This paper explores the role of negative emissions technologies (NETs) in energy systems, bioenergy with carbon capture and storage (BECCS) and direct air capture (DAC) with geological carbon storage (DACCS) in particular, using a bottom-up energy system model TIMES-Japan that participated in the 35th study of the Stanford Energy Modeling Forum (EMF 35 JMIP) focusing on the energy transitions for the long-run climate goals. Modeling results show that large-scale deployment of NETs is essential to achieve the net-zero vision of Japan’s long-term strategy, however, these NETs might not be enough in the case of the highest energy service demands. Within the feasible solution space, earlier deployment of BECCS with domestic biomass can contribute effectively to achieve the target with the support of the DACCS at the later period if both technologies are available. It shows feasible results without DACCS only in the lowest energy service demands, implying the importance of urgent research, development, and deployment of DACCS. Furthermore, this study shows that earlier deployment of DAC system with CO₂ utilization in fuel production is a cost-effective way to lead the large-scale deployment of the DAC as NETs.

本文采用自下而上的能源系统模型，探讨了负排放技术（NETs）在能源系统，具有碳捕集与封存的生物能源（BECCS）以及具有地质碳储藏（DACCS）的直接空气捕集（DAC）中的作用，尤其是使用自下而上的能源系统模型参与了斯坦福能源建模论坛（EMF 35 JMIP）第35次研究的TIMES-Japan专注于实现长期气候目标的能源转换。建模结果表明，NET的大规模部署对于实现日本的长期战略的零净愿景至关重要，但是，在能源服务需求最高的情况下，这些NET可能还不够。在可行的解决方案空间内，如果可以同时使用这两种技术，则在较早的时期内将BECCS与家用生物质一起部署可以有效地在DACCS的支持下实现目标。它仅在最低的能源服务需求下显示了没有DACCS的可行结果，这意味着紧急研究，开发和部署DACCS的重要性。此外，这项研究表明，采用CO的DAC系统的早期部署₂燃料生产中的利用率是引领DAC作为NET大规模部署的一种经济有效的方式。