Wood Mackenzie has placed Sungrow, Tesla and CATL at the top of its first global ranking of battery storage integrators, with CATL taking third, a strong showing for a company whose roots lie in cell manufacturing. The assessment lands at a milestone moment: annual BESS installations worldwide exceeded 100 GW for the first time in 2025.
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The ranking covers AC-integrated battery storage: factory-built products combining batteries, power conversion, battery management, thermal management and controls in a single AC-connected unit. Wood Mackenzie assessed 22 integrators across six countries against ten criteria, from technology maturity and R&D through safety and vertical integration to ESG performance and financial strength. The weightings are revealing: half the total score rests on long-term corporate competitiveness – R&D, supply chain stability and ESG at 15 percent each, financial health a further five – with 30 percent for product capability and 20 percent for delivery track record.
Where the weighting favours CATL
Wood Mackenzie
That weighting plays to CATL's strengths. R&D spending has exceeded RMB 100 billion over the past decade, more than RMB 20 billion of it last year, alongside some 60,000 patents granted and pending. Goldman Sachs analysts have noted that CATL is currently the only listed global battery maker whose return on invested capital exceeds its cost of capital. The methodology rewards exactly this sort of balance-sheet strength, as storage assets must operate, and be serviced, for decades.
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Every company in the top ten manufactures at least one critical component in-house, and vertical integration is scored as the ratio of self-produced cells, power conversion and battery management to shipments. CATL spans cells, battery management, packs and system integration, a chain it credits for product consistency on gigawatt-hour-scale projects. Its track record also runs deep: the company supplied China's Zhangbei demonstration project as early as 2011 and reports 93 percent state of health after eight years, with annual degradation below one percent.
The ranking will now be published annually, assessing suppliers of AC-coupled storage on the previous calendar year's performance. (TF)
