March 9, 2023: China is set to put its first megawatt iron-chromium flow battery energy storage system into commercial service, state media has reported.
The move follows the successful testing of the BESS (pictured) in China’s Inner Mongolia autonomous region, TV news channel CGTN announced on February 28.
The project, which the State Power Investment Corporation claims to be one of the largest such systems in the world, is said to comprise 34 Chinese-manufactured ‘Ronghe 1’ battery stacks and four groups of storage tanks.
Using the redox properties of iron and chromium metals in the electrolyte, the BESS can store 6,000kWh of electricity for six hours, the corporation said.
Details of how and where the BESS will be deployed commercially were not disclosed, but the corporation said the system will be used to help shave peak and modulate power frequency.
According to American Clean Power, formerly the US Energy Storage Association, the iron-chromium flow battery is a redox flow battery that stores energy by employing the Fe2+ – Fe3+ and Cr2+ – Cr3+ redox couples.
The active chemical species are fully dissolved in the aqueous electrolyte at all times. Like other true redox flow batteries, the power and energy ratings of the iron-chromium system are independent of each other, and each may be optimized separately for each application.
Iron-chromium flow batteries were pioneered and studied extensively by NASA in the 1970s through to the 1980s and by Mitsui in Japan. The great leap in progress came with the pioneering work, and commercial deployment, using vanadium by Maria Skyllas-Kazaco. She is professor emeritus in the School of Chemical Engineering at the University of New South Wales in Sydney, Australia.