Biopower is electricity produced from a wide range of biomass (organic materials found in wood, plants, agricultural waste, and other materials). Biomass is a base load renewable energy source that is readily available across the United States, which makes it more reliable than wind and solar for electricity production. Biomass also offers a renewable energy solution in areas where other renewable sources are not as readily available. Biopower is one means by which to meet national goals for the use of clean, renewable energy while promoting economic growth. A successful, sustainable biopower industry can provide clean, domestic, renewable power; revitalize rural economies; reduce impacts to the environment and climate; promote healthy forests; and create diverse job opportunities with agribusinesses, utility and power plant vendors, owners/operators, equipment suppliers, and small businesses. To explore opportunities for biopower in the United States, the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy Biomass Program conducted the Biopower Technical Strategy Workshop in Denver, Colorado, on December 2-3, 2009. The purpose of the workshop was to provide a forum for discussing technical and economic challenges; research, development, and demonstration (RD&D) priorities; and issues related to feed stocks, sustainability, and market transformation. The workshop was attended by a wide spectrum of experts from government, and it generated a wealth of information and ideas. This report presents the results of the workshop which included the following topics: Pretreatment and Conversion Technologies; Large-Scale Systems; Smaller-Scale Systems; Feed Stocks for Biopower; Market Transformation.