This case study delves into the innovative role of Battery Energy Storage Systems (BESS) in stabilising and supporting modern grids, with a particular focus on a large-scale BESS project undertaken by Tata Consulting Engineers (TCE). The Need for Grid-Connected BESSBattery energy storage systems (BESS) use rechargeable battery technology, normally lithium ion (Li-ion) to store energy. The energy is stored in chemical form and converted into electricity to meet electrical demand. gov Cover Photos by Dennis Schroeder: (clockwise, left to right) NREL 51934, NREL 45897, NREL 42160, NREL 45891, NREL 48097, NREL 46526. All procurements must be thoroughly reviewed by agency contracting and legal staff and should be modified to address each agency's unique acquisition process, agency-specific authorities, and project-specific characteristics. INSTRUCTIONS FOR USING THIS DOCUMENT This document is meant to be used. Integration of energy storage products begins at the cell level and manufacturers have adopted different approaches toward modular design of internal systems, all with the goal of improving manufacturing efficiencies, reducing maintenance time and improving operational reliability.