Bait and switchgrass, again
I’ve only just seen this study by Tiffany A. Groode, a graduate student in MIT’s Department of Mechanical Engineering, and not looked at it in detail, but several statements in the press release stand out:
Now a new MIT analysis shows that the energy balance is actually so close that several factors can easily change whether ethanol ends up a net energy winner or loser.
Regardless of the energy balance, replacing gasoline with corn-based ethanol does significantly reduce oil consumption because the biomass production and conversion process requires little petroleum.
Groode incorporated into her analysis the uncertainty associated with the values of many of the inputs. Using a methodology developed by a recent MIT graduate, she used not just one value for each key variable (such as the amount of fertilizer required), but rather a range of values along with the probability that each of those values would occur.
Based on her “most likely” outcomes, she concluded that traveling a kilometer using ethanol does indeed consume more energy than traveling the same distance using gasoline.
So why does the press release proclaim, “MIT ethanol analysis confirms benefits of biofuels”? Because cornstarch ethanol forms part of a continuum, you see:
Groode and Heywood now view the three ethanol sources [corn starch, corn stover, and switchgrass] as a continuum. In the future, cellulosic sources such as corn stover and ultimately switchgrass can provide large quantities of ethanol for widespread use as a transportation fuel. In the meantime, ethanol made from corn can provide some immediate benefits.
By consuming more energy than traveling the same distance using gasoline??
“I view corn-based ethanol as a stepping-stone,” said Groode. “People can buy flexible-fuel vehicles right now and get used to the idea that ethanol or E85 works in their car. If ethanol is produced from a more environmentally friendly source in the future, we’ll be ready for it.”
Here we go again. As I have argued elsewhere on these pages, that kind of logic is specious. One could just as well make a case that subsidies to gasoline (since gasoline will continue to be blended with ethanol for many years to come) or spark-combustion engines (which are required for cars to run on ethanol) would help in the construction of a bridge to that elusive, switchgrass-based ethanol future.
Setting aside the pros and cons of such a future, normally the value of a “stepping stone” is the gap it allows one to cross. But if the time it takes people to “get used to the idea that ethanol or E85 works in their car” can be counted in months, whereas the era of subsidized cornstarch-based ethanol production can be counted in years, if not decades — especially if the 51 cent/gallon federal volumetric ethanol excise tax credit and the 54 cent/gallon import tariff on ethanol are made permanent, as has been proposed in at least one bill before Congress — then that stepping stone is more likely serving as a great big doorstop.