The all-vanadium liquid flow battery energy storage system consists of an electric stack and its control system, and an electrolyte and its storage part, which is a new type of battery that stores and releases energy in a liquid electrolyte.
For the vanadium system, developments are already underway in the PRoC to reduce electrolyte costs 33 and electrode processes of RFBs have been improved to the point where system efficiencies of 70–80% can be expected at the kW- to MW-scales (Table 1).
Are all-vanadium batteries a good choice for large-scale energy storage?
The all-vanadium battery is the most widely commercialised RFB used for large-scale energy storage. It has a low environmental impact with regard to the environmental polluting potential of vanadium 12, especially when compared to traditional lead-acid batteries 13.
The overall internal cost is ≈$3,300 kW −1. Jossen and Sauer estimated that 1 kW to 100 MW scale all-vanadium-based storage systems were economically feasible for specific applications. Moreover, unlike enclosed batteries, the authors considered that the economic favourability of RFBs increases dramatically with nominal energy capacity.
The commercial development and current economic incentives associated with energy storage using redox flow batteries (RFBs) are summarised. The analysis is focused on the all-vanadium system, which is the most studied and widely commercialised RFB.
Primary outcomes of energy storage could include energy efficiency improvements (and thus a reduction in the use fossil fuel-powered utilities) and an increased use of renewable energy sources. The all-vanadium battery is the most widely commercialised RFB used for large-scale energy storage.
Recent developments concerning the all-vanadium RFB technologies in Austria, Japan, China and Thailand reveal a significant level of battery commercialisation, namely with respect to electricity grid load levelling, utility-scale renewable electricity generation and distributed-energy/remote-area power supply.