Development of an integrated renewable energy system with district heating: A comparative study between Japan and Denmark

To achieve a fully decarbonized society, energy system design must account for regional characteristics, including renewable energy potential and patterns of energy consumption. Comparative analysis among regions with similar attributes can provide valuable insights into effective transition pathways. In this study, Japan's decarbonization pathways are explored by developing advanced energy scenarios, with a particular focus on the integration of district heating systems. In addition, seismic vulnerability is explicitly considered through an expected loss ratio approach to evaluate infrastructure resilience. The results show that the implementation of district heating reduces electricity production by 8.4% in a 100% renewable energy system for Hokkaido, a region with heating and cooling degree days comparable to Denmark. The performance of these scenarios is benchmarked against Denmark's IDA 2045 decarbonization plan. The analysis indicates that Hokkaido can achieve lower system costs owing to its abundant renewable resources, particularly biomass. Furthermore, system cost intensity is reduced to 28.6% of the baseline when district heating is implemented. An assessment of seismic vulnerability reveals that seismic risk does not constitute a major barrier to district heating deployment, as the maximum expected loss ratio is limited to 9.9% in Hokkaido.