- Vanadium redox flow batteries remain the dominant flow battery technology but high electrolyte costs continue to limit uptake.
- Alternative organic and iron based flow batteries are moving toward pilot and early commercial deployment.
- The global redox flow battery market is forecast to reach US$9.2 billion by 2036.
Vanadium redox flow batteries have been under development for several decades and are the most mature and widely commercialised redox flow battery technology. They offer strong performance for stationary energy storage, with energy efficiency of around 70 to 80 percent, cycle life exceeding 20,000 cycles, and the ability to decouple energy capacity from power output. This makes them well suited to long duration energy storage applications, with the potential for lower cost per kilowatt hour at longer storage durations.
Despite these advantages, large scale adoption in grid level energy storage has been constrained by the high cost of vanadium electrolyte. Lithium ion battery energy storage systems continue to dominate the market as their costs decline rapidly and supply chains remain well established. The high cost of vanadium has also driven interest in alternative flow battery chemistries that use cheaper and more abundant materials, including organic and iron based systems.
According to IDTechEx, if these alternative technologies can be successfully commercialised and scaled, the global redox flow battery market could reach a value of US$9.2 billion by 2036, as outlined in its latest report, ‘Redox Flow Batteries Market 2026-2036: Forecasts, Markets, Technologies and Players.’
Vanadium supply remains a central challenge. Around 90 percent of global vanadium production is consumed by the steel industry, with the remainder used in applications such as titanium alloys, defence systems and chemical catalysts. Only a small share is available for electrolyte production, keeping prices high and limiting the competitiveness of vanadium flow battery systems.
One approach to reducing upfront costs is electrolyte leasing. Under this model, the electrolyte supplier retains ownership of the vanadium, lowering initial capital expenditure for project developers. This is beginning to gain traction commercially. In the United States, Storion Energy is supplying vanadium electrolyte to Terraflow Energy for a 9.6 MW and 48 MWh vanadium flow battery project.
However, even with leasing models, vanadium systems often struggle to compete on cost with containerised lithium ion solutions. In the longer term, new vanadium mining projects outside China, particularly in Canada and Australia, could help to increase supply and ease price pressures.
At the same time, developers are advancing alternative flow battery technologies. Organic redox flow batteries are moving from laboratory research into pilot and early commercial projects. To remain cost competitive, these systems must rely on simple synthesis routes, limited use of catalysts and solvents, and demonstrate long term stability with minimal degradation. Non flammable electrolytes are also a key advantage, particularly for applications such as data centres.
In the United States, Quino Energy is scaling production of quinone based electrolytes and currently has capacity equivalent to around 25 MWh per year, with plans to expand. Redox One, working with its sister company Arxo Metals, is developing an iron chromium flow battery and aims to scale electrolyte production to several hundred megawatt hours, while refining business models for long duration energy storage.
Beyond these, a wide range of other chemistries are at earlier stages of development, including hydrogen, bromine, carbon dioxide and saltwater based systems. While some offer the potential for lower material costs than vanadium, performance and bankability vary widely.
IDTechEx expects vanadium flow batteries to continue dominating near term deployments due to their commercial maturity. Over time, however, cheaper alternative chemistries could capture a larger share of the market, particularly where they offer clear advantages over lithium ion systems. Their success will depend on cost reduction, proven performance and the ability to target applications where flow batteries deliver distinct value.
Author: Bryan Groenendaal
