As one of the world’s largest energy storage markets, North America holds the most rigid standards for the energy storage system. The ESS ST556kWh-250UD is completely in compliance with UL9540, UL9540A, and the updated National Fire Protection Association (NFPA) criteria NFPA 855, NFPA 70, which are well recognized & authoritative proof of system with high quality, safety and reliable performance. Read more