The Energy Balance of Ethanol versus Gasoline

Just when I thought I was out, they pull me back in.

I am trying to spend more time writing on topics other than ethanol. But I get a lot of e-mails on that subject, and often have 3 or 4 mini-debates going on at a time via e-mail. I just finished a debate involving a government official and some big names over the energy balance of gasoline versus ethanol. There still seems to be a lot of confusion surrounding this issue, so I asked for permission to publish the exchanges. I was reluctantly given permission, provided I deleted the personal information from the government official (name and government agency). The exchange involved myself, a government official that I will refer to as "Tom", Michael Wang from Argonne, and Vinod Khosla.

It all started when I got an e-mail from Tom. It wasn't clear to me which specific essay he had read that prompted his e-mail, but he wrote:

Mr. Rapier,

If your assessment of the ethanol fuel cycle energy balance (and its comparison with the petroleum fuel cycle energy balance) is right, then not only is Vinod Khosla wrong, but many others of us in the energy community -- including the U.S. Department of Energy and Argonne National Laboratory (see attached summary) must also be wrong.


Attached was a summary of an Argonne National Lab report written by Michael Wang, who initiated the following claim (from the report):

As you can see, the fossil energy input per unit of ethanol is lower--0.74 million Btu fossil energy consumed for each 1 million Btu of ethanol delivered, compared to 1.23 million Btu of fossil energy consumed for each million Btu of gasoline delivered.

I must admit that appeals to authority don't impress me much, especially when I know the person making the argument is completely wrong. Remember, this is coming from a government official involved in alternative energy. So, I responded:

Tom,

They are wrong. I have read all of the Argonne studies. I have exchanged e-mails with Wang at Argonne and Shapouri at the USDA. They know they are being misleading in these claims, but most people don't dig into the details to see their sleight of hand.

Here is a very simple test that will demonstrate they are wrong. After people work through this, they always see the problem. Let's say my goal is to make 1 BTU of liquid fuel. Will I consume more energy if I produce ethanol, or will I consume more energy if I produce gasoline? The implication from the Argonne et al. would imply that it should take more energy to produce the gasoline. However, that is not remotely the case. If I presume an energy balance for ethanol of 1.3, then I will consume 1/1.3, or 0.77 BTUs to make 1 BTU. My net is a mere 0.23.

If, however, I make gasoline, the efficiency is 80%. That is where the 0.8 number comes from. In this case, I only consumed 20% of the BTUs to make 1 BTU of gasoline. My net is 0.8 BTUs. What they have done is convolute energy return and efficiency, and act like 1.3 for ethanol is the same metric as 0.8 for gasoline, when they are actually 2 different metrics.

As I like to say, there may be some legitimate reasons for using ethanol. Efficiency of production is one of the most misleading arguments out there. It just isn't true. And I will gladly debate Wang or anyone at the DOE in print regarding these misleading claims.


Tom responded, copying Michael Wang at Argonne and Vinod Khosla (they were copied on all messages from this point).

Robert,

As I see it, the fallacy of your reasoning (similar to that of Pimentel's and Patzek's) originates, at least in part, from an "all Btus of energy are created equal" viewpoint. If continued /expanded use of petroleum was indeed feasible, sustainable, environmentally and politically acceptable, etc., then perhaps your conclusion, that petroleum is a more "efficient" energy option than ethanol, would be more valid -- i.e., just keep burning the petroleum Btus and continue to accept the bottom-line energy result (albeit a continually worsening one in any petroleum-depletion scenario) that the luxury of stored fossil fuel deposits afford us: by reinvesting a fraction (1/5 today but steadily increasing) of the recovered petroleum energy, we can continue to harvest what's left.

But the production of ethanol and other biofuels (which, by the way, should include a broader focus, encompassing other forms of pure and mixed alcohols, biodiesel-type fuels, bio-crude type fuels, etc.), along with other kinds of bioenergy, offers a means of harvesting Btus of solar energy and incorporating this contribution from solar energy into today's transportation energy supply -- an achievement that has thus far proved elusive via other means, such as electric vehicles or hydrogen.

