New Perspectives on the Energy Return on (Energy) Investment (EROI) of Corn Ethanol: Part 2 of 2

The following is the second of two posts based on a recent paper published under the same title in the journal Environment, Development, and Sustainability. I was the lead author for the article. The other two authors were Charles Hall and Bobby Powers. Part 1 of this series can be found at this link.

In the analysis underlying our paper "New Perspectives on the Energy Return on (Energy) Investment (EROI) of Corn Ethanol," we performed four major analyses relating to the EROI of corn ethanol. The first was a meta-error analysis, in which we quantified the error associated with the calculation of EROI of corn ethanol based on various estimates of the energy inputs and outputs found in the literature. The second was a spacial analysis of the EROI of corn ethanol. These two items were discussed in Part 1 of this series.

In this part, we will discuss a two additional research areas from the paper. These two additional research areas are:

  • A sensitivity analysis, in which we assess the extent to which corn yields and co-product credits impact the EROI of corn ethanol.
  • An assessment of how much net energy was delivered to society by ethanol in 2009.

We have also included our more general conclusions.

Sensitivity Analysis: Corn Yields

The assumption about increasing corn yields on the EROI of corn ethanol has resulted in much confusion. For example, Wang et al. (2007) report that yield levels could reach 11,000 Kg/ha (180 Bu/Ac) by 2015, which is roughly 25% higher than the average 2005 level. Yet they do not indicate how this will impact the EROI of corn ethanol or what increases in fertilizer, pesticides, etc. will be required to reach these elevated yield levels. Although it is clear that increasing corn yields will increase the gross output of corn per unit area, its effect on the EROI of the entire corn ethanol process is less clear because the corn itself becomes just one of many intermediate inputs. The effect of corn yields on EROI depends upon its fraction of the total energy input to corn ethanol production.

To address the impact of possible future higher yields on the EROI of corn ethanol, we calculated EROIs for various scenarios using yield levels that were up to three times greater than the average yield in 2005. We do not expect that average corn yields will reach a level three times greater than the 2005 average; rather we include them to serve as a theoretical maximum to show the trend in EROI given changes in yield. Although increasing yields would certainly require increases in the use of at least some fertilizers, lime, and/or irrigation, for simplicity’s sake, we increased yield levels only, keeping other numbers in the EROI calculation constant.

Increasing yield even far beyond the highest levels in 2005 had a trivial impact on the EROI of corn ethanol (Fig. 6). As a result, efficiency gains that occur post-farm gate only (such as the distillation or transportation processes) are able to increase the EROIRG (EROI "Refinery Gate") significantly. To that end, recent research by Liska et al. (2008) calculated the EROI of corn ethanol using various methods of distillation that utilized a variety of current technologies. They found that the EROI range for corn ethanol remained low, from 1.29–1.70 (we excluded two hypothetical scenarios that they also assessed). With the absence of technology to boost the efficiency of the distillation process and the trivial impact that increases in yield have on the EROI of corn ethanol, we conclude that there is no reason to expect that the EROI of corn ethanol will increase much beyond current levels in the foreseeable future.



Fig. 6. EROI as a function of increasing yield. Average 2005 yield (8795 Kg/Ha) was multiplied by the values listed across the x-axis for each respective calculation.

Sensitivity Analysis: Co-Product Credits

The debate over whether the co-products of ethanol production, e.g. Distiller’s Dry Grains, deserve an energy credit warrants exploration. On one side Patzek (2004) believes that the co-products must be returned to the field to replenish soil humus. On the other side Wang et al. (1997), Shapouri et al. (2002), Farrell et al. (2006), and Wang et al. (2007) consider the co-product a valuable output of the corn ethanol production process and assign it an energy credit. Unlike yield, the energy content of the co-products is added directly to the energy content of the ethanol in the calculation of EROI. As a result, energy credits for co-products can have a large impact on the EROI of corn ethanol. To address the concerns about the impacts of both yield increases and co-product credits on EROI, we performed a sensitivity analysis to gauge how EROI will change given changes in either input.

To assess how sensitive the calculation of EROI is to changes in co-product credits, we performed three calculations. We first calculated the EROILIT based on the average co-product credits calculated across all five studies (3.46 MJ/L). Then, we calculated the EROI without co-product credits, called the ‘‘Patzek Case.’’ Lastly, we calculated the EROI using a co-product credit of 5.89, called the ‘‘Shapouri Case.’’

EROI analysis is highly sensitive to co-product credits. When using the ‘‘Patzek Case’’ (energy credit = 0), the mean US EROI of corn ethanol decreases from 1.07 to 0.91, but when using the ‘‘Shapouri Case’’ (energy credit = 5.89), the EROI increases from 1.07 to 1.17. Thus, the co-product credit alone can determine whether the EROI is less than or greater than one. This contradicts Shapouri et al. (2002) who claimed that the EROI is greater than one before accounting for co-product credits. Using an alternative weighting mechanism, such as price, may ameliorate some of the sensitivity of the EROI statistic to co-product credits.

Fundamentally, the disagreement over the value of co-product credits hinges on one’s attitude toward the science of nutrient cycling and erosion. Those who believe that corn yields are maintained without spreading the nutrients contained in the co-products back onto the field will generally assign a co-product credit in the EROI calculation. Those who believe that the science is unclear will generally assign a conservative co-product credit or even omit the credit altogether. We believe that until a clear consensus emerges, the precautionary principle should apply, and one should be very cautious in assigning coproduct credits.



Table 3. Quantity of energy used and produced in the ethanol process reported in various publications (adapted from Patzek 2004).

Net Energy Returned to Society by Ethanol

As I wrote in this post, low EROI resources deliver a low amount of net energy to society because much of the energy extracted is required to run the energy extraction process. Comparing the gross energy produced from ethanol to that from gasoline is hence misleading. In the paragraph below we compare the net energy produced from ethanol to that produced from oil each year in the U.S.

The EROI values for counties with biorefineries ranged from 0.64 in Stark, North Dakota, to 1.18 in Phillips, Kansas. Our analysis of 127 biorefineries indicated that of 31.6 billion liters of ethanol produced in the United States, only 1.6 billion liters were net energy (roughly 5%). As a point of comparison, of the 136 billion liters of gasoline consumed in 2009, roughly 122 billion liters (90%) were net energy, assuming that the 136 billion liters were produced at an EROI of 10 (Cleveland 2005). Adjusting for the lower energy content of ethanol (21.46 MJ/L etoh vs. 34.56 MJ/L gasoline = 0.62), we calculated that the net energy from ethanol is roughly 0.99 billion ‘‘gasoline-equivalent’’ liters. Dividing the net energy supplied to society from ethanol by that from gasoline, we calculated that the supply of net energy to society from ethanol is only 0.8% of that from gasoline (0.99/122 = 0.8%). Thus comparing simply the gross production of gasoline- equivalent liters of both ethanol and gasoline is misleading, as one would conclude that the US production of ethanol is 14% of gasoline consumption (19.6/136 = 14%).

Conclusions

The debate over the EROI of corn ethanol has been concerned mostly with whether it is a net energy yielder. As such, the dialogue has veered away from many of the larger implications of EROI analyses. Our results indicate that the EROI of corn ethanol is statistically inseparable from one energy unit returned per energy unit invested, and it is likely that much of our ethanol production is acting as an energy sink, requiring more energy for production than that contained in the ethanol product. This conclusion was confirmed in our spatial analysis, where the average EROIRG was 0.06 lower than the average calculated from the literature.

Increasing yields is oft-touted as a way to increase the EROI of corn ethanol, but our analysis indicates that the gains in EROI are small even when the average yield from 2005 was tripled. Co-product credits, on the other hand, have a large influence on the EROI from corn ethanol. There is no consensus within the literature regarding an appropriate co-product value, and until one emerges (one way or another), we should err on the side of caution when applying credits to co-products. Finally, the analysis of ethanol production from biorefineries supports our conclusion from the spatial analysis: the EROI is too low in too many locations to make an impact on our gasoline consumption. Our best estimate is that the net energy provided from ethanol accounts for only 0.8% of the net energy provided by gasoline.

The evidence provided in this research is clear: we do not know the exact EROI of ethanol, but even if we are remotely close (± 0.2), we are still, in the best case scenario, gaining an insignificant amount of net energy. Furthermore, Hall et al. (2009) estimated that only fuels with an EROI greater than 3:1 provide the requisite net energy to provide a fuel source and to maintain the infrastructure associated with the current U.S. transportation system. Fuels that have an EROI below 3:1 require subsidies from other energy sources to pay for all of the infrastructure associated with the transportation system of the US. The EROI of corn ethanol that we calculated is lower than the 3:1 threshold, indicating that corn ethanol requires large subsidies from the general fossil fuel economy, and as a result, drains energy from the US transportation system.

This would be a mot more useful if you define EROI - even better if instead of using the term EROI you spell it out. When I saw the use of EROI without a proper definition right at the beginning, I skimmed the article, and decided not read it because without the term being defined, then the whole thing is meaningless.

EROI = Energy Return on Investment
In other words, how much energy you get back out of a system compared to how much energy is put in.

I think the initial explanation of the acronym was in part one of the post, so it got cut off in part two.

And now I look again and it is actually in the title. Can't believe I missed that.

Oh boy, fdoleza must be feeling really embarrassed, at this point.

And anyway, EROI should not need definition on this site. Like the word "oil", it is assumed people know what is being talked about.

I guess I don't know what the proper definition of Energy return on investment is. Why even bother to use the term? I would call it energy efficiency.

When it comes to corn ethanol energy efficiency (EE), do you happen to include the energy used to pump the water used to grow the crop? How far down do you go?

I ask because it seems to me the actual figure (and whatever you want to call the metric) is highly subjective. I've concluded corn based ethanol sucks because it requires a government subsidy. I'd like to see the subsidy end, then we can worry about the energy efficiency.

I've also looked at Brazil's sugar cane based ethanol. That seems to be a much better idea. If the US is really interested in ethanol, it should encourage others to make it using a more viable process.

And that's all I have to say about that.

I guess I don't know what the proper definition of Energy return on investment is. Why even bother to use the term? I would call it energy efficiency.

Energy efficiency is a measure of how well an individual device or processes uses energy. EROEI is a measure of energy production as a ratio of inputs to outputs. They are not the same thing.

do you happen to include the energy used to pump the water used to grow the crop? How far down do you go?

Yes, you go down as far as you possibly can. That's why EROI analysis is so difficult.

I ask because it seems to me the actual figure (and whatever you want to call the metric) is highly subjective.

No, the actual figure is pretty much a fact, like the amount of sunlight falling on the earth. The only 'subjectivity' is in the difficulty of measuring it.

Oh boy, fdoleza must be feeling really embarrassed, at this point.

On the contrary, the failure to properly define EROI is at the heart of much of the junk that gets published on the topic. (Lets exclude the current post, which doesn't appear to be junk...)

As repeatedly pointed out, most of our primary energy is actually used to do work, or to make a direct work surrogate (electricity). But the term energy in EROI is usually taken to include heat energy as well as work. Heat and work are not the same! That's what the whole business of thermodynamics is about. The amount of work extractable from a given amount of heat depends fundamentally on temperature. Any definition of EROI which ignores that is junk, because it denies physics.

An example helps. Consider a conventional coal-fired power station. Coal combustion superheats steam to ~500°C, from which highly efficient turbines manage to extract just 35% of the available energy as work. The rest goes as waste heat at about 30-40°C, which is usually disposed of by evaporating water (cooling towers) or heating the ocean (sea water cooling). Waste heat is called waste because it's basically useless. All the available work has been extracted. (A tiny fraction of the world's waste power station heat is used for space heating, mostly in Russia.) Yet under the common EROI definition, the coal combustion heat energy at 500°C, the electric energy generated, and sometimes even the cooling water waste heat energy at 40°C are treated as equal. That is junk.

Your points are well taken with respect to certain aspects of EROEI analyses. However, some portion of our energy consumption is used simply to provide heat, whether to heat cold people or to provide process heating for industry. That needs to be figured into broad comparisons of energy sources based on EROEI

We've been here before. The proportion used for direct heating is much smaller than you might think (cold-country bias?):

Of the main primary energy sources (in order of size):

  Oil:   Nearly all is used for transport (=work; about 80% in the US, even more elsewhere)
  Coal:   Over three quarters is used for electricity generation (=work; around 90% in the US)
  Gas:   Around a third is used for electricity generation; rest mainly for direct heating (US figures, elsewhere higher?)
  Nuclear:   Nearly all used for electricity generation
  Biomass:   Depends how you measure; nearly all work as per the link above, but third world use is mostly direct heating
  Hydro:   All used for electricity generation
  Wind, Solar, Geothermal:   Mostly electricity; some solar for water heating

So what's the all-up? Don't know, but could be 80% work, 20% direct heating. The fact that we aren't sure is a clear indictment of the EROI literature.

The proportion used for direct heating is much smaller than you might think

I didn't say anything about how big I think it is.

So what's the all-up? Don't know, but could be 80% work, 20% direct heating. The fact that we aren't sure is a clear indictment of the EROI literature.

No, it isn't. The fact that we aren't sure is mainly a testament to how difficult it would be to find out. If you have more than guesses to contribute, I would be genuinely interested. Perhaps you would be willing to help fund some research on the issue.

As far as the EROEI literature, an EROEI study of a particular source of energy (say, ethanol) only has to account for such issues to the extent they effect that source. I wonder if you have any substantive criticism of the methodology involved in David's study regarding heat vs. work energy. If you are just throwing it out as a general criticism of EROEI as a concept, that doesn't hold much water.

It's simple enough mate. EROI calcs attempt to estimate the energy invested for a given energy return. One divides the latter by the former to obtain the famous ratio. Ignoring the fact that different forms of energy are of different value (fundamentally - from physics - not just conceptually) will render the calculation junk. But nowhere did I say that Mr Murphy had made that error.

Given that (as I showed based on easily obtainable US figures) the vast majority of our primary energy is actually used to do work, the matter would be better framed in terms of work invested for work returned ... or at least using work-equivalent energy. Framing it strictly in terms of energy (as much of the literature does) demonstrates a profound physical misunderstanding ... one typical of, well, economists.

In other words, how much energy you get back out of a system compared to how much energy is put in.

If you think that's a clear, unambiguous defintion or a useful definition, you can't have applied any appreciable thought to the concept. There is no single "the EROEI", you must be very explicit in your definition of the EROEI for the particular problem at hand, and in general it is meaningless to compare EROEI from different systems.

Lets imagine a hypothetical factory producing photovoltaics. If solar energy is part of the input the EROEI is strictly less than one. Each panel consumes 50 kWh of electricity in manufacture and will in its lifetime produce 1000 kWh. Taking the electricity consumed as the input and the electricity produced as the output gives an EROEI of 20. This compares electricity in to electricity out, which is appealing; but the two different electricities are not the same; the input is highly reliable, on demand and extensively conditioned to meet the stringent demands of the factor and the other varies with the season, the weather and the time of day. Assume for simplicity that all the input kWhs were produced at a coal plant. If the input is seen as ~150 kWh of coal energy instead of 50 kWh of electricity, the EROEI is only ~7. Now assume that the system boundary is altered, such that the coal mine, coal plant and solar plant are all considered one system. The coal energy is now "free"(because you didn't do anything to create it, just like with sunshine) and the input is instead the energy you had to expend to mine, refine, transport and crush the coal. If it took 10 kWh of electricity and 10 kWh of oil to mine the 150 kWh of coal the EROEI of the coal-mine/power plant/PV factory complex is now ~40.

