Quantifying the flexibility potential of electric vehicles in buildings and determining the investment strategy for charging infrastructure

Abstract

Buildings and electric vehicles (EV) play complementary roles in the energy system, enhancing flexible electricity demand through the integration of charging stations within buildings. This study addresses the gap in quantifying the flexibility potential of EVs within buildings and developing investment strategies for charging piles, which have been overlooked in previous research. To tackle this, we propose an equivalent energy storage model and introduce the discount factor as a metric to assess EV dispatch capabilities and optimize the charging infrastructure installation. The research employs three charging modes and a mixed-integer linear programming (MILP) optimization framework to minimize net load variability. Key results demonstrate a tradeoff between the number of charging piles and dispatch capability. Bidirectional smart charging (BSC) significantly enhances flexibility, while charging piles exceeding 30 kW offer limited benefits. Furthermore, integrating photovoltaics (PV) substantially increases dispatch potential, with PV penetration above 20 % making charging pile investments more advantageous than battery. Once PV penetration exceeds 40 %, nearly all parking spaces in buildings can accommodate charging piles. The study quantifies EVs’ equivalent storage capacity and concludes that strategic investment in slow charging piles and high PV penetration is highly effective. This work introduces new metrics for evaluating EV dispatch capability and develops investment strategies for charging piles based on their comparative advantage over batteries. It also highlights the cost-effectiveness of EV infrastructure in enhancing energy flexibility, providing a clear roadmap for optimizing investments in EV charging systems.