US DA study on Ethanol Energy Balance: 1.67 : 1 energy balance

[JohnWxy]

The recent erroneous report prepared by Cornell University's David Pimentel and the University of California at Berkeley's Tad Patzek continue to perpetuate the myth that the production of biofuels such as ethanol and biodiesel has no energy benefit. Mr. Patzek is the director of UC's Oil Consortium, which receives funding from the oil industry including Chevron and Phillips Petroleum. Previous partners have included BP, Mobil USA, Statoil and Unocal.








THE 2001 NET ENERGY BALANCE OF CORN-ETHANOL
Hosein Shapouri*, U.S. Department of Agriculture (USDA), Office of the Chief
Economist (OCE), 300 7th Street SW., Room 361, Washington, D.C. 20024, telephone:
202 401 0531, James Duffield, USDA/OCE, Andrew McAloon, USDA/Agricultural
Research Service (ARS), Eastern Regional Research Center, 600 East Mermaid Lane,
Wyndmoor, PA. 19038, and Michael Wang, U.S. Department of Energy, Center for
Transportation Research, Energy Systems Division, Argonne National Laboratory, 9700
South Cass Avenue, Argonne, IL. 60439

ABSTRACT
This report estimates the net energy balance of corn ethanol utilizing the latest survey of
U.S. corn producers and the 2001 U.S. survey of ethanol plants. The major objectives of
this report are to improve the quality of data and methodology used in the estimation.
This paper also uses ASPEN Plus, a process simulation program, to allocate total energy
used to produce ethanol and byproducts. The results indicate that corn ethanol has a
positive energy balance, even before subtracting the energy allocated to by products.
The net energy balance of corn ethanol adjusted for byproduct credits is 27,729 and
33,196 Btu per gallon for wet- and dry- milling, respectively, and 30,528 Btu per gallon
for the industry. The study results suggest that corn ethanol is energy efficient, as
indicated by an energy output/input ratio of 1.67.


INTRODUCTION

USDA’s net energy balance of corn-ethanol was published in 1995, 2002, and 2003 in the
American Society of Agricultural Engineers (ASAE), Shapouri et al. Since 1970, many
authors have studied the net energy balance of corn-ethanol.

The major objective of this
report is to improve the general estimation procedure. These improvements include: (1)
regular updating of the estimates based on the latest data on corn production and corn
yield, (2) improving the quality of estimates for energy used in manufacturing and
marketing nitrogen fertilizer, (3) improving the quality of estimates for energy used to
produce seed-corn, and (4) enhancing the methodologies used in allocating the energy
used in ethanol production (to byproducts and ethanol).

In contrast to three previous studies, all energy inputs are reported in low-heat value (LHV).
During the past 2 years, David Pimentel, 2003, Tad Patzek, 2003, and Andrew Ferguson,
2003, criticized USDA’s studies of the net energy balance of corn ethanol. It is argued
that USDA underestimates energy used in the production of nitrogen fertilizer and the
energy used to produce seed-corn, over estimating the energy allocated to produce cornethanol
byproducts. They also argued that USDA excludes energy used in corn irrigation
and secondary energy inputs used in the production of corn, such as farm machinery and
equipment and cement, steel, and stainless steel, used in the construction of ethanol
plants.

THE NET ENERGY BALANCE

This paper, unlike the Dr. Pimentel report, 2003, is based on straightforward
methodology and highly regarded quality data from the 2001 Agricultural Resource
Management Survey (ARMS), Economic Research Service, ERS/USDA, 2001
Agricultural Chemical Usage, and 2001 Crop Production, National Agricultural Statistics
Service, NASS/USDA, and the 2001 survey of ethanol plants.

Direct energy used on farms, such as gasoline, diesel, LP gas (LPG), natural gas, and
electricity, for the production of corn, including irrigation by States from 2001 ARMS,
are available on the ERS Web site. The number of seed-corn planted per acre in 2001,
custom work expenditure, tons of lime used per acre, and purchased water were also from
the 2001 ARMS. Quantities of fertilizers and pesticides used per acre of corn in 2001
were published by NASS. Although corn is produced in every State, we focused our
analysis on the major corn-producing States: Illinois, Indiana, Iowa, Minnesota,
Nebraska, Ohio, Michigan, South Dakota, and Wisconsin. In 2001, these nine States
accounted for 79 and 92 percent of U.S. corn and ethanol production, respectively.

Corn yield is a critical part of the net energy balance estimation. Although the corn yield
has been rising over time, the annual variation is very volatile. Therefore, we used a 3-
year average yield instead of the average yield for the survey year. The 2000-02
weighted average corn yield in each State was used to convert farm inputs from a per acre
basis to a per bushel basis (2001 Crop Production, NASS). Table 1 shows the nine-State
energy input data per acre of corn and nine-State weighted average for the 2001 ARMS.


