Thank you for your reasoned reply:- a breath of fresh air on this thread. Please note: it is not just the ethanol plant that needs fuelling - one also has to harvest the grain. Combine harvesters need fuel and we also need to transport our bio-fuel to the vendor. If we look at the entire process - does it produce excess energy?
The very simplest way of checking this without doing exhaustive sums is to ask the question: does the process require subsidy? Is there free-market investment in a non-subsidised industry? At the moment the answer is no.
The answer might not always be no, of course. A genetically created crop might come along that pushes ethanol over the edge. But Govt subsidy of corn ethanol is actually holding back such research - the profit barrier is raised by having to beat subsidy as well as the normal problems of research
Biodiesel? It's already quite popular with farmers.
That's another problem I have with articles like this. They assume that ethanol is the only nature-based solution to our energy problem when that land can be used to produce biodiesel too, and the energy in - energy out equation for biodiesel more than twice that of ethanol's. And that is using soybeans -- rapeseed, palm oil or algae (grown on sewage treatment ponds) can boost that number dramatically.