Evaluation of cost reduction effects by sector-coupling synergies in timber processing and bioenergy for sustainable forestry in Japan

The greenhouse gas sequestration capacity of forests is an important pillar in combating global warming; therefore establishing a forest resource circulation system is crucial. Forestry, which includes everything from cultivation to harvesting forests that store carbon dioxide as they grow, and the sawmill industry, which processes this timber, frequently face significant economic challenges. Consequently, proposals are needed to establish systems that improve these industries’ economic competitiveness while also ensuring the forest resources circulation. This study developed a model to evaluate the economic relationship between timber processing and energy consumption from a sector-coupling perspective using a prospective techno-economic analysis. It specifically defines wood utilization as a comprehensive forest resource circulation that includes production, planting, processing, energy utilization, and reforestation. It evaluates the economic interdependence between timber processing and energy utilization when all wood is harvested from forests and both uses are combined. The evaluation results show that combining energy utilization in sawmills processing over 36,000 m 3 annually allows for full harvesting from forests, reducing forest residues, and lowering site preparation costs for reforestation. Additionally, using inexpensive electricity from biomass power generation for sawmilling lowers sawmill costs. It has become clear that, at sawmills of a certain size or larger, combining material utilization with energy utilization results in a slight decrease in sawmilling costs, while reducing forestry management costs; overall, this is an effective approach for wood utilization.