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By Robert Rapier on Jan 23, 2008 with no responses

Perpetual Confusion over Energy Balances

People continue to be confused about the energy balance of gasoline versus ethanol. The ethanol lobby, in my opinion, deliberately spreads this sort of misinformation to persuade people that producing ethanol is a wise usage of our BTUs. I have tried to clear up the confusion on a number of occasions, most recently when Vinod Khosla once again claimed “corn ethanol has almost twice the energy balance compared to gasoline“:

The Handy-Dandy Khosla Refuter

But the issue lives on, as strong as ever. A couple of days ago, Stuart Staniford wrote the following essay at The Oil Drum:

The Fallacy of Reversibility

In the essay, Stuart takes on one of the major tenets of many peak oilers: That peak oil will mean a return to localized agriculture. Stuart argued that it would not. I warned him that he would take his lumps for arguing against a popular position (and he did) just as I did when I have argued against the peak oil conventional wisdom that Saudi oil production has peaked.

But in that thread, the energy balance issue once again came up. And here was one response:

I hate to jump in because I went round and round with RR on this a while back, but also because I think the costs of ethanol are being externalized, particularly water costs, and I don’t like seeing food go to fuel. But I agree with you. The slight-of-hand that Nate is using is that he ignores the oil feedstock when refining oil, but you have to include it when making ethanol (system boundaries have to be drawn that way I have been told), so you get this 8:1 number for oil refining and 1.3:1 for ethanol, and all the “awl bidness” folk say QED.

BUT… for grins, lets suppose all the oil you had in the world was 1800 barrels. When that is gone you are out, kaput, no more. Then you can ask what will I do with this. Well you could pump and refine it into diesel using 200 barrels and ending up with 1600 barrels of diesel. 8:1 OK well and good.

Or you could take take that 1800 barrels less pumping cost (let’s say negligent for argument sake) and produce 2340 (1.3 x 1800) barrels of oil equivalent in ethanol.

Now for further grins, let’s assume that the usage is 540 barrels per year. Having pumped and refined diesel you will be out, kaput, done, in about 3 years, but when making ethanol, each year, when a new crop is planted you will still have 1800 barrels, and now you have a sustainable energy supply. Woohoo!

Now these “ethanol haters” will rightfully claim that we can’t replace our current FF useage with ethanol, ignoring the fact that they have been spouting nonsense about efficiency of oil versus ethanol. But with the right ethanol production from say celulosic sources, we could ease the burden on the oil consumption extending our nonrenewable resources, particularly so, if we also agressively conserve oil and recycle some of the water used in ethanol production. Here you will be told that the “devil is in the details”, because there is no viable celulosic process. But hold on now, GE just invested in just such a process, with the idea that they could build many plants and replace about 15% of the FF use in the future. The first plant goes on line this year if everything goes perfectly :) . Anyway, you’ll go blue in the face arguing with some of these folk as they set system boundaries to ensure that oil refineries appear efficient compared to ethanol, wihtout a thought for extending the present supply of FF.

Naturally, I responded to it:

You were wrong the last time, and you are wrong now. You are not making an efficiency argument. The argument “what if there was no more oil…” is not an efficiency argument. You are correct, if there was no more oil, then it’s a different argument. But then if there was no more oil, the whole charade would come tumbling down anyway.

The oil feedstock is ancient, captured solar energy. You do not include that when doing the energy balance, any more so than you include the corn BTUS – recently captured solar energy – when doing the ethanol EROEI. (What you do include is the portion of the BTUs that were due to the fertilizer). This is what you, and so many others who are confused on this issue do not see.

What is counted in the ethanol EROEI is the energy it took to grow the corn, turn it into ethanol, and purify it. What is counted in the gasoline EROEI is the energy to extract the oil and to refine the oil. The portion of the feedstock BTUs that amount to captured solar energy are not counted in either case. Ethanol proponents wish to count them in the case of oil but not ethanol, which is why they say nonsensical things like “It is more energy efficient to produce ethanol than to produce gasoline.”


I think it’s that captured solar energy portion that they don’t seem to get. It’s really not that difficult of an argument, in my opinion. And the argument often shifts, as it did above, to “suppose we had no more oil….” But that is not an efficiency argument. It is a valid argument, just not an efficiency one. But as we debate that argument I think we need to understand, as a society, what it means to transition from an energy return of better than 5/1 in the case of petroleum to something that is around 1, plus some animal feed that gets counted as a fraction of a BTU.