2019 年 40 巻 5 号 p. 180-195
This study develops a regionally-disaggregated global energy system model, aiming to assess the role of low-carbon technologies for climate change mitigation. Detailed spatial resolution, totaling 363 nodes, enables the model to explicitly consider the local resource endowments as well as energy and CO2 transportation infrastructure. Simulation results indicate that energy savings and alternative fuel use—such as hydrogen (H2) and solid biomass—in the end-use sectors, combined with significant decarbonization of the electricity sector, are the cost-optimal strategy. Most H2 is locally produced and consumed near demand centers, implying economic challenges for global H2 trade. CO2 storage in aquifer plays a crucial role for emissions reduction, significantly affecting global marginal CO2 abatement cost. If aquifer storage is excluded from the list of mitigation options, renewables and nuclear become more important; international CO2 trade is also estimated to be cost-efficient to access other CO2 storage sites, such depleted gas wells, which suggests cooperation opportunities between energy consuming and gasrich countries.
