SRIC: Integration of production and harvesting system costs

To achieve the objective of delivering woody biomass to the conversion plant at the lowest possible price, a systems approach in which both biomass production and harvesting costs are considered is required. In this paper, a method for combining biomass production and harvesting cost functions is developed to determine total system costs. Such an approach allows the analysis of how compromises within the function segments can improve total system performance. Efforts have been made to combine all research work in the Department of Energy's Short Rotation Woody Crops Program to create a total system analysis of biomass production. A new method for determining the best rotation age of multiple rotation hardwood stands is discussed. A regression equation of the favored rotation age in relation to planting density is formed. This relationship leads to other regressions of biomass yield to planting density and production (growing) costs to density. Harvesting productivity rates are simulated from research data for the range of tree sizes that plantations of various planted densities should produce. The production and harvesting costs for each density are combined in the form of present net worth and annual equivalent value and illustrated as a function of planting density. The resultsmore » show a logarithmic increase in costs as planting density increases.« less