for corn ethanol, which wastes vast amounts of energy compared with simply burning the corn.


Yes to both.
With both ethanol and biodiesel, there is 'food' left over after the corn or soy is used to make fuel. We grow corn and soy for food. Ignoring this mitigating factor, which Pimental does, makes for garbage analysis. Making fuel from corn and soy leaves less food than using these grains virgin, true, but it is not an either/or choice. The example above combining a feedlot with the ethanol plant makes this easier to understand, but it can be dispersed and still make sense.

That said, soy is a legume which fixes its own nitrogen and therefore needs much less fossil fuel based fertilizer than corn, which has higher N usage than most crops. If remote natural gas can be made into fertilizer rather than being shipped as LNG, and then used to make corn based biofuel that can be used for transportation, maybe it makes sense. I think the case for biodiesel is a lot easier to make, especially for long distance trucks and airplanes that need fuel energy density to function.

Here's an interesting comment that was emailed to me:

Dear Peakguy,

I have just read your posting on EtOH in NY - very nicely done. Since
I am not yet signed up on TOD, here are a couple of points that both
you and all of your commenters missed:

1. EtOH production from corn (and other crops) involves the extraction of sugars and starches from the corn (and some cellulose, but not much), and then the subsequent fermentation of the sugars/sugars from starches into EtOH. In effect, this takes the
carbs from corn and converts these to booze and CO2. The oils, proteins and many other components go along for the ride, or are used by the yeast/bacteria as food, and then these become food. Brewers yeast is well known for Vitamin B's, minerals and proteins.

When fed to cows, pigs and chickens (which most corn is), these animals tend to convert much of the carbs and sugars into either fats, methane and/or CO2. Being penned up, they don't get to convert these carbs into much energy, so they store it or toot it out the back end of "their" process. Another approach is to extract "corn sugar" and use it to load up foods such as pop/soda with lots of useless, fat producing sugar. Just what, in general, we need.

2. As for ammonia... there is a REALLY easy solution for this hydrocarbon input.  Use electricity from renewable sources to electrolyze water into H2 and O2, and then use the H2 with N2 to make
ammonia. As for NY State, here in Western NY, Niagara Falls power is available for industrial or municipal uses at a delivered price of 2 cents/kw-hr. The raw material (= electrical price) for this H2 is 0.428 cents/lb H2, which corresponds to an ammonia raw material price of $191/ton. And using ultrapure electrolytic H2 is much easier on the ammonia catalysts than methane or coal derived H2. In fact, much of a conventional NH3 plant (capital, land, energy) is involved with producing H2 from coal or CH4. And Peak Oil/Peak Gas is making methane an obsolete choice as a H2 raw material.
Once other factors (such as the capital for the H2 electrolyzers, at $1000/kw are factored in, NYPA Niagara Falls and Messena power could be used to make ammonia for around $300/ton. Last time I checked, imported NH3 was going for close to $500/ton in Tampa, from NH3 made in Trinidad.

Anyway, once you subtract the NH3 input from the studies by Pimmental and/or Wang, the energy return from corn is significantly enhanced. Of course, it goes down the tubes when the NH3 is made from coal, and probably from those extremely misguided and hair-brained concepts of using nukes, SO2, I2 and water to make H2 and O2 from H2O.

3. If these folks really want to do something about all the hunger in the world, cut back on the meat consumption. Eat corn, or food products made from DDG/corn instead of eating cows who consume 10 lbs of corn/soybeans to make 1 lb of cow meat. Or better yet, try a variety of foods, as one can obtain all the protein you need from non-meat sources. For starts, try going the Franklin Vegetarian model - Ben Franklin did eat fish, but that was it from the animal kingdom.

Why on earth all this ammonia (in the form of plant protein) is squandered on cows, pigs and chickens) is beyond me. Besides, most of the protein that they consume also goes into the sewage ponds, and then gets returned back to the atmosphere after getting oxidized to nitrates and then reduced back to N2 via various sewage and soil bacterial. As Dr. Spock would have said, "Most illogical".

Buffalo, NY

Several states are in early stages of large scale biodigesters using waste from dairy cattle manure lagoons, recycling the water, giving the ammonia back to farmers for their field fertilizer and having methane leftover either as a cogeneration source or as a stand alone product (natural gas). At todays NG prices, its a nice subsidy to the cost of a cow - at tomorrows NG prices, it might be an integral part of the dairy equation. Of course, at 20 years from now NG prices, it might be better to just bypass the cow entirely and biodigest the crops straight from the field - in which case, no more lattes....
I wouldn't recommend building large-scale digesters serving many farms, unless they were extremely close together. Cow manure from typical dairy operations has a very low total solids content, meaning that it is mostly water. That makes it heavy and expensive to transport to a central facility. You would probably use so much fuel to transport it over any significant distance that it would defeat the purpose, especially if you were using the manure from a lagoon system as that is the most dilute form of manure management (total solids content less than 3%). The most dilute forms of manure, may, in fact, not be compatible with anaerobic digestion meant to generate a useful amount of methane at all. Flaring on site for odour control would be about all that would be feasible.