The fact that today's investment of 1 Btu of fossil energy in the ethanol fuel cycle delivers "ONLY" 1.3 Btus of ethanol to the vehicle fuel tank (the added 0.3 Btu being solar energy incorporated into the fuel cycle) is actually a very beneficial energy result, especially given that this result only gets better with technology advances, potentially including production from cellulosic biomass. Meanwhile, the energy reinvestment necessary to capture remaining petroleum resources promises only to become greater. Ask yourself this question: If producing and operating hybrid electric vehicles (which I suspect have their own underestimated trade-offs besides the obvious higher cost factor), in order to make petroleum Btus go about one-third further, makes good sense in today's energy world, then why doesn't achieving essentially the same result via ethanol production and use (with at least incrementally, if not fundamentally better results in store) offer at least as attractive an option?

While I don't think I would personally try to argue that the ethanol fuel cycle is twice as efficent as the petroleum fuel cycle (i.e., by comparing a 1.3-1.6:1 ratio to a 0.8:1 ratio), neither do I find your analysis compelling from an energy standpoint; in fact, it appears even more misleading. I believe that most of us in the transportation energy community -- along with many in the automotive industry, the oil and other energy industries, the environmental and global climate change communities, etc -- have come to accept the results of Argonne National Laboratory (as summarized in the U.S. DOE webpage document I forwarded to you earlier) as the most authoritative and fair assessement thus far of ethanol's net energy (and greenhouse gas) implications.


Michael Wang also weighed in, to say he wasn't getting involved:

Dear Mr. Rapier,

Instead of wasting everyone's time, let me just simply pointing out that I do not recall that I have extensive communication with you and I do not intend to do so, because of your statement "I have exchanged e-mails with Wang at Argonne and Shapouri at the USDA. They know they are being misleading in these claims, but most people don't dig into the details to see their sleight of hand."

You are entitled to have your opinion, but do not imply personal attack on my professional work.

Michael Wang


I answered both with my next response:

Tom,

There is no fallacy in my reasoning, and my arguments have nothing to do with Pimentel's and Patzek's. To suggest they do indicates that perhaps you still don't understand my argument.

Unlike Pimentel and Patzek, I am using Argonne's numbers to make my point. Your argument, "If continued /expanded use of petroleum was indeed feasible, sustainable, environmentally and politically acceptable...." is a different argument than the one you originally started off with. You are suggesting that there are other reasons for using ethanol. Fine. But you are not addressing the point of my argument, which is simply that ethanol is far less efficient to produce than gasoline, despite the proponent's claims to the contrary. Argue the sustainability issues. Argue the environmental issues. But don't mislead people by suggesting that it takes more energy to produce gasoline than to produce ethanol. That is an incredibly ludicrous claim.

My argument is not misleading at all. It does not convolute efficiency and energy return. It is a measure of the amount of energy that must be consumed to produce two different fuels: gasoline or ethanol. That is a very simple metric, and is not in any way misleading. Wang's metric is misleading, and I am sure that he is well aware that people are misusing it. When people say "ethanol is 1.2, but gasoline is worse at 0.8", they have compared two different metrics. When you write that you accept the authority of Argonne/DOE with respect to the net energy and greenhouse implications of ethanol, you are once again addressing a different argument. Please do not address Red Herrings, since I have accepted their net energy results for ethanol in my analysis.

Regarding Wang's communication with me, I still have it if he would like for me to refresh his memory. I pointed out the same thing I have pointed out here, and his response was essentially "Yeah, but you are looking at the total energy inputs, and there are many different ways to look at this problem." I do not regard the debunking of misleading claims as a waste of anyone's time. I would think that Wang would want to defend his work against critics like myself, especially given that most of it has not been subjected to scientific peer review. Again, I will debate Wang, Shapouri, or anyone else who wishes to argue that it is more efficient to produce ethanol than gasoline. If you want to argue about something else, then you aren't addressing the argument I am making. Yet this is exactly what you did in your second response.

Finally, I want to make it clear that my comments are not meant to defend the status quo. I want to see us move away from fossil fuels as quickly as we can. I am merely using the gasoline versus ethanol issue to show why these claims of higher efficiency of ethanol production are fallacious.


This response covers my biggest gripe about people who want to debate this issue. If I rebut a specific claim, they gallop off to a different claim. That is exactly what Tom did.

At this point, I also asked if they minded me publishing the exchange:

Incidentally, do you have any problems with me publishing this exchange? I will publish it without changing a word, and will include Wang's statement that he doesn't recall having extensive communication with me. I think the public can benefit from these exchanges. I understand your position quite well, however I hope it is clear that you didn't actually address my arguments, but instead addressed other reasons for supporting ethanol.

