Will Redox Flow Batteries be a Widely Deployed Energy Storage Technology?

Conrad Nichols, Technology Analyst at IDTechEx

Over the last decade, redox flow battery (RFB) deployments have been sporadic and few compared to ever-growing Li-ion battery deployments for stationary energy storage applications. However, as the penetration of variable renewable energy (VRE) sources into electricity grids increases globally, so will the need to manage more uncertain and variable electricity supply. ID TechEx's new report, "Redox Flow Batteries Market 2024-2034", shows that the RFB market will be valued at US$2.8B in 2034. There are several factors that will determine how the RFB market will grow over the coming decade.

Future market and advantages of RFBs

Redox flow batteries are well suited to large, grid-scale applications for stationary energy storage. As greater volumes of VRE sources penetrate electricity grids, there may be longer periods of time where these sources of energy are not available. Therefore, energy storage technologies that can provide longer durations of storage, such as RFBs, will be needed to dispatch energy over these longer timeframes.

RFB manufacturers claim their systems have a high cycle life. In some cases, this is 20,000+ cycles, which is much higher than Li-ion batteries. This means that RFBs can dispatch more energy over their lifetime, resulting in a lower levelized cost of storage (LCOS) compared to Li-ion batteries. This presents an advantage for RFBs to be used as an energy storage technology versus Li-ion.

Some RFB technologies, such as vanadium RFBS (VRFBs), can have power output and energy capacity decoupled. To increase energy capacity, electrolyte storage tank sizes require increasing, as well as electrolyte volume. Changes to the cell-stack are only needed when an increase in RFB power output is desired.