Energy Production with Biomass: What Are the Prospects

The advantages and limitations of the U.S. ethanol industry have both become apparent during the current period of high petroleum prices. One advantage is that ethanol is cost-reducing as a gasoline additive and as a gasoline replacement using E85 (motor fuel blends of 85 percent ethanol and just 15 percent gasoline). However, corn supply limits ethanol's role in energy markets; ethanol-based corn demand will surpass exports when the 7.5 billion gallon Renewable Fuel Standard is fully implemented; and even if the Midwest were to secede from The Union, the entire Midwestern corn crop could only supply two-thirds of regional gasoline demand with ethanol. Clearly, a broader resource base and other processing technologies are needed if bioenergy is going to expand its role in the national energy scene. There are wide ranging assessments of biomass-energy's potential role in expanding our national energy supplies. Those accustomed to pumping liquid petroleum scoff at the idea that an energy industry could be based on bulky crops or residues from farm land or forest. Or biotechnologists sometimes multiply laboratory processing yields times the physical intensity of biomass on land times land area, resulting in an enormous estimate for biomass energy potential. Somewhere in between zero and the enormous estimates we should find reality. This paper examines the primary factors that limit the potential size of a biomass-energy industry in the United States. First, the fraction of the existing biomass that can be economically harvested from farmland is reviewed. Second, the current and potential processing technologies and practices are discussed. And finally, the unknowns and uncertainties of bioenergy supply that could be shaped by public policy are also reviewed.