I am confident that my argument as written is completely accurate and not in any way misleading, and I have no problem being judged by public opinion on its merits. I am a strong supporter of publicly debating these technical issues, and I have no interest in misleading anyone. But I also have no interest in allowing people to be misled.


Vinod Khosla weighed in next:

Robert's argument would make solar cells a horrible source of energy at an efficiency of 0.15! And why would we ever use electricity?

Most modern ethanol plants being built have an energy balance of around 1.5 -1.6 as they try and minimize their energy use for cost reasons. That coupled with the higher use efficiency of ethanol energy than petroleum energy (25% less mileage even with 33% less energy is the accepted EPA rating for most flex-fuel cars - the SAAB 9-5 Biopower with Turbo is only 18% less mileage) gives an ethanol "fossil fuel efficiency" of about 2X per mile driven. The current California plants we are building don't especially ship corn (they are built around cattle feedlots where the corn has been shipped in for years) and they don't dry the distillers grain since they use it locally at the feedlot, does better than the 2X number. The E3 Biofuels plant in Mead Nebraska achieves an "energy balance" of five for CORN ethanol according to a report I saw from the National Commission ion Energy Policy.

It is time to stop asking the wrong question of "energy balance" or even the somewhat less wrong question of "energy balance relative to petroleum" but rather ask the two right questions (a) how much petroleum use can we displace per gallon of an alternative liquid fuel and (b) what is the green house gas reduction per mile driven.

For nuance we might add (c) at what cost of production per mile driven (to take away the short term price manipulation going on and (d) in what vintage of plant? Modern, average, old, coal fired, gas fired, with and without dry distillers grain, all the way to the E3 Biofuels model. Today the economics of reducing energy cost work.


I responded to Mr. Khosla's argument:

The solar cell argument is not valid, as several people pointed out on The Oil Drum, because it confuses efficiency with energy return. The instantaneous efficiency may be 15%, but you can get that day after day. The total energy returned from a solar cell far exceeds the energy that went into creating it.

The reason we use electricity is because we convert coal, something not especially useful for doing work in its natural form, into a form in which it can do useful work. That is not the case with most of the fossil fuels that go into making ethanol. We turn natural gas, gasoline, and diesel, all perfectly good transportation fuels, into ethanol. We capture a bit of solar energy in the process, but grain ethanol is primarily recycled fossil fuel. And while this argument has focused on the marginal energy return, not included in those assessments (as Wang can attest to) are the secondary inputs, nor effects from soil erosion from growing corn, or herbicide and pesticide runoff into our waterways.

For the record, I fully support, and have advocated the E3 Biofuels model. In fact, I spoke with their project manager this week for an hour on the phone. I was also recently quoted in National Geographic endorsing the E3 process:

New Ethanol Plants to Be Fueled by Cow Manure

However, a couple of things need to be clarified. Their plant has not yet started up, so claims of energy return from this process are premature. It is definitely a step in the right direction, and I would prefer to see all new ethanol plants built around a similar model.

Regarding "wrong questions" and "right questions", that misses the entire point of my arguments, which are quite simple. There is a horrendous level of misinformation out there surrounding ethanol. When someone claims that Brazil farmed their way to energy independence, or that it is more energy efficient to produce ethanol than gasoline, or that ethanol produces no greenhouse gases - those are claims that must be addressed. Ethanol policy should not be made based on misinformation like this. My agenda is simple, and that is truth in advertising. I am a skeptical scientist by nature, and I feel like these claims deserve critical technical scrutiny. It is not my goal to kill grain ethanol, unless it deserves to die. But we won't know that without an honest debate, and too little of that is taking place. My goal is to separate hype from what the science actually indicates, and pursue those solutions that make the most long-term sense. Corn ethanol, which has been the primary target of my criticism, is not a very efficient use of our resources as it is currently produced. On this, I know that Mr. Khosla agrees with me, because we have spoken at length about this.


Tom indicated that he really didn't want to have this debate in public:

I'm inclined toward Dr. Wang's (and Mr. Khosla's) viewpoints that it is somewhat of a distraction and probably unproductive to pursue this debate with you further or participate in your forum -- especially in light of your unfortunate characterizations of individuals' and organizations' work ("sleight of hand"?). In any case, since you say you accept Argonne's basic analytical results, then this entire debate is all about the interpretation and implications of these results (and who is "right" trying to answer the academic question "Which is the more "efficient" fuel, ethanol or gasoline"), which I don't foresee being resolved in this forum.

