The Oil Drum

Thank you for keeping this going while I was asleep here in Thailand.

It seems clear that the original comment tacked on to Prof Goose's call to promote the story was an uneducated hit piece that doesn't show any evidence that the author even read the study.

However, Sparaxis does have a point, although it doesn't directly contradict mine. Yes, sugar cane-based ethanol looks very different on EROEI and EROFEI metrics, largely because of the use of bagasse to provide heat and sell power externally (which provides an offset).

If there were a perfect regulatory environment and significant use of energy in transport, things could be quite different. In that case, demand for electricity for bagasse could compete directly with demand for ethanol as a transportation fuel. Then, maybe the energy is bagasse would not belong to the sugar cane alone, but would be already a part of the energy system. Then, it would not be included in the ethanol EROEI calculations.

I am not a huge advocate of liquid biofuels. Over time, it seems to be crop acreage will be a base resource that goes into fuel production, like it or not. In that case, I think electricity is a far better pathway. But we are not there yet.

It seems that for developing countries in tropical regions, sugar-cane based ethanol makes sense economically and environmentally in the meantime. I don't have any problem with diverting sugar from the food chain. I do not think tropical forests are being impacted much by ethanol (although they may be for soy and palm oil) and do think that sugar cane for fuel will be largely unirrigated.

Corn-based ethanol seems to be completely bankrupt and would not even be looked at without subsidies in the forms for cash, free water and externalization of environmental damage. I don't think all ethanol sources combined will ever provide much more than 5% of liquid fuels.

But in the right environment and until transportation moves to electricity as a fuel source, I do think some ethanol can make sense.