The future of ethanol

Most experts don't see the future of the ethanol industry taking root in America's cornfields. A more promising long-term solution is cellulosic ethanol, which can be made from a variety of other sources such as corn stover (leaves, stalks, and other leftover parts), rye straw, wood pulp, and possibly switchgrass (commonly used for hay). In Brazil, where every new car runs on at least 20-percent ethanol and many run on pure ethanol, the fuel is made from sugarcane.

"If this country is going to go big into ethanol, we need to tap into cellulosic ethanol," says UCS Research Director of Clean Vehicles David Friedman, "because it's cleaner and requires less fossil fuels than corn [to produce]."

A 2005 study conducted by the U.S. Department of Agriculture and Oak Ridge National Laboratory estimates that by 2030, ethanol from corn and cellulose could replace 30 percent of U.S. oil consumption—about the same as the United States currently imports from OPEC nations. Called the Billion Ton Study, it assumes that 1 billion tons of organic material could be used, with no loss of corn for food or feed, from resources such as forest waste organic residue, and energy crops such as switchgrass.

Companies have developed a number of processes for creating cellulosic ethanol. A few technology companies are working on new chemical processes that could create ethanol from waste streams such as leftover construction materials and even municipal garbage. So far these technologies have only been demonstrated on a small scale, and it will take several years before we know whether they are viable. Today about two dozen cellulosic ethanol plants are under development in the United States.