Wood Mackenzie launches first global BESS integrator ranking as battery storage installations reach an all-time high

The global battery energy storage industry reached a major milestone in 2025, surpassing 100 GW of annual installations for the first time. As battery storage becomes critical infrastructure for modern power systems, Wood Mackenzie's first-ever Global Battery Energy Storage System (BESS) Integrator Comprehensive Ranking finds that buyers are increasingly selecting suppliers based on their ability to deliver across the entire project lifecycle.  

This ranking focuses on AC-integrated battery energy storage systems, defined as factory-assembled solutions that integrate the battery, power conversion system (PCS), battery management system (BMS), thermal management, and control systems into a single AC-connected product. 

Wood Mackenzie's comprehensive ranking reflects how utilities, independent power producers and developers increasingly evaluate integrators during procurement. Suppliers are assessed across ten criteria, including technology maturity, research and development, safety, vertical integration, supply chain resilience, ESG performance and financial strength. 

Sungrow ranked first in Wood Mackenzie's 2026 Global BESS Integrator Comprehensive Ranking, followed by Tesla and CATL. BYD ranked fourth, while Envision and Trina Storage shared fifth place. Fluence, LG, Canadian Solar and Wärtsilä completed the global top ten.  

2026 Global BESS Integrator Comprehensive Top Ten Ranking  

Source: Wood Mackenzie 

“Battery storage is following the same path as other critical infrastructure industries,” said Timothy Shen, senior research analyst, solar supply chain at Wood Mackenzie. “As projects become larger and operate over decades rather than years, buyers are placing greater emphasis on execution certainty. That is elevating considerations such as financial resilience, engineering capability and long-term service support alongside technology performance.” 

The latest assessment shows following key competitive differentiators for the leading battery storage integrators:  

1. Experience and execution capability.

Six of the global top ten integrators have more than a decade of battery storage integration experience, reflecting the growing importance of system design, commissioning expertise and long-term operational performance as projects continue to increase in size and complexity. 

2. Higher value chain controls. 

Every company in the global top ten manufactures at least one critical system component including battery cells, power conversion systems or battery management systems, to support its own deployments. Vertical integration is helping improve product compatibility, strengthen quality control and reduce execution risk for customers delivering increasingly large and complex storage projects. 

3. Technology leadership and financial resilience 

Eight of the top ten exceeded Wood Mackenzie's benchmarks for system efficiency and lifetime cycle performance, while nine invested more than 4% of annual revenue in research and development during 2025. Nine also reported positive profitability, providing greater confidence in their ability to support long-term warranties and service commitments as battery storage assets are increasingly expected to operate for decades. 

In addition, 24 manufacturers achieved Wood Mackenzie's Grade A designation, reflecting the continued maturation of the global BESS industry and the growing number of suppliers meeting increasingly rigorous performance benchmarks.  

2026 Grade A BESS Integrators 

Source: Wood Mackenzie 

The industry's leading suppliers are also expanding their global manufacturing footprint to respond to changing trade policies and local content requirements while maintaining internationally recognised safety certifications and robust thermal management systems. 

“The next phase of competition will be determined less by manufacturing scale alone and more by the ability to execute consistently across global markets,” added Shen. “As localisation requirements, financing expectations and technical standards continue to evolve, suppliers that can adapt while maintaining quality and delivery certainty will be best positioned for long-term growth.” 

Wood Mackenzie's Global BESS Integrator Comprehensive Ranking is published annually and evaluates suppliers of AC-coupled battery energy storage systems based on company performance during the previous calendar year.