Energy Storage Update: WattJoule, Primus, Green Charge Networks

A busy couple of days for energy storage on both sides of the meter: WattJoule says it’s figuring out how to finally solve the puzzle for reliable cost-competitive vanadium redox flow batteries, Primus Power lands more funding for its own flow batteries, and Green Charge Networks tallies up new customer installations, including many tied to solar energy systems.

WattJoule: Solving the Vanadium Redox Flow Puzzle

WattJoule says it’s on the way to solving the puzzle of affordable flow battery technology, thanks to the recent pairing of two technology tracks.

Back in December WattJoule somewhat decloaked with word that it was licensing technology from the Oak Ridge National Labs (ORNL) and U. of Tennessee. A few days ago the company followed up with another licensing deal, this time with Battelle for IP developed at the Pacific Northwest Labs (PNNL). Both are key to pushing the company’s vanadium redox flow battery technology, explained Greg Cipriano, WattJoule founder and VP of business development. The ORNL tech improves the flow battery’s power performance, which the company has applied to altering some of the materials and stack componentry and overall design. The PNNL technology addresses the energy side of the equation, helping more than double the energy density in the company’s electrolyte and widening the temperature range (now up to 60°C and down below 10°C), both of which help improve the system’s scalability and associated costs.

Put together, the two technologies give a clearer overall picture of how the vanadium redox processes interact, and thus can be most effectively improved — into a 65 percent cost reduction in just the material content, Cipriano claimed. “The big surprise was how far off how people working on flow batteries were, how flow batteries work and function,” he said. “The fundamental understandings here are really a quantum leap.” (The combined broader understanding also separates WattJoule from other companies that have licensed the PNNL tech, including UniEnergy, he said.) The company has “80 percent of the solution” to making the battery tech commercializable, with the remaining 20 percent involving other ways to get the overall system costs down. Some of that, he revealed, has been reaching out to nearby U. Mass-Lowell and its stellar polymer (plastics) research, to incorporate “copious” amounts of durable plastic components instead of metal machined parts.

Cipriano claimed the company has essentially finished its first-generation product and is tweaking the system to maximize charging/discharging, on a runway of about 2.5-3 years to market introduction. The next generation will utilize a new electrolyte, which he suggested could use less vanadium or even none at all. Addressing questions about performance and longevity vs. system costs and O&M, he noted that the stack doesn’t require exotic equipment and the electrolyte is mostly water-based. And pumps and filters can be designed in redundancy for failure or O&M, without the safety concerns of lithium-ion technology.

He also questioned projections about pricing and matching li-ion technology, claiming that technology is already at scale which removes the best and most obvious cost-reducing factor. Best pricing for li-ion is around $400-500/kwh but at the cell level, he said, suggesting that the overall stack is more like $600-$700/kwh.

Near-term the company is looking for funding. After its founders put in seed capital, Cipriano said they’re now actively recruiting investors for a first official round of funding which he said should happen by late spring or early summer. They already have a term sheet with an unidentified strategic investor from the wind development community, he said; ideally they’d want a consortium of investors including the venture capital community, which he characterized as “still a little standoffish” after a few years of downturn but willing to listen.

Vanadium redox is getting special attention as an alternative to lithium-ion battery technology, storing energy in liquid form to repeat charge/decharge cycles many times without damaging any system parts, explained Sam Jaffe, senior research analyst at Navigant Research.

Jaffe’s not convinced that lithium-ion battery tech has exhausted its cost-cutting abilities. “I wouldn’t make that bet,” he said. And system reliability is a key concern with any flow battery: there’s a big leap between making a pump work, and proving its reliability with 99.9 percent certainty over 15 years, he said. “Anyone that’s going to manage a big set of batteries, if they have a choice between traditional electrochemical cell encased in metal and a flow battery with pumps and fluid moving, they’ll choose the solid-state cell,” he said. “When you have something that literally sits there, done on the molecular scale, anybody would prefer to make an investment in that.”

Next: Funding for Primus Power’s Flow Batteries


Funding for Primus Power’s Flow Batteries

Another flow battery company, Primus Power, has secured $20 million in a first close of Series C funding, led by one of its supply partners, South Africa-based Anglo American Platinum. That’s a big step-up from the $15 million it had raised in two rounds from 2009-2011, plus some grants from the DoE, ARPA-E, Bonneville Power Administration, and California Energy Commission. CEO Tom Stepien noted Primus’ batteries use a small amount of Anglo American Platinum’s metal as a catalyst in the electrode, so adding them as a backer is strategic for both sides. Much like the market for catalytic converters in cars, “this could also be a beautiful market for them,” he said.

One of the biggest elements in the flow battery cost stack is the separator/membrane, a polymer barrier to separate the liquid components of the system and shuttle protons through. Primus’ architecture eliminates the physical ionic separator and instead utilizes a flow control system, not unlike those that manage some key semiconductor manufacturing processes, explained Stepien — who would know, given his 13 years background at chip tool giant Applied Materials prior to joining Primus in 2009. Eliminating that barrier, in theory, leads to a big cost reduction. The system also uses a metal electrode, not a plastic and felt electrode, which is more expensive on an area basis but runs on 10× the current, and with 10× the power even at double the cost, “we win by a factor of five,” he said. He also heralded the company’s implementation of a single pump and a single tank (others have two of each), and a single set of piping, all of which reduce system costs and increase reliability, he said.

