Recently, the country’s first iron-sulfur flow energy storage device, jointly developed by Hunan Electric Power Research Institute (leading the effort), Central South University, and Zhonghe Energy Storage, was officially connected to the grid and put into operation at the new energy storage demonstration project base of Zhuzhou 220kV Chengjia Substation. The commissioning of this device marks a critical leap for iron-sulfur flow battery technology from laboratory research to engineering application, opening up a new path for the development of long-duration energy storage technologies.
Iron-sulfur flow batteries not only inherit the high safety and long lifespan characteristics of traditional flow batteries but also achieve a significant optimization in electrolyte costs, making them more suitable for long-term, large-scale energy storage. Leveraging the price advantages of bulk materials such as iron and sulfur, their electrolyte costs are 85% lower than those of all-vanadium systems. After achieving large-scale installation, the initial installation cost of iron-sulfur flow energy storage systems is expected to drop below 1 yuan per Wh, and the full-life cycle electricity cost can be as low as 0.1 yuan per kWh. This forms a significant economic advantage over lithium batteries and vanadium batteries, making them a safe and economical solution for large-scale energy storage.
Since January 2024, the “Electricity Doctor” team from the Multi-Energy Complementary Laboratory of the Science and Technology R&D Center of Hunan Institute has been conducting research on flow battery technology in areas such as grid interaction capability, coordination and interaction of new energy storage with grid-connection detection technology, and economics of new energy storage, relying on the “New Energy Storage and Power Grid Integration Collaborative Technology Demonstration” project. By establishing a multi-technology comparative testing system, the team has systematically verified the intrinsic safety, long cycle life (over 15,000 cycles), charge-discharge efficiency, grid integration capability, and long-duration energy storage economics of iron-sulfur flow batteries, providing empirical data support for their large-scale application on the power source side and grid side.
