- System confines fire to a single enclosure under extreme test conditions.
- Adjacent units remain below 51.3°C, far under thermal runaway threshold.
- Milestone strengthens global confidence in utility scale energy storage safety.
Jinko ESS has received the first large scale fire testing report issued by CSA Group under the draft UL 9540A 6th Edition, marking a significant development in the validation of grid scale energy storage safety.
The certification confirms that the company’s SunTera liquid cooling energy storage system can effectively contain a fire within a single enclosure, preventing propagation to adjacent units. The report was formally presented by CSA Group fire testing specialist Josh Dinaburg to Carl Yang, General Manager of ESS Products at Jinko ESS.
The large scale test was conducted on February 10 2026 at a specialised facility in Suzhou in Anhui Province. Four SunTera systems were deployed in a configuration replicating real world plant layouts, with spacing reduced to just 15 cm to simulate highly constrained conditions.
Testing parameters reflected a worst case scenario. Active fire suppression systems were disabled, no human intervention was allowed, and systems were operated at 100% state of charge. The initiating unit recorded flame temperatures exceeding 1000°C. Despite this, adjacent units maintained maximum cell temperatures below 51.3°C, well under the threshold for thermal runaway as defined by UL 9540A.
Results showed that the fire remained confined to a single enclosure, demonstrating strong resistance to thermal runaway propagation at the system level. This outcome validates the robustness of SunTera’s safety architecture under extreme stress conditions.
Wu Wei, Commercial Director of the Industrial Unit at CSA Group China, said the test was conducted in line with the CSA C800 standard and the latest UL 9540A draft. He noted that the rigorous methodology and detailed data collection confirmed the system’s ability to mitigate fire spread risks and meet global regulatory requirements.
Carl Yang stated that certification by CSA Group reinforces Jinko ESS’s ability to deliver energy storage systems validated under extreme conditions. He added that the company will continue to use advanced testing to convert edge case risks into standard engineering considerations, shifting safety from a qualitative concept to a measurable outcome.
The successful test represents a further step in strengthening the global safety framework for battery energy storage systems. Jinko ESS said it will continue to prioritise engineering driven validation to ensure reliability, predictability and control across its solutions as deployment of large scale storage accelerates worldwide.
Author: Bryan Groenendaal
