Ok, I just reread my post (below) on corn-based ethanol, and realized that it’s a tough slog—way, way too long. Here’s the short version:
- Corn ethanol’s chief critic says that it’s a waste of energy—ie., that it takes more fossil fuel energy to grow corn and distill it into ethanol than the ethanol itself contains. But he uses outdated data.
- A widely cited USDA researcher says that corn ethanol can reduce fossil fuel use—ie., that corn ethanol contains considerably more energy than is contained in the fossil fuels used to farm corn and distill ethanol. But he relies on some generous assumptions, and ignores some significant energy costs.
- Averaging the two views, it seems that corn ethanol probably uses about as much fossil fuel energy to produce as is contained in the gasoline it displaces—maybe a little more, maybe a little less, but not a lot either way.
- Which means, as things currently stand, that I’m much more interested in promoting fuel efficient vehicles and compact urban design than I am in even discussing corn ethanol. Those steps can have a big impact on fossil fuel consumption. Ramping up corn ethanol production—unless I’m badly mistaken—won’t.
I hope that’s clearer.
Now, obviously, there are lots of other points to be made both for and against corn ethanol; and these arguments don’t carry over into biodiesel or cellulose ethanol. But they do make me feel like shrugging and changing the subject whenever someone gets all excited about corn ethanol, either pro or con.