Development of a Regionally Disaggregated Global Energy System Model and Analysis of Energy and CO₂ Transportation in a Low-carbon System

Abstract

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.