Wood Mackenzie Unveils Global BESS Integrator Rankings as Battery Storage Installations Exceed 100 GW

The global battery energy storage sector reached a major milestone in 2025, with annual installations surpassing 100 GW for the first time. Wood Mackenzie’s inaugural Global Battery Energy Storage System (BESS) Integrator Comprehensive Ranking identifies Sungrow, Tesla, and CATL as the market's leading suppliers. This ranking reflects a shift in the industry toward prioritizing lifecycle project delivery and financial resilience as storage becomes a critical component of global energy infrastructure.

The global battery energy storage market achieved a record-breaking 100 GW of annual installations in 2025, prompting Wood Mackenzie to release its first comprehensive ranking of AC-integrated BESS suppliers. Sungrow claimed the top spot globally, followed by Tesla and CATL in second and third place, respectively. BYD followed in fourth, while Envision and Trina Storage shared the fifth position. The top ten was rounded out by industry veterans Fluence, LG, Canadian Solar, and Wärtsilä. These rankings evaluate suppliers of factory-assembled solutions that integrate battery cells, power conversion systems, battery management systems, and thermal controls into single AC-connected products.

Wood Mackenzie’s assessment utilized ten distinct criteria, including technology maturity, R&D investment, safety, and supply chain resilience. A key finding of the report is the trend toward vertical integration; every company in the global top ten manufactures at least one critical system component, such as battery cells or power conversion systems. This integration is credited with improving quality control and reducing project execution risks. Furthermore, nine of the top ten companies invested more than 4% of their annual revenue into research and development during 2025, and nine reported positive profitability, which Wood Mackenzie suggests strengthens their ability to honor long-term warranties and service commitments.

The report highlights that the BESS industry is maturing, with 24 different manufacturers achieving Grade A status based on technical and performance standards. Procurement priorities for utilities and independent power producers are shifting away from a narrow focus on technology performance toward a broader evaluation of a supplier’s ability to support projects across their entire multi-decade lifecycle. Timothy Shen, Senior Research Analyst at Wood Mackenzie, noted that buyers are increasingly seeking execution certainty and engineering capability as battery storage is now viewed as critical infrastructure. To navigate evolving trade policies and localization requirements, leading suppliers are also expanding their global manufacturing footprints while maintaining advanced thermal management and safety standards.