Now lets imagine a nuclear plant. If the energy attainable from fissioning uranium is included on the input side the EROEI is unavoidably less than one. If the uranium is "free"(we didn't make it, a super nova did) and you only include the primary energy required to mine, enrich and convert uranium into fuel pellets and the amortized energy used for constructing the reactor, disposal and so on, the EROEI is ~100 when enriching is done with centrifuges and much less when done with gaseous diffusion. If you use secondary energy(electricity) where applicable instead of primary energy the EROIE almost doubles. The reactor consumes about 5-10% of the electricity its generator produces in order to run the various pumps related to the steam cycle; if instead of treating this electricity as internal you include it on both the input and output sides the EROEI can be at most 10-20. This kind of moving the system boundaries is not unique to nuclear, you can just as easily do it with solar thermal, coal or geothermal. The same sort of gerrymandering could apply to natural gas turbines; fully ~1/3 of the mechanical energy they produce is consumed internally to compress the air on the input side; move the system boundary such that this energy first leaves the system and then comes back in and the EROEI can't be higher than ~3. Note that you can do the same sort of moving the system boundaries in reverse; if the system is the nuclear plant plus the enrichment plant you no longer include the electricity used for enrichment on either the input or output sides(i.e. enrichment is treated as internal) the EROEI increases, particularly for gaseous diffusion.

We routinely exchange one form of energy for another at a loss(e.g. a coal plant converts coal for electrical energy at an EROEI of 30-40%). This is exactly analogous to corn ethanol; you are exchanging mostly natural gas for mostly ethanol at an EROEI better the coal-to-electricity conversion and better than you could do, say, methane to DME. This doesn't look too unreasonable from an EROEI stand point(ethanol is a much more convenient vehicle fuel than natural gas). The reason corn ethanol is bad has nothing to do with EROEI; corn ethanol is a tremendous waste of land and water; it is environmentally destructive; it is not cost-effective; it increases reliance on scarce natural gas while putting up a facade of energy independence and renewability.

I agree that EROEI is not well defined. I'll repeat again that I believe it should be looked at as something like "the energy returned for human use over the energy invested by humans."

(e.g. a coal plant converts coal for electrical energy at an EROEI of 30-40%)

Once again we have the confusion of conversion efficiency and EROEI. A coal plant converts 30-40% of the heat energy in coal to electrical energy. However, this is not an EROEI, because the coal's heat energy isn't the energy 'invested by humans.' That energy is whatever energy is consumed in delivering the coal to the plant.

Put another way, system boundaries should be drawn in such a way that 'energy returned' is converted in the analysis back to the form in which it is 'invested.' For example, if electricity were used to mine the coal and transport it to the plant, how much would that be compared to electricity produced by the plant. It is not always easy or possible to determine what the conversion should be, but if it is not even attempted then it is not an EROEI analysis, just a conversion efficiency calculation.

Once again we have the confusion of conversion efficiency and EROEI. A coal plant converts 30-40% of the heat energy in coal to electrical energy.

There is no confusion, the two can be identical, depending on what you include in "energy invested" and "energy returned" which ostensibly is an arbitrary choice with no existing, coherent standard.

However, this is not an EROEI, because the coal's heat energy isn't the energy 'invested by humans.' That energy is whatever energy is consumed in delivering the coal to the plant.

Depends on where you draw boundaries. If the boundary is at the coal plant the coal is energy you've invested in order to obtain the electricity; you could alternately have invest it in producing ammonia or coking coal or something if you wished.

The system boundaries are in practice drawn arbitrarily depending on the political aims of the users, which is why EROEI is such a useless concept.

Witness corn ethanol, where the conversion efficiency of natural gas and electricity into ethanol is branded 'EROEI'. Well, it could be defined as such by opponents. Proponents on the other hand will argue that you're not looking at the whole system of natural gas-well to ethanol, which has a much more favourable EROEI, all the while ignoring the real reasons corn ethanol is asinine(e.g. environmental damage, waste of farm land, waste of water, converting natural gas to DME yields a higher quality vehicle fuel etc.).

Most of the time the inputs are diverse and intractable and so are the outputs; with a major part of the energy 'invested' comming from other types of energy than the energy 'returned'. You might have been able to find a situation where coal is the sole input into producing more coal back when they were using steam engines, but even then I imagine there's a fair amount of horse-drawn labour and man-power involved.

You can say that the standard for drawing boundaries is arbitrary if you like; that's certainly what some people think, but I would argue that they don't understand the point of studying something called EROEI. Therefore I'm arguing in favor of a standard that is not arbitrary. A proper EROEI analysis looks at energy necessary to sustain the process that brings energy to a consumer. Since the coal plant is only a piece of the system that brings energy to the consumer, the term 'EROEI' is not properly applied to its energy dynamics, in my opinion. Whether you hold to such a standard indeed determines whether 'EROEI' is a useful concept or not.

Perhaps you can show otherwise, but I don't buy your assertion that opponents of ethanol are actually using the conversion efficiency of nat gas and electricity to calculate an inferior EROEI for ethanol. After all, the conversion efficiency when using ethanol is generally worse than when using nat gas or generating electricity. Therefore a comparison on a btu to btu basis, which is what is often done, would tend to make the EROEI of ethanol look better.

Once again we have the confusion of conversion efficiency and EROEI. A coal plant converts 30-40% of the heat energy in coal to electrical energy. However, this is not an EROEI, because the coal's heat energy isn't the energy 'invested by humans.' That energy is whatever energy is consumed in delivering the coal to the plant.

Actually that 30-40% conversion rate is not quite accurate, it depends on the kind of coal that is being burned, the amount of impurities in the coal, the efficiency of the of the actual combustion process and on the mechanical efficiency of the turbines and last but certainly not least electrical losses in the copper coils of the generators.

http://www.wou.edu/las/physci/GS361/Energy_From_Fossil_Fuels.htm

Coal is composed of primarily aromatic hydrocarbons, so we can consider the molecule to consist of multiple -CH- units. The actual average energy release per gram of coal from combustion is less than the predicted value since coal contains significant amounts of water and minerals. Hard coals such as bituminous or anthracite have larger energy content (29-33 kJ/g) than the soft sub-bituminous or lignite coals (17-21 kJ/g).

http://www.roymech.co.uk/Related/Thermos/Thermos_Steam_Turbine.html

The ratio output work / Input by heat transfer is the thermal efficiency of the Rankine cycle and is expressed as:

Rankine Thermal Efficiency =(H1-H2)/(H1-H3)

Although the theoretical best efficiency for any cycle is the Carnot Cycle the Rankine cycle provides a more practical ideal cycle for the comparision of steam power cycles ( and similar cycles ). The efficiencies of working steam plant are determined by use of the Rankine cycle by use of the relative efficiency or efficiency ratio defined as:

Relative Efficiency being equal to: The Thermal Efficiency of the Plant divided by The Thermal efficiency of The Rankine Cycle

http://home.earthlink.net/~rtdrury/stc.generator.html

An electric generator converts mechanical energy into electrical energy. When an electrical conductor experiences an external magnetic field of changing intensity, the changing magnetic flux induces an emf (1) in the conductor (Faraday's law). The emf drives a current in the conductor that sets up a magnetic field that opposes the change in the flux it sees (Lenz's law, Ampere's law). If the change in flux is the result of motion, conversion from mechanical to electrical energy occurs.

So to be fair I have to agree that for a discussion of EROEI to be meaningful we do have to be willing to define the system boundaries and that it is probably very difficult to determine what the conversion should be. And furthermore that if this is not done then it is not a true EROEI analysis and ends up being just a conversion efficiency calculation. Which may still be useful in its own right.

To complicate matters even further you really need to decide how far back in the chain of events you want to go and then break down and calculate all the energy inputs and losses through out the entire chain of events that lead up to electricity actually flowing out of your power plant.

It's true that the conversion efficiency of a power plant can easily be much lower than 30-40%. But that range is generally accepted as accurate for US plants. It's true it's not easy to obtain such data. Personally, I have to trust other people for it.

To complicate matters even further you really need to decide how far back in the chain of events you want to go and then break down and calculate all the energy inputs and losses through out the entire chain of events that lead up to electricity actually flowing out of your power plant.

I would argue that the term EROEI is not properly applied to any analysis that does not go far enough back in the chain of events that adding further inputs from the past is statistically insignificant.

While I'm not hopeful about Ethanol in general, mainly due to soil and water implications as additional bottlenecks after the Energy Return issue, I wondered if there has been any consideration of what the EROEI would look like if the distillation heat was provided with Concentrated Solar, and credited accordingly. (As well as using direct Solar for any other relevant process heat applications)

Is there such an evaluation of what that would do for the EROEI numbers?

Even if, for argument's sake, the input of Distillation heat from NG or other sources was removed, and a rough fudge-factor number was created for the building of such a solar facility.. Ultimately I'm asking, how big a slice of the Inputs pie is that heat energy?

Bob

jokuhl -

While I don't have the exact number in front of me, the heat required for distillation is by far the single largest energy input in the production of corn ethanol.

From a purely technical standpoint, concentrated solar would make a nice fit for ethanol production, as a portion of the heat produced can be relatively easily stored to allow the process to continue operating 24/7. However, doing so doesn't really change the overall marginal EROI of corn ethanol, as that heat generated by the solar facility could be put to more productive alternate uses, such as generating electricity.

In other words, the solar facility is going to displace a certain amount of natural gas and coal consumption, regardless of whether it is used to power an ethanol plant or something else. So, in the final analysis one must ask if powering a corn ethanol plant is the most productive use of concentrated solar power.

Thanks, Joule.

Any idea if the contribution of Distillation heat is on the order of like 25% or 75%, etc?

I agree that there are lower-fruits as far as where solar can be applied. But I do think it's helpful to see a 'best case' EROEI for making this fuel. As 'X' and others in the farmlands remind us, there will be an obvious inclination at a certain pricepoint of Gas/Diesel, at which growers will likely put a portion of their fields into such a fuel crop, if just for themselves and maybe some local sales, (notwithstanding the legality of this..) simply due to the availability of all the source materials, right there at hand.

I have to wonder if our CSA will be offering ethanol at their Market Stand someday?

Does anyone know what the difference in energy available from using silage as a feedstock for methane to using digested silage (cowshit).

I do not understand why the EU did not include subsidies for methane production when they were forcing farmers to update their sewage treatment as part of the nitrates directive.

Most of the cost of these systems is in the cost of building the pits to store the cowshit. These tanks are natural biodigesters anyway - adding a membrane to capture methane and a pump to compress it would have been a trivial expense when they were being built, but a lot more difficult to engineer now.

Perhaps it is because it was seen as an agricultural issue rather than a resources issue.

If we reduce the energy input by 60% (assuming free solar heat), then the EROI goes up to 2.75.

Eventually, I don't think it will be an either/or for solar. Current limits are avail. funding - if funding for concentrated solar in the context of corn ethanol production can be obtained there is no conflict, the solar facility would not be otherwise built.
I would like to know the EROEI for corn ethanol if process heat is provided for any source other than fossil fuel - I think it is an important piece of info.
It is important also to note what portion of the fossil fuel invested in corn ethanol is not a transportation fuel - it may be, for example, more efficient to produce ethanol than direct conversion of coal to liquid fuels - I just don't know at this point.

Again, I fail to see the utility of capturing solar energy with plants on food-producing land, adding more solar energy to distill the energy out, etc., when direct capture with photovoltaic systems is an obvious and available alternative.

Everybody buys new cars sometimes...they can be electric...and must be cheap. So lets work on that part of it.

Not "everybody buys new cars sometimes". In fact, I would think that the new car buyer is in the distinct minority.

We'd be better off figuring out how to live without cars altogether. Our planet is facing more problems than just the motive power of vehicles.

If we are going to hold on to a little bit of our current civilization, cheap electric cars are a must.

Hi Dimitry,

I would strongly agree with you if the "cars" are Neighborhood Electric Vehicles (NEV) that have a mandated 35 mph governor. All other types of private cars to be prohibited in 15 years. Human Powered Vehicles (HPV) need to be given first priority on all public roadways. This one step could force a total revolution in how us "developed" nations move people about the face of the planet.

If you elect me god and supreme commander of planet earth, we will get this done - otherwise, not much hope. NEVs and HPVs are not even on the long range radar of most countries.

You sound like a dictator, dude!

To be fair he did say if we elect him... that is the sign of a benign deity >;^)

BTW as someone who actually lived for a time under a military dictatorship I will say that things got done for the benefit of national interest without the downside of special interest interference. Of course power does corrupt and absolute power does corrupt absolutely. So the chances of the decisions of the dictatorship being all wise and truly taking into consideration the needs of the populace are rather slim to nil.

But having said that, I could certainly put my support behind any deity that came down to implement HPVs and other rational measures and took away the toys of the spoiled children and forced them to grow up a bit.

Hey, I might even run for vice (pun intended) god...we all need a little badness in our lives. I'd provide running wine in all homes.

Cheers!

Hi Fred,

As you know, TOD is a hard place to attempt a bit of humor.

My point is simply that I think NEVs and HPVs could be very useful - but I have no clue how any widespread adoption will occur in our current culture.

Don't make perfect the enemy of the good.

The electric cars coming out this year are very practical and can highly reduce the oil consumption. Replacing our 2 cars with Nissan Leaf & Chevy Volt will reduce our oil consumption from 1,030 gallons a year to 75.

http://www.mynissanleaf.com/viewtopic.php?f=7&t=870&start=0

There was a thread in the Prius chat forum about reducing speeds. except for like 3 or 4 of us, everyone was against it. Infact some wanted to arrent people going below maximum posted speeds.

Sustainable rail and/or heavy haulers for long hauling goods is a must to hold on to a little bit of our current civilization; cheap electric cars are a luxury (and gas-powered cars are a simple waste).

Define civilization. Anyway, I would say that "civilization" is possible without any cars at all, especially in suitably constructed cities that are laid out to minimize if not eliminate the need for automotive transport. With the emphasis on civil, I would say that our cities would be a lot more civilized if cars were not permitted. Certainly safer, cleaner, healthier, and more efficient.

In the more rural areas, cars will still be necessary as they will not have the density for viable public transport.

they will not have the density for viable public transport

...keep in mind, rural density is absurdly low now because industrialization provides a multiplication factor of about 50 to the labor of the farmer. Economics (high fuel prices/high food prices) may allow industrial agriculture to be the last bit of fuel intensive civilization to go, but when it does go rural density increases.

The utility is in the great convenience of liquid fuels. Again, the standard disclaimer, I don't look to this as a large scale product, but there are times it may be the right tool for the job.

I'm all for electric transportation and so on, but your conclusion of 'Work on that part of it.' Goes back to the monolithic mentality. We should work on it, sure, but there are a lot of people and situations out there, we can and must be looking at a wide range of sources. It's foolish not to. It's also still completely sensible to look at sources like this one for their overall balances.

"capturing solar energy with plants on food-producing land, adding more solar energy to distill the energy out, etc..." - part of the obvious appeal of that is that we are hardly at a limit as to how much sunlight we can be extracting.. and if a Concentrating Array of Heliostats is suddenly out of it's original job as an Ethanol Distillery, recycling isn't even necessary.. this heat source could quickly be rewired to another MFR process, or an electricity generating plant.. etc.

With a decline in crude production thought to be imminent by many, ethanol could help out with the transition over to EVs because it is a compatible fuel for the current fleet of vehicles. Anything that can be blended with petroleum will probably be used until EVs can be produced cheaply and on mass.

I am sorry, but with such a low net energy gain, ethanol really can't fill the gap in the massive fossil fuel shortfall.

Again, I fail to see the utility of capturing solar energy with plants on food-producing land, adding more solar energy to distill the energy out, etc., when direct capture with photovoltaic systems is an obvious and available alternative.

Well, for one thing, we still have a lot of cars that are capable of running on a distilled fuel, whereas building lots of new electric cars would require large inputs of energy. PV is only an 'obvious and available' alternative if it provides enough surplus energy to create such cars and other electric machines that would replace liquid fuel using machines. Not only that, but from an economic standpoint, it would have to be competitive with liquid fuels.

Mind you, I'm not a biofuel proponent. I'm just saying that if you believe PV is a better alternative than liquid fuels, you have to quantify what makes it better, not just have a gut feeling that it's obvious.

PV is a better alternative to ethanol, for reasons outlined in the original post.

