Japan's energy transition scenarios to achieve carbon neutrality under multiple energy service demand: Energy system analysis using the AIST-TIMES model

Understanding the impact of energy service demand on carbon emission reduction strategies is crucial in the context of climate change and sustainable energy transitions. This study aimed to analyze the influence of varying energy service demand levels on Japan's transition to carbon neutrality by 2050 using The Integrated MARKAL-EFOM System (TIMES) model. A scenario analysis was conducted to explore various energy transition pathways under differing future energy service demands and environmental targets. Our findings indicate that achieving net-zero emissions in the electricity sector and enhancing end-use electrification can significantly lower CO2 emissions in the commercial and residential sectors. Renewable energy will become the main power source in the low-emission electricity system, accounting for 49–59 % of the total power generation in 2050. The use of hydrogen and ammonia as low-emission fuels will further aid decarbonization in the industrial and transportation sectors. Despite significant reliance on renewable energy, hydrogen, and ammonia, fossil fuels are projected to remain in use until 2050, necessitating the removal of 141–169 megatons of CO2 to attain net-zero emissions. As Japan pursues high economic growth alongside carbon neutrality, the importance of hydrogen, ammonia, and CO2 removal technologies will escalate, influencing carbon price trajectories from 2035 to 2045.