Not surprisingly, it is expected that by 2030 the market associated with this technology will reach a value of more than 700 million euros worldwide. All this, driven mainly by the suitability and attractiveness of this technology for use in strategic applications and industries of the future of the energy transition, such as those associated with renewable energies.

This is because redox flow batteries are particularly appropriate for storing energy from renewable sources such as the sun and wind, which are intermittent in nature. Their ability to store large amounts of energy for extended periods without significant capacity degradation allows them to compensate for the variability of these energy sources. In addition, they can release energy during peak demand, which facilitates a more efficient integration of renewable energies into the power grid.

In addition, these batteries are also expected to play a critical role in other uses, such as stabilizing the power grid by regulating power quality and mitigating voltage fluctuations. This is a crucial factor in preventing blackouts and ensuring a constant and reliable power supply. These features are also what position them as a truly attractive alternative for other applications such as data centers and telecommunications, which are clearly on the rise in the increasingly digitalized society in which we live.

Different alternatives with different levels of maturity

As detailed in previous blog posts, a redox flow battery is a type of rechargeable battery that stores energy in two liquid electrolyte solutions, which circulate through a membrane-divided system. Energy is generated by the reduction and oxidation of these electrolytes as they pass through electrochemical cells during the charging and discharging processes. The distinctive feature of these batteries is that the electrolyte, where the energy is stored, is separated from the reactor or electrochemical cell, allowing them to handle large amounts of energy for extended periods of time.

Based on this concept, and as with other electrochemical storage technologies, when we talk about redox flow batteries we are not referring to a single type of battery. This alternative encompasses different approaches that use different materials as the basis for their development.

Currently, vanadium redox flow batteries are probably the most mature solution on the market. They have high durability and stability, can be recharged and discharged simultaneously and do not decrease in capacity over time. This makes them ideal for large-scale energy storage applications such as renewable energy management and grid stabilization.

To a lesser level of maturity, we also find other solutions such as those based on organic quinone compounds, which are abundant and would allow accessible solutions from a cost point of view. Similarly, technologies based on zinc and combinations of hydrogen and bromine are some of the other approaches that are taking place within the science in order to establish redox flow technologies.

Key challenges along the way

Despite the remarkable potential of redox flow batteries to revolutionize large-scale energy storage and their integration with renewable sources, there are still several challenges that the industry is already working on to maximize their impact and long-term viability.

The main one, at present and as can probably be guessed from the information above, is the efficient industrialization of their manufacturing processes. Although technologies such as vanadium are relatively advanced, large-scale production remains an obstacle. Building manufacturing facilities that can produce these batteries economically and to the necessary quality standards is crucial. In addition, scale-up must be done without compromising the efficiency and durability of the batteries, aspects that are essential for market acceptance.

On the other hand, there is also technological optimization. Continuously improving the efficiency and capacity of redox flow batteries is another major challenge. While the energy density of some current solutions such as those based on vanadium is adequate for certain applications, it is crucial to increase this density in all the above-mentioned alternatives to make them truly competitive in the market.

Likewise, heat management and minimizing energy loss during charge and discharge cycles are areas that require significant technical innovations. In addition to all this, cost competitiveness is still being addressed through areas such as improving service life.

Finally, another key aspect is the integration of redox flow batteries into existing power grids and new renewable energy infrastructures, which still presents both technical and regulatory challenges. Appropriate regulation that can accompany technological innovation will be crucial to facilitate the large-scale deployment of these solutions. In addition, batteries must demonstrate their ability to operate safely and effectively in different environments and climatic conditions.

In short, as can be seen, there are still great challenges to be faced where the work carried out by research centers such as CIC energiGUNE is vital. Above all, in order to ensure the deployment of a technology that can add another link in the chain towards a greener and more sustainable future.

With continued innovation and market expansion, redox flow batteries could play a transformative role in global energy storage, supporting the transition to a cleaner and more stable energy future.