Inventory and classification of United States federal and state forest biomass electricity and heat policies

• New classification of forest bioenergy policies from energy producers' perspective.
• In 2008–2013, total number of state forest bioenergy policies grew by 164%.
• Increasing share (17%) of policies is forest biomass and bioenergy specific.
• Cluster analysis identified seven state groups based on policy approach and focus.
• Evidence of policy diffusion across state lines as neighboring states formed clusters.

As of September 2013, federal and state governments had nearly 500 policies to support production of electricity and heat from forest biomass. This research used a four-tier classification structure to categorize policy instruments used in these policies based on: approach (incentive, regulation, information), type (e.g. tax incentive), subcategory (e.g. tax exemption), and specification (e.g. sales tax exemption). More (113) of these policies were enacted in 2007 and 2008, more than in any other two-year period, and there was a significant increase in the number of forest bioenergy (46) and biomass specific (36) policies by 2013. Cluster analysis provided evidence that neighboring states adopted similar numbers and types of policies. Oregon (in cluster by itself) had the highest number of tax incentives and biomass-specific policies, while most Southern, Southeast, Southern Appalachia and Midwestern states (the most dissimilar cluster to Oregon) had a limited number of policies. Most states in remaining clusters offered a mix of integrated policies, rather than policies focused on regulations and technology improvement. Our findings provide guidance for policy development by enabling the transfer of policy approaches among different states and regions.