Older and more labour intensive (and therefore currently less typical) forms of manure management involve less water, resulting in a product which would be easier and more cost-effective to transport. The distances would still have to be relatively small though, and the digester design would have to be compatible with the higher total solids content of the incoming material (in other words a plug flow system) in order to avoid water wasted in having to dilute it.

A better approach would be to have smaller digesters installed on individual farms like this one: http://www.mnproject.org/pdf/Haubyrptupdated.pdf

A dairy farm can produce enough electricity and heat for their operations, with an electicity surplus to sell to the grid at a profit (although grid connection policies for distributed generation vary and not all utility companies are prepared to send cheques in the other direction). It seems the farm can also produce enough fertilizer to replace artificial fertilizers based on natural gas. That would allow them also to grow crops for food or for co-substrate digestion. In addition, there are nutrient management, water quality, greenhouse gas and odour management benefits.

In theory, one could even run farm machinery on biogas instead of liquid fuels, but this might not turn out to be practical as the methane content of biogas is somewhat variable and the sulphur content might be high enough to cause corrosion. Oddly enough, the sulphur level can be controlled with the addition of a small amount of air into the digester. Although methanogens are obligate anaerobes (are killed by the presence of oxygen), it is possible to introduce enough air to precipitate the sulphur without impacting on methanogenesis. It's a fascinating area. If enough loops can be closed to make the practice as sustainable as possible, farms with digesters could act as focal points for economic relocalization in rural areas.

Cow manure from typical dairy operations has a very low total solids content, meaning that it is mostly water. That makes it heavy and expensive to transport to a central facility. You would probably use so much fuel to transport it over any significant distance that it would defeat the purpose, especially if you were using the manure from a lagoon system as that is the most dilute form of manure management...
Most of these schemes are built around integrated operations (corn goes to distillery, DDG goes to feedlot, manure goes to digesters, methane goes to distillery) but you raise an interesting issue.

What kind of volumes are we talking here?  Liquids are uniquely suited to transport by pipeline, and if you've got tanks of stuff sitting there anyway you can power the pumps with e.g. wind turbines when the energy is there and not even have to bother with batteries.  There are also a number of designs for Stirling-cycle pumping engines which could do the job in areas where there's more sun than wind; just use flat-panel thermal collectors.

So long as the laying and maintenance of a bunch of pipe to move manure and effluent (or product gas) is cheap enough, you can get rid of the trucks altogether.

Some rough rules of thumb re animal waste:

Cattle and swine produce roughly 60 to 80 lbs of raw manure per 1,000 lbs liveweight.

The raw manure is typically 10 -12% solids by weight, the rest being water.

In  a feedlot environment, the manure from the animal areas is flushed with with water. As a result, there is anywhere from a 3 to 5-fold increase in waste volume.  Hence, the volume of total waste is roughly  on the order of 25 to 50 gallons per day per 1,000 lbs liveweight.

 (These are very rough numbers, but they should give you some idea.)

As aqueous wastes go, animal feedlot wastes are far more concentrated than human domestic sewage, and as such, are more difficult to treat. The volume is not the problem, but rather the large amount of nitrogen and phosphorus present. Hence, even an extremely efficient treatment system still discharges large amounts of each.

Transporting manure slurries by pipe is possible and has been done. But you must realize that in rural areas, farm locations can be rather far apart, and running piping would often mean crossing roads and other properties, with all the headaches and expense that entails.

Another thing to keep in mind is that while the fertilizer application season is generally a short period in the springtime, manure is generated 24-7 all year round. Hence, animal waste digester systems that depend on providing farmers with treated waste require large amounts of storage tankage to hold the waste accumulated during the off season.

Again, we face the unavoidable problems associated with handling a large volume of low-value material.  

I'm all for generating methane from the anaerobic digestion of animal waste, but am far less bullish about the prospects of generating commerically viable  fertilizer from it.

As I said in my other post, these agribusiness feedlot operations are just too big and concentrate too much nitrogen and phosphorus in one area.  They basically import large amounts of N and P in the form of corn and other animal feed; part of that N and P goes into meat; and the remainder gets discharged as waste.  No way around that simple fact.

