Optimization of Energy Storage Size and Operation for Renewable-EV Hybrid Energy Systems

This paper focuses on sizing and operation optimization of hybrid energy systems (HES), which integrate multiple electricity generation units (e.g., nuclear, renewable) and multiple electricity consumption units (e.g., grid, EV charging station, chemical plant) for effective management of variability in renewable generation and grid demand. In particular, the operation optimization considers the optimal charging and discharging profile of energy storage element (ESE) so that the variability of the industrial scale chemical plant is minimized. The receding horizon optimization approach is adopted to solve this operation optimization problem, which is then reformulated into a linearly constrained quadratic programming problem, suitable for running in real-time. The design optimization problem finds the optimal sizes of ESE to balance the variability of the chemical plant and the economic cost of ESE installation. Global optimization technique (e.g., DIRECT) is employed to numerically solve the proposed sizing optimization problem, due to its non-convexity.