One of the most confusing aspects of the alternative energy industry has to be the story about ethanol. Simply put, is ethanol good or bad? Does it help or harm the environment?

The confusion and controversy stems from evaluating the net effect on CO2 emissions of ethanol production and use, relative to the production and use of the incumbent fuel, gasoline. Largely, this is driven by questions concerning the energy balance of ethanol — how much energy is really required to fertilize, grow, harvest and process the ethanol, and what are the CO2 emissions associated with these steps. The proper quantification of these factors has seemingly been a matter of dispute between those who favor ethanol and those who see ethanol promotion as merely a means of subsidizing the agricultural sector.

A Reuters summary of an article in the January 2006 issue of the journal Science, written by several researchers from UC Berkeley, indicates that the current corn-based means of producing ethanol is in fact a dubious environmental proposition. However, the use of emerging technologies to convert cellulosic matter — the tougher fibers as found in trees, bark, woody wastes, etc. — in ethanol should be net environmentally positive.

Not surprisingly, the downside is that cellulosic technologies are now on the costly side. But, perhaps with additional clarification of the type on the net environmental benefit (along with the energy supply benefit) that can be generated by cellulosic ethanol, this controversy can be put to bed. With the concerns more definitively allayed, more effort and capital might flow to this potentially important source of energy.