Clarification to previous post - That should read: 60 to 80 lbs PER DAY of raw manure per 1,000 lbs liveweight.
I'm trying to eat lunch here, dude.
Hey, this stuff IS my bread and butter :-)
I have some experience with the anaerobic digestion of animal wastes, both as a waste disposal method and means of producing methane for use as fuel.

While methane generation is quite common, I am not familiar with any full-scale systems that actually recovers ammonia from the digester liquor. The amonia that is present in the liquor is in the soluble ammonium form. It can only be removed by elevating the pH (such as by adding lime or caustic) and then sending the liquor so treated through a stripping column and further processing.  The whole process is rather difficult and not very rewarding in terms of what it costs to get a relatively small amount of ammonia back.  

Feedlot and piggery wastes, as received at the head of a treatment plant, typically have a total nitrogen content of around 0.5%, which is strong from a waste treatment standpoint but very dilute from the standpoint of a usable fertilizer. While digested wastes are often provided to local farmers, it is not a particularly attractive fertilizer due to the costs and handling problems associated with a large-volume dilute material. As such, it doesn't have much commercial value.

While the methane recovered does have significant value, the nitrogen content of the waste has far less.  Surface and groundwater pollution from the nitrogen and phosphorus of animal wastes will continue to be a serious and difficult problem.  It is inherent to the highly concentrated factory-farming that is now practiced by US agribusiness.

Crazy idea time:

Is the output from a digester, with its dissolved nitrogen, usable as irrigation water? And would the nitrogen be available to the plants? Is there any need to process it except to produce a saleable/concentrated form? Or is there some kind of process that can be done to the diluted nitrogen, without trying to concentrate it?

Being able to spray the water right back on the fields would reduce the above-mentioned need for fertilizer storage until spring, yes?


As for ammonia... there is a REALLY easy solution for this hydrocarbon input.  Use electricity from renewable sources to electrolyze water into H2 and O2, and then use the H2 with N2 to make ammonia....

Niagara Falls power is available for industrial or municipal uses at a delivered price of 2 cents/kw-hr.

Maybe it's easy and cheap with power at the old 2¢ contract price, but
  1. You won't get that price ever again, and
  2. You certainly can't build more plants to deliver power at that price.
You might be able to get surplus wind power at a price like that, but you won't be able to use your capital equipment to anything like its best advantage.

It's probably cheaper to gasify crop wastes to make hydrogen than it is to use hydropower, and the ecological damage is probably less as well.

SO long as ethanol is being produce so American's can continue on their wasteful ways, its a bad idea. The idea of an ever expanding economy is another idea that will come to end with less oil!!  

I don't believe that PAtaki and others that advocate the use of corn based ethanol are looking at the bigger picture down the road.  

SO we can argue all we want about positive and negative EROEI, but the fact remains, the world is slowing sucking out the remaining reserves of oil and nobody's offering solid solutions of what to do after that..

Gentlemen: thoughtful posts one and all, with wisdom, facts and scientific expertise.  There's a problem though.  Pataki is grandstanding for his <choke> Presidential campaign, is positioning himself for the Kansas farm vote.  None of what he said is likely to have any effect on NY laws or policies.

But it's all farcical.  Pataki is an absolute non-entity. When Dorothy Parker was told of Coolidge's death, she quipped 'How could they tell?'.  Same thing with Pataki. Years ago the NYTimes Sunday Magazine had a piece on him entitled Bland Ambition.  The man has all the sizzle of a week old loaf of bread.  He desperately wants to be somebody, he has reached the end of the road in NY, so, if George Bush could be President (with no qualification or intelligence), then he figures he has a shot at it.  Hm...what does Bush have that Pataki doesn't?  Big time connection, power and money?  A certain rotten charisma?

Pataki is going nowhere, and, alas, the ethanol proposal in his speech was typical Pataki flailing, there to provide the illusion of vision and thought.

Pataki is a complete joke.  I don't know if anyone saw the Daily Show epsiode from when he started going to Iowa.  John Stewart looked like he was about to die of laughter when he said the words "President Pataki".  I think that the personality of the Bob Russell character from the West Wing is a perfect description of Pataki.  That being said, at least he is talking about some options that make sense, and especially if you look at the speech as a whole and not worry about the details, he is at least heading in the right direction.  
The coming/current enegry crisis isn't just about the environment, or dependence on foreign oil, or the continued growth of our economy.  It is a combination of all three which is what makes this crisis so completely daunting.
If there were no envrionmental concerns, we could just keep building nuke plants or digging more coal and wouldn't have to worry about a lack of electricity.

