Flow batteries

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In the field of electrochemical innovations, water-based batteries (flow batteries) stand out as a revolutionary solution. They work on the principle of chemical components dissolved in liquids that pass through a system separated by a membrane, providing a unique approach to the utilization of chemical energy.

Flow batteries can currently provide 10 – 12 hours of energy storage, and it is predicted that in the future the storage time will be greater than 100 hours. They are reliable, have a low price and are an environmentally sustainable solution.

A single flow cell A

Why are water-based batteries an exceptional technology?

Water-based batteries are mostly produced from cheap materials, and without ‘conflicting’ materials such as cobalt. Vanadium, the most commonly used electrolyte in flow batteries, is widely available. It can be obtained from waste products such as metallurgical slag, oil field sludge and fly ash.

When a water-based battery with Vanadium electrolyte is retired, the Vanadium electrolyte can be recovered and reused up to 97%, reducing environmental impact and overall costs.

Flow batteries can use organic electrolytes that completely avoid the use of metals. Sodium chloride, a key raw material in organic flow batteries, is widely available on the European market. The general availability of materials for making flow batteries, the possibilities of application and the price would significantly reduce Europe’s dependence on other supply chains.

Water-based batteries have a very long lifespan that can exceed 20,000 cycles and 20 years. During this period, flow batteries can be charged and discharged with almost negligible power losses. This results in higher amortized energy over the entire life of the battery. In addition to a longer lifetime, flow batteries also have lower operating costs for installation and maintenance.

Flow batteries are modular, which means that individual components can be replaced or reused as needed, further increasing the sustainability and flexibility of the system.

invinity home hero img energy2store

Safety is a fundamental characteristic of flow batteries, and the low flammability of the material, together with the aqueous electrolyte, makes them a reliable and safe choice for various applications. This inherent safety makes them an ideal solution for a wide range of environments, from households to industry.

Universal size

Flow batteries represent an energy storage technology that can be scaled to a variety of sizes, from small systems suitable for individual homes to much larger systems suitable for industrial or commercial applications. From size S to XXL – everything is possible.

The scalability of flow batteries is a key advantage compared to other energy storage systems. The ability to adjust the size makes them a versatile energy storage option, adaptable to the specific needs of different applications.

Scalability makes it possible to adapt flow batteries to the specific needs of different applications. A household can install a smaller battery system to store excess solar energy generated during the day, for use at night or during periods of high demand. Alternatively, a company can install a significantly larger flow battery system to provide backup power during outages, manage peak power needs, or reduce energy costs.

Performance, safety and durability

Flow batteries have extremely long operational lives, especially models such as zinc/bromide flow batteries (ZBFBs) and VRFBs, which can exceed 20,000 cycles and 20 years. They can be cycled and recharged during this period with almost no loss of power. This characteristic results in a very low specific cost, approaching the target of 5 c€/kWh proposed by the energy administrations of different countries.

Flow batteries show low flammability, because the key component of the non-flammable electrolyte is water, so there is no risk of explosions. An important safety feature is the storage of active materials separately from the reactive source in the flow battery, reducing the risk of undesirable situations during short circuits.

Studies conducted at VRFB have shown that the technology exhibits stability during external interruptions, with minimal consequences such as smoke, leakage or fire. Additionally, there is no change in efficiency during cycling. Flow batteries offer the highest level of safety compared to other battery technologies on the market today.

Global forecast until 2030. years for flow batteries

Flow batteries have an ambitious goal of reaching 20 GW and 200 GWh capacity worldwide by 2030. Currently, they account for approximately 3-5% of the long-term electricity storage (LDES) market, with the largest installed flow battery having a capacity of 100 MW and 400 MWh.