Verdict on crop-based ethanol

There is a lot of controversy surrounding ethanol these days, and it will be interesting to see how all of this plays out. Two scientists from our Sugarcane Research Unit just returned from Brazil. They were obviously impressed by what they saw and were told while they were there. Sugarcane continues to be the model crop for ethanol production, with its impressive energy output/input ratio. The Brazilians claim a ratio of 8:1, which is far superior to the less than 2:1 ratio for corn in the midwest. Apparently the Brazilians are continuing to increase their ethanol production capacity from sugarcane, building new ethanol plants and increasing acreage. The Brazilians are quick to point out that these increases are in non-Amazon regions of Brazil. So what we see happening in Brazil could be thought of as THE best case scenerio for ethanol production from a crop.

Chief among ethanol detractors are David Pimentel and Tad Patzek. One question I am sure has been frequently posed to them whenever they have argued against ethanol production from a crop, is this. "What about Brazil? You say it can't be done, yet Brazil is successfully doing it on a grand scale!" Pimentel and Patzek have taken the 8:1 output/input claim head on, presumably with the expectation that if they can debunk the 8:1 output/input claim, they can pretty much take the wind out of the the sails of any argument for biofuels. They recently published a paper basically aimed at raising doubts about the Brazilian sugarcane output/input ratio. Based on their own calculations, they reported the output/input ratio for sugarcane-based ethanol industry in Brazil to be no better than 1.38:1, claiming that important energy inputs were not accounted for, to get the 8:1 ratio. Most of the unaccounted for energy costs that Pimentel and Patzek allude to are associated with the factory component, rather than the field component. Using their numbers, it wouldn't matter what the yields are in the field; you couldn't improve much on their ratio even if the cane and sugar yields were triple or quadruple what they are today. Personally, I think their numbers in the factory component need a closer inspection. From the massive amount of fibrous residue (bagasse) produced when sugar is extracted from sugarcane, mills around the world today provide all of their own power and feed excess power into the electric grid of the surrounding community, and in some cases, a lot of excess power into the electric grid. There are huge differences in boiler efficiencies. It makes a huge difference if the factory energy input numbers were meant for production of crystallized sugar rather than production of ethanol. So I am skeptical of the Pimentel and Patzek numbers, especially knowing that they have an agenda to begin with. I don't believe they adequately account for the energy output potential of baggase in their calculations.

The 8:1 ratio may be inflated, but 1.38:1 when factories are net exporters of energy before the energy from ethanol is even factored in...you've got to be kidding!

We had a field day on Friday. I was asked to discuss some of the energy crop activity we are involved in. We highlighted sugarcane, energy cane (behind me in the photo), sugarbeets, sweet sorghum, and tropical maize (non-flowering tropical maize in my right hand; a so-called sugarcorn hybrid from Illinois in my left hand). The corn I was holding for demonstration purposes was planted only 60 days ago (April 8). Needless to say, the topic stimulated a lot of interest and questions. When I passed the tropical maize plant around, people couldn't believe how heavy it was. It will be interesting to see how tall our tropical maize gets before it finally decides to flower. Right now, it is about 8 feet tall. Believe it or not, it was only 18 inches tall 30 days ago.