RESULTS
All energy inputs used in the production of ethanol is adjusted for energy efficiencies
developed by GREET model. The estimated energy efficiencies are for gasoline (80.5
percent), diesel fuel (84.3 percent), LPG (98.9 percent), natural gas (94 percent), coal (98
percent), electricity (39.6 percent), and transmission loss (1.087 percent). After adjusting
the energy inputs by these energy efficiencies, the total estimated energy required to
produce a bushel of corn in 2001 was 49,753 Btu.

Table 3 summarizes the input energy requirements, by phase of ethanol production on a
Btu per gallon basis (LHV) for 2001, without byproduct credits. Energy estimates are
provided for both dry- and wet- milling as well as industry average. In each case, corn
ethanol has a positive energy balance, even before subtracting the energy allocated to
byproducts.


The net energy balance estimate for corn ethanol produced from wet- milling is 27,729
Btu per gallon, the net energy balance estimate for dry- milling is 33,196 Btu per gallon,
and the weighted average is 30,528 Btu per gallon. The energy ratio is 1.57 and 1.77 for
wet- and dry- milling, respectively, and the weighted average energy ratio is 1.67.

[Massacure]

1. There are plenty of other better crops though.

[JohnWxy]

8. Yes, that's true, but we already have considerable capability with corn.

Yes, I agree.

But it's better than doing nothing and its much better than debating the issue ad infinitum and not getting anything moving. We already have ethanol production capabilities and considerable knowledge re corn ethanol production, it's just a matter of expanding that. This would be a huge improvement over the current situation. Development of ethanol production from cellulose (plant waste and switchgrass for example) is starting, and should continue - as rapidly as possible. But we shouldn't wait around and not take advantage of what we already have available. Bringing cellulosic ethanol production up to where we are with corn right now will take a few years(by a 'few' I mean , probably something like 10 years). These things don't happen over night). Even when we start producing ethanol from cellulosic sources we still will want to take advantage of corn ethanol. It just wouldn't make sense to walk away from an efficient(The USDA study shows Corn ethanol with an energy return of 1.67 : 1 ), cleaner (17%-24% GHG reduction over gas) and cheaper fuel than gasoline - to be used to extend the gasoline supply.

By the way, this years corn crop was so huge that grain elevator operators ran out of space for it all and started dumping it on the ground!

ONe of the things we need to be concerned about is our vulnerability to interuption of the supply of oil. This is a very real possibility (especially with terrorists running around - think: Saudia Arabia). What happened with Katrina is a little sample of what could happen. Now, we could start replacing some of the gasoline we are currently using by going to Ethanol 15 , which all gasoline engines can run on. That would extend our gasoline supply by 15%. This would insulate us from an oil shock of 15%. That's a very valuable cushion, when you consider what a disruption in oil supply of that magnitude would do to our economy. That is, it might avert an economic disaster.

But certainly, we should also be pushing ahead with development of other ethanol sources. We currently produce millions of tons of plant waste and forest product waste each year. Switch grass which farmers use now for erosion control can also be used for cellulosic ethanol and it can be grown on land otherwise unsuitable for cultivation. This can, and will, be used as a source of ethanol. Cellulosic ethanol will reduce Greenhouse Gases (GHG) by 85%. That's right, 85%!

[NNadir]

2. I'm not sure if ethanol works, but your link doesn't.

[Massacure]

3. Ethanol applies a force to move something over a distance.

Of course Ethanol works, silly.

:P

[JohnWxy]

6. Sorry about that - try these

The report on this study is NOT easy to find. I hope this works.



Wang's study

[rfkrfk]

4. the real issue should be, should ethanol be subsidized,

as vehicle fuel?

I just don't believe the EROEI stuff, too many variables

how productive is the land?
value of inputs, fertilizer, tractor fuel, by-products, etc
is low value steam available for distilling?
is off-peak electricity available, what price, how sourced.

In the Cornell 'study', the worst case is assumed for everything.

I don't have the answers, but don't believe
everything you read.

[Dogmudgeon]

5. This study found an EROEI of 1.67

It's only one study, but it's promising.

The overall question, though, is: "Are biofuels a desirable replacement for petroleum?" I believe that the answer is a qualified yes, but the qualifications need to be answered with big-picture engineering and social change.

For instance, biofuels are also "carbon sources" (cf "carbon sinks"). There are some major contraints on biofuel production, too. And in a world with an increasing population, we will need solutions that are qualitiative, not just quantitative. Right now, nuclear energy looks like a best-bet, but whether you're pro- or anti-nuclear, you'll probably agree that we ought not stop looking for other, perhaps better energy sources.

But personal, residential, and industrial energy use all have to be re-engineered. I also strongly support an industrial space program to move as much heavy industry off-planet as possible. This will, of course, take some time, but it provides a tremendous incentive for long-term investment, which would keep the terrestrial economy from collapse in a short-term severe energy "gap". If financing can be deliberately distributed among the population, it will also provide a large pool of dividend money that can reduce the need for social programs, like a modernized ESOP/Kelso plan.

--p!

