Hybrid Portable and Stationary Energy Storage Systems with Battery Charging and Swapping Coordination

As a key technology for renewable energy integration, battery storage is expected to facilitate the low-carbon transition of energy systems. The wider applications of battery storage systems call for smarter and more flexible deployment models. Here we propose a hybrid energy storage system (HESS) model that flexibly coordinates both portable energy storage systems (PESSs) and stationary energy storage systems (SESSs) in power grids. PESSs are batteries and power conversion systems loaded on vehicles that travel between grid nodes with locational marginal price (LMP) difference to alleviate grid congestion. Meanwhile, they integrate renewable energy by charging and discharging at these nodes or swapping (part of) batteries with SESSs. We introduce an on-demand spatiotemporal decision-making model for HESS and analyze the optimal operation strategy and economic benefits of HESS in the case study. The results show that, compared with the total revenue and battery degradation of SESS and PESS alone, the spatiotemporal arbitrage revenue of HESS could increase by up to 6.4% with the amount of battery degradation decreased by 19.6%, in some representative operating periods.