I once again tried to convince Tom to take this debate into the public arena:

How else do you characterize the comparison of an EROI for ethanol to an efficiency of gasoline, other than sleight of hand? A straightforward assessment would be to consider either EROI to EROI, or efficiency to efficiency. Perhaps it wasn't Dr. Wang's intention to have this issue so thoroughly muddled, but the public has certainly muddled it. I have lost count of how many times someone claimed that it is twice as efficient to produce ethanol as to produce gasoline.

My impression then is that you do not want this exchange made public? If we posted this at The Oil Drum, it would be read by a tremendous number of people, and would have advocates on both sides. If your argument is correct, then you should have no concerns given that I will post this exchange verbatim. I think these are the kinds of open exchanges that need to take place so people can sort out hype from truth. My main objective is education, and I think it would certainly suit that purpose.


We exchanged 1 last pair of e-mails that I won't entirely reproduce (because I told Tom I wouldn't). Suffice to say that Tom agreed to publication, provided I removed some information on him and his organization. In his final response to me, Tom accused me of rancor (passion is not the same as rancor!), questioned whether my rancor explains my e-mail identity (tenaciousdna), and once again invoked the argument from authority, suggesting that my argument was subjective and merely my opinion, and he and all those other authorities couldn't be wrong. Needless to say, my reply was "pointed", but I offered to take up the matter with him at any time.

This exchange may help explain why I haven't been posting as much lately, which some have asked about. These things take up a bit of my time every day, so I decided to kill two birds with one stone and make a post out of this debate. Let this also serve as a warning to those who want to bang heads with me. :-) If you want to win a debate with me, make sure you are arguing from a factual position.

Robert,

Clearly the ethanol advocates are not concerned about net energy. Mr Khoslas comment

It is time to stop asking the wrong question of "energy balance" or even the somewhat less wrong question of "energy balance relative to petroleum" but rather ask the two right questions (a) how much petroleum use can we displace per gallon of an alternative liquid fuel...
entirely misses the point that replacing one gallon of oil that society receives leverage of 10-15 times with one gallon of ethanol which society gets .3-.6 'leverage' implies borrowing resources from other areas of the non-energy economy in order to produce the ethanol.  This does not imply that ethanol in itself is a bad product, but misses the larger issue that the commodity its trying to replace is truly awesome in its impact on our world, and cannot be replaced easily. See A Net Energy Parable for a primer on net energy.

Also, (although you take Argonnes results as given), I disagree with their boundaries of analysis, especially for long term sustainability purposes.  When doing energy (or financial) analysis, we need to include the widest boundaries possible. Oil is so ubiquitous in our societies transportation, that to count all the energy inputs is nearly impossible. If oil triples in price, can we assume all products necessary to make ethanol will be available, irrespective of price? (like steel for pipelines, new trucks, highway maintenance, tractors, fertilizer, farm tools, labor, insurance, etc).  Furthermore, Argonne models assumed the best yields and states for growing corn. To use corn ethanol nationally, it needs to be trucked because it picks up water in normal oil pipelines. This energy cost isnt factored into the models.  Also, a tankful of ethanol can transport a car only 70% as far as a tankful of gasoline, so requires more fillups and driving 'downtime'.

Most importantly, the ethanol debate is ignoring multicriteria analysis and your critics are focusing exclusively on the irrelvance of the energy balance. Energy may or may not ultimately be the limiting factor in corn ethanol infrastructure. What is the Energy Return on Soil Invested? or Energy Return on Water Invested? These questions are not being addressed because currently we have bumper crops and the ecological deficits are not being calculated in financial ethanol models.

If government subsidies were removed and full ecological and societal boundaries were used in the analysis, corn ethanol would take the same path it did in the 1970s.

Thanks TLS, RR;
  Is there a reliable evaluation available for the amount of water required to produce a gallon of Corn Ethanol, including Ag inputs and whatever would be involved in refining, if any?  I think that this argument, which is already very valuable, needs to start adding some of the other very real costs of building a dependency on Ethanol, to add to the Eroei question.  Whether Khosla or 'Tom' or Wang is convinced of that particular Value Judgement, I think the costs of this 'alternative' need to include some of the other costs that laypeople will recognize as a vital part of the equation.

  (Those who think regular people can't add might not agree with this.  I think people are smart when given good information and a chance to process it)

Bob Fiske

Excellent, Robert.

