Impact of EV Charging Schedule on Storage Requirements for a Renewable-driven Grid in California

California is going through a transition towards electric vehicles (EVs) as a pathway to its decarbonization goals. As the number of EVs on the road increases, the load profile will shift, and will affect the role of energy storage in a renewable-driven grid depending on whether the charging infrastructure enables EV charging to be a flexible or inflexible load. This paper considers daytime and nighttime EV charging profiles assuming the anticipated number of EVs and investigates the impact on different types of storage in a renewable-driven grid in California. A hierarchical-storage technique is used to understand the role of different charging profiles on the minimum number of cycles and size of energy storage required in a zero-carbon grid.