The number Austex came up with was 23% of the BTUs for a gallon of ethanol was from gas/diesel.

Unfortunatly he didn't save his work and only posted the results.

Last night after the fact I found this piece of analysis that I did not see the other day when I was trying to calculate the crude oil inputs. By far the most detailed and thorough piece of work that I've seen to this point. Many of the numbers are justified as well, which I did not see much of the other day. Check it out if you have time. It's few years old, but should still be fairly applicable to today's situation

http://www.ncga.com/ethanol/pdfs/energy_balance_report_final_R1.PDF

If you don't have time, in his conclusion (pg 55/56) it's stated that the makeup of btu's comes from 7.3% petroleum, 75.2% coal/natural gas, and 17.5% captured solar energy by the corn.

I'm thinking these percentages do not include transportation of feedstock and finished product which is why my conclusion came out with a higher percentage.

The link refers to the energy balance of corn ethanol. Until the recent foolish burst of subsidized ethanol production from the US, the single largest producer of ethanol was Brazil and it was done with 100% sugar cane.

Sources that I have frequently posted here cite energy balances of 8-10 from sugar cane-based ethanol rather than the 1.2-1.3 from corn.

So even if crude based inputs constitute 50% of the energy input into sugar cane based ethanol production, they woudn't be more than 5-6% of the BTUs in the final fuel.

So instead of double counting, in the case of sugar cane, it is more like + 5% counting. Biodiesel presumably comes somewhere in between.

I believe that the world could derive 5-10% of the BTU content in all liquid fuels from sugar cane without much damage to the environment (and ideally with improvement to health). This would be a significant offset to waning oil supplies and would have little actual oil content.

By the way, I think it makes sense to count and track both C & C figures as well as all (net) liquids, but for different purposes. C&C is the best measure of peak oil. All (net) liquids is the best measure for how mankind will cope with it.

'By the way, I think it makes sense to count and track both C & C figures as well as all (net) liquids, but for different purposes. C&C is the best measure of peak oil. All (net) liquids is the best measure for how mankind will cope with it.'

A succint and important point, well worth keeping in mind as the inevitable decline of crude production will lead to a number of different directions in how that reality is accepted, from starving those who can't pay for a tank of gas (based on the data that the corn required for one tank of vehicle fuel is equivalent to what one human requires for a year) to utopian visions of peaceful powerdown, or in the German expression, 'Frieden. Freude. Eierkuchen.' (a slightly nonsensical expression meaning 'Peace, Joy, and Pancakes' - or if you are from Berlin, then 'Peace Joy, and jelly filled Doughnuts' - sort of like 'happily ever after,' it tends to refer to something very desirable, but which will never really occur.)

I believe that the world could derive 5-10% of the BTU content in all liquid fuels from sugar cane without much damage to the environment (and ideally with improvement to health). This would be a significant offset to waning oil supplies and would have little actual oil content.

Explain the basis of this belief, please. How much topsoil is lost annually to achieve this process? How much silting occurs annually to achieve this process? How much water table damage occurs annually to achieve this process? What level of salinization occurs annually? Under what population scenarios? Under what consumption scenarios?

Please provide the data for your conclusion, as I do not believe the statement you made.

Thank you.