Estimating national costs, benefits, and potential for cellulosic ethanol production from forest thinnings

Since 2004, wildfires have been responsible for the destruction of 3.5 million hectares of forestland per year. Fuel reduction activities such as prescribed fires, cutting and burning in situ, and biomass removal (thinning) have been shown to reduce wildfire severity, but with mounting costs of fighting wildfires and a tightening budget, public agencies such as the USDA Forest Service may find it difficult to continue funding these preventative treatments. By using thinned biomass as a cellulosic ethanol feedstock, these agencies may be able to generate funds for these treatments. Here, we estimate costs of producing cellulosic ethanol from forest thinnings based on forest thinning supply curves. Nationally, 27 to 34 million Mg of biomass could be removed from overcrowded forests per year at collection costs of $55 to $110 per dry Mg. Given a mature cellulosic ethanol industry, ethanol produced from these thinnings could generate revenue at gasoline prices of $0.5 to $0.8 per liter. By using thinned biomass as an ethanol feedstock, it may be possible to generate significant funds for socially beneficial thinning treatments.

► Forest thinning operations could generate feedstock for cellulosic ethanol.
► For a mature industry, cellulosic ethanol cost could be $0.5 to $0.8 per liter gasoline equivalent.
► Forest thinnings could provide 30 million Mg of feedstock annually.