Miscanthus for Renewable Energy Generation: European Union Experience and Projections for Illinois

Abstract

When considering renewable energy from plants, corn ethanol and reforestation have been widely promoted. Herbaceous perennials, which produce an annual crop of above ground shoots, may have some important advantages over both of these systems. Herbaceous perennials require far fewer energy and financial inputs than annual arable crops. They can be higher yielding than forestry crops and utilize existing farm equipment. Perennial energy crops can sequester carbon into soil previously under annual arable crops, providing potential additional income in carbon credits. The advantages and disadvantages of different plant types are explained to show herbaceous perennials hold special promise as bioenergy crops. C4 photosynthesis allows greater efficiencies in the con- version of sunlight energy to biomass energy, and of nitrogen and water use. However, few plants in temperate climates use this more efficient process. One exception is the rhizomatous perennial grass Miscanthus ,w hich is aC 4 plant and exceptionally cold tolerant. Miscanthus is now being grown commercially in the European Union (EU) for direct combustion in local-area power stations. It may also have longer-term potential as a feedstock for other bio-based industry. The lessons learned from trials of this crop in the EU are summarized, potential yields in Illinois predicted and a tentative comparison of the economics of growing Miscanthus versus traditional row crops developed. Overall, the results suggest that Miscanthus could yield an average of 33 t of dry matter per hectare in Illinois. At current energy prices the crop would be profitable, if grown for 4 or more years, even without subsidy.