There are many studies − 1 to 2 dozen—showing that producing a gallon of corn ethanol takes more energy than is contained in a gallon of corn ethanol. Usually, the conclusion is that it takes n=1 to 1.4 times as much energy. There are other studies claiming the opposite; they fail to take into account factors such as irrigation and transportation costs.
I wrote to Wired magazine and to somewhere else (I forget where) to correct their outrageously-incorrect assertions about corn ethanol. (Wired underreported n by 2 orders of magnitude, which is disturbing because this wasn’t like ordinary irresponsible journalism where someone took one “expert’s” numbers uncritically. The figure they gave for corn ethanol efficiency was AFAIK much, much higher than those of even the most biased ethanol advocates.) My responses were unpublished. It’s even worse journalism when you make an extreme error on a point important to public policy, and then someone points it out to you, and gives you a dozen literature citations, and you don’t correct it.
Also, for the less wrong pedant community, phil meant that it takes 1 to 1.4 times more energy input where “energy input” EXCLUDES the solar energy that the corn plants absorb to produce 1 litre of corn ethanol than is contained in 1 litre of corn ethanol.
There are many studies − 1 to 2 dozen—showing that producing a gallon of corn ethanol takes more energy than is contained in a gallon of corn ethanol.
Well, of course. And it takes more energy to produce a gallon of oil, or an equivalent amount of coal or what have you, than is contained in that amount of fuel.
Anyone who knows the laws of thermodynamics will tell you that.
I think you may have a valid point somewhere, but it’s not being expressed properly.
We have to actually invest the energy that goes into producing ethanol. Coal and oil were produced without such intervention and all we need to do is dig them up. If people were talking about synthesizing these things, that would be a more sensible comparison to make.
I believe Annoyance’s point was that it takes more energy to create virtually any fuel than you get out of it, and if PhilGoetz meant anything further than that, he should have said so. I also did not feel informed after reading PhilGoetz’s comment, for the same reason.
The core distinction here is between energy production and energy storage, and confusing the two is the sort of thing Roko was complaining about (I am not saying anyone here is confusing them).
Ethanol is a valid means of storing energy, although producing it from corn is a terribly suboptimal way of doing so anyway.
Ethanol is not in any useful way a means of producing energy, but it is often presented as if it was, and the inability of the general public to understand this is the heart of the matter.
Fossil fuels, like other non-renewable energy sources, are energy that was stored in advance by natural processes, and are only useful for energy “production” because the energy cost of extracting them is far lower than the energy they store. Corn ethanol is just a very silly way to store solar power.
Almost completely correct. The only quibble I have is with the claim that “Ethanol is not in any useful way a means of producing energy”.
That’s not quite true. It would be more accurate to say that trying to use corn as an industrial energy source while simultaneously growing it with methods that require artificial fertilizers (which are extremely energy-intensive to synthesize) and mechanical tillage and harvesting (which requires amounts of industrial-level fuel that are prohibitive for that task) is utterly pointless, because the total process requires more industrial-level fuel than it produces.
You can get more energy out of the corn than you invest into it—obviously. But you can’t do so with modern industrial agricultural methods, which expend lots of energy (considered in total, including fertilizer manufacture) to capture a relatively small amount of solar energy in a form that people and animals can consume.
Even when we used draft animals to do the labor required and relied on organic fertilizers only, farmers couldn’t make their planted crop areas provide all of the energy and resources necessary to keep the system going. Large areas of forage (usually grass) were needed to feed the beasts so that human-edible crops could be produced—an ‘external’ energy input for the crop areas. The farms as a whole were powered by the sun only, of course.
When humans do all of the work of agriculture, farming is far, far less efficient (depending on the methods used) and with very primitive methods has a return barely greater than the investment of (human-provided) energy.
I don’t think you understood Phil’s comment. Thermodynamics does not dictate it takes more energy to produce some fuel than is contained in the fuel. Producing fuel is energetically inexpensive—if you have sufficiently concentrated precursors.
Thermodynamics does not dictate it takes more energy to produce some fuel than is contained in the fuel.
Yes, it does. Second law. You need all of the energy that the fuel will store, plus more to run the process that creates it.
Either you’re producing lower-energy fuel from higher-energy fuel, or you’re taking base constituents and available energy and synthesizing a higher-energy configuration.
Yes, it does. Second law. You need all of the energy that the fuel will store, plus more to run the process that creates it.
It’s conservation of energy, not second law.
Either you’re producing lower-energy fuel from higher-energy fuel, or you’re taking base constituents and available energy and synthesizing a higher-energy configuration.
High-energy fuel is simply fuel that allows to restore more energy per unit of weight. Take more low-energy fuel and convert it into less high-energy fuel.
I still don’t think you understood Phil’s comment.
Presumably, you won’t be able to make sense of this either:
“In addition, production of ethanol is energy efficient, in that it yields nearly 25 percent more energy than is used in growing the corn, harvesting it, and distilling it into ethanol.”
The problem appears to be that you are incorrectly imagining that the other people in the discussion are trying to account for factors such as sunlight.
Thermodynamics has everything to do with the statement in question.
There is the sun outside this open system.
Exactly.
What I suspect Phil was trying to express was that ethanol manufacturing requires us to expend more of the desired level of fuel than we derive from the process—which is a good point—and that this rules out ethanol as a viable energy source—which is NOT a good point.
We invest more energy in building and charging batteries than we can get out of them. That isn’t an argument against batteries, because they’re a means of transmitting energy in usable form. And extremely useful ones. Carrying around a steam-powered generator to operate a flashlight isn’t an option.
