Expansion Planning Model Coordinated with both Stationary and Transportable Storage Systems for Transmission Networks with High RES Penetration

Variable Renewable Energy is becoming relevant in power systems across the world as it supplies an increasing percentage of the demand. In that respect, both integrated and distributed Battery Energy Storage Systems can play an increasingly relevant role in modern power system transition. This paper focuses on Battery-based Energy Storage Transportation (BEST), that is the transportation of modular battery storage systems via train cars or trucks, representing an innovative alternative for managing transmission congestions and enhancing variable renewable energy utilization. In particular, this paper proposes a transmission expansion planning model coordinated with both stationary and transportable storage systems investment. The objective function of the coordinated planning problem is the minimization of the total system cost, which includes the investment cost of candidate units, and the system operation cost. The BEST vehicle scheduling problem is addressed through the use of a particular mathematical function that avoids the inclusion of several binary variables and results therefore suitable for large scale power systems. Moreover, case studies are carried out to identify the storage systems optimal location and both optimal location and size of storage systems. The model has been implemented and successfully validated in the modified Garver's 6-node system. The BEST usefulness is analyzed for both the above-mentioned case studies and the relevant results are discussed.