As pointed out before, ethanol is a very inefficient way to convert sunlight and a whole bunch of chemicals and some fossil fuels into a little bit of alcohol, while taking up valuable land that otherwise could produce food.

I don't even understand the point in it.

The point is nobody needs the corn as food. No body wants the corn as energy either. However, the Petroleum industry does need it to keep the price of gasoline low and to keep the gasoline junkies from going elesewhere. So that is the point from their perspective.

Burning the corn directly would obviously be more efficient if the only thing you cared about was releasing the energy efficiently from corn.

I think there are many hungry people in this world that would strongly disagree with your assessment of their nutritional needs.

US farm exports and corn exports in particular have done far more to cause hunger and poverty than they have done to meet anybody's nutritional needs.

The recent development of ethanol production in the US has been and will continue to be a boon to third world rural economies that have been beaten down and destroyed by decades of predatory US farm exports.

free corn in swaziland care of the UN, destroyed their local food growing so I agree with you. get swazi orphans anything other than corn mashed up with salt and sugar can be difficut.

PV is a better alternative to ethanol, for reasons outlined in the original post.

In point of fact, the post didn't even mention PV. Efficiency alone isn't enough to judge the efficacy of land use, as I mentioned in another response to you below.

Joule,

I don't think I have ever flatly contradicted you on a matter of fact as opposed to values or opinion until now, but saying that solar energy that COULD BE put to use to partially power ethanol distillation can be put to better uses is not up to your usual standard of thinking, unless I am missing something .

First, the cost of a solar input into the process must be evaluated strictly as a matter of the cost of constructing and operating and maintaining the collection system.

There is no shortage of sunpower whatsover, except at night and during bad weather.

Using some solar power for distillation need not result in the use of less solar power for other purposes.

As a matter of fact, it will probably result in the use of MORE solar power overall, as the result of ramping up the solar industry in general, and driving down costs..

Remember Jevon's paradox.

The effective cost of solar is essentially the cost of equipment used in capturing it.The cheaper the equipment gets, the more attractive it will become to potential users.

As far as the technical issues go, I am not an engineer. I do understand the basics of physics and machinery.

It seems to me that since distillation of ethanol occurs at relatively low temperatures (and does not require a mechanical transformation of the energy from heat to motion, which is required to generate electricity,and which is quite inefficient, compared to the simple exchange of heat from a collector to a boiler) ethanol distillation is an ideal way to capture and use a lot of solar energy very economically-m eaning with a high eroi as well as a satisfactory monetary return.

The real question is whether solar equipment can deliver this energy economically;if it doesn't work in such a basically simple application as this, it is not likely to work in other industrial processes where the temperatures necessary are usually higher and space for the collectors may be at a higher premium.

This said, I am not a fan of corn ethanol for reasons having to do with the environment and long term sustainability.

oldfarmermac -

Well, I did say that concentrated solar might be a good fit for corn ethanol from a purely technical standpoint. This is mainly true because ethanol distillation only requires low-grade heat. However, the point I was trying to make was that just because the energy for ethanol distillation comes from a renewable resource (i.e., solar) doesn't change the marginal EROI, which is sort of inherent in the whole process itself.

Having said that, I would agree that from an energy resource standpoint, it would be better to have solar-powered ethanol plants than gas or coal-fired ones. But there is no getting around the fact that once you've produced usable solar energy, either in the form of heat or electricity, you've got a very large number of alternative uses to which you could put that energy. Some of these uses make more sense than others, and running an ethanol distillation column is not my idea of a very effective use of that energy.

Hi Joule and Mac,

Although not a farmer, I bike thousands of miles every year in farm land. I have lots of farmer friends and relatives (even if I would not want my sister to marry one :-). I agree with many of Mac's earlier comments about the need to use modern machines and ag practices to produce any meaningful amount of food.

I also am a certified hater of private ICE cars (regardless if I have to own one at this point in time). It seems to me that this is not an either/or deal. I would like to see a model whereby farmers could produce some type of bio-fuel strictly to power thier tractors and transportation vehicles - they should not be able to sell it for use in private cars. If a solar gadget helped produce that fuel then all the better.

I think there is an important role for post FF production of liquid fuels for specific applications - like farming. The total stupidity of our current culture is to rape the planet so that millions of people, every single day, can creep along on crowded roadways.

Good to hear from someone who walks, err, bikes the bike.

However, doing so doesn't really change the overall marginal EROI of corn ethanol, as that heat generated by the solar facility could be put to more productive alternate uses, such as generating electricity.

Along with ofm, I'll point out that this isn't logical. Potential alternative uses of energy inputs have no bearing on an EROEI calculation for a given technology. Whether or not using concentrated solar as a source of process heat would improve the EROEI of ethanol would depend solely on the EROEI of the required type of concentrating solar, as compared to whatever sources are currently being used.

Bob, I concur on the soil implications for corn, even attenuated with co-product being returned to the land. What I am most interested in is the EROEI for bio-diesel from soybeans. Here in central pennsylvania hybrid GMO corn is the standard monoculture to keep the dairies supplying hormone doped cows to make milk in other products for the vast east coast population. I'm interested in a non-esterfied scenario, as I see this entire "production silo" as ultimately doomed.

On a side note, I just bought another 110 acres that were in the corn of above, and totally frustrated the previous renter by fallowing the field in anticipation of conversion to something organic but in the end "anything but GMO corn". I took a look at the acres of volunteers from dropped cob and seeds during last year's harvest. They were all sterile, not a single cob. Great seed control design.

But Frightening for all my neighbors.

see Fig. 1 in
http://www.pnas.org/content/103/30/11206.full
Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels

.6 MJ "facility energy use" of .94 MJ total input is 64%.

FYI more info in:
"Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower, David Pimentel and Tad W. Patzek"
at
www.c4aqe.org/Economics_of_Ethanol/ethanol.2005.pdf

EROI is junk science. Energy is an abstraction. Just because energy has a unit of measure does not mean it is defined. Not all energy units are the same and it matters.

Some are renewable and some are in a form that has higher utility than other forms.

No one wants to discus the EROI of electricity which according to some old posts is about .6 if I recall correctly. Yet no one makes a big deal about it. Why?

It's because energy in the form of electricity has high utility in a sophisticated infrastructure based on it.

We have a large infrastructure using oil based liquid fuel. Any new energy supply has to be compatible with that infrastructure. It matters that the energy be in liquid form just as it matters that computers run on electricity and not coal or natural gas.

If natural gas used to process corn into ethanol can be directly converted into a liquid form that can be used by the automotive infrastructure, why is it not done? The reason is it can't be done or it is uneconomic.

When 5 or 6 gallons of diesel is used to produce a 150 bushel per acre corn crop, it is hard to imagine that the 450 gallons of ethanol from that corn is not yielding an energy gain. Yet that is what EROI studies claim.

Those who think EROI means anything are delusional. Renew-ability and the form the energy is in matter more than fallacious studies that reify an abstraction.

Suppose we did the same thing with another abstraction: metal. Suppose we got in a big snit because the tons of metal return on metal investment for gold was negative due to more metal in the form of iron was used to mine gold than the amount of gold produced.

See how stupid that is. Yet that is what is being done to ethanol using EROI.

Those who oppose ethanol based on EROI have to explain why a negative EROI for electricity that is even lower than for ethanol doesn't matter.

They can't because EROI is junk science nonsense.

EROI seems important at the surface, but in reality it is not. Your comment brilliantly illustrates why this is. I personally think it's easier for people to understand with terms such as "portable energy" and "non-portable energy". The real question is: What is the difference in value between portable energy and non-portable energy? If that were calculated into this whole EROI thing, it actually might mean something.

...Are you saying we should not produce net energy? Converting energy at a loss is a good idea? Using a limited resource (agricultural land) to "grow" lossy energy is a winning strategy?

I understand the point about utilization using current infrastructure. For example, we need food to live and that process is kind of lossy. However, I think changing the transportation infrastructure is far more doable than changing our biological engine.

No, I am just saying that not all forms of energy are equal. For instance a gallon of gasoline is far more valuable then the equivalent amount of electrical energy derived from a local utility company. The reason for this is quite simple; there are far more applications for the gallon of gasoline. That being said, our "biological engine" is actually making matters worse by promoting unsustainable population growth. Perhaps dedicating a portion of our agricultural land can help to kill two birds with one stone....perhaps not, but using EROI to as the sole gauge for the practicality of making corn based ethanol is misguided at best.

Geez, I part company with strategies that involve artificially created food shortages, starvation and mass die-off as acceptable tradeoffs.

See ya...

I was not suggesting it as a strategy, only a train of thought, thus the "...perhaps not". Perhaps food shortages, starvation and mass die-off's are much better when nature does them, who can really trust people to make that decision anyway.

It seems to me that when this Administration tells the World Bank not to make loans for development of more coal power plants that people are trying to make just that kind of decision.

The world needs development, and it needs it now. China, India, and Indonesia are moving ahead, but US blackouts are increasing:

http://www.huffingtonpost.com/2010/08/06/dte-energy-sued-by-federa_n_673...

http://www.cnn.com/2010/TECH/innovation/08/09/smart.grid/index.html?hpt=C1

The world needs development, and it needs it now

The world is dying of over-development, we are in the midst of a major extinction event, we may well be past the tipping point on climate, and we are likely far past the point of no return on population.

For two hundred years "development" has been the solution to everything - at some point its no longer the solution, but the problem itself. The edge of the petri dish approaches, and "more of the same" is no longer a sane perspective.

The world needs to downsize. Dieoff will occur. Your recipe is to pump up the world even higher so it can deflate even worse.

Wind,

1) I have never said that EROI should be the "sole gauge" used. Just that it is one of many, and one that I find particularly useful.

2) Energy quality is often times considered in EROI analysis.

3) electricity is generally considered to be of higher quality than gasoline.

David
Just two quick questions:
If the only energy sources you had were ethanol and sunlight, could the system be made to produce a net surplus of ethanol?
Have you done a similar study on sugar cane?

Alan C,

"If the only energy sources you had were ethanol and sunlight, could the system be made to produce a net surplus of ethanol?"

I am a bit confused by this. Can you ask it another way?

Sugarcane - I have not done a study on sugarcane. The numbers are better, but still fall far short of gasoline.

There could be two interpretations of the question:

1. Assuming everything is set up, can an ethanol plant/process using solar energy for the energy inputs, the net energy would be positive. This would most certainly be the case.

2. Assuming all the solar energy sources need to be built and then "depreciated" over the life of the equipment, is there enough net energy in the solar/ethanol process to generate a positive net energy.

i.e., is the payback of a solar/ethanol process greater than the energy required to set up the process?

This is why I prefer to use money to make these decisions, as you can roll all the energy inputs/costs all the way from ore through design all the way to completion- not sure how you incorporate the energy for the design engineer to take his family on vacation otherwise...

David

Yes, now I think about it the question is confusing. Basically I was thinking about Henry Ford and his original expectation that alcohol would be the fuel for his Model Ts. Got to wondering if alcohol could have worked if oil had (hypothetically) never existed.
The sugar cane question arises due to living in an area surrounded by the stuff but with no ethanol industry to speak of. (North East Australia)
Sorry, I should do some research first.

David,

Point 1 noted

Point 2 It should always be considered in EROI analysis.

Point 3 Electricity may be considered to be of higher quality then gasoline, but it is still not nearly as valuable. Now if someone invents a new battery that is cheap to produce, charges very rapidly and is at least close to as energy dense as gasoline, then electricity will become more valuable then gasoline. In fact if that were to happen then wind energy could easily supply all our needs and this website would be moot.

Re electricity quality...

You're talking about energy value (for a particular use (transportation) where energy density is a paramount factor). That's not the same as what's usually called energy quality, which has more to do with the amount of its energy a form makes available, or the number of ways it can be used. Energy quality is subjective. (So is energy value.) So it's kind of pointless to say that energy quality should always be considered in EROI analysis. Unless you've got some fairly concrete criteria regarding the technologies you're studying and the forms of energy they use, the notion of energy quality can't really inform an analysis in a meaningful way.

"a gallon of gasoline is far more valuable then the equivalent amount of electrical energy derived from a local utility company. The reason for this is quite simple; there are far more applications for the gallon of gasoline."

Try running your computer, television, stereo, and refrigerator on a gallon of gasoline. And don't even think about buying a generator, which apparently would be just turning that gasoline into a far less valuable form of energy. When you perform that trick, I might start listening to you about why concerns about the EROI of corn ethanol are misguided.

"Try running your computer, television, stereo, and refrigerator on a gallon of gasoline. And don't even think about buying a generator, which apparently would be just turning that gasoline into a far less valuable form of energy."

That is the entire point Micanopy. It is very easy to put gas in a generator and create electricity, its practical and economic. Now try to put electricity into a car and say the same thing.

We're sort of talking past each other here, Wind. Even though they're not our dominant transport vehicles, there are such things as electric cars and electric trains. Thus, electricity can be used as the direct power source for locomotion. There is no such thing as a direct gasoline-powered computer, and I'll go out on a limb to say there probably never will be. You'll need your handy generator to ensure that the gasoline can be converted into electricity.

Given your hostility to the EROI concept, you might find it ironic to learn that we almost certainly have used petroleum-based liquid fuels for car transport precisely because the historic EROI (as adjusted to distance/equivalent energy sources invested) has been higher for the internal combustion engine than the electric car pathway. If you can efficiently accomplish something (e.g., vehicular transportation) with an abundant, lower quality energy source with high EROI (e.g., the historic story of gasoline), then it generally doesn't make much thermodynamic sense to bother converting into a higher quality energy (e.g., electricity) to achieve that same purpose (e.g., vehicular transportation). You only bother making the conversion when a higher quality energy form is needed (e.g., to power a computer).

Ultimately, I think you'll be hard-pressed to find many people who know anything about energy to agree with your assertion that gasoline is higher quality than electricity.

Nice comment.

Most of the EROI people, including the authors of this study, are fully aware that not all energy units are the same and that the form of energy matters. The systems ecologists quantify these differences as "energy quality." (http://en.wikipedia.org/wiki/Energy_quality)

Because electricity has a higher energy quality than, for example, coal, it would be inappropriate to calculate an EROI based simply on input Joules (coal)/output Joules (electricity). EROI only makes sense when all the input and output energies are normalized to a similar energy quality.

If one reads this study carefully, you'll see that (even if one might quibble about the details) the authors have indeed done this energy quality normalization. The metals to gold analogy, which X claims is an obvious reductio of EROI, is actually a non sequitur because it clearly compares metals of different quality.

"Because electricity has a higher energy quality than, for example, coal, it would be inappropriate to calculate an EROI based simply on input Joules (coal)/output Joules (electricity). EROI only makes sense when all the input and output energies are normalized to a similar energy quality. "

Sure energy quality is very important in this discussion but I am talking about storage and portability.

"EROI only makes sense when all the input and output energies are normalized to a similar energy quality."
This still ignores the practicality of portable energy...this is why EROI doesn't make sense.

OK, so I guess that you're argument is that the corn ethanol process takes a bunch of natural gas and coal, and makes it more "portable and storable" in the form of a liquid fuel. Even if I grant you this, your comment is still largely a non sequitur in terms of judging whether EROI is a meaningful term. Do you not think it makes a bit of difference if your return on investment is 8:1, versus 1:1? I'll grant you that it could conceivably make some sense to produce some amount of corn ethanol as an oxygenate, even if the net energy is negligible or even non-existent. However, it is beyond wrongheaded to think that something with a negligible or negative EROI (e.g., corn ethanol) can serve as a large-scale, sustainable substitution for a high EROI fuel (e.g., gasoline).

Oxygenates are an irrelevancy today-just about every car on the road now has a computerized fuel injection system that maintains the precise fuel air ratio to needed to minimize the production of pollution;the rest that don't will be gone before too long as older less fuel efficient cars are going to get junked faster than ever before, other than a few which will be driven very little.

