Worth a reread: Vanadium Electrolyte https://www.energy-storage.news/vanadium-electrolyte-the-fuel-for-long-duration-energy-storage/
Vanadium electrolyte: the ‘fuel’ for long-duration energy storage
Excerpt
Vanadium redox flow batteries (VRFBs) provide long-duration energy storage. VRFBs are stationary batteries which are being installed around the world to store many hours of generated renewable energy.
VRFBs have an elegant and chemically simple design, with a single element of vanadium used in the vanadium electrolyte solution. The supply of this vanadium electrolyte is now playing the most important role in the batteries’ market growth….
Since the advent of COVID-19, everyone has become a lot more aware of supply chains. For vanadium electrolyte the major producer is currently China, which also consumes a lot of that electrolyte for its own VRFB installations….
How that translates into serving VRFB end-market demand
In this nascent market, numbers used for vanadium electrolyte switch between the equivalent megawatt-hours, the number of litres of electrolyte and the contained amount of vanadium. One megawatt-hour (1MWh) of stored energy equals approximately 68,000 litres of vanadium electrolyte or 9.89 tonnes of vanadium pentoxide (V2O5), which can include a proportion of vanadium (III) oxide (V2O3) depending on whether a chemical or electrical method of production is used.
Specifications for elements contained in the electrolyte vary between VRFB manufacturers. The molarity, or concentration, of the solution also varies, but will usually be between 1.6 and 1.8 molar. Vanadium electrolyte manufacturers work with VRFB manufacturers to ensure that their electrolyte is suitable for supply, with some manufacturers insisting on particularly stringent requirements.
There are three primary vanadium mines in the world outside China that are currently in operation. One in Brazil which is operated by Largo Resources and two in South Africa which are operated by Bushveld Minerals and Glencore. However, 75% of the world’s vanadium is currently produced by China and Russia, not from primary production i.e., mining and extraction of vanadium from the ground, but as a by-product in the production of steel.
Why it matters
Vanadium electrolyte’s characteristics mean that VRFBs have the advantage over other energy storage mediums of being non-flammable and not having any degradation of performance over the battery’s lifespan.
VRFB manufacturers are generally offering 25-year warranties on their batteries. With good maintenance of pumps and other mechanical elements, they could last a lot longer. At the end of the battery’s 25+ year lifespan, the vanadium electrolyte can be reused in another battery. It might only need to be rebalanced to recover any minor capacity loss over that time. For example, VRFB manufacturer CellCube reported a ~1% capacity loss for a VRFB that had been operating for 10 years.
If there is no longer a requirement for the vanadium electrolyte to be used in a VRFB, the vanadium pentoxide can be reclaimed and used in a different application. US Vanadium can recycle spent electrolyte from VRFBs at a 97% vanadium recovery rate. This makes the VRFB a truly sustainable solution – the vanadium resource is only being borrowed from future generations, not consumed at its expense.
One of the main costs affecting vanadium electrolyte is the price of moving it. Essentially when you transport the electrolyte you are moving acid and water. To reduce the cost of the battery, manufacturing the electrolyte close to the installation makes a lot of sense.
Vanadium electrolyte makes up 40% of the battery’s cost for a 4 to 6-hour battery, rising in percentage as the duration is increased. VRFB power and energy is decoupled, meaning that the energy can be increased without having to pay for increased power. In comparison, an increase in energy storage for a lithium ion battery requires a related power increase which is then paid for, but not used.
Because vanadium electrolyte doesn’t degrade, it is an appropriate commodity for leasing. The customer then has an operating expense rather than a capital expense. This also provides comfort to the customer as at the end of the battery’s life the electrolyte belongs to someone else who will then be responsible for retrieving and repurposing it.
With a wide consensus on demand growth for VRFBs and the resulting demand for vanadium pentoxide and vanadium electrolyte supply, there is a bright future ahead for this versatile decarbonisation material.