Ethanol technical potential in Hawaii based on sugarcane, banagrass, Eucalyptus, and Leucaena

An assessment of ethanol production potential from dedicated energy crops was conducted for the State of Hawaii considering lands, crop species, and conversion technologies. Evaluation of the spatial distributions of soil types, zoning, and annual rainfall was conducted using geographic information system data. Saccharum officinarum (sugarcane), Pennisetum purpureum (banagrass), Leucaena leucocephala, and Eucalyptus grandis were selected as potential feedstocks for sugar-based and lignocellulosic ethanol production.The analysis shows that only one cropping scenario applied to all available agriculturally zoned lands in the state would be capable of producing enough ethanol to meet the state's current motor gasoline consumption on an energy equivalent basis. State goals of displacing 20% (volume) of highway fuels by 2020 could be met by 14 of the 16 cropping and land use combinations. This indicates that the State of Hawaii could promote energy diversification through its choice of land leases. Distribution of suitable lands among islands is not consistent with motor fuel demand, suggesting that provisions must be made to support development of adequate storage and harbor facilities to enable movement of fuel between points of production and use. Comparison of possible production volumes with economic plant sizes indicates that sufficient feedstocks could be available on Maui, Hawaii, Oahu, and Kauai to realize economies of scale in production facilities.This study should be refined in the future to adequately address issues of environmental preservation, water consumption, and land use to provide additional guidance for policy and economic decision making.