Then why does the local fuel pump warn that my gasoline has ethanol oxygenate? Are the the laws outdated, or the ethanol lobby too powerful? Or is it because I'm at 8600 feet?

politics and laws.

http://en.wikipedia.org/wiki/Oxygenate

E85 gets the car makers benefits under CAFE, but there's so little demand for it
(less energy density, more expensive).
The EPA came up with a brain-dead scheme to fight smog by using oxygenated fuel,
thus E10.
Some older, simpler engines, particularly small engines like mowers/trimmers/etc. have trouble with oxygenated fuels, due to less energy density.

Ethanol got a waiver (from G.H.W. Bush, at the behest of the ethanol lobby) for vapor pressure, so E10 gasoline is more volatile than the law would otherwise require, resulting in more volatile hydrocarbon emissions -> more smog.

http://ncseonline.org/nle/crsreports/air/air-7.cfm

While ethanol per-say does reduce CO emissions, it seems to increase NOx emissions,
so things are unclear if there's any benefit, except to the pocket books of agri-biz.

This abstract notes that modern vehicles with combustion sensors get no benefit from oxygenated fuels with respect to CO emissions, so I think the whole ethanol as fuel thing is just politics and wishful thinking.

http://dx.doi.org/10.1016/S0140-9883(03)00040-9

Which indicates that using farmland, water, coal, and gas to make ethanol "fuel" is a complete waste, no? It's not used as fuel, but as a safer anti-pollution additive than MTBE. And it probably makes pollution worse anyway.

You can argue with the EPA about the value of oxygenates. They have done scientific studies. But the real value of ethanol is not as an oxygenate.

The real value of ethanol as a blend component is that it boosts the octane of gasoline. Having an octane booster has always been very economically beneficial to oil refineries. That is why the oil companies have used poisons like lead and MTBE in the past even though every one knew those substances would poison the environment. The calculus was that poisons were better than more expensive prices at the pump.

So ethanol is now the octane booster in use today. An octane booster is even more economically important today than it was in the past. Today refineries are producing 84 octane gasoline and blending it with ethanol to get the 87 octane regular gasoline required by law. Producing 84 octane instead of 87 saves the refinery money. It saves them money mostly because it saves them energy.
The higher the octane mix a refinery needs to produce the greater will be their costs, because in general the processing that produces high octane components is more expensive and uses more energy than the processes that produce low octane components. These processing costs vary with the type of crude oil that is fed into the processes, but in general the crude that produces higher octane at less cost is more valuable and thus will cost more per barrel.

How much more the refinery octane costs will be depends on the refinery feedstock as well as the required octane output. Light sweet conventional oil can produce higher octane fuels at much lower costs than oils that are heavy and/or sour. The world is running out of light sweet petroleum and where it is available it usually costs more. So if you are a refinery that needs to remove a lot sulfur and process a lot of heavy molecules to make your gasoline your savings from being able to produce a lower octane product are going to be greater than a refinery that is processing light sweet conventional crude. But if both refineries are buying crude on the open market the one that is processing the light sweet oil will be paying more up front.

Besides sulfur, refineries are also required to remove aromatics like benzene from the gasoline. Those 2 things both make it more expensive to produce a higher octane components. Removing heavy metals also tends to lower the octane level of the gasoline.
It also goes without saying that when oil companies add ethanol it lowers the amounts of components such as sulfur and benzene in the final product, making it cheaper to meet those requirements.

"However, it is beyond wrongheaded to think that something with a negligible or negative EROI (e.g., corn ethanol) can serve as a large-scale, sustainable substitution for a high EROI fuel (e.g., gasoline)."

I never made this claim. I just don't think EROI is a good way to determine the practicality of a process if it doesn't take into consideration the value of the end product.

This still ignores the practicality of portable energy...this is why EROI doesn't make sense.

Although serious EROI studies would account for such factors, EROI does not necessarily have to account for the practicality of portable energy ('energy density' being a more common term to refer to more or less the same thing, btw). That only has to be accounted for to the extent that a comparison of technologies involves different practicalities that change the numbers accordingly.

Regarding the case in point, ethanol production involves a lot of inputs of diesel and gasoline. The practicality of diesel and gasoline are not significantly different from ethanol. Even so, we have reliable figures on how far you can drive a vehicle with a certain amount of each type of fuel. If you want to answer the question "Can one drive a vehicle as far on the diesel and gasoline used to produce ethanol than one can on the ethanol itself?", the way to answer that question is with a EROI calculation. For one thing, it gives you a fairly good idea of how much ethanol you would need to produce ethanol, if you didn't have diesel and gasoline available.

Energy is an abstraction.

Energy is no more an abstraction than the corn you grow. Energy certainly has different forms, but they are measurable.

RR;
I think he just means the 'energy' required to untangle his screwy take on EROEI.

It's an Abstraction driven to Distraction.

Bob

When 5 or 6 gallons of diesel is used to produce a 150 bushel per acre corn crop, it is hard to imagine that the 450 gallons of ethanol from that corn is not yielding an energy gain. Yet that is what EROI studies claim.

You have made a particular claim of EROEI (450/5-6) to defend you contention that EROEI does not matter. How odd.

x does have a valid point, but he manages to obscure that fact brilliantly by failing to understand the basic agreed upon conventions of the sciences and the engineering profession.

His point is that coal and natural gas are cheap, and that from a businessman's pov, it is good business to turn cheap coal, natural gas, and possibly some hydro or nuclear power into much more expensive liquid motor fuel, regardless of losses along the way, just so there are monetary GAINS.

In a real pinch, his arguments are still technically erroneous but highly relevant under certain real possible real world conditions- for example,given that we are committed to truck transport for the forseeable future, it would be reasonable and expedient to manufacture ethanol to power trucks and farm machinery from plentiful coal and ng rather than concievably unobtainium oil.

Explaining chemistry , physics, and such other mysteries to a person trained only in business is about as hopeless an undertaking as inventing a perpetual motion machine.

If it is only about adding "value" (in his opinion) to coal etc. then why go through all the multiple steps and bring in unrelated entropic processes. Why not simply Fischer–Tropsch?

Answer: because we know from Germany and South Africa's example that Fischer–Tropsch does not work as a PO mitigation, in the long term either because of similar "externalties" including agricultural scale, competition for food, and prohibitive cost.

"Long term" in the view of a businessman is only so long as it takes to get in make a buck, and get out again, if necessary.

As I have said before, I am not a fan of corn ethanol-I'm simply trying to make some of the more obscure arguments a little easier to understand by putting them into plainer language occasionally, when I write about certain other comments.

Such comments are totally irrevelant to the narrow discussion of eroi,generally being technically inaccurate, but they are highly relevant to the bigger picture of social and economic policy-or the lack thereof.

I think the real world situation will be we will still produce ethanol from corn, even with the low EROI, because we need to offset declines in crude production. You get beter EROI from solar and wind but if you dont have transport infrastructure in place for EVs you have to make use of what you do have.

I think the real world situation will be we will still produce ethanol from corn, even with the low EROI, because we need to offset declines in crude production.

If the EROI of ethanol is really lower than 1, we will probably see ethanol production decline in some proportion to the crude oil inputs needed to sustain it. I don't really see how ethanol production can stay constant in such a situation. That is, unless ethanol can be produced with other inputs.

Jaggedben,

I am no expert in this field by any means, but unless i am badly mistaken, the return in alcohol produced in terms of diesel and gasoline burned in the start to finish process of growing corn and distilling it is high-several hundred gallons of ethanol for a few gallons of oil and gasoline.

The larger part of the fossil energy going into ethanol is derived from natural gas (used in fertilizer and burned for electrical generation or process heat) and coal-mostly burned to generate electricity but also to smelt steel, etc.

So wehile the OVERALL EROI apparently is kinda paltry, but the return on an "oil only" basis is great.

So long as coal and natural gas are cheap and abundant, ethanol production will probably not be curbed by an oil shortage;just the opposite result is more likely.

Fair enough. I did say "in some proportion." Perhaps that proportion is small with regard to crude oil derived fuels. In any case, running out of natural gas and coal is only a matter of time, just like oil. As I know you know well.

x does have a valid point, ...

His point is that coal and natural gas are cheap...

Which isn't a point about EROEI. Coal and gas are cheap because we have an abundant supply of them (and are willing to forget the danger to the climate of using them). But the basic point of doing EROEI studies on alternatives to coal and gas (and oil) is to try to answer the question "what if coal and gas weren't abundant and cheap?"

In other words, x's point, in your interpretation, is still not valid. According to you, he is trying to argue that "EROEI is junk because it doesn't describe the current economic situation." The whole purpose of studying EROEI is to imagine how life would be in a different economic situation. (For example "Would ethanol be an economically viable liquid fuel if there were no oil or natural gas available to the economy?") x's argument is a complete and total strawman.

You are correct in that x's point is not valid in technical terms -meaning the discussion of eroi in the narrow sense, which is what the primary discussion is all about tonight.

I said so myself earlier.

But in terms of the BIGGER picture -supplying the energy necessary to keep the economy functioning, in forms usuable with our existing stock of machinery/infrastructure-I agree with him to the extent of insisting that he has a valid point.

So far as x is concerned, your arguments are just as subject to being judged strawmen.

Although I am convinced he does not really understand the physics involved, he has, as a practical matter,in terms of short term day to day bau , made his point-the point being that we NEED liquid fuels MORE URGENTLY than we need gaseous or solid fuels not suited to existing ice powered equipment.

Liquid fuels are in short supply;coal and gas aren't;cornfields aren't;farmers and distilleries aren't;ergo,the discussion of eroi is irrevelant and of academic interest only from a PRAGMATIC POV.

This is not my mindset, but it approximates that of x.Questions of academic interest only to him are "abstractions".

I don't agree, for many reasons, but his point is still valid if you accept his premises;and we all base our values based arguments on premises of our own choosing, do we not?

we NEED liquid fuels MORE URGENTLY than we need gaseous or solid fuels not suited to existing ice powered equipment.

I can understand this viewpoint, but I don't really agree with it. It's just as reasonable to say that what we 'need' a way to survive without liquid fuels. In any case, if that is his point, it still has nothing to do with EROEI, and is no justification for calling EROEI junk science.

So far as x is concerned, your arguments are just as subject to being judged strawmen.

Yes, one thing you realize by the end of a first-year college philosophy class is that if someone really wants to believe or disbelieve an argument, they will do so, and can endlessly offer any nonsense rhetoric to support their position, whether it makes sense to reasonable people or not. That it is possible to judge my arguments a strawman does not make it reasonable. All I argue is that well established scientific principles allow for a coherent concept of EROEI. With regard to the practical import of that concept, I don't argue that EROEI is anything other than a way to make some educated guesses about the very long-term prospects of certain energy technologies. In point of fact, David Murphy doesn't go very far (if at all) beyond this in his work. I think it is clear enough that x is the one who is reading too much into the concept of EROEI in this situation.

I don't agree, for many reasons, but his point is still valid if you accept his premises;

No, his arguments are not merely based on different premises (often false ones) than yours or mine, they are illogical. For example, it is illogical to expect chemical elements (iron and gold) to behave the same as energy, just as it is illogical to expect any two different things (monkeys and icebergs, say) to behave the same. This is true whether or not you accept x's apparent belief that everything in the world is an 'abstraction'. (Bishop Berkeley thought something similar, btw, but unlike x he was logical about it.)

_______________________________________________________________________
." The whole purpose of studying EROEI is to imagine how life would be in a different economic situation. (For example "Would ethanol be an economically viable liquid fuel if there were no oil or natural gas available to the economy?") x's argument is a complete and total strawman.

____________________________________________________________________________

Do you think that introducing reality into the argument is a "total strawman"?

If you want to consider hypothetical situations why not consider something that at least has some possibility of becoming real? Consider this: How about an equivalent of $2/gallon increase in taxes levied on all forms of fossil energy. And I mean for all users including farmers, truckers, motorists, consumer, businesses - everybody.

What would that do to these EROI calculations?. Well obviously it would give them new meaning. Suddenly there would be a lot less energy going into every part of all these processes.

It is not as if energy consumption in the modern world is producing much of anything of any real value. The vast majority of infrastructure, durable goods and products that are built are designed mostly for the purpose to both facilitate and increase the consumption of energy. Most of everything that is manufactured or built loses considerable value if you can not feed it cheap abundant energy. And of course, that artificially synthesized fact is used as evidence to argue that we must have cheap and abundant energy sources. And woe be to any one who might suggest otherwise.

In the end analysis the vast majority of energy is consumed with nothing but hot air to show for it. So what is the EROI on the production of hot air?

Do you think that introducing reality into the argument is a "total strawman"

Obviously not, and I can't find the logic in why you ask this. "Introducing reality into the argument" consists of gathering empirical observations; in the case of EROEI, empirical data as to energy flows. One then attempts to analyze that data to understand the nature of such energy flows. That is called science, and it is what David Murphy is doing here. Offering a few anecdotal (and also some false) observations, based on a personal perspective, as x has done, is not science.

If you want to consider hypothetical situations why not consider something that at least has some possibility of becoming real?

Currently ethanol production requires energy from crude oil, coal, and natural gas. I consider the possibility that these things will be in short supply in the future to be very real. I wish to understand how ethanol production might be affected by such a situation. If you can offer me a way to do this without getting involved in something very similar to an EROEI analysis, I'm all ears. Maybe you have a crystal ball.

EROI is junk science. Energy is an abstraction. Just because energy has a unit of measure does not mean it is defined. Not all energy units are the same and it matters.

Many people here have asked you to explain what exactly it is that you mean by "Energy is an abstraction" I have yet to hear a satisfactory response from you, but that aside...

If natural gas used to process corn into ethanol can be directly converted into a liquid form that can be used by the automotive infrastructure, why is it not done? The reason is it can't be done or it is uneconomic.

While in the US this may not as a general rule be commonly done, in Brazil it is done routinely. DIY kits are available or your friendly local auto shop is usually certified to do the conversion for you. So at least in Brazil it is done so it obviously can be done and if it weren't economically attractive I'm sure it wouldn't be done there either.

In Brazil at most fueling stations you can purchase gasoline, diesel, NG, or ethanol and many vehicles are equipped in such as way that you can switch between multiple kinds of fuel. Having said that, EROEI most definitely does matter!

Sorry, this link is in Portuguese.

http://carros.hsw.uol.com.br/gas-liquefeito-de-petroleo5.htm

Fred;
I think Mac might have put his finger on it.

Clearly, X is talking about something completely different than anyone else here in the EROEI discussion.

Maybe, as with his comparison to 'Grains' and 'Metals', he is really just seeing all these fuels and 'Energy' as product groups. I don't know, and I don't see him ever engaging in a discussion that would reveal the language disparity.

.. and thanks Mac for trying to see both sides. We need to do that more than we do.

Bob

I think Mac might have put his finger on it.

Clearly, X is talking about something completely different than anyone else here in the EROEI discussion.

Hmm, I've gone back and reread X's comments on this post and also OFM's attempt at translation of those comments into something the majority of us might understand in a more conventional sense of physics and chemistry based parlance.

I think I may have gotten a bit closer to understanding what I think OFM is attempting to clarify with regards how X interprets these terms.

So if I understand correctly EROEI is irrelevant or an abstraction in X's view because:

The value of not having to discard and replace the currently existing transportation fueling infrastructure and vehicles we have on the road now is far greater than value of the energy we would invest in producing some kind of liquid fuel because what we use now is liquid fuel.

So transforming say corn, into ethanol, because liquid ethanol, would be able to be used as fuel without a major disruption to all that exsisting infrastructure makes it all worthwhile from an economic sense even if the energy we need to invest in making the ethanol is higher than the energy we get out of it?

Dang! if that is the case and I really had to twist my thinking into multiple knots of illogic to get here, then I think I see where OFM is coming from, but X would still be wrong and be guilty of using terminology that has a very specific meaning in an incorrect way and therefore his conclusions would be incorrect because they are based on faulty premises.

Am I even close? Wow, that made my brain hurt, I'm throwing in the towel.

