In this article, we'll explore how a containerized battery energy storage system works, its key benefits, and how it is changing the energy landscape—especially when integrated into large-scale storage systems. The largest grid-scale battery in Arizona is now activated and dispatching stored electricity to utility APS. Our energy storage system creates tremendous value and flexibility for customers by utilizing stored energy during. . Containerized energy storage systems (ESS) have emerged as the most scalable and efficient solution for stabilizing energy production and improving project economics.