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# The German-American Vanadium Flow Battery Connection
CellCube, one ofthe fewcommercialscale flow batteries. gets NREL testing via a stateside partner and would-bevanadium supplier

. .JeffSt. Jqbn FebNllry

### 24.Z014

Overthepast

### few

### years,flowbatterystartupssuchas prudent Energy. prjmus Power. EnerVay(t. lmergv(formerly Deew 

### Energy), andothers have beenvyingfor mediaattentionfor theirattemptsto

### bringthis potentiallydisruptivetechnologyfor long-term,grid-scaleenergystoragetothecommercialmarket.

Meanwhile.there's another

### flow batterymakerwithdozensof commercial-scale projects underitsbeltthat has hardlyspoken aboutitstechnology.That's Germany'sGildemeister. 11 

### century-old industrial machine tools makerwith a majority stake in Cellstrom. the Austrian-based maker ofthe CellCube vanadium redox flow batterysystem.

Gildemeister has reportedly sold morethan 50 of its CellCube devices in Europe and Asia, including a project with German utility E.ON. It's also working with partnerYounicos to create "battery parks" meantto serve broad grid-balancing functions in Europe's increasingly renewable-energy-disrupted energy markets. But the company hasn't made much ofa splash here in the United States.

That hasn't been for want oftrying from partnerAmerican Vanadium, however. The Canadian mining company has been Gildemeister's North American distribution partner since May 2013, and CEO Bill Radvak has been promoting the technology heavily at trade shows and conferences since then.

Last week, the Vancouver, British Columbia-based company announced a potential milestone in those efforts, with the deliveryofthe first Cellcube units for testing by the Department of Energy's National Renewable Energy Laboratory (NREL) in Golden, Colorado. That testing could be complete bythis summer, at which point at least one U.S. utility, as well as various integration partners, are interested in deploying it stateside, Radvak told me in a phone interview last week.

Radvak declined to say which U.S. utility planned to deploy Gildemeister's Cellcube units. But a November blog post from Crystal Eguity Research noted thatAmerican Vanadium has proposed a trial with NewYork State Energy Research and Development Agency (NYSERDA) to demonstrate a Cellcube unit in Manhattan, in partnership with Consolidated Edison and the NY-BEST energy storage industry group.

Thatjibes with a recent contributed article Radvak wrote for Greentech Media, noting NewYork state's newly created gridscale storage incentives as a development that will open that market to new opportunities. It's also aligned with ConEd'swork testing new batterytechnologies as part of its goal of reducing grid congestion and improving reliability in NewYork City.

As for the NREL tests. "This is a prettyall-encompassing grid trial." Radvak said. including grid-connected and off-grid applications involving long-term storage and balancing of renewables like solar and wind power. ·we don't believe that they've been able totest a long-duration, larger battery-- likely because there aren't any commerciallyavailable. long-duration. multi-hour batteries out there."



### Flow Batteries' Role in Long-Term Grid Energy Storage

He may be right. While lithium-ion batteries developed for
consumer electronics and electricvehicles are increasingly finding theirway into grid applications. they're better suited for storing large amounts of energyover shorter durations, rarely for more than an hour ortwo.

Flow batteries, bycontrast, pump liquid electrolytes through stacks of electrochemical cells. instead ofcontaining them in closed systems, allowing for replacement of depleted materials and reduction ofthe degradation ofthe anode and cathode materials involved. That could help them store megawatts of grid energyover multiple hours oftime at costs that could compete with alternatives like natural-gas-fired power plants.
Gildemeister, which since 2009 has been part ofa strategic partnership with Japan's DMG Mori Seiki and tookthat company's name as its own in September. has been very shy about revealing details of its Cellcube deployments. It declined interview requests from Greentech Media in mid-2013.