FM,

You have in essence got it.

x most likely thinks all this discussion of eroi, which to him is in a foriegn language-the langauge of physics and chemistry-is equivalent to a discussion among kids in Sunday school of the number of angels that can dance on the head of a pin.

This is why he keeps (in my opinion) of talking about energy being an "abstraction".

What I fail to understand is why so much energy is devoted to understanding X, who is incomprehensible and nonsensical.

For the same reason one might propose sprinkling psilocybin in ones beer so that ones psychopathic next of kin might not seem so queer. >;^)

It's more of a kumbaya thing than anything else.

Probably because (for me) he's often been very sensible and clear on other topics, and is generally a useful poster here. The discrepancy drives me to try to understand.

This is a site where many come to try to understand things better, to stretch our perspectives beyond our old boundaries. It is especially interesting to me to try to reach into such Language conundrums, where people have talked past each other, due to cultural, political or linguistic mismatches.

Remember the first word in the Site Mission up top.. DISCUSSIONS about.. yada yada - It's as much about communication as it is about energy.

http://www.youtube.com/watch?v=SnO9Jyz82Ps

Clearly, X is talking about something completely different than anyone else here in the EROEI discussion.

Yes, he is engaging in philosophical mysticism. His comments have about as much relevance to EROEI as the Book of Ecclesiastes.

Energy is an abstraction...Not all energy units are the same and it matters....
Many people here have asked you to explain what exactly it is that you mean by "Energy is an abstraction" I have yet to hear a satisfactory response from you

Baloney.

You're pretending he didn't answer.

Now you explain how all energy units are the same.

EROI is for the simple-minded.

Baloney.

You're pretending he didn't answer.

Now you explain how all energy units are the same.

EROI is for the simple-minded.

That's a ridiculous straw man, when did I ever say all energy units were the same? I was disputing the point that energy is an abstraction.

Of course it might matter to me which unit I choose to use because of convenience or because I wish to highlight or underscore a particular point or make a specific comparison but it doesn't change the essence of what energy is, or how much work I can accomplish with it or the final result of a particular chemical reaction. That will never change and makes no difference what units I use.

I might choose to calculate something in calories, something else in horsepower and something else again in Kilowatts. It may be that because of efficiency losses in my machinery or my electric circuits it doesn't make practical sense to convert one kind of energy into another, or a particular chemical reaction without a catalyst is too slow for my intended purpose but that doesn't mean it can't be done or that it can't be measured and it certainly doesn't follow that energy is an abstraction.

As for EROEI being for the simple minded, it may well be that I have a simple mind but I think I grasp that if I'm inputting more energy in whatever form into a process that is intended to provide me with portable energy as the output, which I will then use to power my machines to do work and the amount of energy that I get out is consistently much less than the energy I have input then I sure better have an unlimited easy and inexpensive source of energy to power that the entire process.

Up till this point that universal energy source has been mostly oil and we have managed to extract large amounts of it with relatively small inputs of energy. It seems that the dynamics of this fortuitous arrangement may slowly be changing as we find we need to work harder and it takes ever more and more energy to run the processes that we depend on to extract the energy dense fuels on which our entire civilization has been built.

But what would I know?

Just because energy has a unit of measure does not mean it is defined.

LOL Yes it does.

Not all energy units are the same and it matters.

All units of energy can expressed in terms of each other according to their definitions and empirical evidence. This is what many engineers spend their time doing for a living.

No one wants to discus the EROI of electricity which according to some old posts is about .6 if I recall correctly.

You don't recall correctly. Perhaps you are thinking of conversion efficiency rather than EROEI.

When 5 or 6 gallons of diesel is used to produce a 150 bushel per acre corn crop, it is hard to imagine that the 450 gallons of ethanol from that corn is not yielding an energy gain. Yet that is what EROI studies claim.

And then there is the diesel to transport the corn to the refinery, and to process and distill the corn... What does all that add up to? These are basic points of understanding. I think you are deliberately obfuscating the issue here.

We have a large infrastructure using oil based liquid fuel. Any new energy supply has to be compatible with that infrastructure.

Or we could build new infrastructure. It's a choice.

Suppose we got in a big snit because the tons of metal return on metal investment for gold was negative due to more metal in the form of iron was used to mine gold than the amount of gold produced.

I think that if someone expends a lot of diesel to produce ethanol, only to find that they can't drive a vehicle as far on the ethanol as they could have on the diesel, that person will end up in a big snit. That's what we're talking about when we talk about EROI.

Combined with Farmer Mac,

Very good summary.

If we had infinite coal, would it make sense to build a transportation economy on coal? EROI can be very helpful in answering this question.

1) Is it cheap to mine coal in coal terms?

2) How efficient is it in coal terms to convert the mined coal to product X?

3) How valuable is the product X in usefulness terms (I would say how much practical work can it do is a decent first shot) relative to the loss of coal in the process

If the EROI on mining coal is really high (which by all accounts it is relative to alternatives) this allows for wide leeway in efficieny of conversion down the line while nonetheless maintaining high cumulative EROI.

Now lets exit the land of fantasy as someone put it (although I think its clear fantasy land is pretty useful because it quantifies such things as: is it rational to build our need for product X in a vacuum based on resource Y, coal, corn, etc...)

Critical Question

4) How much coal does it take to build the capital stock necessary to allow coal to be transformed into product X.

And now the shit hits the fan. Because at all times we actually have an existing capital stock and it can produce a whole bunch of things where energy input is a minor cost. And all of those things it produces use energy. And it really might be "cheaper" to produce existing cars with the human and physical and technological capital of the automotive business that already exists powered on a crappy EROI fuel then to rebuild the capital stock to produce cars on a high EROI fuel.

But, this in no way means that ethanol, for example, is smart planning. It just means that if the other factors of production actually are REALLY strained, it might make sense to even further strain the energy factor, (in this case by converting coal and natural gas to an oil substitute, if it used a lot of oil itself this would never make sense) to produce the least painful result. I say least painful because the usefulness of the existing capital stock will decline, it just might decline less than under other scenarios.

Personally, I find the above abstract defense of ethanol HIGHLY unlikely to apply empirically to the the current situation. We have existing technologies that can scale in terms of using fossil fuels for transportation that we know right now have positive paybacks. The payback for a Prius is four years at current prices. That is substantive return and it is "widely available", meaning no reason to think that the ability to build Priuses is more or less constrained that the ability to produce ethanol infrastructure (capital, resources, labor, etc...) In light of this empirical fact, why would you put money into a questionable technology that produces gains exclusively of transformation (and limited ones at that considering as someone noted, much high quality energy is actually used in the process) when you could put money into a proven technology that allows for additional use of scarce high EROI resources?

I dont see a strong argument for why we should invest in marginal technology on the fuel production side when we already have technologies that work on the fuel consumption side. I see plenty for the converse. Occam's razor leads me to this conclusion, EROI helps a lot.

"They can't because EROI is junk science nonsense."

It's not junk science, but it is also not the only thing that matters, which is the error many people here are hooked on.

A coal to liquids plant also has a negative EROI, but if you have a train to move, it's worth doing because the liquid fuel has a much higher value than the solid fuel. It's worth it to eat the energy loss. As you point out, the same applies to electricity. There you lose 2/3 of the energy when converting coal to electricity, but it's worth it.

Back to the argument about whether and how to count the value of the byproduct cattle feed, counting the cattle feed solely as energy is also faulty. Cows can't eat coal either. But you can assign a dollar value to the feed, and the ethanol, and the corn inputs. Then you can see if the process makes sense.

By the way, cows don't do well on a pure corn diet, as there is too much starch. Converting the excess starch into ethanol would actually improve the utility of the cattle feed.

-

It would seem to me that using food growing land to capture the energy of the sun for transportation, almost at a loss...is not a good deal.

From an engineering persective it is a very convoluted and complex way to move energy around. It seems that photovoltaic arrays, situated on non-food producing terrain would be far better investment, coupled with a push toward electric transportation.

Now, it could be that without a real break-through in battery technology that approach would run into resource/pollution limitations also...

It's ridiculous to leave out the coproduct energy per Patzek because you do get a return on that investment. That coproduct replaces additional corn grown for livestock feed. That Patzek felt this was honest accounting undermines his credibility.

The post completely ignores the fact that we add ethanol to gasoline to reduce smog in urban areas. Similarly, ethanol releases less CO2(another form of pollution--a cost, always ignored by 'EROI economists') than gasoline also ignored.

Yet another mistake is comparing ethanol with gasoline. They should compare gasoline with E10 or E15, in which case the EROI of E15 is nearly the same as E0;
.85 x EROI of 8? for gasoline + .15 x EROI of 1 for corn ethanol as an energy fuel = 6.95 x .94 = 6.53

It's also silly to try to make corn ethanol the issue, when the government is promoting cellulosic ethanol from a true energy crop like switchgrass or miscanthus and capping corn ethanol.

Cellulosic ethanol from switchgrass initially had and EROI(net energy balance) of 3.43 which recent studies suggest in more like 7.0. This is well over Hall's magical red line of EROI=3.

Net energy production has been used to evaluate the energy efficiency of ethanol derived from both grain and cellulosic biomass (6). Typically, studies have used net energy values (NEV), net energy ratios, and net energy yield (NEY) and have compared biofuel output to petroleum requirements [petroleum energy ratio (PER)] to measure the sustainability of a biofuel. In initial analyses, switchgrass was estimated to have a net energy balance of 343% when used to produce biomass ethanol (7)<'b>. More recent energy model analyses that used simulated biomass yields and estimated agricultural inputs indicate that switchgrass could produce >700% more output than input energy (8–10), whereas GHG have been assumed to be near zero (1) or estimated to be slightly positive (8) for ethanol derived from switchgrass.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2206559/

So why aren't we overrunning with cellulosic ethanol?
Because farmers don't plant switchgrass, they plant corn
and their ethanol refineries make alcohol from starch not cellulose(something POET is changing).
Convincing highly conservative farmers to switch crops is
a big task but this is again ignored by the energy bean counters who claim that slow acceptance of ethanol is based on their magical concept, EROI.

If you are a stickler for joules, why not count in the energy of the sun? Just because it is free from money, doesn't make it free energy, right?

Why use agriculture land to capture sun energy, requiring giant refinaries to do it?

Direct conversion seems like a way to go.

Cellulosic ethanol from switchgrass initially had and EROI(net energy balance) of 3.43 which recent studies suggest in more like 7.0.

None of this has been demonstrated. It is based on models which are based on assumptions. One thing about those assumptions is that they have to be validated in practice, and one thing I have learned is that this is frequently where things break down.

So why aren't we overrunning with cellulosic ethanol?

In my opinion it is because invalid assumptions have been made relative to the energy return. You simply can't produce a 4% beer of ethanol (typical for cellulosic ethanol), distill it to high purity ethanol, and do that with reasonable energy efficiency. The inherent high concentration of water in the process is a very big problem.

FURTHERMORE the fact that this article refers to the Petroleum Energy Ratio (PER) which is much different than the EROI calculated in my paper. The Petroleum energy ratio accounts for the petroleum inputs only, i.e. fertilizer, irrigation etc... don't count as costs. Therefore it is a more restricted version of the EROI i calculate and must, by definition, be higher than the standard EROI.

No posts yet on the passing of Matthew Simmons? Isn't he one of the great P.O. theorists/writers of all time?
http://www.businessweek.com/news/2010-08-09/matthew-simmons-peak-oil-the...

Thank you.

May God bless and comfort the loved ones he leaves behind.

Twilight in the Desert was my true peak oil awakening.

Mr Simmons may have made odd claims of late, but he will always be one of the giant figures in shaping the understanding of our oil dilemma. "Twilight in the Desert" is a classic in the Peak oil field. His phrase "Rust never sleeps" when dealing with infrastructure is one that plays in my mind often also.

A thinker, a persuasive peak oil advocate and an iconoclast.

RIP and condolences to his kin.

Really sad to hear. His thoughts and presentations are really great inspiration. All the best to his family and friends.

EROI is not the point. Ethanol is primarily a means of converting domestically produced energy derived from coal and/or natural gas into a domestically produced liquid fuel.

The value of domestic ethanol production is that it keeps US dollars in the US. Ethanol is a politically attractive fuel that really has limited or no energy gain advantages.

Wow, that's a long way to go...why rope corn into it, then?

Aren't there ways to convert coal into liquid fuel?

As for natural gas, we can use it directly for transportation, with engine conversion.

“Wow, that's a long way to go...why rope corn into it, then?”

Politicians want to get energy money to farmers.

“Aren't there ways to convert coal into liquid fuel?”

Yes, and that is being done, also.

“As for natural gas, we can use it directly for transportation, with engine conversion.”

One name comes to mind: T Boone Pickens

The value of domestic ethanol production is that it keeps US dollars in the US

...well, sort of. Doing nothing whatsoever keeps US dollars in the US. Bicycling and walking keeps dollars in the US...its not "the dollars we keep in the US" that really make the difference - its what we do with them. The corn ethanol situation reminds me of the story of the kid who traded his dollar bill for two quarters, because "two is more than one!".

We can talk and write and calculate about this. The only way to be 100% sure is to grow corn and to produce ethanol in the sands of a desert. Never in history this has been profitable.

Maybe I am a lightweight without proper statistical methods (See. I can't even spell "methodologies") but I fail to see how all this meta-analysis and meta-meta-analysis trumps the baseline EROEI study, "Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower, David Pimentel and Tad W. Patzek"

Here the authors simply catalog the embodied energy of the equipment and fuels that go into fuel productions, and conclude, for instance, that "Ethanol production using corn grain required 29% more fossil energy than the ethanol fuel produced"

Even minor tweeking by unpublished critics (see shapouri et. al. on distillers grains etc.) does not substantially alter the basic fact: the 400 million acres of arable land in the United States would, if all converted to corn ethanol production, only supply at best (given the rosiest net-energy returns) 19% of our gasoline needs. Then there would be no more food. Simple stuff really. Don't need no fancy dense impenetrable meta-meta-meta analysis.

The beauty of a meta-analysis is that it captures variability in the assumptions/numbers of different researchers, and gives a broader picture of the issue at hand. As it turns out, the conclusions of this study are ultimately not all that different from Pimentel and Patzek, as even the most wildly optimistic results for corn ethanol are still pretty dismal when looked at in full context.

Nice one ANewLand.
Similar here in UK for biofuels.
We do not do much corn - wrong climate.
Even biodiesel (oil seed or 'Canola') with reputed EROI about 3:1 grown on maximum area possible for this crop would supply less than 6% of our present UK diesel total. (Diesel and gasoline are about half and half of our total transport fuel.
'Nuff said.

__________________________________________________________________

Even minor tweeking by unpublished critics (see shapouri et. al. on distillers grains etc.) does not substantially alter the basic fact: the 400 million acres of arable land in the United States would, if all converted to corn ethanol production, only supply at best (given the rosiest net-energy returns) 19% of our gasoline needs. Then there would be no more food. Simple stuff really. Don't need no fancy dense impenetrable meta-meta-meta analysis.

_____________________________________________________________________

This is all fantasy that you created out of thin air.

The fact is 9.5% of all gasoline used by motor vehicles in the US is now ethanol and there has been no noticeable change in farm acreage. Sure that recent increase in ethanol production has meant that US is now producing very slightly leaner beef, pork and chicken meat. And it also means we no longer are able to prop up quite as many African, Asian and S. American dictators with our surplus ag production. For much of the impoverished of the world US Agriculture exports have been the new improved version of colonialism.

Farmers could easily increase production of ethanol to 19% with no negative impact on food production. Sure it would mean animal fat and soft drink sweeteners in the US would get a little more expensive, but those are not negative impacts. And converting 19% of the motor vehicle gasoline to ethanol would require fewer acres of corn than US farmers planted in 1940. It would also mean millions of farmers in rural third world countries would be able to rise above the bondage of subsistence farming that US grain exports have imposed upon them.

Sad news on the death of Matthew Simmons. RIP.

I would like to briefly address an argument I've heard time and time again from the pro-ethanol people.

