Life cycle assessment of co-firing coal and wood pellets in the Southeastern United States

Coal-fired power plants produce nearly 40% of the electricity in the United States, contributing more than three-quarters of all carbon dioxide emissions from the electricity sector. While many European coal-fired power plants have been transitioning to wood pellets to abate carbon dioxide emissions, such a changeover has not occurred in the United States electricity sector. This analysis examines the environmental implications of co-firing coal and wood pellets in the Southeastern United States, where the vast majority of wood pellet exports to Europe originate. Utilizing primary data from existing wood pellet manufacturers, a life cycle inventory is presented that characterizes the full cradle-to-grave environmental performance of co-firing coal and wood pellets for electricity generation. Furthermore, the avoided life cycle emissions related to shipping wood pellets to Europe are calculated. Life cycle assessment modeling scenarios for co-firing wood pellets in existing coal-fired power plants within the Southeastern United States result in reductions in eight of nine impact categories. The results presented here indicate that co-firing with wood pellets could be a viable interim solution for the aging fleet of coal-fired power plants within the Southeastern United States, particularly if stricter emission regulations and renewable portfolio standards are implemented.