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.

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.

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.

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.

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.

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.

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

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..

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.

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.

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.

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.

DonInVa,

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?