(should your discussions start up with the gentlement again, you can use New Orleans as a good example of how authority always gets it right. er, wrong)

PS: Can you recommend a good summary document that lays out the Ethanol debate succinctly? I need something that I can pass by people to engage them before losing them...

I am not an advocate of grain based ethanol production and think it can, at very best, be a minor and temporary part of the solution to oil depletion.

However, I find your case regarding the enrgy balance unconvincing. It seems to me that in the case of gasoline, you start with one unit of crude (in BTU terms) and wind up with .8 units, albiet far more useable ones.

In the case of ethanol, the inputs are much more diverse, but may or may not be more useable. You have one unit of mixed inputs mainly coal (to create the steel and electricy inputs), and natural gas (fertilizer, electricity). I don't think the gasoline and diesel inputs really count. They could be offset by using ethanol and eventually will be to some degree. However, we don't produce trucks, etc. that run on ethanol. In this case all that happens is a quantity of liquid fuel is added to both the numerator and the denominator. This reduces the ratio, but doesn't involve the waste of any energy.

So you do put in one unit of scattered energy sources and get back 1.2 (or more) units of ethanol.

I agree that crude oil on its own is not useful and coal/natural gas are. I also think the measure is somewhat arbitrary as crude to gas is only one stage in a process. Comparing the entire cycle from stuff in the ground to useful product is more meaningful.

I don't think it is useful to compare crude to gasoline with coal/natural gas/corn to ethanol. But I am not sure that the argument is actually wrong.

Comparing the entire cycle from stuff in the ground to useful product is more meaningful.

That is one of Roberts main points. He is rightly pointing out that the efficiency of gasoline is being compared to the (slightly positive) energy balance of ethanol. To start from the stuff in the ground, oil/gasoline beats ethanol by a factor of 20 (or more)times, depending on boundaries.

Ethanol does in fact transform some solar energy into usable fuel. But its replacing something that is millions of years of stored solar energy that is more energy dense and of higher quality. To reiterate, if ethanol has an EROI of 1.3:1 and the entire find/refine/distribute oil/gasoline cycle has an EROI of 8:1, then gasoline, from a societal perspective, has 7/.3 =23.33 times more energy return than corn ethanol.

I don't think the gasoline and diesel inputs really count. They could be offset by using ethanol and eventually will be to some degree.

If some of the produced ethanol is used to replace the gasoline and diesel inputs, then that ethanol is no longer available to society, which means smaller input and smaller output. While this might lead to higher net energy, it would require a larger scaling of non-energy inputs.

We have time to aim, fire and shoot only a few alternative energy bullets (along with reducing our energy footprint as a culture). Corn ethanol is a misguided shoot from the hip national waste of one of these precious bullets. I too am tired of rehashing these arguments, but smart well intentioned people are confused. 3 ethanol plants are being built every month, and a year from now there will be 8 built every month, largely coal fired. When the grain ethanol bullet is fired, it will take a decade before the bullet stops. Which is why its important to not go down this path, at least not nationally.

Actually, I agree with just about all of that. In the US ethanol is a farm subsidy first and an energy policy second. From an energy perspective, I think the US would be better served by reducing import tariffs to ethanol and seeing how the whole thing plays out.

However, I see the arguments for and against as being equally confusing. My objective isn't to promote ethanol, particularly grain-based. I have no opinion as yet on cellulosic, but have no reason to believe it is any better at this point.

However, I do think that sugar cane-based ethanol makes sense in a certain regions and only to a scale not greater than 10% of current global consumption.

I think the lack of care in referring to corn-based ethanol as if it is all ethanol is no less confusing than the pro-ethanol falsehoods.  I think that failure to be clear that the accusations are only accurate in referring to a specific process (grain) is as willful and wroimg as any from the other side. The same goes for damning ethanol (or any other potential solution) just because it can not replace every bit of oil product we now use.

I see the arguments for and against as being equally confusing.

YOUR problem!!!

Why is it that we have to rehash these arguments again and again among TOD posters?
You should have made up your mind one way or another and be able to support your position by at least PLAUSIBLE arguments even if challengeable and challenged.

If you don't know what you are talking about keep reading and STFU instead of spreading your confusion.

When you have a good point to make, I wish you would refrain from weakening it with petulant Acronyms. ('STFU')  If it was only your own reputation that was affected, maybe I'd leave it alone, but it really undermines making and keeping a productive discussion going here.

Even without the 'TF' in the middle of it, 'Shut Up' is beneath you or any of us.

