There's an interesting debate in the December issue of C&EN, which pits two professors and well-known energy experts- David Pimentel of Cornell and Bruce Dale of MSU- on opposite sides of the biofuel debate, specifically the ethanol from corn debate.
The debate is quite instructive and you can read about it yourself (access should be free). I have been an opponent of ethanol from corn ever since I first heard one of David Pimentel's viewpoints. The main issue concerns the "energy balance" of corn production. It turns out that by many estimates, more energy from fossil fuels (in terms of corn fertilizer, transportation etc.) is put into producing ethanol from corn than is obtained from using the ethanol. Pimentel believes that this balance is negative; you put in much more energy than what you get. Dale makes some arguments which I find strange, arguing that one must consider the exact character of the fossil fuel sources that are being used (gas, coal or oil) otherwise one is comparing apples to oranges. As far as I am concerned, all are fossil fuels, so it's not going to matter which one is used. All are going to be expensive in the future, in one way or the other. Ethanol from grass provides a better alternative to that from corn, but even there Pimentel contends that that sheer volume of carbon source that one gets from grass is less than that from corn.
In any kind of energy source evaluation, it is always important to consider the ancillary sources involved that may contribute unfavorably. For example, in considering solar and wind-power, one must consider the cost of materials for construction, the land used and the fate of those materials in the future to name a few significant factors.
Many Americans don't realise that diverting corn away from food production can have an immense impact on the American way of life. Michael Pollan's truly excellent The Omnivore's Dilemma makes it clear how much dependent Americans are on corn, which pervades almost everything they buy in the supermarket. We should shudder to think of an "American Corn Famine" akin to the Irish Potato one. If corn is diverted to produce ethanol, Americans will wake up to an unpleasant shock, where almost everything they buy for their daily consumption has become expensive. More than 60% of all corn goes not in human food products directly, but into animal feed. Cattle, hens, and even salmon are fed corn these days. (Maybe that's why grandmothers don't like meat that much anymore). Cheap corn-fed beef is a luxury we may not enjoy if corn supply starts getting diverted into producing ethanol. And even with much corn being used for fuel, as Pimentel demonstrates, it won't fulfill more than a small amount of this energy-hungry nation's energy needs.
In any case, I have always thought that the reason ethanol from corn has received so much attention is because of the gratuitous lobbying in Washington from corn companies, and the resulting shameless pandering that Bush and other officials have demonstrated in terms of the obscene subsidies that corn gets. Seriously, is the United States truly a free market economy, with such ridiculous subsidies offered to corn and oil?
Clearly there has to be a better solution. As with so many other things, ethanol and corn seem to have been oversold by George W. Bush, along with the accompanying corny lines.
Subrahmanyan Chandrasekhar: A study in fortitude and rigor
1 day ago in The Curious Wavefunction