MSU Professor says 'Net Energy' is a Misleading Term

[jpak]

http://www.renewableaccess.com/rea/news/story?id=49654

As new fuel options develop, the world needs a means of assessing which are most effective at replacing petroleum. So far, many scientists have used a measure called "net energy." However, Professor Bruce Dale from Michigan State University (MSU) claims that "net energy analysis is simple and has great intuitive appeal, but it is also dead wrong and dangerously misleading -- net energy must be eliminated from our discourse."

"As we embark on this brave new world of alternative fuels we need to develop metrics that provide proper and useful comparisons, rather than simply using analysis that are simple and intuitively appealing, but give either no meaningful information, or worse still, information that misleads us and misdirects our efforts to develop petroleum replacements."-- Professor Bruce Dale, Michigan State University

Instead of using the term net energy, Dale recommends comparing fuels by assessing how much petroleum fuel each can replace, or by calculating how much CO2 each produces per km driven.

A fuel's net energy is calculated by attempting to assess how much energy a new fuel supplies, and then subtracting the energy supplied by fossil fuels needed to create the new fuel. The calculation is often carried out in a way that leaves grain ethanol with a net energy of -29%, giving the impression that it uses more fossil fuels to produce it than the new fuel supplies. Dale claims that this figure is then used by opponents of biofuels to pour scorn on the new products.

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[phantom power]

1. Indeed. I often wish that I could eliminate certain concepts from discourse...

when they prove that I'm wrong. In fact, I have in the past sent several memos to my coworkers and CEO, requesting that we refrain from discussing things like Shannon's Information theory, and NP-completeness, because they undermine so many of my otherwise-brilliant algorithms.

I think that Dale is actually being too timid. His case would be made even easier if he can eliminate any discussion of the laws of thermodynamics.

:eyes:

[OKIsItJustMe]

2. A simple argument

When faced with this question, I say, "Okay... if ethanol is such a good power source, let's see all of the tractors on the farms, all of the equipment at the plants that produce it, all of the tanker trucks that deliver it run on the ethanol they're producing. Whatever is left over is the real product." (I realize this discounts the petroleum used to make fertilizer.)

[razzleberry]

3. why draw the line there?

I suggest,

coal-mines + farms + distilleries

as the system

[NickB79]

4. Coal-fired ethanol plants

I am dumbfounded by the stupidity of that suggestion.

[razzleberry]

6. just a calculation .n/t.

[NNadir]

5. Well, you must admit that the laws of thermodynamics are annoying.

I see no reason we apply them when solar energy is free.

[JohnWxy]

15. how about a little emperical research in place of rhetorical double talk with no conclusions.

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x108703#109656

[Dogmudgeon]

7. "Net energy must be eliminated from our discourse."

Ooh, that's gotta hurt.

I would try psyllium husks for a week, then Miralax if that doesn't work.

And water. Plenty of water.

--p!
Poop and the whole world poops with you,
Piss and you piss alone

[amandabeech]

8. Considering petroleum replacement potential and CO2 emissions

in evaluating energy sources or carriers is not a bad idea, IMHO.

However, I think that they should be used to supplement net energy calculations, not supplant them.

[JohnWxy]

9. Dale's net energy not the same as net energy balance

Most people don't understand when Dale used Net Energy this is defined differently than the popular NEt ENergy Balance often used with regard to ethanol:



http://www.ncga.com/ethanol/pdfs/Allocation_Procedures_Fuel_Ethanol-Final.pdf

Allocation Procedure in Ethanol Production System from Corn Grain
I. System Expansion
Seungdo Kim and Bruce E. Dale*
Department of Chemical Engineering & Materials Science, Room 2527, Engineering Building, Michigan State University

~~

The net energy is cumulative energy, defined as energy consumed
in the fuel life cycle including the heat content of fuel
so that the energy quality is implicitly taken into account.
For instance, one MJ of electricity might be different from
one MJ from coal or another fossil fuel in terms of the energy
used because electricity requires more energy to generate
than it delivers at the end use. For example, the net energy
for electricity in the United States is 2.1 MJnet/MJ of
electricity <10>. This value indicates that 2.1 MJ of energy is
required to generate one MJ of electricity. Therefore, the
net energy is cradle-to-use energy, which is typically shown
in life cycle inventories.

~~
~~


The net energy associated with ethanol in the system expansion
approach is 0.56 MJnet/MJ of ethanol in the base
scenario, including ethanol transportation to consumers.
Therefore, the available energy from ethanol is much higher
than the input energy for producing ethanol. In other words,
using ethanol as a liquid transportation fuel would significantly
reduce domestic use of petroleum even in the worstcase
scenario.

~~--------------------------------------------------------------------------------------------------------------------------------


CONVERTING DAle's NEt Energy to the popular NEt ENergy ratio yields a Net ENergy RAtio for electricity (for the most part from coal and natural gas) of: 1/2.1 = 0.476190476

for Ethanol from corn: 1/.56 = 1.785714286

[Ready4Change]

10. Hence why ethanol is the #1 most promoted alternative fuel right now.

Ethanol is one of the worst alternative fuels. Corn based ethanol in particular stacks up poorly. It is no mistake that is all you hear about, if you only listen to news in a shallow manner. If corn ethanol is all you know, then you can be easily convinced alternatives have no future.

[razzleberry]

11. ethanol cuts the middle east, out of the deal. .n/t.

[Ready4Change]

12. Nice soundbite.

Middle East loves ya for it, too. Don't believe me? Look behind all the Ethanol propoganda and see what corporations are funding it.

[razzleberry]

13. who would those corporations be?

for every 1.3 gallons of ethanol brewed,
(the energy equivalent of a gallon of gasoline)

0.9 gallons of gasoline do not need to be
made from middle eastern oil.

[JohnWxy]

14. NO INUENDO HERE, IF YOU HAVE INFO STATE IT. Bill Gates and Craig Branson have invested heavily in

Ethanol. Gates is has a healthy stake in Pacific Ethanol(a publicly traded firm). Vinod Khosla is another investor in ethanol.

http://www.iht.com/articles/2006/03/26/business/biofuel.php

Khosla: "Ethanol is cheaper to produce, unsubsidized, than gasoline today," he said. "As these technologies ramp up, they will be cheaper, unsubsidized, than gasoline even if petroleum drops to $35 a barrel."

the newer ethanol planats are far more efficient than the 20 year old plants critics like to restrict their data to.