If were solely a matter of freeing ourselves from foreign oil, we could just drill our way to energy freedom, and build all of the polluting power plants we needed.

Third, if was just a matter of continuing to grow our econmy all we need to do is produce more energy.

The problem is that we need to worry about all three of these things simultaneously, plus the biggest problem is that there just won't be enough energy in the world.

My (completely) uneducated guess is that the world would today have enough fuel, no cars, but plenty of fuel if there had never been a large scale switch to oil for transportation in the beginning of the twentieth century.
However, if we had done that I would not want to be a person with any sort of breathing problem.  Or rather we would all these breathing problems.

NO ONE and I mean no large group of people on earth would happily accept a decrease in the quality of their life.  Even the least materialistic of us wants to have if not more at least the same amount of stuff we have now.  We all want computers, we all want a television, or a car, or that hot new electronic gizmo, or the real American dream, our own homesteads.  This isn't just materialism, it's growth, it's human nature to want to improve our conditions.  Unfortunately while humans are very smart animals, the vast majority don't have the ability or inclination to look twenty, thirty or forty years down the road.  The closest we come is when we dream about what our children will be like or who our spouse will be or where our careers will have taken us.  
Unfortunately humans are not beings that are really capable of thinking and looking at long term strategy.  We are excellent at short term tactics and middle range operational planning.

We can plot out a five year plan very well, but ask a 30 what hey want to be doing when they are 70 or 80 I'll bet you get one of two answers.  Either dead, or retired.  There is no thought of where one would be living, when they would have liked to retire(other than the lottery dollar and a dream type of thoughts), or even what sort of financial state they'll want to be in, other than comfortable.  Does comfortable mean not having to worry about paying your basic bills and having a little left over, or doesn't it mean what "comfortable" in the sense of being well off and being able to take a nice vacation every year and so forth.

Brazil has a viable ethanol program that produces ethanol for under $1.50 per gallon.  Plus, they are gaining in efficiency 1-2% per year.  This proves that ethanol can be competitive against gasoline.

Using corn to produce ethanol is probably not viable to replace the world's gasoline consumption, but it is a viable option to reduce gasoline consumption.

Pimentel's methodologies are okay.  If you analyze his actual formula and substitute his data with USDA data on corn output per hectare and amount of fertilizer required, you will get a ratio closer to 1:1 rather than EROIE of less than 1 as Pimentel reported.  
Anyways, it is suffice to say that Corn produced Ethanol is not a very energy profitable method.
I have yet to see SugarCane production numbers.

I don't have the sugarcane ethanol EROEI numbers, but I think they are better than the corn numbers. Mostly because sugarcane ethanol don't come from starch (that need be broke to sugar), sugarcane produce a good deal of sugar (doh!) and sugarcane is a C4 plant that grow at tropical countries (more efficient photosynthesis). To make things better we use the sugarcane "bagaço" (the surgane dried from the sugarcane juice that contain the sugar) to burn and give energy to the distilies that produce the ethanol.

The only problem with sugarcane ethanol here at Brazil is the sugar's price: higher international sugar's price, higher ethanol price. Ethanol is too less efficient than gas, so the ethanol price need be 70% the gas price for be consumer's friend. Other problem is that maybe we can produce ethanol enough to all cars inside Brazil, but no more than that.

By the way, we aren't trying use soybeans for make the biodiesel, we are trying to use some native tree species that have seeds that produce more oil thant the soybeans.

João Carlos

Sorry my bad english, my native language is portuguese.

Pimentel and Patzek do not include the energy required in environmental cleanup of the damage caused by growing crops for fuel, but they point out that if these energy costs were included, biofuels would be out of the question.

Some of the environmental impacts of growing corn are: depletion of aquifers, pollution of groundwater, and eutrophication of lakes, rivers, and oceans from nitrogen runoff.  The Gulf has an enormous dead zone, and the energy contained in the lost fisheries and shrimp are not entered into net energy equations by anyone.

We're mining the soil 18 to 84 times faster than it's being built up by nature. Cultivating plants for biofuels would only worsen the matter.  A high biodiversity of micro-organisms in the soil leads to healthy plants.  By applying massive amounts of nitrogen fertilizers and other chemical inputs, we kill off some of the critters in the soil, requiring ever increasing amounts of pesticides, which kill off more critters...

Every college level soils science textbook mentions the negative effects of industrial agriculture on soil:

1) Increases soil erosion
2) Harms soil health, fertility, and structure/tilth by removing crop residues
3) Leads to greater aquifer depletion
4) Increases water pollution from pesticides, herbicices, and fungicides
5) Increases nitrogen eutrophication of bodies of water from nitrogen fertilizer runoff  
6) Decreases biodiversity from application of pesticides, fertilizers, monoculture, etc
7) Increased salinization of soils where irrigation is used  

Growing crops for biofuels will cause us to resort to the use of marginal land for more acreage, which means cutting down forests and growing crops on highly erodable non-level land.  

