Giant flow batteries can provide large-scale energy storage for the power grid, and falling costs will create a 360 MWh market, led by vanadium-based systems, said Lux Research
Large-scale stationary energy is key to a smarter power grid and for integration of renewable energy. Redox flow batteries are touted as an emerging option, but have been too expensive. Now, falling costs will carve out a 360 MWh market in 2020, worth $190 million, according to Lux Research.
Within the stationary energy storage market, four flow battery chemistries, led by vanadium-based systems, are gaining commercial traction. The vanadium redox flow battery (VRFB) is the most mature technology, and accounts for 75 MWh of deployed systems.
Lux Research analysts evaluated factors driving cost reduction in flow batteries, and market strategies. Among their findings:
ZnBr is cheapest but questions remain. In Lux Research’s model, VRFBs are the most expensive flow battery chemistry, costing $516/kWh in 2024. Zinc bromine (ZnBr) will be the cheapest flow battery at $391/kWh in the same year, but questions remain surrounding their lifetime and operating costs.
Improving power density is key. Flow batteries suffer from relatively poor power density, and improving this metric will drive down costs. Improvements in cell stack power density, for example, can cut VRFB system costs by 33 percent.
Lowering vanadium input costs will not be a panacea. VRFB developers are claiming that sourcing vanadium from flyash will reduce costs from over $500/kWh today to $300/kWh at scale. However, Lux finds that even in the unrealistic scenario of a free vanadium electrolyte, VRFB system costs will be $324/kWh in 2024.