Optimal configuration of shared energy storage for multi-microgrid systems: Integrating battery decommissioning value and renewable energy economic consumption

Abstract

With the evolution of energy structures and the rise of the sharing economy, shared energy storage is poised to become a standard for managing energy demand and enhancing flexibility amidst wind and solar variability. This paper introduces a two-layer optimization method for shared energy storage configuration in multi-microgrids, focusing on economic efficiency in combined cooling, heating, and power (CCHP) systems. It accounts for the residual value of retired batteries to facilitate future battery recycling and improve energy utilization. The upper layer addresses capacity allocation, while the lower layer optimizes system operations. Using the Karush–Kuhn–Tucker conditions, the lower layer’s constraints are integrated into the upper layer, with the Big-M method applied for linearization. The model’s effectiveness is demonstrated through four scenarios, showing that shared energy storage increases renewable energy consumption from 73.05% to 99.93%, reduces annual operating costs, and achieves cost recovery in 4.44 years. However, battery degradation is higher than anticipated, necessitating an 17.6% increase in capacity allocation when battery life is considered. Service providers should procure low-degradation, high-performance batteries and plan battery retirement around the twelfth year to maximize residual value, fostering a beneficial scenario for both users and providers.