But piecing togethervarious announcements and company information indicates that the Cellcube devices come in modular units of200 kilowatts. with a rating of 1.6 megawatthours per unit, which indicates they're capable of delivering power for up to eight hours.Other grid-scale batteries, such as sodium-sulfurtechnologies,
can store energy for long periods. but operate at high temperatures and require a good deal of hands-on maintenance, whereas flow batteries have been deployed to back up cellphone towers foryears nowwith little complaint. Startup Xtreme Power's advanced lead-acid batteries have
some long-term storage capabilities, butwith its recently announced bankruptcy, it's unclear whether that technology has a future.

While emerging technologies like Eos' zinc-based batteries, Aquion's sodium-aqueous batteries orAmbri's liquid-metal batteries could achieve breakout energystorage durations at competitive cost, they're stillyears away from commercial production.

The drawbacks for flow batteries include their reliance on pumps that may be subject to mechanical trouble and expensive maintenance, as well as their relatively low "roundtrip" energy efficiency (a measure of how much energy put into the battery can be retrieved from it). Flow batteries tend to hover at 60 percent efficiency and strive for 70 percent, whereas lithium-ion batteries can theoretically get back more than 90 percent ofthe energy put intothem.

But ifthe difference between thevalue ofthe energy being stored and the energy being put back into the grid is broad enough, those efficiencies maystill pay off. Considerwind farm operators that maywant to store energywhen grid prices go negative and bid it back to firm their output, or solar systems that could store powerto meet late afternoon grid ramping needs that are emerging in solar-rich grids.

Business cases like these are already starting to pencil out on isolated grids where storage can replace expensive. polluting diesel fuel-fired generation. Now Gildemeister and American Vanadium are hoping to see broader applications, particularly in markets that are mandating energy storage. such as California,
or are beginning to offer incentives for grid-scale**projects~** as NewYork state.

### Breaking Ground on U.S. Production ofVanadium for Grid Storage

Different flow batteries use different chemicals, including zincbromine and iron-chrome combinations, as well as vanadium--
a much rarer metal, but one unique in its ability to undergo multiple phases of electrical charge. Vanadium is used almost exclusively for strengthening steel today, and China, Russia and South Africa are the countries where it's mined at commercial scale, Radvak said.

American Vanadium was founded in 2006 with the goal of opening up the first large-scale vanadium mining and refining project in the United States. That's its Gibellini project. a wellknown but poor-grade deposit ofvanadium in Nevada that has been worked on and off since World War Two.

The vanadium deposits at the Gibellini site will be extracted via
a sulfuric acid leaching process, at a cost ofabout $5 per pound, compared tothe $6 to $12 per pound the metalfetches
on global markets, he said. Importantly, the vanadium-acid mixture that results could be almost directly put to use as a battery electrolyte, he claimed

-- and Gildemeister has agreed to buy all the electrolyte it needs for its North American Cellcube deployments through American Vanadium.
Going from concept to full-scale mining operation will take
moretime and money, ofcourse. The scale-up ofthe Gibellini project could cost $100 million or more, and isn't expected to get underway until2015 or so, Radvak said. In the nearer term, American Vanadium plans to set up avanadium electrolyte production facilityto supply Cellcube deployments, and potentially other flow battery makers, as long as they're not competitive with Gildemeister, he said.

American Vanadium, which is traded on the TSX Venture Exchange underthe symbol AVC, raised $1.5 million Canadian ($1.6 million) in late 2012. Late lastyear it announced the closing oftwo tranches of private placements of shares and warrants, valued at about $4.065 million Canadian ($3.66million) and $1.765 million Canadian ($1.59 million), for a total of about $5.25 million, both centered on its role as an energy storage materials supplier.

The company's stock has been trading in the sub-40 cents per share range in recent months, and has seen a steady decline in price from its early 2011 high of $1.92 per share. A Long path Lies before it in getting Gildemeister's Cellcube tested by NREL, deploying it in North America, and building up a resulting vanadium electrolyte business.

TAGS: ambri. american vanadium, aquion, batteries, cellcube, energy storage, enervault. eos, flow batterv, gildemeister, grid storage, imergy, primus power, prudent energy, sodium-sulfur