<DrumBeat: October 11, 2006 The Oil Drum DrumBeat: October 12, 2006>

167 comments on Report: Brazilian Ethanol is Sustainable

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pstarr on October 11, 2006 - 12:44pm Permalink | Subthread | Parent | Comments top
8 workers/hectare is not 'handwork' It is industrial human labor and is not calculated in these rosy eroei calculations. A hard day is 3000 calories. The food, transport, room and board, and medical costs for these labors are 10X that amount.

No one calculate 30,000*8 laborers/hectare in the energy formulas

Sugar cane is not energy positive and studies that suggest it are not robuts.

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Nate Hagens on October 11, 2006 - 12:55pm Permalink | Subthread | Parent | Comments top
This is one of the areas of net energy analysis that needs to be expanded upon. We live in an interconnected world where it is increasingly difficult to parse everything into one common denominator. Society has attempted to do this using a global monetary system, but its proving difficult to put proper dollar values on air, water, ecosystem services, etc. Would you rather a new $50,000 mercedes or clean air to breathe for the next 10 minutes?

Net energy analysis in my opinion, will be critical in the coming transition from fossil fuels to renewables (irrespective if there ends up being 10 billion people or 1 billion). But to parse everything into energy terms is not paying attention to systems analysis. We need to consider the impact on land, on labor, on soil, etc as well as energy. We still dont have a mechanism to synthesize and compare all these things. EROI is one measure. Dollars are another. We need something better.

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BartB on October 12, 2006 - 2:59am Permalink | Subthread | Parent | Comments top
Nate,

Look at the scientific work of H.T. Odum on emergy. Emergy provides a accounting system for the work of nature and humans.

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Nate Hagens on October 12, 2006 - 11:16pm Permalink | Subthread | Parent | Comments top
I should have written 'we still dont have a system other than Odums eMergy' for assimilating all inputs other than energy
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Robert Rapier on October 13, 2006 - 12:11am Permalink | Subthread | Parent | Comments top
In fact, the criticism of the paper with the lower EROEI, in addition to having the diesel input wrong, was that it represented emergy, and not energy.
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toilforoil on October 11, 2006 - 2:18pm Permalink | Subthread | Parent | Comments top
"8 workers/hectare is not 'handwork' It is industrial human labor and is not calculated in these rosy eroei calculations. A hard day is 3000 calories. The food, transport, room and board, and medical costs for these labors are 10X that amount."

Sure.  And to get a fair comparison let's calculate the energy burned by the advertising agency staff for the heavy machinery for the oil and gas service industry trade show.  And for that matter, their babysitters, so that the ad agents can work overtime.  Yeah, and the energy burned by the mother's of the pimply faced servers at the fast food joints, who send up sandwiches to the security staff so that the ad agents babysitters can babysit without risk of kidnappers.

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pstarr on October 11, 2006 - 7:40pm Permalink | Subthread | Parent | Comments top
this is unreasonable because all these post production costs are exactly the same for ethanol and petroleum

no, the cost of those 8 field laborers is repeated year after year in the field while the crude essentially flows under its own power into the refinery. 240,000 calories are burned for the production of that hectare. I wonder what percent of the final fuel that represents?

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Pitt the Elder on October 11, 2006 - 9:19pm Permalink | Subthread | Parent | Comments top
240,000 calories are burned for the production of that hectare. I wonder what percent of the final fuel that represents?

Less than 1%.

240,000 calories = 8 gallons of gasoline (source).  Brazil is getting about 7,000 litres of ethanol per hectare (source), meaning that 240,000 calories is only about 0.8% of the energy content of the fuel.

i.e., totally, completely, and rather obviously inconsequential.  Think about it logically -- if the energy for food was more than the amount of energy in the fuel, how could this be economically viable, which it clearly is?  Drop your preconceptions and think about it for a moment.

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Jack on October 11, 2006 - 11:15pm Permalink | Subthread | Parent | Comments top
Drop your preconceptions and think about it for a moment.

If pstarr dropped his/her preconceptions what would he/she have left?

There are some real serious concerns about biofuels, primarily the environmental impacts of biodiesel on rainforests in South America and SE Asia. It is esential to address these and to recognize that they will and should limit the use of biofuels.

However those sticking their fingers in their ears and chanting EROEI, EROEI, EROEI aren't helping much.

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zaster on October 13, 2006 - 6:31am Permalink | Subthread | Parent | Comments top
240,000 calories = 8 gallons of gasoline (source).  Brazil is getting about 7,000 litres of ethanol per hectare (source), meaning that 240,000 calories is only about 0.8% of the energy content of the fuel.

i thought 8 gallons for the workers is per day while 7000 liters is per year?

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Jack on October 13, 2006 - 6:42am Permalink | Subthread | Parent | Comments top
If the workers were consuming 240,000 calories per day they would explode.
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Oil CEO on October 14, 2006 - 2:54pm Permalink | Subthread | Parent | Comments top
Apparently that's not relevant. What can I tell you? I never believe any numbers that don't match mine. But I've got none in this case and you've got nobody to contradict you. So I've got to go with my original statement. Apparently nobody gives a shit that people will blow up. Maybe I phrased that wrong. Maybe I should've have said the proletariat. Careful. There are hardcore communists in our midst. I'll draw the fire. But you may have to carry it.
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Syntec on October 12, 2006 - 12:11pm Permalink | Subthread | Parent | Comments top
Brazilian sugarcane production is shown to be energy positive study after study after study and yet some of us just don't seem to get it do they pstarr?
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167 comments on Report: Brazilian Ethanol is Sustainable

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