Energy Cane for Indonesia’s E20 Transition: From High-Biomass Agronomy to Integrated 1G–2G Bioethanol on Suboptimal Land

Abstract

Indonesia’s emerging E20 gasoline–ethanol agenda creates a feedstock challenge that cannot be resolved by considering ethanol-processing capacity alone. Large-scale deployment requires an integrated assessment of feedstock productivity, land suitability, conversion efficiency, logistics, environmental performance, and industrial readiness. This qualitative literature review examines whether energy cane—a high-biomass Saccharum feedstock bred more strongly for vegetative biomass than sucrose concentration—could complement conventional sugarcane and other crops in Indonesia’s bioethanol transition. Recent evidence shows that energy-cane genotypes can substantially outperform conventional sugarcane in biomass and fiber yield, although performance varies considerably among genotypes and environments. Type I energy cane retains sufficient fermentable sugars to support first-generation ethanol while supplying additional lignocellulosic biomass, whereas high-fiber Type II material depends much more strongly on economically viable second-generation conversion. Consequently, high biomass productivity cannot automatically be interpreted as high commercially recoverable ethanol productivity. The review further finds that “suboptimal” or “marginal” land should not be treated as unused land: biophysical suitability, existing livelihoods, biodiversity, water resources, infrastructure, tenure, and opportunity costs must be considered simultaneously. Integrated 1G–2G biorefineries, cogeneration, and coproduct valorisation could strengthen the economics of energy cane, but pretreatment, enzymes, pentose fermentation, capital intensity, and biomass logistics remain significant constraints. A staged Indonesian pathway centered on genotype evaluation, spatially explicit land screening, demonstration-scale integration with existing sugar infrastructure, and progressively larger 2G deployment is therefore proposed.