Researchers Identify Energy Gains And Environmental Impacts Of Corn Ethanol And Soybean Biodiesel: This discusses a study into the full lifecycle costs and energy gains in producing Corn Ethanol And Soybean Biodiesel. Such a study is worthwhile because if these fuels are to produce any benefit over fossil fuel, there must be an excess of energy coming from the fuel that is produced.
For example, the widely held belief is that ethanol from corn produces less energy than the energy required to produce the corn. Hence, corn ethanol should be a net loss and not worth pursuing. The study in question shows the opposite, that there's a net gain in energy.
The study also tracked the amount of fertilizer and weed killers and the like used to produce these crops.
However the study shows that neither fuel can come close to providing U.S. needs. If all U.S. production of corn or soybeans were diverted to biofuel production, it would only provide 12% of current demand.
Soybean based biodiesel comes in far better in this study than does corn ethanol.
Unfortunately diesel vehicles are rare among passenger cars, which makes biodiesel only suitable for the big trucks and trains. Elsewise there would need to be a resurgance of diesel engines in passenger cars.
