Short-rotation forestry as an alternative land use in Hawaii

Abstract

The traditional mainstays of Hawaii's economy: sugarcane and pineapple crops, have declined such that as much as 80,000 hectares of agricultural land are now available for alternative land uses. Concurrently, imports of fossil fuels continue to accelerate and now provide over 90% of the total energy supply at a cost exceeding $1 billion annually exported from the local economy. The feasibility of short-rotation forestry on these former sugarcane and pineapple plantation lands to produce a variety of wood products, including biofuels, is being evaluated using a species-and site-specific empirical model to predict yields of Eucalyptus saligna, a system model to estimate delivered costs of wood chips to a bioconversion facility, and a geographic information system to extend the analysis to areas where no field trials exist and to present results in map form. The island of Hawaii is showcased as an application of the methodology. Modeling results are presented for using tropical hardwoods as dedicated feedstocks from biomass energy plantations to produce methanol, ethanol and electricity. A hypothetical, integrated, high-value hardwood, veneer, utility lumber and wood-chip operation is featured in contrast to the biomass energy plantation scenario. Short-rotation forestry may hold some promise for the greening of Hawaii's energy system and even greater promise for the industrial production of value-added wood products for the benefit of the state's citizens and visitors. The methodology is readily transferable to other regions of the United States and the rest of the world.