Enhancing Urban Energy Storage and Optimization through Advanced EV Charging and Vehicle-To-Grid Integration in a Renewable-Based Zero-Energy City

Abstract

The variable natures of renewable power sources and the additional demand from EV (electric vehicle)-charging present unique challenges to electrical grids. This paper explores the potential for optimized energy synchronization at an urban scale in a city striving for net-zero energy status, utilizing wind and solar sources. It examines three scenarios for EV charging: smart, opportunistic, and V2G (vehicle-to-grid), with a specific city as the case study. The research aims to decline the discrepancy among energy supply and demand through intelligent charging and V2G strategies, formulated within the framework of quadratic programming. The analysis indicates that V2G integration, in conjunction with a balanced mix of wind and solar power, significantly enhances load matching in a zero-energy urban context. The transition from basic opportunistic charging to smart mode and then to V2G progressively improves the energy alignment. Within the ideal NZES (net-zero energy system), load matching-efficiency enhances from 67.6% with opportunistic plan to 72.5% with smart ones, and significantly to 83.4% with V2G integration. Further, the full utilization of EV flexibility, particularly through an integrating a battery for EV (2400 MWh) in V2G framework as an alternating ESS (energy storage system), was equivalent to having a 1412 MWh stationary ESS in improving load-matching at an urban scale. The study also highlights the comparative effectiveness of EV batteries in a V2G configuration versus stationary ESSs in optimizing urban-scale energy-matching. These insights demonstrate the substantial potential of EVs to introduce flexibility and resilience into urban energy systems, facilitating the transition to sustainable urban living.