Published on April 29th, 2014 | by Tina Casey


Floodgates Open For Vanadium Flow Batteries

April 29th, 2014 by  

Vanadium flow batteries offer the kind of low cost, high capacity energy storage solutions that will help transform the wind and the sun into power sources that rival fossil fuel plants for stability and reliability, but as always there are a couple of catches: where to get the silvery transition metal vanadium, and how to keep the price down?

CleanTechnica has been following one company, American Vanadium, that is solving the US vanadium problem by developing the nation’s only vanadium mine. Located in Nevada, the mine will deploy some low cost operating strategies to keep the price of vanadium down. Putting its money where its mouth is, American Vanadium will also power the mining operations partly by a solar array/vanadium flow battery combo.

Now, here’s another vanadium flow battery company, Imergy™ Power Systems, which has come up with an interesting solution of its own.

Imergy vanadium flow battery

Vanadium flow battery (cropped) courtesy of Imergy Power Systems.

Imergy Power Systems

According to an email we received from an Imergy rep, rather than digging for new vanadium Imergy is recovering vanadium from mine tailings and abandoned oil wells. That’s a sustainable strategy which results in significantly lower costs, but the sticky wicket is the quality of the vanadium from those sources.

Imergy has engineered a workaround through a series of patented improvements covering the chemistry and chemical processes of the flow battery itself, as well as materials and stack components, instruments and sensors, and engineering and control systems.

The latest patent, just announced last week, is a new DC-DC converter that Imergy calls the Bi-Directional Buck-Boost Circuit.

Vanadium Flow Batteries For Grid And Renewables

For those of you new to the topic, flow batteries work by the interaction between two liquids flowing in parallel, typically separated by a membrane (some next-gen flow batteries ditch the membrane).

Compared to their lead-acid and lithium-ion cousins, flow batteries are relatively inexpensive to scale up because the basic infrastructure consists mainly of tanks and pumps.


Flow batteries also complement intermittent sources like wind and solar, because they can sit idle for long periods of time without losing their charge and kick into gear quickly when needed.

Both of those factors dovetail with the Obama Administration’s push to get more wind and solar power into the grid, so it’s little wonder that the Department of Energy is pursuing new vanadium flow battery technology on several fronts.

Imergy is also pursuing the market for energy storage solutions that replace diesel generators, such as those typically used by the telecom industry for its remotely located wireless transmission equipment.

Follow me on Twitter and Google+.

Keep up with all the latest clean tech news from CleanTechnica: subscribe to our newsletter.  

Check out our new 93-page EV report, based on over 2,000 surveys collected from EV drivers in 49 of 50 US states, 26 European countries, and 9 Canadian provinces.

Tags: , , ,

About the Author

specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. Views expressed are her own. Follow her on Twitter @TinaMCasey and Google+.

  • Zvyozdochka

    My employer has been watching this tech for years, but a basic question seems unanswered (I’ve asked before) – how much Va is readily recoverable and how much might we need?

    • bink

      Va is in abundant metal, not an rare earth material , is found in 65 different elements, can be and is recovered from slag during the steel making process and oil drilling operations, coal ash etc., found in abundance in the ocean everywhere in the soil you are standing on but of course that is not easily recoverable. The main catalyst to make high strength steel for aviation and marine vehicles, high rise buildings, an element within lithium ion batteries which increases the power and energy density.A Vanadium air battery has the highest theological volume of energy density for all batteries 27,000/L
      practical energy density is equal to gasoline (rechargeable air battery)

      • alysdexia

        Eh? Titanium oxidation has a greater enthalpy, thorium and uranium even more.

        • A Real Libertarian

          A Vanadium air battery has the highest theological volume of energy density for all batteries

          • alysdexia

            theological? Dumb hick. And no it doesn’t, as I said; vanadium somehow can be recharged 10,000s of times.

          • Bob_Wallace

            Can the name calling.

          • alysdexia

            You mean the honest criticism.

  • Michael Berndtson

    There’s a whole hell of a lot of vanadium in Alberta Oil Sands. It looks like it will stay in the upgrading ash or in pet coke. So this could be how tar sands becomes “green.” From the second link I attached, there’s about 200 to 500 ppm (mg/kg) of vanadium in upgraded bitumen. So let’s see how much they’ll get:

    1.5 million barrel per day at 42 gallons per barrel and 7 pounds per gallon and 2.2 pounds per kg = 200 million kg of bitumen per day. This is about what Canada is producing today. It going to be a lot more.

    Vanadium = 350 mg/kg X 200 million kg bitumen per day = 70,000 kg per day

    Vanadium (in American units) at 25 percent recovery = approx 20 tons per day. The recovery is my SWAG. Could be more or less, don’t know.

