Due to fluctuation in power produced by renewable energy sources such as wind and solar power, energy storage devices are in-separable component of the renewable energy power plant. Energy storage devices like rechargeable batteries stores the surplus amount of the energy produced by renewables and delivers back to the grid when in demand. However, most battery technologies suffer from limited cyclability, poor scalability in terms of power and energy especially when power modules of several hundred kilowatt and energy on a scale of MW-h to GW-h are needed.
Vanadium redox flow batteries (VRFB) are attractive in this respect as it employs highly stable and durable liquid electrolyte for generating the power. This allows scaling up the batteries independently of nominal power and energy storage capacity. When higher power is required, the area of the electrode can be increased and when higher energy storage capacity is required, the amount of the liquid electrolyte can be increased.