Saudi Arabia is expanding renewable energy deployment, while electricity demand is influenced by summer cooling peaks, significant industrial loads, emerging digital infrastructure, and geographically distributed giga-projects. As a result, grid-scale battery energy storage systems (BESS) are becoming essential power-system assets. This review establishes a Saudi-specific framework for deploying BESS to integrate solar and wind generation, manage peak demand, enhance grid reliability, and minimize curtailment. The paper adopts an MDPI-style review methodology, incorporating technology classification, thematic synthesis, multi-criteria decision analysis (MCDA), and implementation-focused discussion. Recent literature from 2020 to 2025 is synthesized, covering battery technologies, energy management systems, hybrid storage, smart grids, planning models, market design, safety, and Saudi renewable-energy development. The review determines that lithium-ion BESS is most appropriate for four-hour grid services, renewable smoothing, and peak shaving, while flow batteries, sodium-ion batteries, hybrid BESS-supercapacitor systems, and hydrogen-linked storage are better suited for longer-duration or lifecycle-sensitive applications. The proposed architecture integrates renewable plants, substations, grid-scale storage units, energy management systems, cybersecurity controls, and performance key performance indicators (KPIs). The study concludes that effective Saudi deployment relies on situating BESS to alleviate network constraints, reduce evening peaks, maintain battery health, enable transparent dispatch, and support the national transition toward a diversified, reliable, and lower-emission electricity system [1-5].