Given the depletion of the Ogallala reservoir within the next two decades, I suspect this marginal acreage will be used to grow food, though if the choice ever comes down to guns or butter, it's possible that deploying our military will matter more than starving citizens.

The pro-ethanol/biomass USDA, funded and controlled to a large extent by agribusiness, with an enormous public relations department, has an easy time promoting their point of view and funding pro-ethanol researchers.  The USDA likes to show a slide of all the researchers who refute Patzek and Pimentel, implying that the sheer number of papers proves them wrong. Somehow David Pimentel & Tad Patzek managed to find the funding to refute this research, but they don't have large PR departments to explain how their point of view is distorted by special interests.

If you think I'm exaggerating about agribusiness control over the USDA, read Marion Nestle's "Food Politics: How the Food Industry Influences Nutrition and Health".

Shaupori's USDA paper criticizing Pimentel, "The Energy Balance of Corn Ethanol: an update", states: "Energy used in the production of secondary inputs, such as farm machinery and equipment used in corn production, and cement, steel,and stainless steel used in the construction of ethanol plants, ARE NOT INCLUDED [my emphasis] in our study".

Well of course if you leave energy inputs out, the odds are you'll get a good net energy!  Here's a simple experiment: get rid of the billions of dollars in subsidies and see what happens.

Charles Hall, who's been studying net energy a for a long time, estimates you'd need an EROI of at least 5 to keep civilization humming.

So we're talking about turning the land into a salty desert as past civilizations have done -- look at Iraq for instance -- to produce a truly trivial amount of fuel (biomass supplies less than 3% of our energy now), with a negative EROI that wastes the remaining fossil fuels and will pollute the groundwater for centuries.  Sounds like a plan dreamed up by deep ecologists to rid the world of pesky, biodiversity destroying humans.

Here's one issue to consider when promoting ethanol. I currently own an E85 flex-fuel car. I live in Florida where there are (count 'em) two places where you can buy E85. Neither is open to retail sales.
DonInVA said, "Please do not cite Prof. Pimentel regarding the corn to ethanol EROEI.  His work on this subject has been superceded by numerous other studies in recent years, and Pimentel is now discredited.  Numerous recent studies show EROEI greater than one for corn ethanol."


If all those studies showing ethanol has a positive EROEI are correct, why is the corn ethanol industry built on a foundation of fossil fuels?  If they produce more energy than they make, why don't they use some of that excess energy as their source of energy for making more ethanol? If they really make more enrgy than they consume, wouldn't they be smart to do that instead of consuming vast quantities of natural gas and diesel fuel to grow corn and make ethanol from it?  Of course they would. It only takes common sense to realize Pimental is more correct than the studies you say discredit his work.

The hard truth is that corn-based ethanol production is unsustanable without consuming fossil fuels -- no matter what the USDA study claims. At every step of the production process, "renewable" corn-based ethanol consumes unrenewable fossil fuels:

1. Natural gas to make the essential nitrogen fertilizers corn farmers must have.

2. Diesel fuel for farmers to cultivate, plant, harvest, and transport their crop.

3. Diesel fuel to transport fertilizer, seed, and finished ethanol.

4. More natural gas on the farm to dry corn; more at the ethanol plant to mill and distill corn into ethanol; and still more to dry the waste distiller's grains after fermentation.

The unfortunate fact is that making corn ethanol is unsustainable without burning irreplaceable fossil fuels. Until corn farmers and ethanol plants show they can use ethanol instead of fossil fuels to grow corn and make ethanol, it is incorrect to think corn-based ethanol will reduce the demand for fossil fuels.

If corn ethanol ever became our primary liquid fuel, we would still be dependent on an overseas fossil fuel -- natural gas.

Almost all nitrogen fertilizer is now made from natural gas. What is not widely known is that an increasingly large percentage of that fertilizer is made overseas and must be imported into the U.S. I've even seen estimates that within five years we will be importing 100% of our nitrogen fertilizers, all made overseas from foreign natural gas.

Using ethanol made from "renewable" corn sounds great until one looks more deeply and sees what goes into growing corn and turning it into ethanol.  Take away fossil fuels, and the corn-based ethanol industry would soon wither.

Do you think it makes sense to replace our dependence on foreign oil with an equally ill-advised dependence on corn ethanol that must use imported fertilizers made from foreign natural gas?