If you believe for a second that an EROEI of 1.67 is a good thing, then I can see why you lost about ethanol!!
Dear Mr. Rapier,
Thank you for your email. Apparently, you know that I was pretty upset with your original way of characterizing my work and my character. Working in the scientific area, I am very careful in using language for characterizing others’ work and personalities. I expect that others would do the same to me. Simply put, just like you with great intention of pursuing facts, I have been doing the same myself in my professional career. To characterize me of knowingly misleading the public in biofuel debates is simply wrong. I am gratified that you realized that I treat such mischaracterization seriously.
Getting into the technical discussion that you originated, we all agree that energy efficiency is defined as energy output divided by all energy input (including energy in the feedstock itself). That is, we will take into account Btus in gasoline, ethanol, and all process fuels consumed for producing gasoline and diesel in our accounting for energy input. The amount of process fuels is about 0.25 for each Btu of gasoline produced from 1 Btu in crude oil. Meanwhile, for each Btu of ethanol produced from corn, which is from solar energy during corn growth, about 0.75 Btu of energy are consumed. This amount includes fossil energy (namely, petroleum, natural gas, and coal) in fertilizer production, corn farming, ethanol production, among many other activities. With this definition of energy efficiency (as it is accepted by all of us), ethanol has worse energy conversion efficiency (1/(1+0.75)=58%) than gasoline (1/(1+0.25)=80%). Note that in both calculations, the one Btu in ethanol and gasoline is taken into account as energy input, since they are energy eventually from solar energy in the ethanol case and petroleum energy in the gasoline case. Now you can see that such efficiency calculations take all Btus into account (renewable or non-renewable). That is, the efficiency calculations treat all Btus the same. In reality, all Btus are not created equal. I will get back to this point later.
What has been debated about bioethanol is ENERGY BALANCE, not energy efficiency. Energy balance is defined as the energy in the fuel minus FOSSIL energy input to produce the fuel. Why only fossil energy? That is because to many, fossil is non-renewable. As long as we use it, it will be gone, and it takes millions of years to get it back, if ever. But anyway, we can debate whether energy balance is a right matrix to use for energy policy evaluations. I, together with Mr. Khosla and many others, maintain that energy balance is NOT a good matrix for energy policy debates. But energy balance for ethanol has been debated for more than 20 years and it seems that there is still no way near an ending of this debate.
Now if one thinks a little more about energy balance calculations, one realizes that the calculation excludes renewable energy in energy input accounting, which a small step to the right direction to differentiate different types of Btus. But it adds all three fossil energy types (petroleum, natural gas, and coal) together. The calculation treats all fossil Btus equal, which is still not accurate for energy policy debates. For example, the US has several hundred years of coal supply, while it may have only 10-20 years of oil supply. I do not think that both of us would disagree that the US should value petroleum Btus more than coal Btus. But energy balance calculations do not provide us results to differentiate these two different types of Btus. Mr. Khosla alluded you about the flaws of energy balance calculations in his email.
With the energy balance definition, fossil energy input for one Btu of ethanol produced is still 0.75 Btu. However, fossil energy input for one Btu of gasoline is 0.25 Btu of fossil process fuels consumed PLUS the one Btu in crude oil that is converted into gasoline. Now you may see that the difference between a fossil energy-based fuel (gasoline) and a renewable fuel (ethanol) lies in the Btu embedded in the fuel itself. If it was not this difference between fossil fuels and renewable fuels, we all would conclude without any calculations that renewable fuels could not compete with fossil fuels with respect to energy (that is, all Btus are taken in account with differentiation).
I have made arguments against energy balance comparisons among energy products because they can be less meaningful or misleading. In the past ten years, I have tried to steer the debate on energy products to meaningful issues such as petroleum reductions, fossil energy reductions, greenhouse gas emission reductions, and reductions in criteria pollutant emissions. My point has been that even though corn ethanol has a positive fossil energy balance value, such debates are not that meaningful. I elaborate this step by step in some of my conference presentations. If you read my publications, you would see the consistency in what I think is more important to debate.
I hope this clarifies my positions. By the way, you indicated that you have read some of my publications, I encourage you to take a look at of the report that I coauthored in May 2005 in which I discussed problems of energy accounting and presented well-to-pump energy efficiencies for many transportation fuels including gasoline and corn ethanol. The report is posted at
http://greet.anl.gov.Regards,
Michael Wang