China's largest vanadium flow battery storage system operates in Xinjiang

In Jimsar county of Changji Hui autonomous prefecture, Xinjiang Uygur autonomous region, sits a solar power project that combines 1 million kilowatts of photovoltaic power generation with a battery system that can put out 200 megawatts of power and store 1 million kWh of electricity using vanadium flow battery technology.

Its all-vanadium redox flow battery stores and releases electricity by "driving" vanadium ions to undergo chemical reactions between different valence states, a process similar to "putting electricity into a liquid and releasing it from the liquid".

Run by the Xinjiang branch of China Three Gorges Corporation, the project entered commercial operation in May. The energy storage system is the largest of its kind across the country, said Deng Fubin, who is in charge of the production team at the company's Jimsar power generation division.

Deng said the system comprises 240 energy storage units, with a storage duration of five hours. A single charge can fully power 16,000 electric vehicles.

Wang Yaoshen, a staff member at the division, said: "Compared with traditional energy storage stations, all-vanadium redox flow battery stations have larger capacity, greater scalability and a longer life cycle, which can reach 20 years or more.

"They are also safer, with no risk of thermal runaway compared with lithium batteries. We can store daytime solar power and discharge it at night."

Deng said the clean electricity generated by the project is used within Xinjiang and beyond, reaching as far as Anhui province in eastern China.

The project is capable of supplying 1.72 billion kWh of clean electricity annually, equivalent to saving 519,000 metric tons of standard coal per year and reducing carbon dioxide emissions by 1.42 million tons, while also cutting emissions of sulfur dioxide, nitrogen oxides, dust, and wastewater.

According to Deng, the project marks a breakthrough in the application of large-capacity, long-duration energy storage technology in China. It is fully domestically produced, and the crystalline silicon photovoltaic modules adopted are among the most cutting-edge technologies in the field.