    Why even start a new mine since tar sands are screaming with vanadium?

    “Leaching of vanadium and other metals from Athabasca Oil Sands coke and coke ash”

    “Tutorial on Upgrading of Oil sands Bitumen”

    • Matt

      Normally with a high acid approach, so then you got that to clean up also. But yes there already mountains of the by-product piling up in the NA. Another reason to stop the mining.

    • Bob_Wallace

      I suspect that’s not enough to turn the tar sands pig’s ear into a silk purse.

      Probably wouldn’t bring it even to knacker bag status.

      • Calamity_Jean

        More like, “There’s no great loss without some small gain.”, to quote Caroline Ingalls.

  • Matt

    Nice and cheery, but where is the beef? No estimated timelines or costs. Is either in prototype development, testing in field, limited marketing, selling yet?

    • Bob_Wallace

      “On Wednesday (April, 2014), New York City’s Metropolitan Transit Authority (MTA), which suffered its own Sandy-related shutdown, announced one of the city’s biggest energy storage projects to date: a 400 kilowatt-hour array of CellCube vanadium redox flow batteries at its new facility at 2 Broadway in downtown Manhattan.

      The demonstration project features the first U.S. installation for the CellCube, built by Germany’s Gildemeister and brokered by Canadian partner American Vanadium. Partners including the New York State Research and Development Authority (NYSERDA) and utility Consolidated Edison are also involved, looking to test how multi-hour, modular storage systems like the CellCube can serve multiple tasks for the MTA and for the grid at large.”

      • Bob_Wallace

        I distilled the main points out of bink’s comments. (I think I’ve got them right.)

        75% – 80% efficiency (claimed)

        20 year, unlimited cycling with no capacity loss. Pump may have to be replaced after 10 years.

        Millisecond response for frequency regulation

        Multi-hour deep discharge for capacity. (Hours per day)

        Electrolyte is 30% of total system cost. Adding electrolyte (and storage for electrolyte increases capacity)

        Low annual O&M (2.5% of capex).

        No fire hazard and no off-gassing.

        No self-discharge.

        Ambient temperature operating range -40c to 60c.

        Can sit with pumps off for months and start up in 5 minutes.

        Can discharge over tens of hours so replacing peak is never a problem for this battery, if it was built for that application. And a battery park full of VRBs could provide days of storage.

        “by the way that little niche as you call it is where the money is for grid applications, you get capacity and energy payments which pay much much better than ancillary services”

        • Matt

          So CellCube is at the demonstration project stage, great!. The two in this “release” are likely not that far. We need all these player to get to that point. Once they are in the real world then people will start to believe in them. When they are only a TED talk it is still dreamware. Even loosing 20-25%, that beats giving it away at night (wind) when this would let you move it to when it is needed. Even if I’m a power company, I can park one close to town. charge it when spot market is cheap and sell during the the peak times.

          • bink

            Matt, Vanadium Redox batteries were developed in the early 80’s. There are 100’s of systems deployed around the world mostly in Europe and Asia and have been for close to 30yrs.

            The basic chemistry and platform have been field tested and proven for durability. The electrolyte has an indefinite life and is recyclable as well as being traded and valued as a commodity. Early on there were issues with durability of pumps and ambient temperature operating range.

            Even though balance of system are off the shelf parts (PVC) and hoses, the per kW cost of the system was expensive due to the cell stack component, mostly if not all of that cost being the membrane.

            Those issues have mainly been resolved over the years but in the interim lithium ion battery technology came to dominate the frequency and ancillary services market.
            To those in the know lithium is limited in application and operating range besides being a safety hazard in grid applications.

            But we are in America where anything considered sexy has a hard time being shown to have flaws. Plus these manufacturers have a vested interest in promoting the myth.

            VRBs were the future back then and the future is now. American Vanadium has deployed dozens of these batteries over the last 5 years in Europe and around the world so this is no prototype.

            Like I said the electrolyte is proven with one unit having close to 35,000 thousand cycles completed and no loss of capacity (degradation) recent improvements over the last 2 years have improved ambient temperature operating range -40c to 60c. improved energy density 100% and more recent breakthroughs have improved power density 5-10x’s which exceeds current lithium ion technology.

            it still has low energy density in comparison but the platform allows for discharge over multiple hours if not days which allows for energy capacity payments. Lithium captures the power opportunity (1-2) hours but not both. Redox batteries can match millisecond response times of lithium batteries but lithium cannot match discharge capacity of Redox batteries.

            Finally, they need no trickle charge and can sit dormant for months and years with no damage to electrolyte and will start and produce power in 5 mins after turning pumps on after that period of time.