Bob Fiske

100 grain ethanol plants in operation.

40 more being built.

7 existing facilites are being expanded.

Not only has the path been paved but they're putting up lights.

It seems to me that the simplest (i.e. ignoring infrastrcture cost, water use, soil damage, etc) relevant metric from a peak oil perspective is the ratio of fossil fuel inputs to useable energy outputs.

Thus:
gasoline: 1 BTU (petroleum) input -> 0.8 BTU output
ethanol: 1 BTU (mix hydrocarbon) input -> 1.3 BTU output

In this context, inputs are just inputs; they may be, but are not necessarily, consumed.  It seems inappropriate to ignore the "input" of oil that becomes gasoline, just because it isn't literally consumed (i.e. burned) in the process.  You still have to put it in the front end, in order to get product out the back end.

Calculated this way, ethanol does beat gasoline.  Fine, so be it.  But it's a very simplified metric, and the net benefit, while positive, is small.

I think that this entire arguement is really a distraction from the bigger question of appropriate energy policy.  The detractors of corn ethanol are wasting their time splitting hairs over the definition of efficiency or EROIE, at least in the context of public debate.  The points that need to be made, loudly and clearly to the public, are these:

  1. If you're concerned about peak oil, ethanol is no solution.  It's positive, but it's not positive enough to offset rising demand coupled with declines in production.

  2. If you're not concerned with peak oil, but just want to reduce oil use (e.g. for national security reasons), then ethanol is still a waste of time.  The externalities are very high, and the return on investment is low compared to energy efficiency measures.

The pro-ethanol lobby has completely bollixed those who are interested in actual sane, sustainable energy policy by focusing excessive attention on the energy return question.  And the ethanol detractors have, for the most part, fallen for it.  We need to stop dancing to their tune, and talking from their frame.  Instead, accept their arguements as being "close enough" to correct, and demonstrate why those arguements are not sufficient to support a national move towards ethanol.

Disclaimer: all the above statements are specifically about corn ethanol.  Sugarcane ethanol is a different story, and cellulotic ethanol is a largely unknown story (and is therefor not a proper basis for making energy policy, IMO).

This is pretty much what I have been trying to say. Thank for doing a better job.
you start with one unit of crude (in BTU terms) and wind up with .8 units, albiet far more useable ones
No, Jack. The raw material is crude, in this case. The energy input is the cost of producing that one unit of raw material. That energy input has been something like .05, in the past (or lower) and, I believe, is typically more than 0.2, for conventional oil. When refining that raw material into gasoline, a bit more energy input is used, but you'd still end up with most of the raw energy that was produced at the well head. The energy inputs you cited for ethanol are really energy inputs, not the raw material (which is CO2, sunlight and soil). So your simple comparison is not a comparison at all. Kind of like what robert was talking about when he was pointing out the different metrics being used to talk up ethanol.

Tony

Isn't the difference between raw materials and energy inputs semantics?

What is the difference between the coal that goes into ethanol and the oil that goes into gasoline?

In either case you start out with one of them (coal or oil) and at the end you don't have them anymore, but you do have a liquid fuel.

I understand and agree that the energy input to crude is something along the lines of the figures you cite. I acknowledged this in my initial comment.

But isn't the same true for coal. The energy input to get the coal is much less than the BTU content. It seems to me that you count one way or other, but make it consistent for both.

Isn't the difference between raw materials and energy inputs semantics?

NO!
It it very precisely stated by sofistek and you just reject it with NO backing argument, hand-waving isn't an argument.

Isn't the difference between raw materials and energy inputs semantics?
No, it's not semantics. We are talking about the energy available for us to use. That 1 unit of crude, that you mentioned, is not expended, it's available for use (or 0.8 is available after it's been refined), it wasn't expended. The 1 unit of energy that went into ethanol was expended and no longer available; what we got out was 0.2 units (if the figures are to be believed).

So let's say you expend 1 unit of energy. For oil production, you get, say, 5 units of raw material for producing your gasoline. If those 5 units are converted at 80%, then you end up with 4 units of energy available for every unit of energy expended. With ethanol, the 1 unit of energy expended results in some biomass that is then converted to 1.2 units of available energy. So the available energy with gasoline production is far higher than ethanol (4 units, versus 1.2 units), for the 1 unit of energy expended in producing those fuels.

You can do the same calculations with coal. I think it's only confusing for those who want a different outcome from those calculations.

