Energy systems using renewables with adequate energy carriers are needed for sustainability.Before accelerating technology implementation for the transition to the new energy system, region-specific implementation effects should be carefully examined as a system. In this study, we aim to analyze an energy system using hydrogen as an energy carrier with the approach of combining life cycle assessment and a regional energy simulation model. The model calculates the emissions, such as CO 2 , nitrogen oxides (NOx), sulfur oxides (SOx), and volatile organic compounds, and their impacts on human health, social assets, primary production, and an integrated index. The analysis quantitatively presented various environmental impacts by region, life cycle stage, and impact category. Climate change was dominant on the integrated index while the other impact categories were also important. Fuel cell vehicles were effective in mitigating local air pollution, especially in high-population regions where many people are adversely affected. Although technology implementation contributes to mitigating environmental impacts at locations of energy users, it also has possibilities to have negative impacts at locations of device manufacturing and raw material processing. The definition of the regional division was also an important factor in energy system design because the final results of life cycle assessments are highly sensitive to region-specific characteristics. The proposed region-specific analysis is expected to support local governments and technology developers in designing appropriate energy systems for regions and building marketing plans for specific targets.
K E Y W O R D Sfuel cell vehicle, hydrogen energy system, industrial ecology, life cycle impact assessment method based on endpoint modeling (LIME), region-specific characteristics, urban employment area
INTRODUCTIONRenewables-based energy systems are greatly needed for sustainability, mitigating global warming, resource depletion, and energy security. Photovoltaic (PV) and wind turbine power generation have been rapidly installed all over the world (IEA, 2017), although such power generations have issues of stable power supply because of their intermittent generation characteristics (Armaroli & Balzani, 2011). A wide range of measures to accommodate a large amount of intermittent renewable electricity has been studied (Lund, Lindgren, Mikkola, & Salpakari, 2015), for example, demand-side management, storage, thermal power plant response, curtailment of renewable-based electricity, and development of grid transmission capability. Energy carriers (ECs) can facilitate the storage and transport of renewable-based energy for applications in energy demands such as vehicles (International Energy Agency [IEA], 2015).