And that is (to paraphrase as best I can): 'EROI is a fiction deliberately used to make ethanol look bad, and it is hypocritical to use such a concept because the EROI of generating electricity is less than 0.50, at best, and no one is against generating electricity'

First off, I fully recognize that some forms of energy have greater utility or value than others. This used to be referred to as 'form value'. No argument there, but I think where the pro-ethanol people get into trouble is by inadvertently confusing EROI with energy conversion efficiency. As I have said several times before, the concept of EROI should be confined to the acquisition of primary energy sources, i.e., energy that is ready for use.

EROI is fairly easy to calculate for fossil fuels such as coal, crude oil, and natural gas, as it will include all the readily measurable energy inputs from extraction up to the point of delivery for that fuel. It is a bit more difficult to calculate the EROI for renewables, such as solar and wind power, but it can be done using reasonable agreed-upon assumptions.

Now, when you go to burn coal or natural gas in a power plant to generate electricity, you are no longer engaged in obtaining a primary energy source, but rather are using a primary energy source already obtained to produce a usable product, in this case electricity. In which case the appropriate concept is no longer EROI, but rather energy conversion efficiency. Due to conservation of energy, it is impossible to produce any product that entails an energy conversion efficiency of greater than unity. So, it is a bit specious to point out the low 'EROI' of a power plant.

In the same vein, when one produces ethanol from corn, one is not engaged in primary energy production in the same sense as in extracting coal or crude oil, but rather one is engaged in a downstream energy conversion exercise, in which various fossil fuel inputs (plus agricultural solar energy) are converted into liquid fuel, the overall energy conversion efficiency being less than unity.

Thus, while it is valid to view corn ethanol as a useful product, it is not valid to treat it as a source of energy, because it is not. It is merely a politically popular way to convert solid and gaseous domestic fossil fuels into liquid fuel capable of being used in automobiles. It displaces a certain amount of imported oil, and that has definite benefits. In this sense ethanol is much like hydrogen: an energy carrier but not an energy source. I feel quite comfortable in saying that when you make corn ethanol, you are producing fuel but you are not increasing our supply of energy.

I would argue that the primary conversion is solar energy to liquid fuel, with additional energy additives of all kinds.

The alternative to plant ethanol is direct sunlight to electricity conversion, at least in energy terms.

While the sun is obviously necessary for growing corn, the much higher percentage of fossil fuels in the corn ethanol life cycle makes it very odd to argue that the primary conversion process is solar to liquid fuel.

Dimitry -

I'm not sure that's really true, as the largest energy input to corn ethanol is the heat required for the distillation step and that comes from fossil fuels.

The process of photosynthesis is actually quite inefficient in terms of the fraction of incident sunlight actually converted to energy in bio form.

Ethanol plants and solar PV have almost nothing that is directly comparable.

I think the above comments are quite wrong.

Plants are direct converters of solar energy into biomass. Fossil fuels, HELLO?

It rather strange to hear a discussion of plant ethanol energy, without mentioning of the PRIMARY energy source ALL PLANTS USE.

The other stuff is the energy required for conversion of chemical energy in the plant to liquid fuel we can burn in the car (as opposed to a stove, or a fire pit which humans have been doing for eons).

Since photosynthesis is inefficient, it makes even MORE SENSE, not to use food-growing lands to capture solar energy via biomass conversion, but go direct to electricity.

Why would you use good fossil fuel to heat up a keg of corn mush, for the purpose of converting it into a similar amount of a different liquid fuel? Just burn the fuel you got in the first place. But with ethanol you took agricultural land, a bunch of other chemical inputs, labor, a large chemical plant and for what?

If you are going to trade land for energy, at least use the kind you can't grow food on and use direct solar to electricity conversion. Why do anything else?

No wonder this "debate" is so weird. We have serious first semester physics defficiencies here.

Dmitry,

You're talking about the efficacy of using land for one purpose or another. That's a separate issue from EROEI. There's no need to try to conflate the two. EROEI has it's uses, and can very well contribute to the question you're talking about.

The reason that EROEI doesn't include solar energy as an input is that it isn't a input from us. There is no point in talking about how much sunlight energy is available if we have no way to harness it. Harnessing it requires that we invest some energy in planting corn, or producing PV panels, or what have you. That is the energy invested.

Finally, the efficiency of corn vs. PV panels (or anything else) is only one number that goes into an EROEI calculation. The energy inputs also make a huge difference in which makes 'more sense'.

For the record, I agree with you that PV makes more sense, because it likely has an EROEI at least 3 times better than corn ethanol.

If you are going to take up land that can be used for a productive use (food) and convert it into an energy producing system, I think it is entirely fair to compare the energy method you chose to another that can be situated on this land. Land efficiency (and other resource efficiencies) are every bit as important as energy efficiency. For example, our local CSA farm is VERY land efficient but only average in energy efficiency. Land is at a premium where we live, so that land efficiency is very important to us.

So from a energy/land ratio perspective, PV panels will beat the pants of any plant based liquid fuel system - it is not even close.

Dmitry, it's like this...

Even if you can get more energy from PV panels than corn on a given piece of land, if it takes more energy to build and maintain those PV panels than they produce in their lifetime, then it would be pointless to put them up. (Suppose, for the sake of argument, that the energy is interchangeable at no cost.)

Suppose I get 100 units of energy from an acre of PV in 30 years, but it takes 110 units of energy to build and maintain them.

Now suppose I get 2 units of energy from an acre of corn in 30 years, but it only takes one unit of energy to plant and grow the corn.

Long term, the corn would make more sense, even though I get produce less energy from it in absolute terms.

As I said before, I agree with you that PV is the better bet. That's not because it has a better land efficiency, but because it (AFAIK) has a better EROEI.

Obviously life cycle analysis has to be considered.

It is clear to me that PV panels produce far more energy than is required to manufacture them.

Corn, on the other hand has already been shown to have a very poor energy density AND efficiency.

The fact that you believe this,

So from a energy/land ratio perspective, PV panels will beat the pants of any plant based liquid fuel system - it is not even close.

shows you must be the poster child for EROI-induced brain damage.

This shows how the EROI meme can overwhelm all traces of common sense. You are outside reality.

Have you forgotten Brazil? Ethanol provides 50% of light vehicle demand.

The importance of ethanol in Brazil’s domestic transportation fuels market will only increase in the future. According to Petrobras, ethanol accounts for more than 50 percent of current light vehicle fuel demand, and the company expects this to increase to over 80 percent by 2020. Nearly 90 percent of all new cars sold in Brazil are flex-fuel vehicles, which will slowly remove gasoline-only cars from the fleet.

http://www.eia.doe.gov/cabs/Brazil/Oil.html

How many electric cars are there in the USA?
A couple thousand?

How much electricity is produced by solar cells?
In the US .9 Twh comes from all solar.

What's more insane is the suggestion that it makes more sense to turn farmland for biofuels into PV solar, when the best location for solar PV is the desert.

Brazil is a very large country with a small population density and not a lot of cars.

It is not easily comparable to the US.

I never suggested turing farmland into solar farms. Farmland should be for food. It should not be turned into fuel farms, that's all.

Robert Rapier did an excellent review of the concept of EROEI with a closer look at Brazilian Ethanol production from sugarcane back in 2008.

http://www.theoildrum.com/node/3707

The EROEI of Brazilian Ethanol

The case of Brazilian sugarcane ethanol deserves special mention. It is often quoted as having an EROEI of 8 to 1. I have even repeated that myself. But this is misleading, and I have to give credit to Nate for challenging me on this. The oft-cited Brazilian EROEI is really a cousin of EROEI. What is done to arrive at the 8 to 1 sugarcane EROEI is that they only count the fossil fuel inputs as energy. Boilers are powered by burning bagasse, but this energy input is not counted. (Also, electricity is sometimes exported, and credit is taken for this). For a true EROEI calculation, all energy inputs should be counted. So what we may see is that the EROEI for sugarcane is 2 to 1 (hypothetically) but since most inputs are not fossil-fuel based the EROEI based only on fossil-fuel inputs is 8 to 1.

Ironically when I worked for Petrobras back the late 70's and early 80's I owned and drove a 100% ethanol powered Voyage, which is the same car basically as a VW Fox. I also have a friend who is an agronomist who was involved in soil maintenance of sugarcane plantations.

I was born in Sao Paulo Brazil and have firsthand knowledge of Brazil, it's social structure, it's politics, its culture and people. There is no way you can make a direct comparison between the US and Brazil with regards its automotive fleet. You are comparing pineapples to lemons but I suspect you already knew that.

As for placing large scale PV on land where one could grow sugarcane I've not done the calculations but I'm sure it would be a lose lose proposition all around. Having said that I think it totally misses the point that EROEI is not a fundamentally import calculation to consider when making decisions as to where our energy investment dollars or Reals might give us a better return on both our energy and financial investment.

As someone who currently works in the Solar photovoltaic industry I will readily admit my personal bias as to where I think we should be investing our money. It should be going much more heavily into renewables such as solar wind and hydro than biofuels. A biofuel based business as usual economy is simply not sustainable based on EROEI calculations and a whole cost biophysical analysis.

For that matter neither is it possible with the renewables I just mentioned, what we really need to be thinking about is a major paradigm shift in how we use energy for personal transportation and we must ultimately transition away from private automobiles as they exist today.

Something like this might be a partial solution: Human powered hybrid solar ultra efficient velomobiles for short distance local transport connecting to electrified rail for longer distance.

http://www.pnwlocalnews.com/sanjuans/isj/business/89546537.html

BAU as we know it is dead.

Respect photosynthesis. Its inefficient but thats a price to pay for stability. The ultimate method of capture all energy output of sun is dyson sphere and given enough technology, most notably nanotechnology it can be made in a thousand years but we can't change laws of nature. Due to law of gravity, a dyson sphere would be inherently unstable and can easily be over-heated.

In nature, planets are sphere for a reason: stability and rotation, so that there is day and night, so that energy received by one portion of surface of a planet at day can be radiated back to space at night to avoid over heating. The space between planets is also for stability to reduce effect of gravity. At the end, earth receives only 1% of total energy output of sun. With this level of efficiency it happily survived its structure and temperature for billions of years.

Not all the energy received by earth's surface is used by plants. Earth's surface being three quarter water means three quarters of energy input on earth goes in maintaining the water cycle (ignoring plants' photosynthesis at sea to support life in sea). On the land surface of earth only 40% of area has plantation, rest has rocks or glaciers or deserts or swamps etc. Why not lets say 80% of earth's surface has plantation? Its to make the system stable. Imagine a major forest fire, a plant disease, a pesticide attack on plants etc. If bulk of earth surface has plantations then there would be tiny islands of non-fertile lands in between and at most points plantations would be connected to each other if oceans not come in between. So, we would have plantations spreading from korea to europe and even africa continuously. It would make the entire system very unstable. Nature don't work this way. Nature has isolated plantations by placing frequent non-plantations lands like deserts and rocks in between so that if one area fails the entire system don't fail. Placement of oceans in between groups of continents serve the same purpose but at a much higher level.

When there is plantation, the energy of sunlight falling at surface is not all used by plants. Photosynthesis is truely highly inefficient, a mind boggling number of 1/10,000 at the most and another mind boggling number of 1/1400 at the least. Why? To make the system stable. First of all the ozone and other upper layers of atmosphere reflect back lots of harmful components in sunlight. Then some energy is taken away by the lower atmosphere itself even on clear-sky days. There are cloudy days, fog days etc so that cut off a lot of energy. Finally whatever energy did reach the plantation not all fall on the green leaves, a lot of it fall around the plant and places in between. Whatever energy leaves do get atlast, they don't use all of it, infact they use very little of it. This helps in ability of plants to adapt to different climates and temperatures. There is also a factor of angle on which light is falling, most efficient angle is ofcourse on equator and least on poles.

We humans should work on increasing the efficiency of the part of natural system that we use but only through respecting the need of low efficiency at the first place and not do anything to disturb the stability of system. If the system do become unstable then we really have no way to fix it. Remember, higher the inefficiency, higher the resiliency and therefore higher the stability.

The capital,energy, personal, and other resources required to produce ethanol would be better utilized to implement alternatives to the internal combustion engine simply because we need to get off fossil fuels to the greatest possible extent. The great scam involving ethanol, which is found in the industry's advertising is that it is green and that it is not a fossil fuel. Well, in essence, it very much is, given all the inputs required to produce it. That is where the EROEI analysis is helpful -- to expose the b.s. coming from the ethanol industry.

Alternatives include the restructuring of our cities to not require the use of the auto, whether it be an ICE or an EV. Any so called transitional fuel that uses fossil fuels, especially coal, will just worsen our predicament with regard to global warming.

Further, we should keep in mind that this industry is being subsidized and spends millions in lobbying and advertising to ensure that it keeps being subsidized. If EROEI is so meaningless, then let it stand on its own and demonstrate how unimportant EROEI is.

Ingredients:

(1) 1 Convex lens
(2) 3 mirrors
(3) 1 metal pot
(4) 1 glass tube. L shape
(5) 1 turbine
(6) 1 battery
(7) Some metal rods and stands to make structure
(8) Some water

Procedure:

(1) Take all of the above to an open place getting direct sunlight, preferably a desert. Desert to get clearer sky, more heat and enough sand to make lens, mirrors and glass tube in future. Placing the stuff in desert disturb least amount of people and other visible life.

(2) Place the stand. Place the pot over the stand. Put some water in the pot. Place one mirror below the pot and others around at appropriate angles. Fix the smaller side of glass tube at the mouth of pot. Fix the other side, the longer side of glass tube, to a turbine.

(3) In day time, around noon, that is 2 hours before and after noon, put the lens to converge sunlight to a point at one of the side mirrors. Use mirrors to reflect light to the mirror placed below the pot.

(4) Wait for a few minutes till the pot becomes hot. This heat get transferred to the water in the pot and boils it. We get steam.

(5) The steam goes to the test tube and through the test tube to the turbine. It start moving the turbine converting kinetic and thermal energy into mechanical energy.

(6) The turbine's mechanical energy get converted into electrical energy and after conversion into DC get stored in battery.

Feasibility:

(1) Very simple, even primitive technology. Not need a degree or even a diploma to make or run the apparatus.

(2) The primary ingredients: lens, mirrors and glass tube can easily be made from silica, that is, sand. Once made these can be used over and over to exceed the energy needed to make them. Made of sand, this apparatus is extremely scalable.

(3) The non-glass apparatus is the metal stuff: the pot, metal in battery, metal rods and stands. This apparatus can also be used again and again, literally for decades before getting running out due to rusting, however placing the apparatus in a dry desert with little humidity can reduce the rusting factor significantly. Also, if some oil is saved, paint made out of oil can be used to reduce the rusting factor further.

(4) Nitrogen or phosphorus based battery can be used. A scientist recently invented a battery that save electrical charge in a liquid of nitrogen or phosphorus and the charge / recharge cycle can occur for thousands of times before the battery get destroyed. Usual batteries in cell phones and laptops usually work for only 180 charge / recharge cycles before getting destroyed.

(5) At extreme situations, if a very large pot, lens and mirrors are used, the electrical energy can be transmitted by wires to a suitable place outside the desert to a water source such as a lake, river or canal, where electrical energy can be used to lift the water up to store energy in the form of potential energy. This energy can later be retrieved by letting the water fall down and using turbines there to get electrical energy out of it. The whole process is admittedly of very low efficiency. The transmission can lose 20% of energy, the conversion of electrical energy into potential energy can atmost be 33% efficient, the energy retrieval from potential energy into electrical energy by letting the water flow down can also be atmost 33% efficient. At the end, less than 10% of energy is used. That is still better than getting nothing.

(6) The whole thing is easily scalable to very large degree until we run out of any of desert, sand, water or metal.

(7) Unlike solar cells, no advanced technology is needed.

(8) Even if water is retrieved from the turbine there would still be some losses of water in atmosphere. So the apparatus needs a continuous supply of water.

