Corn-based ethanol fuels have received a lot of well–deserved criticism lately. This includes criticisms that they take more fossil fuels to produce than they replace, that they have a marginal effect on total greenhouse gas emissions, and that they raise food prices and starve the poor. Ethanol defenders use two approaches to counter-attack. They claim that these problems are not as severe as reported, and they argue that corn ethanol is a necessary step on the road to cellulosic ethanol, which will be made from non-food crops grown in ways that don’t use fossil fuels intensively.
A recent post at R-Squared questions whether that transition will ever occur. Rapier argues:
Cellulosic ethanol, and by that I mean cellulosic ethanol in the traditional mold of what Iogen has been working on for years – will never be commercially viable.
If so, this is bad news for biofuels in general. Rapier points out problems including the large amount of lignin in biomass, the difficulties in transporting such quantities of biomass to refineries, and the energy use involved in drying the stuff out.
Additional criticisms of cellulosic ethanol can be found in a recent study from Iowa State University. According to their economic analysis, cellulosic ethanol will never be produced at the levels envisioned by the American Renewable Fuel Standard, and will only be produced in substantial quantities if it gets three times the subsidy already granted to corn ethanol:
Competition for land ensures that providing an incentive to just one crop will increase equilibrium prices of all. Also, at pre-EISA subsidy levels, neither biodiesel nor switchgrass ethanol is commercially viable in the long run. In order for switchgrass ethanol to be commercially viable, it must receive a differential subsidy over that awarded to corn-based ethanol.
Largely, this is on account of how growing any crop in massively increased quantities will affect factor prices for other crops: from land to labour to farm equipment.
There is no doubt about it, if technology is going to help us transition to a low-carbon society without giving up liquid-fuel driven transport, we are going to need to come up with some awfully clever new ideas.