Tony

Tony,

I'm sorry if I am seeming oppositional. I don't want to believe one outcome or the other. I have said separately that I do not think corn-based ethanol is viable. I appreciate your patience.

However, I am still not convinced. Here is how I see it (oversimplified):

Ethanol:
Start with one BTU of coal
End up with 0 units of coal and 1.25 BTUs in the form of ethanol

Gasoline:
Start with one BTU of oil
End up with 0 BTUs of oil and .8 BTUs in the form of gasoline

I still see the distiction between converted and consumed as meaningless. Energy can not be created or destroyed, so really both are converted.

Actually, I also agree that this conversation is a side issue and not that important. I think the process of growing corn and running an ethanol refinery is more destructive and expensive than running a refinery. Again, corn ethanol is not worth the effort and the oil to gas / energy to ethanol comparison is trivia rather than analysis. However, I do not think you can say Robert is right and other are wrong.

If the process produced more energy (like sugar cane) or used less resources (water, land, etc), ethanol can make sense.

Jack, here's my take on this: it's about energy consumed. Assume ethanol and gasoline production are both coal fired:

  • Corn: You consume 1.0 BTU of coal to convert one unit of raw material (corn) into 1.2 BTU of ethanol.

  • Crude: You consume 0.2 BTU of coal to convert one unit of raw material (crude) into 1.0 BTU of gasoline.

IMHO, the energy content of the raw material is irrelevant.
I agree with how you are looking at this, but disagree that the energy content of the raw material is irrelevant. We are on this website because we think oil is running out. If you could substitute corn in the first equation in your comment with something that is abundant and harmless, it would save the world. Unfortunately, corn doesn't meet that requirement.

Jack

I agree that corn is probably the worst possible feestock for ethanol. But I was trying to illustrate the 1.2 / 1.0 ethanol EROI (= 1.2) versus the 1.0 / 0.2 gasoline EROI (= 5.0). This I believe is the crux of the debate.
Jack,

Think of the problem as follows.

1 bushel of corn contains X Kcal of raw energy. Produced from an input of sunlight, water, fertilizers, natural gas (or coal,) inputs from liquid fuels that go into cultivation and harvesting equipment. Of that raw energy (corn energy + other input energy) only E% gets converted to ethanol.

This E% is what you should be comparing to the 80% figure that is quoted for gasoline.

This only makes sense if you subtract the solar energy in the ethanol process from the ethanol equation. In this case, the ethanol process would be extremely energy negative.

The solar energy in ethanol and the original energy content of the crude oil are 'found' energy sources and aren't properly included in the equation.

The solar energy is not practically limited - the oil is, and the fertilizer necessary to utilize that solar energy is.

If you want to speak of closed systems and account for all externalities, then every single chemical process has a negative ROIE.

Vinod is arguing that taking all our fossil fuels, putting it 1 BTU at a time into the "black box farm" equipment + fertilizer, and getting 1.3 BTU of ethanol out, is better than taking 1 BTU of oil, putting it into a "black box refinery", and getting 0.8 BTU of gasoline out.  I think I'd agree with him on that narrow point, IF it's completely sustainable, esp because it's more useful fuel than, for example, coal.

The reality is that

A) Capacity is almost as important as efficiency.  If your average farmer can make an energy profit, but isn't making enough total to drive to walmart every weekend and buy groceries, you have a problem.  Likewise, yields are low enough that we are highly farmland limited, meaning that we can't really offset a significant portion of the country on corn ethanol, no matter if someone works out the microeconomics (which I think Vinod is working on, entirely dependant on government subsidies) or the energy economics.

B) 1.3 ROI is horribly difficult to work with.  Right now we have an oil infrastructure that supplies hundreds of thousands of people with margins on which to live, and those margins are taken out of a 10-20x energy balance.  Do you think our current version of society can survive if it requires 30x as many people to be working the mines or the fields?

"Do you think our current version of society can survive if it requires 30x as many people to be working the mines or the fields?"

No. But two points:

  1. We will have to/be able to cut out a lot of wasteful or luxury energy use. I do think we can live as well or better using less energy than we do now.

  2. Ethanol could account for a very small portion of overall energy use. If oil gave use a 1:10 EROEI, but we had 10% less upply which was met by ethanol at 1:1.2, we would have an overall EROEI of 1:9.2.
However, I am still not convinced. Here is how I see it (oversimplified):

Ethanol:
Start with one BTU of coal
End up with 0 units of coal and 1.25 BTUs in the form of ethanol

Gasoline:
Start with one BTU of oil
End up with 0 BTUs of oil and .8 BTUs in the form of gasoline

The thing that strikes me here is starting with one BTU of coal. As ever, we're still depleting a fossil resource. Where is the renewability factor?

