Evaluation of net cost savings for daytime charging to support transportation electrification

This study explores the impact of light-duty electric vehicle (EV) charging patterns on California's utility-scale energy storage and charging infrastructure needs. Daytime charging reduces storage requirements as solar electricity can be used directly rather than being stored in a battery for EV charging after the sun sets, reducing storage costs by an order of a billion dollars. However, daytime charging will require new infrastructure. We estimate the needed infrastructure cost by comparing level-1 with level-2 charging. We find that by using level-2 chargers at today’s prices, the added infrastructure cost will be comparable with the cost savings from the reduced storage needs. Moreover, if a significant fraction of level-2 chargers is replaced with level-1 chargers, non-residential charging infrastructure costs will be reduced significantly, making daytime charging economically more attractive. The insights help develop future strategies and policies for charging infrastructure and energy storage systems.