Analyzing incentivized self-consumption and integration of rooftop solar and battery electric vehicles in residential energy systems

The integration of rooftop solar photovoltaic (PV) systems with battery electric vehicle (BEV) in residential settings offers potential for improved energy efficiency and reduced reliance on grid electricity. However, achieving high levels of solar self-consumption is challenging due to the mismatch between solar generation and the stochastic nature of BEV charging behavior. This study aims to assess how varying levels of solar PV adoption and the presence of vehicle-to-everything (V2X) capabilities influence solar self-consumption and household energy self-sufficiency in BEV-owning households. Using an agent-based PV–vehicle grid integration (PV–VGI) planning tool and Monte Carlo simulations, the study models realistic household energy use and BEV charging behaviors across 14 zones in the Tokyo Metropolitan Area. Four scenarios—based on different PV penetration rates and rooftop suitability—are analyzed with and without V2X capabilities. Results show that V2X enhances solar self-consumption by improving temporal alignment between solar generation and charging demand. However, this added flexibility can also increase overall household energy demand, potentially reducing energy self-sufficiency under limited PV capacity. Without V2X, BEV charging remains poorly aligned with solar availability. To maximize the benefits of integration, coordinated action is required from energy regulators, utilities, urban planners, and consumers. Supportive policies should include incentives for smart charging, dynamic pricing, investment in residential grid infrastructure, and the adoption of system-level performance metrics that reflect energy flow efficiency and flexibility.