Redox Flow Batteries were initially developed by NASA in the 70's for its space programme. The expiry of a number of patents related to RFBs in 2006 has sparked an industrial race to commercialization, which will grow to become a $4bn market by 2027.
Often perceived as an underdog, redox flow batteries (RFB) may not deliver the same power of a Li-ion battery, but they can compete in terms of cycle life, safety, and reliability for stationary applications. Utilities around the world are avidly testing RFBs in pilot projects, while China is underway in the construction of the largest battery in the world (200 MW / 800 MWh), which will be entirely powered by redox flow batteries. If successful, this project will be replicated across the country and probably also in Europe and the US.
Stationary energy storage is a cost-effective way to increase renewable energy utilisation, as well as to implement energy efficiency measures, both at residential, industrial, and grid level. The redox flow battery technology, despite higher upfront costs and lower energy density, has a shorter payback time thanks to a good capacity retention even after many thousands of cycles. Additionally, redox flow batteries (RFBs) retain most of their initial value thanks to the possibility to recycle their core components more easily than other battery chemistries. Some RFB chemistries, like that based on vanadium, are already commercial and set to capture most of the $4bn market value.