I’m not too surprised to read this. I have known for a while that most biofuels (ethanol, biodiesel, etc) have an Energy Returned On Energy Invested (EROEI) of about 1. That is they require one BTU of energy invested to get about one BTU of energy out.
But...most of the EROEI studies only include the direct energy used to produce the biofuel. They don’t include the indirect energy used to produce the biofuel. If all of the energy sources(indirect and direct) were included then the real EROEI would be about 0.5. So you burn more energy making these products than you get out and you emit more greenhouse gases than you save.
For those who aren’t aware, here are some examples of the differnces between the direct and indirect energy involved:
All of the diesel fuel used by the tractor to till the field, fertilize the field, and harvest the crops is direct energy...but the diesel fuel used to make the tractor (including mining the raw materials), transport the tractor to the farm and maintain the tractor over its life are indirect sources of energy.
All of the process heating used in the biofuel plant is a direct source of energy, but the entire energy demand for the plant (including the energy to run the offices, lighting and warehousing (forklifts, etc) is indirect energy.
By comparison, oil coal and natural gas have EROEI in the range of 7 to 10.
I have tried to make the same point; the energy used to grow and make the fuel HAS to be less than the energy obtained in order for any alternative fuel to allow energy independence to happen.
If the energy balance is negative, then energy independence will not happen and we will dig a deeper hole. We may as well use the fossil fuels directly for what the biofuels being made are intended since in that case we will be further ahead.
Whenever anyone suggests the energy balance of biofuels may not favorable, they are shot down as disciples of Pimintel without discussion.
Pimintel claims that the energy used to make the machinery (etc) used to create the fuel must be included in the energy balance and his detractors say that is not valid since this is activity that is not included in the energy balance for fossil fuels.
This is a point I am not certain about but am very interested in. I can't help but to think that biofuel production and the industry that supports it is like a big energy perpetual motion machine that will eventually use more energy than it creates, ultimately coming to a screeching halt. There are some very smart people on both sides of this issue and I am not sure which side is correct. I'd like to see biofuels make sense, but I think the bandwagon is a bit premature.