Core Viewpoint - The article discusses the increasing importance of large-scale fire testing for energy storage systems, which is becoming a mandatory requirement under the upcoming 2026 NFPA 855 standard, shifting from an optional practice to a necessary entry threshold for the industry [1][13]. Group 1: Participation in Fire Testing - A total of 13 energy storage companies, including major players like Envision, Fluence, and BYD, have engaged in large-scale fire testing (LSTF) [1][2]. - The majority of these companies are energy storage system integrators, with a notable presence in the overseas market [2][3]. - The testing has expanded from primarily top-tier companies to include second and third-tier brands, indicating a broader industry engagement [3]. Group 2: Testing Equipment and Standards - Most of the tested equipment consists of containerized energy storage systems, with SigenStack from Sige New Energy being the only exception focusing on commercial energy storage [4]. - The testing is primarily based on standards such as CSA C-800, CSA TS-800, and UL 9540A, with the latter being updated to separate large-scale fire testing as a core guideline [12][13]. Group 3: Testing Conditions and Results - The testing conditions are rigorous, often involving multiple battery units placed in close proximity, with systems charged to 100% state of charge (SOC) and fire suppression systems disabled [9][10]. - Companies have reported varying results, with some achieving significant control over thermal runaway and fire spread, such as Envision maintaining low temperatures in adjacent units during testing [10][16]. - The costs associated with these tests are substantial, with some companies like Sungrow estimating expenses around 30 million yuan for a single test [6]. Group 4: Future Implications - As the NFPA 855 standard is implemented, large-scale fire testing will become a critical requirement for energy storage companies, serving as a testament to their technical capabilities and financial strength [13][14]. - The current lack of similar standards in domestic markets raises questions about whether large-scale fire testing will become a technical barrier in the industry [14].