Actually we were just using the one BTU of coal to simplify the analysis. In reality, the fuel stock can be broader. You are right in the cast of grain-based ethanol that it is only 20-30% renewable.  

Again, with sugar cane-based ethanol, the non-renewable inputs are far smaller (10-15%) and could come from hydropower (which haas its own problems - but is "renewable"). Given this ratio the ethanol is far closer to renewable and the impact on the climate is far less.  

Ethanol:
Start with one BTU of coal
End up with 0 units of coal and 1.25 BTUs in the form of ethanol

I think I would be more comfortable with:

Start with one BTU of ethanol
End up with 0 units of ethanol and 1.25 BTUs in the form of ethanol

It's the same as RR's challenge to run an ethanol plant on its own energy stream. (like we routinely do in petroleum refineries). I mean this literally: run the farm equipment on ethanol, the transport trucks (to/from) the distillery on ethanol and the distillery on ethanol. Test a closed loop system.... measure everything... the irrigation water volume, the fertilizers, all ethanol inputs to equipment and distillery operations.

No sarcasm is intended here... this seems like a terrific project for the University of Iowa. Let's prove out the facts on the ground.

It really is as simple as that.  It needs to be done.
Investing in ethanol is investing in politics (and subsidies).  Right now it is rewarding venture capitalists, farmers, and politicians at the expense of precious fertile land and water resources in an attempt for continuing our "nonnegotiable" lifestyle.  A big issue in addition to debating EROI with these guys is how the time, resources, and government money could be better spent. One of the big absurdities of ethanol is its temporary nature.  Each year the corn needs to be grown and transported and processed under a different set of circumstances (drought conditions, storms, etc.) Let's compare that to spending our efforts on expanding rail in this country, and wind and solar into our electrical grid.  Those efforts would be much more long-lasting as well as meeting future needs in our "nonnegotiable" powerdown.  Ethanol is leading us farther down the road to industrialized farming and an inability to feed ourselves if and when we face oil shocks.  These ethanol supporters assignment should be to read "Omnivore's Dilemna". It is my own belief that these ethanol plants won't be operating in the near future because of increasing cost of fossil fuel inputs, constrained government budgets limiting subsidies, GW causing increased crop failures and increasing public acceptance of the fallicies of ethanol.  As soon as politicians realize that more votes can be gained by opposing ethanol, their story will change.  Robert, keep up the good work and thanks for all that you do.
But you're forgetting how valuable moonshine is -- maybe our cars won't run on ethanol, but when we go back to muscle power, farm workers will "run" on liquor from the ethanol plants.  Probably be paid with it too, Captain Cook partly paid his men's' wages with booze.
I disagree.

The production of green fuels benefits each and every one of us, not just venture capitalists, farmers and politicians.  

Moreover, as the US ethanol industry is in its infancy, I suggest that it will be around for some time to come as new technologies, best practices and 2nd generation production paths begin to take hold -elements all- of a rapidly expanding and exciting sector whose actors are well aware of the hurdles in front of them.

It's naive to assume that ingenuity does not have a place in the grain->ethanol world especially as ethanol producers such as E3 and others are right now proving otherwise by implementing cogen energy streams wherever possible.

Yes, I know.  I've read your posts before.
When you disconnect a refinery from the grid and run it on crude/new product alone, then the challenge could be legitimate. Until then, it is hoop jumping.

Or build a windmill using just wind. Try that!

Actually in the case of ethanol it can be done, it is just impractical and expensive to create a custom, parallel infrastructure.

Or build a windmill using just wind. Try that!

I could come close with the industrial structure of Iceland.

Electric arc smelting today creates ferro-silicon alloys and could be used for simpler alloys.  Massive sources of aluminum (Al blades instead of fiberglass).  Towers from Al.

Recycled copper from autos melted down by electric arc.

Ammonia plant closed down recently, could be used for many organic chemicals with modest changes.

Iceland has superb wind resources, but better hydro & geothermal resources.

OK, good idea.  Let's give them a $10 million ethanol plant and lets give the wind farm $10 million worth of wind generators. Then we'll start keeping track of EROEI's.