(9) There are only two key components of project: lens and mirrors. Lens need to be convex to converge light from a large surface area of lens to a very small point, better the quality and larger the size of lens better the efficiency and level of output. Mirrors are to be used to transmit light to desired angles, angle of incidence being equal to angle of reflection desired point at the bottom of pot can be hit by light by placing the lens and a set of mirrors at appropriate angles. Not much loss of efficiency there at both lens and mirrors are already highly efficient.

You've just described Concentrating Solar Thermal Power.
This is already established, and growing rapidly.
http://en.wikipedia.org/wiki/Solar_thermal_energy
or
http://en.wikipedia.org/wiki/Concentrating_solar_thermal

["Other organizations expect CSP to cost $0.06(US)/kWh by 2015 due to efficiency improvements and mass production of equipment.[23] That would make CSP as cheap as conventional power. Investors such as venture capitalist Vinod Khosla expect CSP to continuously reduce costs and actually be cheaper than coal power after 2015.

On September 9, 2009; 10 months ago (2009-09-09), Bill Weihl, Google.org's green energy czar said that the firm was conducting research on the heliostat mirrors and gas turbine technology, which he expects will drop the cost of solar thermal electric power to less than $0.05/kWh in 2 or 3 years "]

I am sorry, but these projects have WAY too many moving parts and are quite complex to execute.

Again, the easiest the smartest way to harness the only energy we have on this planet, which comes from the sun is PV cells. The faster we find a way to make them cheap and good the better our chances of energy survival.

Growing plants from solar energy and lots of chemicals and mashing them up into alcohol is really ridiculous.

Why don't we add some more interesting steps, like shaping the corn or grass into decorative baskets before distillation?

CST and PV, are complementary technologies.

Solar PV is already ramping quickly, and on a steep downward price curve.
Some spot price, (moderate volumes) can be seen here
http://www.ecobusinesslinks.com/solar_panels.htm
GigaWatt factories, are now commonplace.

CST has spare heat, and has relatively easy smoothing-storage, but is still 'Power Plant' technology. It can also Dual-fuel, if needed.

PV has lower efficiency, but a wider application footprint than CST.
(No one is contemplating a CST on their roof! )

Also, I'm not sure what point you were trying to make with complexity ?

Most power generation today, (Goal, Gas, Nuclear) use turbines, and have done quite reliably so for many decades.
So, 'complexity' is not a non-issue. It's mature, proven and works.

( indeed, the Solar PV factories, are MORE complex, and newer technologies )

My feeling is we need to get away from as much complex machinery as possible. And I am an aerospace engineer...

In our energy challenged future, large turbine producing factories that require tremendous industrial upkeep will be very difficult to maintain and feed.

Automated facilities cranking out standard low-tech PV panels are likely to be easier to maintain with degraded industrial/energy infrastructure.

PV is also much easier to use on a retail level and can be installed almost anywhere. No moving parts, no or very little maintenance.

In our energy challenged future, large turbine producing factories that require tremendous industrial upkeep will be very difficult to maintain and feed.

Automated facilities cranking out standard low-tech PV panels are likely to be easier to maintain with degraded industrial/energy infrastructure.

? That's backwards.
If Solar PV really were that simple, it would be the mature technology, not the one with intensive R&D, and rapidly changing Fab-Systems.

By contrast, turbine power is VERY mature (120+ years!), and we have no problems maintaining turbines now.
Our Industrial systems can collapse back 100+ years, and we can still make Turbines; not so for Solar PV.

Have you seen the R&D, or the process technologies and materials refinements needed for Solar PV ? Low tech is it NOT.

That's why it is still emerging, if it were that simple, we would not be having this discussion :)

Maybe it's what I know. I have been around precision machine shops all my life and I know it is difficult to keep everything in good running order. Building and maintaining a high-efficiency turbine takes a lot of work, spare parts, access to precision machinery, all manner of mechanical/industrial infrastructure that may not be available.

Maybe it is wishful thinking on my part, but it seems to me that an automated PV plant may be easier to maintain in at least some ways. However, PVs may need some super-special ingredients that are not going to be available without a mining/chemical infrastructure either...

Some of the Solar comments miss important points:

a) It is not a OR usage, but can be a DUAL usage.
That's because simple heat is needed for Ethanol production, which can be a dual-cycle (waste heat) usage of concentrating solar power plants.

b) Solar energy for grid usage, needs peak management and often some storage, as well as transmission losses.
When you site Solar power next to a large consumer, that does not need storage (that energy smoothing is effectively done in the Ethanol) or incurs transmission losses, you have made some significant jumps.
If that same consumer is a waste-heat user, then you've gained even more.

All those factors, render the 'but the solar could have be used elsewhere' arguments void.

jg-

Yes, if one is dealing with a concentrated solar power system that generates steam in a heat engine to turn a generator to make electricity, then waste heat will be available, and that waste heat could be used to power a corn ethanol still. (Or something else.)

However, these concentrated solar power-generating systems appear to be most applicable to desert type locations, which are generally far away from corn producing regions. In other words, would it be economical to set up an ethanol plant in Arizona just to be near a concentrated solar power installation and then ship corn from Iowa to Arizona?

Anyway, I was largely speaking in terms of a dedicated concentrated solar plant built solely to serve an ethanol production facility. In which case, I think my argument still holds that there are better uses of solar energy.

Is there possibly a better way to use solar energy than to heat up a distillation keg?

Possibly?

"Is there possibly a better way to use solar energy than to heat up a distillation keg? Possibly?"

Anything is possible.
If they crack quantum-dot PV, then the goal posts can expect to move.

I'd ask if there is a smarter crop than corn, to convert Solar Energy into usable Fuel.
Corn seems to be used, simply because it was 'already there', and it seems some food-usage-byproduct is still deployed (see above).

Also, the food-usage aspect gives a fall-back, should the fuel economies shift, and it is a moving target right now.
Not sure I'd invest in Corn Ethanol tho ?

However, these concentrated solar power-generating systems appear to be most applicable to desert type locations, which are generally far away from corn producing regions. In other words, would it be economical to set up an ethanol plant in Arizona just to be near a concentrated solar power installation and then ship corn from Iowa to Arizona?

Yes, Grid-feed CST systems target the highest insolation regions, but once you factor in transmission loss, and dual-heat usage, those move the goal-posts quite a bit, and so lower insolation areas are drawn into the 'viable' footprint for sites.

From the history of americas, slave labor was able to produce 500 kg sugar per person per acre in a year. A slave can work on as much as 10 acres. The time between crops was used to produce food for the slaves themselves and in processing of sugar cane to produce sugar. The farming was ofcourse 100% organic.

1 kg of sugar = 1 kg of carbohydrates, because sugar is pure carbohydrates and nothing but carbohydrates. One gram of carbohydrate contains 4 calories. One calorie is equal to 4200 joules. One liter of petrol contains 33.4 million joules. Therefore, one liter petrol is equal to 8,000 calories or 2 kg sugar. Therfore, one acre can produce 250 liters of petrol equivalent primary energy and one worker, working with hand, using no fossil fuel machinery, can produce 2500 liters of petrol equivalent in primary energy. We have yet to see the efficiency of conversion of sugar or ethanol into something that can be used by cars.

World uses 30 billion barrels of oil per year and that is 40% of total energy used by world. So, adding up other fossil fuels coal and gas, fossil fuels provides equivalent of 64.5 billion barrels of oil. It is because all fossil fuels provides 86% of energy used by world. One barrel of oil contains 160 liters so 64.5 billion barrels of oil equivalent means 10.32 trillion liters of petrol equivalent.

At the rate of 250 liters petrol equivalent per acre, there is a need of 41.28 billion acres of arable land dedicated to production of sugar cane / ethanol / sugar. There is also need of 4.128 billion workers, each working on 10 acres to produce that. Note that this is when the workers work as efficiently as slave labours in americas, that is, getting beaten, chained and constantly harrased. Free labour would achieve something like 50% of the efficiency of slave labour at the most. Also note that only 50% of human population at any given time is of working age, rest are too young or too old to produce any significant amount of output even when pressed.

Our planet earth is a sphere with land area 150 million sq km which means 37.5 billion acres. Atmost, 40% of it is arable if we count all farms, grass lands, forests and even fertile under water ground that produce plants that fishes eat. So, throwing everything on it we can't get more than 15 billion arable acres, we need 41.28 billion arable acres.

Ok, so that number, 41.28 billion acres is when we plant totally organically and also have other features of traditional farming like relying on rain only, one crop a year etc. Lets suppose we can have two crops a year, though that requires dams and canals to have water in winter and dams run out in 60 years and after that its nearly impossible for us to rebuild a dam, also dams can only be built at some specific places, we can build barrages to store water but once in a 5 year or 10 year or 20 years at most a very large flood comes that can destroy the dam and barrage but lets ignore this. If we can have dams and canals we can have twice as much water and in winter so two crops a year. We can use green revolution seeds to increase output to further 2.5 times, though those seeds are unhealthy and can't stand plant diseases and pests attacks on their own, they need supply of pesticides, also those green revolution seeds requires far, far more soil nutrients and water than is naturally present so we have to have a urea industry etc. So, having those two multipliers under our belt we can increase farm productivity 5 times as compare to the traditional farm. Still we would be needing 8 billion acres of farm land. That is more than all the land under cultivation on the entire planet. Even if all humanity becomes vegeterian we can't survive giving even 3 billion acres to ethanol production.

Forget about EROI of ethanol. It can have an EROI of 100 but if its not scalable then its useless.

Very interesting. I'd guess that a free worker could produce just as well as a slave without being abused (some evidence of this in US history actually) but your analysis of the necessary land pretty much kills it. If we are going to produce sufficient liquid fuel from sunlight it's not going to be via agriculture.

The 2009 corn crop in the US had a lot of mold. Mold produces mycotoxins, one of which is vomitoxin. Ethanol from corn relies on selling the DDGS (Dried Distiller Grains) for animal feed in order to be economical and produce a net energy. The process kills the mold but does not destroy the mycotoxins. In fact it concentrates them in the DDGS. Too high a level and it sickens the animals eating it. Thus this year some corn was being turned away from ethanol plants if it tested to high in mycotoxins. http://www.apsnet.org/education/IntroPlantPath/Topics/mycotoxins/Pages/i...

Any large scale dedication of land to produce ethanol or any other bio fuel, even if contain feasible EROI and is scalable still have one problem, the destruction of environment. There is also problem of loss of resiliency as having a single crop over a large area is a very attracting place to diseases and pests, its like fire in a dry forest where everything is combustible.

One solution is to grow feed for draft animals and use these draft animals to do work, mechanical work, transportation work and even run turbines to produce electricity once we have enough number of such animals. Growing feed for animals don't have problem for destroying ecology because once a bed of grass is maintained, its upper portions can be eaten repeatedly without destroying the bed. It also requires far less human labor. If the excretions of draft animals are put back to soil then we have a nearly sustainable and very stable system.

See horse vs car to get some basic data and analysis. The most efficient draft animal is no doubt donkey. It eat those plants and those parts of plants that horses don't eat. It work far longer and harder than horses. It can breed.

Its low tech, highly efficient, highly ecological and also very beautiful solution.

I think we can eat them, too!

Lets get really simple. Why not compare burning ethanol with direct burning of the biomass that it was produced from? That was done here:

http://www.technologyreview.com/energy/22628/

I would like to see a comparison of an automobile burning E85 (no subsidy) to one that was converted to burn wood (eg: corn) gas. Here's a study comparing wood gas to diesel:

http://www.fao.org/docrep/t0512e/T0512e0k.htm

I'll bet corn burned vs corn ethanol burned is cheaper.

I've been a member and poster on TOD for almost 4 1/2 years and I've read the essence of this thread umpteen times. I'm tired of this crap. There are two basic memes - it (fill in the blank) is an energy looser; it's an energy winner. Yet, both presuppose some form of BAU.

Gang, BAU is a dead end. All of this discussion is an intellectual circle jerk. Get over it and move on. No, I'm not Mr. Mellow. I have a planned post for tomorrow's DB that should PO a lot of people.

Todd

What's a "BAU"?

BAU is a TLA* meaning "Business As Usual"

* TLA = Three letter acronym.
* BUA = A Typo ?

Excellent!

I would have never guessed...

When corn ethanol first came on the energy scene, it was viewed as a winner in the GHG reduction game and was bestowed with the financial attention that a potential winner should have. Now that we clearly see that corn ethanol is not an energy winner, but rather, a loser, we need to do the wise thing and bail out, pull subsidies, and shift our time, money, attention and resources into transitioning to a business not-as-usual world.

Dave et.al. - keep up the great work!

Hey editor, you were quick to delete entire thread that i started once, long long ago, about palestine. What about above two comments from mbt, thats pure scam and cheap publicity.

Delete this one too after you delete that.

Flag it. There was another on Drumbeat, and it's gone already. They'll ban this person fairly soon.

Discussion here is about EROEI. The target is to get to know some technology / method / process through which net energy supply to world's economic system can be maintained or increased. The theme is to get as much net energy as we can, but the more important question is why do we want to get as much net energy as we can? Thats simple, to get more goods (but not services as services are provided by humans though quality can be improved with technology). That leads to even more fundamental question, why do we think we need more goods? Why do we want to get technologically advanced. What is our basic pursuit?

Our basic pursuit, other than what the true religion tells us, is to get a happy life, as much happier as it can be with as much little trouble as there can be.

One question I often asked myself and also asked a lot of people is, given there are four technological levels of civilization available: hunting-gathering, farming, industralization and service base economy, which one they like to live if given a choice provided no security problem from a neighboring higher technological level society. I also define each of these eras as follows:

Hunting-gathering era means you can use stone tools, live in caves or in adobes, hunt wild animals and birds for food, steal eggs of birds, gather naturally growing fruits and herbs, not do any farming, not keep any animals besides dogs, can lit fire, no division of labor, isolated groups of 50 to 150 people living in dense forests or lush green grass lands, no personal property, probably longer lives like centuries due to less stress, very low level of work, frequent holidays like working one day and resting the other as done by some wild tribes, frequent raids by groups of wild animals like lions or wolves etc.

Farming era can vary from the birth of civilization, the first village, about 7,000 bc to the peak of ancient civilization to middle ages civilizations all the way to year 1800 A.D. (precisely 1784 A.D. when modern steam engine was developed), one crop a year, work 240 days a year, 6 hours a day from dawn to noon that is 1440 hours a year, low level of cross province and cross country travelling, very good quality of food, living in natural environment, everything being done by hands, keep a variety of animals for a lots of purposes, lots of wars but mostly leaving working class unaffected etc.

Industralization age is like living in 19th century europe or america or 20th century asia (and perhaps 21st century africa), easy to buy a car, work year around 8 hours a day, 9 am to 5 pm, consider typical factory labor at assembly lines, spread of railways all over the country for easy travel, radio and tv but no computers, cinema being very important, get industralized food, get cold drinks and chips, an era that ended around 1990 in usa.

Service base economy one where everybody depends on computers, where nurses earns more than engineers, where high levels of efficiency is achieved through advanced and strict management arts, where marketing is very important, where its not hard to work from home using a computer and internet connection, where toys like cell phones are very advanced and common, where unemployment can really become a problem because most of the work is done by machines etc.

The answer that I get from myself and from every person I asked is farming era. Its surprising. Even those dreaming about colonization of the galaxy ultimately want to live in a farming era. Why? Its because of simplicity, stability, resiliency, closeness to nature, less emphasis on efficiency etc but there is another important factor, a very important factor, the lower the technological level the lesser the difference of power between working class and elite. Once camera technology became sufficiently cheap, you see an army of those placed everywhere to help the elite : govt and large business men, to keep an eye on you. Once chips technology gets sufficiently advanced and biologized, it would not be a surprise to see one being enforced in everybody's brain. Once wormhole technology gets sufficiently advanced, it would not be a surprise to have frequent visits of cops and other regulatory govt officers as well as your boss and managers to your homes right inside your drawing rooms without knocking doors and even passing through a door or wall or window.