Corn ethanol is a terrible net-producer of industrial-grade fuel because its production consumes more of that level of fuel than it produces, NOT because it “takes more energy to make it than it provides”, which is trivially, obviously true of any fuel.
There are many studies − 1 to 2 dozen—showing that producing a gallon of corn ethanol takes more energy than is contained in a gallon of corn ethanol. Usually, the conclusion is that it takes n=1 to 1.4 times as much energy. There are other studies claiming the opposite; they fail to take into account factors such as irrigation and transportation costs.
I wrote to Wired magazine and to somewhere else (I forget where) to correct their outrageously-incorrect assertions about corn ethanol. (Wired underreported n by 2 orders of magnitude, which is disturbing because this wasn’t like ordinary irresponsible journalism where someone took one “expert’s” numbers uncritically. The figure they gave for corn ethanol efficiency was AFAIK much, much higher than those of even the most biased ethanol advocates.) My responses were unpublished. It’s even worse journalism when you make an extreme error on a point important to public policy, and then someone points it out to you, and gives you a dozen literature citations, and you don’t correct it.
Also, for the less wrong pedant community, phil meant that it takes 1 to 1.4 times more energy input where “energy input” EXCLUDES the solar energy that the corn plants absorb to produce 1 litre of corn ethanol than is contained in 1 litre of corn ethanol.
Can you give us some references?
Well, of course. And it takes more energy to produce a gallon of oil, or an equivalent amount of coal or what have you, than is contained in that amount of fuel.
Anyone who knows the laws of thermodynamics will tell you that.
I think you may have a valid point somewhere, but it’s not being expressed properly.
We have to actually invest the energy that goes into producing ethanol. Coal and oil were produced without such intervention and all we need to do is dig them up. If people were talking about synthesizing these things, that would be a more sensible comparison to make.
I believe Annoyance’s point was that it takes more energy to create virtually any fuel than you get out of it, and if PhilGoetz meant anything further than that, he should have said so. I also did not feel informed after reading PhilGoetz’s comment, for the same reason.
The core distinction here is between energy production and energy storage, and confusing the two is the sort of thing Roko was complaining about (I am not saying anyone here is confusing them).
Ethanol is a valid means of storing energy, although producing it from corn is a terribly suboptimal way of doing so anyway.
Ethanol is not in any useful way a means of producing energy, but it is often presented as if it was, and the inability of the general public to understand this is the heart of the matter.
Fossil fuels, like other non-renewable energy sources, are energy that was stored in advance by natural processes, and are only useful for energy “production” because the energy cost of extracting them is far lower than the energy they store. Corn ethanol is just a very silly way to store solar power.
Almost completely correct. The only quibble I have is with the claim that “Ethanol is not in any useful way a means of producing energy”.
That’s not quite true. It would be more accurate to say that trying to use corn as an industrial energy source while simultaneously growing it with methods that require artificial fertilizers (which are extremely energy-intensive to synthesize) and mechanical tillage and harvesting (which requires amounts of industrial-level fuel that are prohibitive for that task) is utterly pointless, because the total process requires more industrial-level fuel than it produces.
You can get more energy out of the corn than you invest into it—obviously. But you can’t do so with modern industrial agricultural methods, which expend lots of energy (considered in total, including fertilizer manufacture) to capture a relatively small amount of solar energy in a form that people and animals can consume.
Even when we used draft animals to do the labor required and relied on organic fertilizers only, farmers couldn’t make their planted crop areas provide all of the energy and resources necessary to keep the system going. Large areas of forage (usually grass) were needed to feed the beasts so that human-edible crops could be produced—an ‘external’ energy input for the crop areas. The farms as a whole were powered by the sun only, of course.
When humans do all of the work of agriculture, farming is far, far less efficient (depending on the methods used) and with very primitive methods has a return barely greater than the investment of (human-provided) energy.
I don’t think you understood Phil’s comment. Thermodynamics does not dictate it takes more energy to produce some fuel than is contained in the fuel. Producing fuel is energetically inexpensive—if you have sufficiently concentrated precursors.
Yes, it does. Second law. You need all of the energy that the fuel will store, plus more to run the process that creates it.
Either you’re producing lower-energy fuel from higher-energy fuel, or you’re taking base constituents and available energy and synthesizing a higher-energy configuration.
It’s conservation of energy, not second law.
High-energy fuel is simply fuel that allows to restore more energy per unit of weight. Take more low-energy fuel and convert it into less high-energy fuel.
I still don’t think you understood Phil’s comment.
Presumably, you won’t be able to make sense of this either:
“In addition, production of ethanol is energy efficient, in that it yields nearly 25 percent more energy than is used in growing the corn, harvesting it, and distilling it into ethanol.”
http://www.ethanol-gec.org/corn_eth.htm
The problem appears to be that you are incorrectly imagining that the other people in the discussion are trying to account for factors such as sunlight.
Termodynamics has nothing to do with this. There is the sun outside this open system.
Thermodynamics has everything to do with the statement in question.
Exactly.
What I suspect Phil was trying to express was that ethanol manufacturing requires us to expend more of the desired level of fuel than we derive from the process—which is a good point—and that this rules out ethanol as a viable energy source—which is NOT a good point.
We invest more energy in building and charging batteries than we can get out of them. That isn’t an argument against batteries, because they’re a means of transmitting energy in usable form. And extremely useful ones. Carrying around a steam-powered generator to operate a flashlight isn’t an option.
Corn ethanol is a terrible net-producer of industrial-grade fuel because its production consumes more of that level of fuel than it produces, NOT because it “takes more energy to make it than it provides”, which is trivially, obviously true of any fuel.