Argument: There is not enough land to grow sufficient cellulosic ethanol
David Schneider. "Loser: Grassoline's Dark Side." IEEE Spectrum. January 2010: "even if a market does emerge and DDCE’s production process proves highly profitable, this technology can’t be considered a winner. Why? Because it will fail to satisfy the main premise for adopting it in the first place: to benefit the environment. A simple thought experiment sheds light on the dark side of grassoline. Suppose you replaced all the gasoline the United States now uses with switchgrass-derived ethanol. How much land would that take? The United States consumes 522 billion L of gasoline a year. Because of the difference in energy density, you need about 1.5 L of ethanol to replace a liter of gasoline. So the yearly requirement for ethanol would be about 780 billion L. A hectare of switchgrass can supply about 4700 L of ethanol a year, so the United States would need to devote roughly 170 million hectares (420 million acres) to it. That’s an enormous quantity of land—almost as much as the country now devotes to farming. And even if you covered all that land with switchgrass, it wouldn’t produce enough fuel to supply the country’s diesel trucks and buses, its jet aircraft, or the homes and businesses that use petroleum for heating fuel."
Sebastian Blanco. "Chevy Volt, cellulosic ethanol named two of the year's biggest losers." AutoBlogGreen. Jan 19th 2010: "As for cellulosic ethanol, the idea of making our own gasoline from switchgrass or other non-corn source is nice, but a 'simple thought experiment' shows that it won't work. IEEE Spectrum says there isn't enough farmland in the U.S. to grow enough fuel."