            They are not combustible

          • Bob_Wallace

            Information laden comment. Thanks

            Is there any publicly released data on round trip cost for daily cycling? I.e., are vanadium flow batteries affordable enough to flatten the duck?

            If not, any clear path for them getting there?

          • bink

            Bob, round trip efficiency is quoted at 70%, though charts from testing I have seen make it more like 75-80%.

            I guess they can guarantee the lower figure, this is not a problem in most grid applications when you site the units at different locations throughout your distribution grid and charge at night.

            Several national labs and field testing put the O&M below 8 cents per kWh on the high side and 6 cents at the low end.

            Reportedly the lowest (capex) at 2.5% in the industry.

            I have first hand knowledge of their performance versus Lithium ion battery technology in regards to expense and operations.

            They are superior due to their wider application range which answers your question in regards to the duck.

            The issue is not with the batteries its that the industry, mostly regulators and utilities don’t know what to do with a piece of equipment which captures so many value streams so they revert to Lithium ion batteries and focus on the frequency and ancillary markets.


            Download the above PDF to see what I mean. Utilities are slow to recognize and change their modeling.

            The Lifecycle cost of these batteries are the lowest for energy storage. Expected life is 25 years for VRB but no one talks about battery replacement and degradation for Lithium ion over a 5-10 year period.

            In other words when battery pricing is being quoted for Li ion they do not include replacement costs, because the figure would surely almost double

            Yes it will take care of that duck curve because it can level out peak for 4-6 hours at the distribution system level.

            Several batteries would be placed at different locations within the service territory for load control via demand response, displacing a service areas peak load and thus peak load charges from the load serving entity (wholesale power producer) which are calculated on a per kW basis.

            Capacity markets are not an area Li ion can play in with any success due to battery degradation and inability to discharge for an extended period.

            VRB’s will replace peakers and perform all ancillary services, utilities are worrying about cross payments of services with these batteries, that is the problem, “too many applications for its own britches”

          • Bob_Wallace

            ” O& M below 8 cents per kWh on the high side and 6 cents at the low end.”
            Don’t you mean total cost 6c to 8c? Not just the O&M.

            Not questioning your veracity, but could you give some links for vanadium battery per kWh costs? If I comment with “6-8c/kWh” someone is almost certainly going to challenge me.

            I agree that storage should be spread around the grid. This is where batteries excel over PuHS. They can be distributed which lowers grid load and increases local grid reliability.

          • bink

            Bob, sorry i made an assumption that someone would know I was referring to total cost. When I am discussing amongst industry people we assume that. I in relation to per kWh costs believe it or not that is going to vary because of the independent power and energy components (scaled individually) as you would suspect manufacturers who are actually producing are not running around publicizing their costs to the general public.

            For 1-4MWh’s $750-$1,000 per kWh installed would be a range
            5+MWhrs anywhere from $500-750 per kWh (range) installed
            As you scale capacity you only increase tank size and electrolyte (30%) of total system cost,

            This does not account for recent breakthroughs to stack which will drive down total system costs. System will be very attractive because MW or kW cost component will drop below per kWh pricing

            I cannot go any further than that or else I start treading into disclosure area but I stand by those figures

          • Bob_Wallace

            This is (I think clearly) not an industry site. It’s for a much more general audience. Best to assume that the readers know roughly nothing but are interested in learning.

            The idea here is to get information about what is working out to a broad audience so that people can make wise choices in their daily life and at the ballot box.

            I’d suggest that it’s probably in the industry’s best interest to keep the general public dialed in to roughly what things cost. If they want general support then people need to know why they should support. There are a lot of people who are eager to see us move away from fossil fuels and storage is the missing link. I understand keeping contract details private, but it’s possible to communicate the ‘state of the art’ without printing a copy of the contract.

        • omar

          Any idea of how much cost $/kwh a vanadium flow battery with solar or wind system compared to $/kwh by fuel plant.

          • Bob_Wallace

            I don’t know how much a vanadium flow battery system would cost. I suspect they will cost a bit less than the EOS zinc-air battery. The EOS battery is priced at $160/kWh and is designed for 10,000 cycles. The company is is saying that they can deliver power for 10 to 12 cents per kWh. Add in wind at 4 cents and solar at 6.5 (both without subsidies) and you end up somewhere in the 8 cent range depending on how sunny/windy the region is.

            Much cheaper than new coal, eve before you add in the external costs. Perhaps not cheaper than combined cycle natural gas with today’s NG prices (6 to 9 cents/kWh).

            The price of solar should keep dropping and wind should go down a little more. Flow or liquid metal batteries could make storage cheaper. We haven’t yet hit lowest prices for renewables and storage. Were one interested only in electricity at the lowest possible price then a CCNG plant might be the choice.

Back to Top ↑