Interactive multi-factor analysis for enhancing the economic viability of integrated rooftop PV and EV systems: A Shenzhen case study

The economic viability of integrated photovoltaic and electric vehicle (PV+EV) systems is influenced by multiple interacting factors, creating significant challenges for investment decision-making. To address this complexity, this study develops a comprehensive evaluation framework that integrates three key factors—travel behavior, technological progress, and socio-economic development—into a coupled PV+EV simulation system using the System Advisor Model (SAM), while accounting for their evolutionary uncertainties through scenario-based analysis. This integrated approach enables systematic examination of both individual factor impacts and their synergistic effects on system economics under diverse conditions. Applied to the rooftop PV project in Shangmeilin Village, Shenzhen, the framework demonstrates that technological advancement serves as the primary economic driver through cost reduction, while electricity demand growth enhances economic performance by improving self-consumption rates. Crucially, travel behavior interacts with battery degradation and electricity demand to determine battery cycling patterns, which directly constrain the system's achievable net present value (NPV) by influencing replacement costs. This analysis highlights the critical importance of considering multi-factor interactions rather than examining them in isolation when assessing system economics. Furthermore, comparing economic outcomes across diverse scenarios effectively identifies NPV-maximizing conditions, enabling optimized system design. The local PV self-consumption rate also emerges as a critical determinant in selecting between standalone PV and integrated PV+EV development models. The proposed methodology provides a transferable approach for assessing PV+EV systems across different contexts, offering valuable insights for evidence-based investment planning and policy formulation in distributed energy systems.