A single test can burn up an entire energy storage container, with direct costs exceeding one million yuan. Over the past two years, the wave of "container burn tests" in the energy storage industry has made many people wince at the expense. From leading domestic integrators such as BYD, Sungrow, and Huawei Digital Power, to international giants such as Tesla and Fluence, more than a dozen companies have publicly showcased their large-scale fire test results.
Previously, unified mandatory standards for large-scale fire testing of energy storage systems had not yet been fully implemented, so manufacturers paid out of pocket to begin this costly testing race. Today, as globally authoritative standards are successively taking effect, the true value of this seemingly "luxurious" investment has become unmistakably clear.
Ⅰ. The Convergence of Market Demand and Standards
In recent years, fire incidents at energy storage power stations have occurred from time to time around the world, and safety anxiety has gradually become a major concern limiting industry growth. Downstream power station investors, insurance companies, and fire authorities are demanding ever-higher levels of safety from energy storage equipment. Frequent lithium battery energy storage incidents in North America, for example, have greatly dissatisfied authorities having jurisdiction, AHJs, and caused heavy losses for insurers.
But unlike the earlier gap between urgent demand and incomplete standards, the energy storage market has now officially entered an era of mandatory compliance:
1. NFPA 855, 2026 edition, fully takes effect:
The new version elevates the large-scale fire test, LSFT, in Annex G.11 into a core guideline, making it a mandatory standard for fire acceptance in North America and many other regions worldwide. Without the latest LSFT report, a project may not even be able to obtain a construction permit or pass engineering acceptance.
2. UL 9540A, Sixth Edition, has been released:
This internationally authoritative standard has upgraded LSFT from a voluntary assessment to a mandatory requirement. It not only requires testing of a single container or cabinet, but also mandates that active fire suppression systems be disabled to simulate the "worst-case scenario" in a real site array, directly verifying whether thermal runaway will propagate to adjacent cabinets.
From companies' voluntary exploration in 2024 to today's extreme real-world tests completed by companies such as Huawei Digital Power, Sungrow, and Hithium based on UL 9540A:2026 and the latest NFPA 855 requirements, LSFT has quietly reshaped the logic of market selection. The market now gives priority to companies with large-scale fire test data.
The cost of testing cannot be ignored. A complete large-scale fire test destroys not only an energy storage container worth hundreds of thousands of yuan, together with internal batteries, PCS equipment, and other systems, but also requires payment of third-party testing fees and related expenses. The total cost of a single test is generally over one million yuan. If multiple rounds of optimization and iteration are carried out, the cost rises even further. But when it comes to the red line of safety, this investment is far more than simply following a trend.
Ⅱ. Why Must Companies "Burn Money"?
1. Resolving safety anxiety: building market trust with data
For the energy storage industry, safety must be proven with data. In the past, small-scale tests on individual cells or modules could not simulate chain reactions such as thermal runaway propagation, pressure relief, and structural deformation inside enclosed spaces. LSFT, by burning a complete energy storage container or even simulating a cabinet array, demonstrates to the market that the product can still control risks under extreme fire conditions, such as preventing deflagration and limiting fire spread. Such empirical data is far more convincing than any marketing claim.
2. Extreme testing and breakthroughs in new scenarios
Recent test conditions are becoming increasingly stringent. For example, Hithium challenged an "open-door burn test." Huawei Digital Power and other companies have verified intrinsic safety isolation capabilities under extreme conditions such as weak fire protection and large-space environments. The industry has even completed the world's first large-scale fire test in an indoor environment, such as an AIDC computing center backup power scenario, verifying that even if severe thermal runaway occurs in an enclosed space, propagation can be blocked without damaging the building structure.
3. A dual "passport" for insurance and fire approval
For insurance companies, the compensation risk associated with energy storage power station fires is enormous. They urgently need real fire data to assess risk exposure. By providing data verified through authoritative testing, companies can more easily unlock financing for high-value projects and obtain significantly reduced insurance premium rates. For fire regulators, key information in the test report, such as fire growth rate, flame height, toxic gas emissions, and structural collapse risk, can directly guide fire response plans and equipment configuration.
4. Optimizing product and engineering design
In a raging fire, weak points in product design are fully exposed. Testing can not only optimize battery management strategies, ventilation and pressure relief design, and fire protection linkage, but also feed back into engineering construction. With accurate LSFT measured data, power station builders can demonstrate to regulators the system's own anti-propagation capability, thereby significantly reducing equipment spacing and lowering the complexity of fire protection construction, cutting engineering costs while improving the overall safety margin.
From voluntary testing to mandatory compliance, large-scale fire testing has evolved from a "luxury" used by companies to showcase competitiveness into a true "passport" and hard threshold for the global energy storage market.
As technology advances and testing procedures become more standardized, LSFT is raising the entry threshold for the entire energy storage industry and eliminating weaker companies that lack intrinsic safety design capabilities. As an inevitable choice for the safe development of the energy storage industry, large-scale fire testing has shifted from "we have to burn" to "we choose to burn," ushering in a new normal where companies simply cannot enter the market without it.
