It says an acre of switchgrass makes 1150 gals of ethanol/year. The average driver uses 1100 gals of gas/year. So if we had a car that ran on 100% ethanol it would take an acre/year to run one car/year? I don't do math. Is that right? Wiki says there were app. 250 mil registered vehicles in the US in 2005. Seems like a very small expensive drop in a very large bucket to me. They also don't mention the air pollution findings, conveniently. I went looking around and found this:
For corn ethanol to completely displace gasoline consumption in this country, we would need to appropriate all U.S. cropland, turn it completely over to corn-ethanol production, and then find 20 percent more land for cultivation on top of that.
Ethanol Makes Gasoline Costlier, Dirtier
I say drill our own oil and build refineries. I think using food to run cars is immoral. Sorry for the long post.
...For corn ethanol to completely displace gasoline consumption in this country, we would need to appropriate all U.S. cropland, turn it completely over to corn-ethanol production, and then find 20 percent more land for cultivation on top of that.
I'm not going to parse the numbers but the gist of what you're arguing is correct but incomplete. The old baseline estimate, which is being left in the dust, is that corn ethanol gets us out to 15-18 billion gallons/year without much difficulty. That's equivalent to about 10% of U.S. gasoline requirements. Cellulosic ethanol, based on first-generation feedstocks (i.e., what we have lying around right now), can supply about 30% of our transportation fuel needs. After the plant scientists have a few years to identify new feedstocks and boost energy yields, most expect very substantial increases above that, although it's too early to put a figure on it.
Then comes the fun part. Think about E-85 in a flex-fuel plug in hybrid that gets 150 miles per gallon of gasoline input (because it runs most of the time on the electric charge and mostly on ethanol when the engine is running). That is a route to energy independence. It's not about a direct gallon per gallon substitution of ethanol for oil; it's about higher ethanol/oil blends in hybrids.