Abstract
Wide-scale integration of inverter-based renewable energy sources (RESs) poses new technical challenges in contemporary power systems, which are characterized by lower system inertia, reduced grid strength, higher intermittency, and network congestion. Battery energy storage systems (BESSs) have been recognized as a key enabling technology in modern power systems, providing both operational flexibility and requisite support services. This chapter presents a unifying perspective on the role of BESSs in improving both the economic and reliable operation of power systems. To this end, reliability-oriented BESS planning for the provision of virtual inertia under uncertain RES conditions is discussed, alongside uncertainty-aware BESS energy management that accounts for variability in both renewable generation and load demand. Emerging BESS deployment models, particularly community battery systems, are also considered, highlighting their potential for shared utilization among multiple stakeholders and improved economic efficiency. By establishing a linkage between system-level reliability requirements and associated operational and economic considerations, this chapter provides a holistic view of battery energy storage systems and their multi-faceted role in supporting reliable power systems, both today and in the future.