Urban Energy Transition Toward 2050 Through Gradual Diffusion of PV, EV, and V2H: A Scenario-Based Assessment in Suita, Japan

Source abstract

Achieving carbon neutrality toward 2050 requires not only the adoption of renewable energy technologies but also long-term planning based on their gradual integration into urban systems. This study presents a novel scenario-based framework that quantifies year-by-year impacts of deploying rooftop photovoltaics (PVs), electric vehicles (EVs), and Vehicle to Home (V2H) systems from 2018 through 2050. Five key dimensions are assessed: CO2 emission reduction, cost savings, self-consumption, energy sufficiency, and self-sufficiency. Using Suita City, Japan, as a case study, we analyzed two diffusion scenarios, “baseline (current growth case)” and “accelerated deployment case”. The results indicate that despite high initial investment, an accelerated scenario can achieve up to a 60% CO2 emission reduction and over 25% cost savings by 2050. Importantly, the integrated deployment of PVs, EVs, and V2H surpasses PV-only systems in overall effectiveness from around 2035 onward. By capturing the dynamic evolution of technology impacts over time, this study provides unique and actionable insights for designing data-driven policies supporting long-term urban decarbonization.