Growing renewable penetration will lead to an increased demand for grid-level storage systems. Lux Research says redox flow look likely to fill a part of this niche, with vanadium redox flow batteries (VRFB) gaining the most commercial traction, as it is the most mature technology. VRFB currently account for 75 MWh of deployed storage.
VRFBs will remain the dominant system for the medium-term but bromine-based systems are cheaper and will eventually be better-performing on a 10-year horizon, said Dean Frankel, Lux Research Associate
Lux has presented its findings in its report: Flow Battery Cost Reduction: Exploring Strategies to Improve Market Adoption.
The analyst report has investigated a range of flow battery technologies and market strategies and found that improving power density will be a key factor in the technology coming down in cost. However Lux notes that reduced vanadium 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, writes Lux Researchs Frankel. However, Lux finds that even in the unrealistic scenario of a free vanadium electrolyte, VRFB system costs will be $324/kWh in 2024.
ZnBr redox flow technology is the cheapest flow battery technology, likely to achieve $391/kWh by 2024 putting it below the forecast of $516/kWh for VRFB, however the reports authors say doubts remain regarding ZnBr technology lifetime and operating costs.
Somewhat of a wildcard is lithium-ion-based technologies, such as batteries used in mobile computing devices and e-mobility solutions.
Flow batteries will remain limited to longer-duration applications, and are competing directly with fast-moving targets in Li-ion and other next-generation storage technologies, said Frankel.
The January 2015 edition of pv magazine will feature an exclusive insight into the ambitious plans of Chinese manufacturer BYD, with its lithium-ion-phosphate technology.