Recently, encouraging news emerged in the field of energy storage technology. The 5 kW iron–sulfur flow battery energy storage system jointly developed and manufactured by Shenzhen ZH Energy Storage Technology Co., Ltd., Central South University, and China Huaneng Group Clean Energy Technology Research Institute Co., Ltd. (Huaneng Clean Energy Institute) has obtained a full performance testing report issued by the authoritative third-party agency Beijing Jianheng Certification Center. All test results met the required standards, and the system successfully passed the on-site acceptance of the Huaneng Clean Energy Institute, marking a significant step forward in the commercial deployment of this technology.

According to the testing report (No. CGC-B-CNC-2026-202 A/0) issued by Jianheng Certification Center, the inspection was conducted strictly in accordance with T/HNSDCHYXH003—2024 “General Technical Requirements for Iron–Sulfur Flow Batteries” and the customer-specific testing protocol. After nearly three months of rigorous testing, the system achieved all its key performance targets, including rated power, rated energy, rated energy efficiency, and energy retention.

The iron–sulfur flow battery, as an emerging electrochemical energy storage technology, is gaining attention due to its unique advantages:

High safety: The electrolyte is aqueous, eliminating the risk of fire or explosion and offering outstanding safety.

Low cost: Sulfur and iron are abundant and inexpensive, providing substantial potential for cost reduction.

Long lifespan: With stable active materials and cycle life far exceeding traditional batteries, the overall lifecycle O&M cost is significantly reduced. The recent testing further validates its strong energy retention performance.

Passing both third-party authoritative testing and the acceptance of the Huaneng Clean Energy Institute not only demonstrates strong recognition of ZH Energy Storage’s technological capabilities but also establishes a solid foundation for the large-scale application of iron–sulfur flow batteries in the energy storage sector. Moving forward, ZH Energy Storage will focus on engineering scale-up of this new technology, including the construction of megawatt-level demonstration projects to accumulate operational experience for commercialization and accelerate broader deployment.

In the future, ZH Energy Storage will continue advancing low-cost, high-safety, and long-lifetime energy storage technologies, while collaborating with industry partners to promote the development of long-duration energy storage and contribute meaningfully to building a new power system and achieving China’s “dual-carbon” goals.