COSL LNG‑powered Vessel HAI YANG SHI YOU 551 converted to Battery Powered Vessel

The Haiyang Shiyou 551 is an LNG-powered platform supply vessel (PSV/OSV) owned by China Oilfield Services Limited (COSL). By standardizing and replicating the mature technical pathway first validated on its sister vessel, the Haiyang Shiyou 551 underwent a power battery system retrofitting project in December 2025 – marking Fujian Province’s first ship power battery system retrofit. This project rigorously adheres to the principle of “preserving the vessel’s existing principal dimensions and functions,” employing a containerized power energy storage system that seamlessly integrates with the original LNG dual-fuel propulsion system. With a rated capacity of 1,560 kWh, this storage system achieves full-power load “peak shaving and valley filling” – enabling LNG usage to reach 90.82%, achieving annual savings of 170 tons, a cost reduction of RMB 1.45 million. CATL's power battery technology helped to transition the project from a single pilot to full-scale, standardized replication, successfully obtaining CCS additional notations and providing a replicable and scalable green upgrading model for China‘s entire OSV sector.