Oak Ridge National Laboratory has estimated quantities of biomass that are potentially available at delivered prices of less than $50/dry ton in five feedstock categories: urban wood wastes, primary mill residues, forest residues, agricultural residues, and dedicated energy crops. Other biomass resources exist, but have not been included in this analysis. Additional information can be found in Biomass Feedstock Availability in the United States: 1999 State Level Analysis.

We estimate an annual total of 512 million dry tons of biomass equivalent to 8.09 Quads of primary energy could initially be available at less than $50/dry delivered. This includes at least 74 million dry tons (1.2 Quads) of biomass currently being used for fuel. Quantities could potentially be increased to 800 million dry tons (about 12.4 Quads) in the next two decades. Increases will require additional research, coordinating agricultural and energy policies, and dialog with the environmental community and other stakeholder groups. The factors considered in the estimates and trends that might affect future quantities are summarized below.

We estimate that 36.8 million dry tons (0.63 Quads) of urban wood wastes are currently available annually. The estimates are based only on the wood portion of wastes disposed of in municipal solid waste landfills, construction/demolition landfills, and yard waste taken directly to compost facilities. Estimated quantities include the approximately 4.7 million dry tons (0.08 Quads) of wood waste currently used for fuel and also include wood that is currently recycled, composted, or used for other products. Quantities of urban wastes could increase if non-wood wastes (such as paper) were included. Additional urban wood wastes may be available but do not enter the waste management stream through municipal solid waste landfills and construction/demolition landfills. It seems unlikely that the available wood waste will increase substantially in the next two decades, even as population increases, due to efforts to reduce waste production at the source and increased recycling.

An estimated 90.5 million dry tons (1.5 Quads) of primary mill residues are generated, on average, each year. All but about 2 percent of these residues are currently used for energy (approximately 40 million dry tons or 0.7 Quads), paper, veneers, composite wood products, and other uses. In the past, as fiber prices have increased, new mill technologies that reduce waste and new end product technologies (such as oriented strand board) that use waste have been developed. It is likely that these trends will continue in the future, limiting growth of mill wastes even if primary fiber demands increase.

We estimate that 45 million dry tons (0.76 Quads) of forest residues per year are available at delivered prices of less than $50/dry ton. Estimated quantities include only logging residues, thinnings, and rough, rotten, and salvable dead wood; no harvest of growing stock of merchantable species is included. This is the largest category of the forest inventory and could potentially add another 90 million dry tons (1.5 Quads) of biomass at prices of less than $50/dry ton. However, the sustainability of increased harvest of forests for energy use will need to be thoroughly examined before such quantities are included in biomass resource inventories.

An estimated 150.7 million dry tons (2.3 Quads) of corn stover and wheat straw, the only agricultural residues examined, are available annually. On average, these figures assume that about 40 percent of the total residue produced is collected, with the remaining residues left to maintain soil quality. Quantities of feedstocks could potentially be increased substantially (perhaps doubled) through the inclusion of residues from other agricultural crops such as soybeans, barley, rice, oats, cotton, etc.; through increased yields of crops; and through increased use of no-till site preparation practices which would permit greater quantities of residues to be removed. Other options such as tailoring crops to produce specialty chemicals either as dedicated sources or in addition to traditional food/feed roles have not been considered.

In a joint project between the Department of Agriculture and the Department of Energy, the potential to produce biomass energy crops has been evaluated. An estimated 188 million dry tons (2.9 Quads) of biomass could be available annually at delivered prices of less than $50/dry ton by the year 2008. The analysis includes all cropland suitable for the production of energy crops that are currently planted to traditional crops, idled, in pasture, or in the Conservation Reserve Program (CRP). It is estimated that 42 million acres of cropland (about 10 percent of all cropland acres) could be converted to energy crop production including 13 million CRP acres. Harvest of CRP acres will require a significant change in the current laws and must be structured in a way that maintains the environmental benefits of the program. The estimated quantities represent the maximum that could be produced at a profit greater than could be earned through existing uses. Farmer adoption of new crops is based on several factors. Greater profitability will encourage, but not necessarily ensure, the adoption of a new crop.

Energy crop yields will increase over time, but so will traditional crop yields. The interplay of demand for food, feed, and fiber with traditional crop yields, and crop production costs will determine the number of acres allocated to traditional crop production. International demand for food, feed, and fiber is expected in increase in the future.

Biotechnology is expected to substantially increase crop yields in the future, although studies (such as by Office of Technology Assessment and the Resource Conservation Act assessments) indicate that the biggest yields will likely occur after 2020 rather than before this time. Potential quantities of energy crops could increase in the near future, but increases may be due more to increasing yields per acre than from increasing acres. Opportunities to tailor biomass energy crops to serve multiple purposes have not been considered in this analysis.

Dr. Marie Walsh
Oak Ridge National Laboratory
P.O. Box 2008
Oak Ridge, TN 37831-6205
865-576-5607 (phone)
865-574-8884 (fax)
WalshME@ornl.gov (e-mail)