Micahel O'Hare has a good post on the much-maligned, heavily-subsidized, use of ethanol as a gasoline additive and, eventually, replacement:
A gang at the Energy and Resources Group and the Goldman School at UC Berkeley, who invited me to play with them over the summer and fall while we did the project, have clarified things greatly. In my view our most important finding is that the "net energy" measure, which looks only at the fossil fuel energy consumed to make a unit of energy in the form of ethanol, asks the wrong question. For example, if ethanol provided a means to take 100 joules of energy from coal and obtain 50 joules worth of ethanol, it would not necessarily be a bad idea. Coal is abundant and cheap; the problem with it is that when burned, it releases the "greenhouse gas" CO2. So one would want to ask about the greenhouse gases released (and other costs, of course), not the net energy, and if the CO2 from burning the coal were captured and sequestered, this notional technology would be a prima facie policy winner, allowing us to run cars cleanly on domestic abundant coal rather than imported, scarce petroleum.
Our article in Science (Farrell et al) is behind a paywall (today's issue, if you have access to it) but also posted here, with the analysis behind it. This LA Times story is a pretty good report. What we found, adjusting six studies of ethanol input demands so they could be compared is that ethanol from corn (maize) as we make it today is a big petroleum saver, and offers modest gains in global warming, compared to gasoline. The specific technology used to make it matters a lot, but what matters more is the crop you start with: ethanol from grass or wood will be a very attractive fuel on energy, global warming, and petroleum displacement grounds.
Interesting stuff. Debates about ethanol tend to vanish into the gap between detractors talking about yesterday's blends and supporters boosting tomorrow's technologies. What you're seeing now is the slow shift from a reality that conforms mainly to the predictions of critics, where corn is heavily subsidized and an energy-intensive process turns it into ethanol, to a world where cellulosic ethanol, which is both plentiful; and cheap, has descended within reach.
Cellulosic ethanol is the conversion of otherwise useless biomass, like switchgrass and corn husks, into ethanol -- it releases 80% less CO2 and no sulfur dioxide. The ethanol is then put into a blend with 15% gasoline to create E85, a flex-fuel that requires minimal retrofitting for cars or gas stations. Folks talk about the hydrogen economy and the exciting new distribution system that would require. But in this case, boring is better and the cheap, easy tweaks required by ethanol would make any changeover infinitely easier.
Better, every ounce can be produced and converted domestically. And in the event of a widescale adoption, the biomass economy would not only create a renewable fuel, it would renew the economies of those states, like Iowa, that manufacture it. It's a win-win product. And this isn't bullshit boosterism: in Brazil, three quarters of cars already run off the stuff, and the country is now independent of imported oil. We could, and should, do the same. And given the amount of interest among venture capitalists and domestic car producers, not to mention the current price-per-barrel for oil, it's a near certainty that we will.
See? I can write about things other than health care.
