Proponents maintain that state-of-the-art battery energy storage systems are safe, but more localities are enacting moratoriums. A large lithium battery energy storage system operated by Key Capture Energy that can power 15,000 homes for two hours during outages or high demand sits surrounded by a fence in Blasdell, N.Y., Tuesday, Sept. 9, 2025. At least a few dozen localities around the United States have moved to temporarily block development of big battery systems in recent years. A large battery system might consist of rows of shipping containers in a fenced lot, with the containers holding hundreds of thousands of cells. China and the United States lead the world in rapidly adding battery storage energy systems.