$\text{CO}_{2}$ and Cost Impact Analysis of a Microgrid With Electric Vehicle Charging Infrastructure: A Case Study in Southern California

As a part of an innovative Intelligent Transportation System (ITS), this paper investigates the effectiveness of transportation-based microgrid configurations in reducing carbon dioxide $\left(\text{CO}_{2}\right)$ emissions and electricity costs. A case study at the University of California, Riverside (UCR) utilizes high-resolution California Independent System Operator (CAISO) $\text{CO}_{2}$ emission data to assess the environmental impact of each microgrid configuration. It also compares electricity costs to determine potential consumer savings. The results demonstrate that a load-following transportation microgrid strategy can significantly reduce $\text{CO}_{2}$ emissions $(67 \%-84 \%)$ and achieve annual cost savings of approximately $\$ 24,000$, even when accounting for the additional demand from daily electric vehicle (EV) charging at the building. However, battery sizing is crucial for cost-effectiveness, as load-following exhibits diminishing returns. Doubling battery capacity may yield negligible reductions in electricity costs and $\text{CO}_{2}$ emissions after exceeding certain threshold. This emphasizes the importance of optimizing battery capacity to achieve a balance between cost and environmental impact. The study further reveals that Level 2 chargers in a commercial building generally have minimal impact on building demand and energy charges. Conversely, a single Level 3 DC fast charger has a more significant impact, requiring increased solar and battery storage capacity for further cost reduction.