There was a reason in past autocratic families were established. There was a very little difference between a king and a slave materialistically speaking, both have the same level of technology, almost the same level of information, and as read in folk tales the first person entering a city at a date pre-decided by ministers (and unknown to that person) would be made a king after the death of previous king if that king have not left a heir. This stranger can run the country after some basic training. In modern era, those who really run a country, that excludes show-pieces presidents and prime ministers get decades of education and training.

Why did humans develop technology? It was developed by pressure of elite to make elites even more powerful. Not only do working class lose privacy and opportunities to escape once technologies get developed, the working class also have to work more efficiently producing more goods and work for more time for the elites. Higher the efficiency, lesser the happiness. Top achievers in education and job usually lives a dry, friendless, family less, children less lives. If you are a carpenter working by hand and can produce lets say 4 chairs a day working at your natural speed, that is when not pressed or "motivated", and then forced to produce 8 chairs in the same time you have to lose free-time-in-between at work, you have to lose your smile, you have to get more tired when you leave the work place so that when you reach home you would already be a dead person who only want to eat and sleep and not have any time for your family. Nobody likes to live in such hell, but people are hypnotized by media, greed is implanted in people, low efficiency and easy jobs are systematically eliminated from society so that you get more and more tied and less and less free. People do complain about this, they know something is going wrong but what exactly they can't figure out as they are already pressed to the ribs. You can easily find people complaining that life is getting tougher, level of competition has increased, living a decent life is getting harder and harder, demands of employers are increasingly insane and we have no practical alternate at current time. That happens when elites get technologically advanced. Working class ofcourse do get technologically advanced too but at a much lower rate and whatever level it is, it is heavily dependent on the higher level. Your boss would always have the more advanced cell phone, more advanced computer, more advanced car, not just more expensive but also more technologically advanced. Your cell phones and computers depends on satellites controlled by elites so even where you feel you are free you are not.

Even at industralization level of 1850 A.D. uk, elites have superior technology than the working class. When the most sophisticated technology a mill workers has ever seen was a railway engine, the elites might have seen inter-continental ships. When in 1910, a factory worker can take advantage of pubic mailing system for rapid communication to a relative in a far off city, his boss can use a fax machine for near instant communication.

A hunting-gathering level of society is merely surviving. Its very probable that a group of 80 wolves invade your adobes at midnight and kill all of the 60 people of your group. Not knowing about weathers and rain patterns you would only know about a drought when you see it. Not having proper maps you can get lost in a desert instead of reaching the lake you were heading.

So, ultimately, farming is the most desired, most fair, most stable level of civilization. Media in industrial and service-based civilizations scare their people of farming, lieing that farmers had to work from dawn to dusk, lieing that majority of humanity was living hand to mouth etc. People don't care to think that having one crop a year, half of the year is practically rest time. In the other half too there is lots of time between sowing and harvesting, the time in which plants grow and requires very little care. People also don't care to think that decades of education needed to live in an advanced civilization is no longer needed in a farming civilization. People don't care to think that farmers, working with hand, living close to nature, keeping farm animals, live far more healthy, pure, care free and meaningful lives than an average citizen in europe or america today. People don't care to understand that elites not have that high power in farming era than today, imagine no gps, travelling by animals, dense forests, lots of help to escape from society if one wishes too.

Interesting thoughts, Wisdom;
No time to respond, but it gives me good food for thought.

Bob

"lieing that farmers had to work from dawn to dusk, lieing that majority of humanity was living hand to mouth etc" "People don't care to think that having one crop a year, half of the year is practically rest time"

I grew up on a dairy farm. I can state without question that you are completely wrong. Even with fossil fuels, machinery and hydraulic systems, you are wrong. Without those things, the family gets bigger (Dad is one of five, Mom one of eight) or the survival margin gets smaller, or both.

As for the second point, get out and read. Start with "The Little Ice Age" by Brian Fagan, an anthropologist. He makes some pointed comments about academic misconceptions about subsistence agriculture.

You were raised in a dairy farm, not a traditional farm which is both dairy farm and crop farm and orchard at the same time. Probably you have never seen a traditional farm. If you are from usa, canada, non-russian europe, australia then you have to look back to prior to 1800 A.D. If you are from russia then look back to prior to 1930 A.D. that is prior to soviet collectivization of farms, if you are from non-russia asia, africa then you have to look back to prior to 1950 A.D.

You have missed the entire point. In presence of hydraulic system you have enough water in winter to have second crop so you missed a lot of traditional free time. My other point was the almost free time between sowing and cultivation, the middle 3 or 4 months where practically very little care is needed by plants. Traditionally, that is like farming in lets say 1000 A.D. or 1500 A.D., using a pair of oxen, a farmer can plow one acre in one day, infact the very concept of acre come from this. Traditionally land need to be plowed 2 or 3 times depending on which part of world you are. Sowing was done along with plowing consuming no extra time because as oxen and plow move forward, the farmer or his wife spread side walking behind. Given that there is one month in each crop for the farmer to plow and sow, that is, for proper growth of plants you must sow within one month, so if your land needs to be plowed three times then you work on 10 acres, if 2 times then 15 acres. Given that harvesting takes usually 15 days and at maximum 30 days and plants takes 5 to 6 months to grow (unless they are vegetable plants) so you have 3 to 4 months in between.

If the farmer has a family of lets say 8 people then traditionally speaking some of the children would be employed in work. Its child labor but there is nothing wrong in it because its done on their own farm, their own business and is not forced, so no need to get paranoid over there. Given less density, as in traditional farms, more land can be used for farming. Also note that, the very fact of large farmer families comes only after the birth of industralization, when mechanization of farming resulted in large production of food per worker, therefore giving a message to farmers that they can afford to have large number of children because there is more than enough for everybody and even more. Also, due to industralization effect in the field of chemicals, better medicines were developed that resulted in less loss of mothers during giving birth, less loss of young age children and overall long ages, that means population growth and population growth can't come without large families. What I talked about was a traditional society where population growth not exist or is very very little like 4% a century. Better to learn steady state first, then apply the knowledge to dynamic state, not the other way round or it would get too complicated.

I have not read "The Little Ice Age" but by title it seems like it discuss the era between 1700 A.D. and 1850 A.D. or something like that and this book is probably written long after the end of the little ice age. I recommend even more classical books that are themselves written in the classical era to give a true, eye-witness picture of the accounts of a traditional farm. Following is a list of some books, you can try getting a translation:

(1) Kitab ul Khiraj by Imam Abu Yousuf, written in 132 hijri or 742 A.D. Arabic Language.

(2) Canterburry tales. Written somewhere between 1000 A.D. and 1200 A.D. Classical English Language.

(3) Ain e Akbari. Written in 10 years between 1555 A.D and 1565 A.D. Classical Persian Language.

(4) Various taxation, land and population information books written by english tax collectors, surveyors etc of british india between 1857 A.D and 1914 A.D. There are lots of these books for each of the dozens of provinces of british india and even individually for each of the districts sometimes. A particular, very interesting and informative such books was written in 1887 about sindh province.

(5) Autobiography of Ibn e Batoota. He is the most traveled tourist of all times. He not returned home for 22 years and traveled over 22 million kms. He kept a diary for all his tourist life. He met with kings, ministers, govt officers, workers, traders etc and got tons of information. Original text in arabic.

(6) Tsarist land reforms of 1870, 1907.

Also please read various articles on internet and various classical legal documents about lands transfer, knighthood, taxation, droughts etc all about fuedal europe of era about 800 A.D. and 1400 A.D. There is a wealth of information waiting to be rediscovered. Look especially on the various crops, their average yields per acre per year as well as level of variations between yields year to year, also please look at level of human labor calculated in man hours needed to work on each acre. Before all this please educate yourself about seven components of diet (carbohydrates, proteins, fats, minerals, vitamins, fiber, water) things like how much of each is needed per day per person (for that you have to understand the concept of relation between age and height, relation between height and body mass; you have to understand population pyramid), how much of these seven components can be produced in what land with what effort with what degree of variation. You have to make an understanding of average diet with different items of food in what quantity per day and their production per acre per year. I have put a wealth of this information here http://wisdomfrompakistan.blogspot.com.

Please also get information about prices of food items in 1500 A.D. at various parts of world and compare that with incomes of working class.

Subsistence agriculture did happened for over 40 centuries in classic civilizations of egypt, babylon, nenwa, persia, rome, china and india.

WisdomFromPakistan is correct in many areas regarding a 'traditional' farm

And it is also correct when applied to many non-traditional farming.

For instance. A couple friends of mine farm the normal 3 crop/2 year rotation of corn, wheat and soybean(with wheat many times not planted).

Right now at this very time we are between the planting season and the harvesting season. So for about 3,4 or 5 months they have very little to do. The crops are growing and so the most they might do it call a spray couple from the nearby AgChem company to spray. The farmer does nothing expect pay the cost.

And also during winter he is on slack time. A couple more months of doing nothing.

On the 'traditional' farm little is done when weather is inclement. Also almost nothing in the form of serious work is performed during the winter months. You may milk the cows and do the chores but its very marginal work.

And having several offspring makes it even easier.

Milking twice a day? If you are just providing your own milk and not selling it then you do not have to milk twice a day. The calf can handle one of those milkings.

I do know of some farmers who work very hard but thats because they have another off-farm job. Many can do this but they shouldn't bitch just because they do it simply to keep up with their city cousins and go out spending lavishly on items not really needed. Like dining out.

Mom on todays farm does NOT do the housework and cooking like before. I will agree to that and therefore time is wasted replacing that venue. However its by CHoicE and not need.

Actually preparing meals traditionally is not that hard nor time consuming. When farmers are doing hard physical labor , as they are wont to do for periods of time, then they need a goodly supply of nutrients per food intake and SOMEONE will have to cook or else eat junk food and other nonsense.

This is the way it works. My cousin's husband owned a dairy farm. They had plenty of leisure time. They now have 4 chicken sheds and have even more leisure time.

That is NOT traiditonal. That is Industrial Farming and a horse of a differing color.

Given that there is one month in each crop for the farmer to plow and sow, that is, for proper growth of plants you must sow within one month, so if your land needs to be plowed three times then you work on 10 acres, if 2 times then 15 acres.

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Plowing the soil 3 times is really a crime against nature.

In the area where I live the vast majority of farmers never plow the soil in which they plant their corn. Year after year the soil is never turned over. This practice not only saves fuel and time it also counteracts the number one reason why traditional farming is not sustainable.

The reason traditional farming is not sustainable is because it depletes carbon in the soil. Tilling the soil releases carbon into the atmosphere. The difference between a desert soil and fertile ground is one thing and that one thing is the carbon content of the soil. Traditional farming with all its plowing, harrowing, tilling etc. turns fertile ground into deserts.

I recommend searching "farmers of 40 centuries". All classic cultures be them ancient egyptians, greece, chinese, babylonian, nenwans, indians, japaneses, germans, french, english, all of them, do plowing. The fact that they are farming the same soil for 40 centuries (actually more than that) shows that their farming is sustainable. They do have to do certain activities to support the soil, things like have cover crops, putting humans and animals excretions back to soil, putting human and animals dead bodies back to soil, taking water from canals once in a while (or let nature do that) to get precious sediments full of nutrients (infact all of the ancient egyptian farming depends on annual flood of nile). Medieval europeans gone even further by their three crops system in which each acre was cultivated for grain crop only once in every three year, the second year it got cultivated for cover crop and third year it lay fallow (still serve for feeding ground for animals that eat whatever naturally grow their that year).

All classic cultures be them ancient egyptians, greece, chinese, babylonian, nenwans, indians, japaneses, germans, french, english, all of them, do plowing.

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You named many of the countries that have the best examples of depleted soils due to poor agricultural practices.

Hi Dave, Almost got mislead by different units in table 3. Suggest you add another column showing MJ/L for agri phase - in fact can you do that now?

5 of 6 studies show reasonably close agreement - how come Farrell has different input values?

To what extent do these individual studies rely on their own raw data acquired by doing field work? There is sometimes a danger of different studies agreeing when all are using same base inputs - just adjusting these a bit depending upon prejudice.

But none of this really matters. I'd query the EROI value of 10 used for gasoline - in most cases I'm guessing the figure is much higher, reinforcing your conclusion that corn ethanol provides little net energy as % of liquid fuels used. How to get that message across to policy makers?

I'd also query the logic about EROI increasing with yield. EROI will increase by using much less energy during production.

Euan,

To get the agri phase in MJ/L you divide it by the last column, i.e. ethanol yield (L/Ha).

I would not say that 5 of 6 show reasonable agreement. Generally Wang and Shapouri are close in value, and Pimentel and Patzek are close in value.

Farrell et al (2006) is a review study that attempted to give all the other ethanol studies consistent boundaries so that they could compare them. So I do not think that they use their own data, but they do change some values reported by others. Wang uses the GREET model for most of their data, and Shapouri borrows from this work as well. Likewise, Pimentel and Patzek share some data as well.

Turning fuel into food seems like a good idea, turning food into fuel just seems wrong.
Are there any other fuel sources that have such a low EROI? Are there any that come even close? I think that the market should decide if this is an efficient way to harness solar energy. Remove the corn subsidies and other government subsidies and the market will put an end to this folly.
If it is only practical if solar energy is used in the distillation then this becomes a debate about ethanol as a solar power storage device and the EROI is not a critical consideration. It is clear that more efficient ways to store and transport solar power already exist.
Edit- I recommend a movie called King Corn for a look at corn farming. It is available streaming on Netflix.

Using this methodology, we'd have to give Electricity from coal an EROI of about 0.25 to 0.30, because, well, we could be using that heat energy in Coal for heating homes for the next 1000 years. Let's just go with natural gas, which is probably a more fair comparison. If use 100,000 BTU (high heating value) of natural gas to heat my house, then the 'normal' natural gas EROI which is somewhere upwards of 20 applies. If I make electricity from natural gas instead, in a 60% thermodynamically efficient combined cycle plant, then is this EROI 20 x 0.6, or 12? Or is it 0.60?

So, if EROI of corn ethanol is 1.07, and let's just assume for argument that all the energy input is natural gas (60% in the ethanol plant, for distillation, and let's just say the remaining 40% from ammonia fertilizer). We've just converted 1.0 units of natural gas to 1.07 units of ethanol, with a current value of oh, $4/MMBTU, to ethanol, which is $17/MMBTU (84000 btu/gallon, $1.50/gallon)... we've had very small net energy gain... and a rather substantially huge economic gain.

Liquid-at-room-temperature is worth *a hell of a lot* in the real world.. which is why we don't see a lot of natural gas fueled vehicles. Can anyone tell me what the EROI of LNG as a liquid transportation fuel is? I expect it's around 0.80 or something like that at best. However, since it's so much cheaper, interest in LNG-fueled semi trucks is starting to pop up... and the cost of cryogenic storage and conversion kits starts to get attractive.

Now... Throw in some ethanol plants that outright own wind turbines (there are two of them I regularly drive by, and I don't think they are on that map), this issues gets to be a bit more complicated. I saw mention of solar-powered distillation, which I find kinda amusing. The economics for wind-energy powered ethanol distillation will likely work out in the next 5 years. We already have 3.6 GW of installed wind in Iowa. The turbines coexist quite nicely with cornfields, and some farmers find the access roads to get turbines *in* very useful for getting corn *out*.

If you just use 'hydrous' ethanol, which is 90% ethanol, and 10% water, like Brazil does, you have a huge reduction in distillation energy cost. And bog-standard vehicles (like my 2001 Prius) will run on up to 50% ethanol... I have been running 6 gallons of E85 and 4 gallons of regular gas per tank for the last 70,000 miles or so. I have also put a gallon of hydrous ethanol I distilled myself into the tank (which had maybe a gallon of regular gas in it).

90% ethanol & 10% water changes the EROI quite a bit... I would love to be able to re-run this paper's analysis on the sensitivity of hydrous ethanol and ethanol plants with integrated wind generation. *That* would be quite a bit different.