A follow-up report to the U.S. DOE’s 2005 “Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply,” commonly referred to as the Billion-Ton Study, has found consistency with the original in terms of magnitude of resource potential under the same assumptions. But the follow up, “U.S. Billion-Ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry,” finds differences in specific feedstock availability and includes a number of elements the Billion-Ton Study did not.

A key outcome of the update is the estimation of feedstock supply curves by county for all major primary cropland and forest resources at the farm gate or forest roadside, according to the DOE. The initial report had only national estimates and no spatial information. The new report also features environmental sustainability modeled for residue removal; land-use change modeled for energy crops; annual projections based on continuation of baseline trends; and annual projections based on changes in crop productivity, tillage and land use.  

Based on a number of assumptions, both studies evaluate the potential agricultural and woody biomass availability through 2030. The initial Billion-Ton Study sought to determine whether the land resources in the United States are capable of producing a sustainable supply of biomass to displace 30 percent or more of the country’s petroleum consumption by 2030. The goal would require 1 billion tons annually, the report found, and concluded that the nation could produce 1.3 billion tons per year, about 1 billion from agricultural biomass and 368 million tons from forestlands.

The forest residue potential in the updated report is determined to be somewhat less than in the original, as measured by the unused resources and by properly accounting for pulpwood and sawlog markets that provide the demand and the residue, the report states. The crop residue potential is also determined to be less because of the update’s consideration of soil carbon in crop residue removal, as well as the omission of any residue produced on land that is conventionally tilled. The energy crop potential, however, is estimated to be much greater because of higher planted acreage—a result of the spatially explicit land-use change modeling that was used.

“This updated resource assessment for the conterminous United States identifies sufficient biomass feedstock to meet near-term and potentially long-term bioenergy goals, depending on different cost and productivity scenarios,” the report states. “The assessment finds significant biomass resources across the United States with the exception of some areas of the arid west.”