[JohnWxy]

7. Re your questions and Dr.M. Wang's competence to analyse these issues-

You raise a number of valid questions. As I have said before I am not going to repeat in detail Wang's report or others studies. Interested parties can find this information out from the source by looking for it on the web. My point here is not to cover teh subject exhaustively as this can be done by, and should be obtained from, the experts. My purpose is to alert interested people to these insights/conclusions which, in my opinion were reached by people who know what they are talking about. Naturally, any critically thinking person would want to investigate this issue for themselves before reaching any conclusions.


Nevertheless, I will address some of the questions you raised, as best I can, here.

"how productive is the land?"

Wang assumed current productivity (1990's) of American farmers would continue. Of course,
realistically, it will most likely increase, but he didnt't assume that in the study.

"value of inputs, fertilizer, tractor fuel, by-products, etc" -
This was of course, considered in Wang's and all valid studies. It is mentioned in the report of
his study.

"is low value steam available for distilling?"

I do not know what the answer to this is. This information is available from Wang at the
Argonne National Laboratory.

"is off-peak electricity available, what price, how sourced."

Advise you check details of the Wang study and the USDA study. I'm sure you can email the
office of Dr. Wang and that of Dr. Shapouri to get a detailed answer.


The Cornell 'study' was done by Dr. Pimentel, who is by the way, an entymologist. I think that
is the study of bugs. His studies are widely regarded by real scientists in this field as
fallacious and of no scientific value.


REgarding Dr. Michael Wang, and his competence to perform such studies of alternative energy sources and production of same, you might find the following informative:

Dr. Michael Wang received his Ph.D. degree in environmental science from University of California at Davis. He is an environmental analyst in the Center for Transportation Research at Argonne National Laboratory specializing in the area of energy and environmental impacts of motor vehicle technologies and transportation fuels. At Argonne, he is the manager of the Systems Assessment Section of the Center for Transportation Research.

Dr. Wang has been working in the area of evaluating emission and energy impacts of new transportation fuels and advanced vehicle technologies for over 17 years. He has developed the GREET model at Argonne National Laboratory. The model has been used by governmental agencies, industries, universities, and research institutions to evaluate life-cycle energy and emission effects of advanced vehicle technologies and new transportation fuels. At present, there are more than 1,900 GREET users in North America, Europe, and Asia.

Dr. Wang is the chairman of the International Subcommittee on Transportation Energy and Alternative Transportation Fuels of the Transportation Research Board. He is a director of the Board of the Energy Foundation. Dr. Wang is a member of the Energy Conservation Committee of the Transportation Research Board. He is a member of the Society of Automotive Engineers, and the Air and Waste Management Association. Dr. Wang has served on technical advisory committees for several major international studies on advanced vehicle technologies and transportation fuels conducted by or for governmental agencies, automotive companies, and energy companies in North America, Europe, and China. He has more than 120 publications in peer reviewed journals.


Now , should ethanol be subsidized? Yes, it should:

For far less than the billions of dollars in R&D required for hybrid vehicles and deep drilling under the Gulf of Mexico or in Alaska, you will get a very quick pay-out in terms of extending our precious supply of fossil fuel. Ethanol is a working technlogy right now. Enormoous expenditures in R&D to find out if it's practical are not needed. Additional investments to expand production capacity is. The additional fuel supply for cars would be realized relatively quickly compared to further development of hybrid vehicles (which is still worth exploring, for the future) or drilling for new oil.

All car engines built to run on gasoline can use Ethanol 15. Making all gasolinie E15 would alone increase our fuel supply by 15%. That would certainly remove the oil companies' rationale for jumping up prices because of 'limited supply' problems. ( NOte that the integrated oil companies have been buying up independent refiners for years just to close them down - to control and limit supply to control prices.)

Greenhouse gases reduction. Ethanol fuel reduces GHG by 17% - 24% for Corn ethanol and 85% for cellulosic ethanol (plant waste , forest products waste, switchback grasses). Cullulosic Ethanol even as a 10% blend will reduce GHG by 85% over strait gasoline.

Concerns about mileage with Ethanol 85 (85% pure ethanol blend) dissolve when gasoline hits $2.50 a gallon as Ethanol 85 is selling for about $2.06 a gallon. Also, if U.S. car manufacturers would optimize FFV engines for the higher octane of Ethanol 85 (octane 105) you would get just as good, if not better, mileage with the E85! Saab is selling a 3,700 lb car that gets 23.5 mpg on E85.

Imported crude oil accounts for about 35% of our negative balance of payments. Expanding ethanol production is the quickest way to reduce out imports of foreign oil.


more on ethanol

[JohnWxy]

9. CORRECTION re GHG reduction

"Cullulosic Ethanol even as a 10% blend will reduce GHG by 85% over strait gasoline."

that statement is in error. cellulosic Ethanol 85 yields a 85% reduction of GHG. cellulosic Ethanol 10 (10% pure ethanol) would only get about 6% reduction in GHG.