Billion-Ton Update results presented in DOE webinar
The U.S. DOE held a webinar, "The U.S. Billion-Ton Update," on Sept. 22, which provided in-depth analysis of the study processes, results and differences from the 2005 Billion-Ton Study.
The 2005 study estimated the biomass potential within the country based upon assumptions regarding then current production capacity, availability and technology. Expanding on the original, the “2011 U.S. Billion-Tom Update: Biomass Supply for a Bioenergy and Bioproducts Industry,” known as the 2011 Billion-Ton Update, included more direct inventory analysis regarding primary feedstocks, focused price and supply quantities and “rigorous treatment and modeling of resource sustainability,” according to the DOE.
Presenters included Robert D. Perlack, senior scientist for Oak Ridge National Laboratory, Bryce J. Stokes, senior advisor for CNJV LLC, Douglas L. Karlen, soil scientist for USDA, and Kenneth E. Skog, economist for USDA Forest Service. Presenters noted that 50 different individuals provided report research and analysis, while more than 100 people contributed through reviewers and other specialists.
The update evaluated biomass resource potential nationwide while improving upon the 2005 study. The researchers hoped to quantify biomass supply under improved calculations and determine how biomass can be developed for future use.
The update reviewed the lower 48 states as a resource base. The forest land resources included 504 million acres of timberland and 91 million acres of other forestland. The agricultural resource base included 340 million acres of cropland, 40 million acres of idle cropland and 404 million acres of pasture.
The study used scientific modeling methods to determine current agricultural and woody biomass availability and also projected the supply to 2030. The update provided quantities based upon two scenarios, the baseline, providing conservative calculations, and a high-yield scenario showing full potential. Focusing on more than just quantities, the update integrated environmental measures to ensure sustainability.
Dedicated energy crops showed increased potential in the update, however, in an attempt to maintain sustainability restrictions were placed in the modeling process. The restraints included integrating best management practices, not allowing energy crops to be produced on irrigated cropland or pasture, and allowing only 10 percent of cropland and 25 percent of all lands within any one county to be planted to energy crops. The crops reviewed were perennial grasses including switchgrass, woody crops (eucalyptus, southern pine, poplar and willow) and annual energy crops such as sorghum.
The study utilized USDA Forest Service projections for forestry-related feedstock. A major part of the woody biomass analysis was done using integrated logging calculations, meaning the forestry industry is collecting merchantable products and biomass for energy purposes, where the biomass includes the residues and thinnings. Sustainability was also integrated heavily into the woody biomass portion of the study, where actual removal practicalities were analyzed. Not all areas of forest were included in the availability. If land was too steep, wet or inaccessible, it was not considered available.
Showing significantly different results than 2005, the update showed a current baseline scenario supply of 473 million dry tons per year and 1.1 billion in 2030. The high-yield scenario reached nearly 1.4 to 1.6 billion dry tons annually of available biomass.
The update found that enough resources exist to meet the 2022 advanced biofuel goals, potential resources are widely distributed across the U.S. and energy-defined crops are the single-largest source of new feedstock potential. In comparison to 2005, the amount of available forest residues is lower due to removal of unused resources and decline in pulpwood or sawlog markets. Similarly, crop residue potential is lower due to environmental consideration of soil carbon and residues from conventionally tilled acres removed.
The webinar explained how to research data on the DOE’s Bionergy Knowledge Discovery Framework website, which helps researchers obtain specific study data including county and state level statistics, selected crop data and complete study files.