there is an elephant in the room. Whilst I applaud the adoption...

there is an elephant in the room. Whilst I applaud the adoption of vanadium flow batteries, in the very, very short term it will be steel makers who will be absorbing all the vanadium they can get........... this article from metal bulletin. In fact some snippets here opens the door to a great deal more research.
FORECAST: China's vanadium consumption to surge 30% on revised rebar standards
A revision to the standard tensile strength of rebar products in China may see vanadium metal consumption in the country grow by 30% or 10,000 tonnes per year, according to an official at the China Iron & Steel Research Institute (CISRI).
“The [revision] has been forwarded to the Standardization Administration of China and is very likely to be formally released in September,” the CISRI official, who was involved in the drafting of the document, told Metal Bulletin. The new standard is an improved edition of the GB 1499.2-2007 and proposes to eliminate the 335MPa strength rebar, replacing it with a 600MPa strength rebar, to increase rebar grades with earthquake resistance. The CISRI official also noted that China produces approximately 160 million tonnes of hot-rolled high strength steel rebar, including HRB400 (65%), HRB500 (20%) and other products (15%). “The [required] amount of vanadium to be added is 0.03-0.05% for HRB400 and 0.05-0.08% for HRB500, so the demand growth of vanadium metal will be around 10,000 tonnes per year,” the official added.

Given the recent natural disasters in China, their stance on this will NOT weaken.
Note that that is an increase in consumption of 10000 tonnes, which is in addition to what they already use.