Flow batteries are long in lifespan, and convenient in assembly and expansion, while also capable of storing 1-20 hours of batteries. Chinese vanadium redox battery (VRB) supplier Rongke Power has now constructed the largest VRB energy storage plant in Liaoning, which is scheduled to commence operation starting from October.

The technology is derived from the VRB energy storage technology developed by the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and attains mutual conversion of electricity and chemical energy through the redox generated by vanadium-ion electrolytes by treating vanadium ions in various valences as active substances. The official initiation was in 2016.

The first phase is expected to have an investment of RMB 1.9 billion and an installed capacity of 100MW/400MWh, with 100,000kWh of electricity as the hourly rated power that can store 400,000kWh of electricity at most. The China Energy Storage Alliance (CENSA) pointed out that the total investment would arrive at RMB 3.8 billion.

Rongke Power aims to offer peak cut grid services in the future through flow batteries, since the elevated penetration rate of intermittent renewable energy such as solar and wind power would require energy storage systems to stabilize the supply of power grids.

Flow battery is a form of electrochemical energy storage, and most flow batteries are currently used for energy storage at power grids due to their larger sizes, where vanadium-ion electrolytes are circulated through pumps under chemical reduction and oxidation. Flow batteries, thanks to their safety and longer life span, can be used for more than 20 years, and are now gaining increasing popularity.

Solar and wind power can lend a helping hand to the flow batteries when power consumption is low, before releasing electricity during peak power consumption periods. Flow batteries can also provide auxiliary services for power systems such as peak shaving and frequency modulation by pairing with thermal power generation and nuclear power that would elevate flexibility of power systems.

 (Cover photo source: Dalian Institute of Chemical Physics)