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The German-American 

Vanadium Flow Battery 

Connection 

Cell Cube, 

one of the 

few 

commercialscale flow 

batteries. 

gets NREL 

testing via a 

stateside partner and would-be vanadium 

supplier . 

.Jeff St. Jqbn 

FebNllry 24. Z014 

Over the past few years, flow battery startups such as prudent 

Energy. prjmus Power. EnerVay(t. lmergv (formerly Deew 

Energy), and others have been vying for media attention for 

their attempts to bring this potentially disruptive technology for 

long-term, grid-scale energy storage to the commercial market. 

Meanwhile. there's another flow battery maker with dozens of 

commercial-scale projects under its belt that has hardly spoken 

about its technology. That's Germany's Gildemeister. 11 century-
old industrial machine tools maker with a majority stake in 

Cellstrom. the Austrian-based maker of the CellCube vanadium 

redox flow battery system. 

Gildemeister has reportedly sold more than 50 of its CellCube 

devices in Europe and Asia, including a project with German 

utility E. ON. It's also working with partner Younicos to create 

"battery parks" meant to serve broad grid-balancing functions in 

Europe's increasingly renewable-energy-disrupted energy 

markets. But the company hasn't made much of a splash here in 

the United States. 

That hasn't been for want of trying from partner American 

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 

delivery of the first Cellcube units for testing by the Department 

of Energy's National Renewable Energy Laboratory (NREL) in 

Golden, Colorado. That testing could be complete by this 

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 that American Vanadium has 

proposed a trial with New York 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. 

That jibes with a recent contributed article Radvak wrote for 

Greentech Media, noting New York state's newly created gridscale storage incentives as a development that will open that 

market to new opportunities. It's also aligned with ConEd's 
work testing new battery technologies as part of its goal of 

reducing grid congestion and improving reliability in New York 

City. 

As for the NREL tests. "This is a pretty all-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 to test a long-duration, larger battery-- likely 

because there aren't any commercially available. 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 electric vehicles are increasingly 

finding their way into grid applications. they're better suited for 

storing large amounts of energy over shorter durations, rarely 

for more than an hour or two. 

Flow batteries, by contrast, pump liquid electrolytes through 

stacks of electrochemical cells. instead of containing them in 

closed systems, allowing for replacement of depleted materials 

and reduction of the degradation of the anode and cathode 

materials involved. That could help them store megawatts of 

grid energy over multiple hours of time at costs that could 

compete with alternatives like natural-gas-fired power plants. 

Gildemeister, which since 2009 has been part of a strategic 

partnership with Japan's DMG Mori Seiki and took that 

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 together various announcements and company 

information indicates that the Cellcube devices come in 

modular units of 200 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-sulfur technologies, 

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 for years now with little complaint. 

Startup Xtreme Power's advanced lead-acid batteries have 

some long-term storage capabilities, but with 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 or Ambri's liquid-metal 

batteries could achieve breakout energy storage durations at 

competitive cost, they're still years 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 of the energy put into them. 

But if the difference between the value of the energy being 

stored and the energy being put back into the grid is broad 

enough, those efficiencies may still pay off. Consider wind farm 

operators that may want to store energy when grid prices go 

negative and bid it back to firm their output, or solar systems 

that could store power to 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 New York state. 
Breaking Ground on U.S. Production of Vanadium 

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 of vanadium 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 of about $5 per 

pound, compared to the $6 to $12 per pound the metal fetches 

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 

more time and money, of course. The scale-up of the 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 a vanadium electrolyte 

production facility to 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 under the symbol AVC, raised $1.5 million Canadian 

($1.6 million) in late 2012. Late last year it announced the 

closing of two tranches of private placements of shares and 

warrants, valued at about $4.065 million Canadian ($3.66 
million) 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