Pimental is a life long skeptic and opponent of corn ethanol. I actually agree with Pimental’s opposition to corn ethanol and corn ethanol subsidies, as a biofuel source corn is one of the worst plants out there. It is soundly trounced by sugarcane, switchgrass, and I think even soybean is better.
Over the past thirty years most people have said Pimental is a crackpot clinging to 30+ year old data to denounce corn ethanol. I don’t go that far, but I do agree with what MIT researchers say:
However, I tend to think the studies that put corn in the range of 1.2-1.4 energy ratio is probably more valid. But yeah, corn has the lowest ratio, so variations in how you calculate input/output can erase its positive energy ration–however the majority of reports published in the past 10-15 years seem to side with corn ethanol being a positive energy ratio.
Pimental basically asserts everything remotely connected to corn production be counted as part of its output, including the energy used at factories that produce farm equipment. That might be the right way to do it, but when people compare it to the crude oil–>refinery process are we factoring in every single possible input in that process? Including the shipyards that build all the tankers and the fuel used by all the tankers, all the factories that create the tools used to build the refineries, pipelines etc etc etc.
We’re getting into stuff I don’t even know about tangentially (I know we have some energy industry people on the boards who would probably know more), but I have to wonder, even if we count things the way Pimental does is that really a problem? I could imagine a scenario in which even if something has a negative energy ratio it could make sense to use it at least for some time. In the original GQ thread that created this discussion, I would say if you had a situation in which you didn’t have crude oil anymore, but you still needed a type of liquid hydrocarbon fuel for special applications (plastics etc) it might still make sense to make it at a “loss”–because the input energy doesn’t have to be ethanol, it could be natural gas, geothermal, electric from a nuclear plant etc.
Or rather, imagine we have a chemical plant to produces a specialty chemical used in medicine that’s very important, the production of the medicine is a net energy loser, but it might still be worth running the chemical plant. So in a hypothetical in which we had no more crude oil, it might still make sense to synthesize oil for any of those special applications where you can’t replace oil as an input.