Also in the cost-reduction theme, Primus is contracting out its manufacturing, including assembly and testing. Stepien said a decision would be reached “in the next several months” among several candidates, all of whom have facilities in Silicon Valley. (Flextronics is one of them, he acknowledged; the company already has deals to make other companies’ batteries, including fellow flow battery company Imergy.) The plan is to establish a “copy-exact” set of processes — another takeaway from the semiconductor world — and duplicate that elsewhere in the U.S. and “in a reasonable timeframe, other parts of the world,” he said.

Primus is targeting large grid-scale stationary storage, in the form of investor-owned utilities and municipal utilities, and microgrids. The company will officially ship systems later this year to Puget Sound Energy (taking the place of a new substation) and to the Marine Corps Air Station in Miramar, California (part of a microgrid setup), both of which were announced last year. Primus’ partner in the aforementioned DoE grant, the Modesto (California) Irrigation District, is also progressing; the plan is to put 25 MW/75 MWh of the company’s EnergyPods throughout the site’s 45-substation network, though actual system size is still being worked out. He also cited “several municipal utilities mostly in California” that are expressing interest, including a letter-of-intent from one of them. The commercial/industrial segment, e.g., distribution centers, is also attractive as an application to reduce demand charges, he said — “shav[ing] the peak and fade the demand charges pencils out very nicely.”

Primus was ahead of the pack (technically the second wave of flow battery developers) in reducing costs, getting around $600/kWh around five years ago, but li-ion has continued to keep pace with that benchmark to erase the cost-value proposition for flow battery tech, noted Sam Jaffe. Flow batteries still have advantages in long-term energy storage (4-10+ hours), but today’s market the ROI is in shorter-duration applications such as frequency regulation and voltage smoothing: “they need the power, not the long-term energy storage,” he said. Prices will continue to come down dramatically, creating gigawatt-level markets and regulatory changes around them — as we’re starting to see in California and to a lesser extent in Canada and Long Island — but a broader addressable market is still several years out, he suggested.

Penciling out costs is part of the equation — but can the tech work as efficiently and/or as long lifetime as promised? Stepien took the reliability issue head-on, noting that Primus has had “third-parties look over our shoulder to really make sure we’re not being premature about the robustness we need.” That includes taking the system to a local utility this fall (PG&E’s San Ramon facility) before going to Puget Energy. “It has taken more time, but ultimately we think we have a more solid product,” he said.

Note that this is the “first close” of a Series C round of funding — Stepien acknowledged that the company will need to add to that within the next year, a “similar-size amount” to the ~$35 million raised so far. “We’ll need about that much to be cash-flow breakeven,” he said.

Next: Green Charge Networks, Why Storage and Solar Behind the Meter Works


Green Charge Networks: Why Storage and Solar Behind the Meter Works Best

And finally, Green Charge Networks says it added about 750 kW of new installations in the fourth quarter of 2013, the vast majority of its 1-MW cumulative roster. The company continues to focus on the demand side of the equation, addressing energy usage behind the meter and targeting peak shaving and demand charges. Customers include 7-11, Avis, and Walgreens. CEO Vic Shao emphasized this sweetspot application of leveling out demand, pointing to a divergence on the customer end where electricity prices (¢/kWh) are trending down but costs to customers ($/kW) are going up. Month to month, he said, customers are “getting killed on $/kWh demand charges.”

Painted very broadly, flattening energy demand at the customer level can translate into an easier time for a grid operator, who then doesn’t have to throw as much transmission/distribution “copper” at the problem, and ultimately more intelligently deploy more renewable energy generation into the grid. In that scope, 1-MW is barely a drop in the bucket — but sized and sited behind the customer meter it means a whole lot to help lower costs, he explained.

At the same time, though, about half of the company’s installations in 4Q13 involved integration into existing solar energy systems, Shao said, and most of that was a large university in southern California tying into an existing carport solar array. “There’s definite interest on the customer side as well as our channel partners to combine those two,” he said. And a combined solution makes the entire project ROI better, usually with 5-year paybacks or sooner, partly because additional solar-connected energy storage can take advantage of tax credits. He foretold of a big partnership being closed in the next month or two that will widen that pipeline.

The company still wants to keep its focus on the customer side of the meter vs. addressing energy storage on the transmission or distribution side. But even in that sweetspot he expects to do more installations hooking into existing or even new solar, to help level out and dampen power ups and downs. “We believe our customer base expects it,” he said, adding that they’ve been approached to integrate with on-site wind energy too.

That pairing of energy storage and solar is critically important within the commercial/industrial slice of the market, Navigant’s Jaffe emphasized. For businesses, peak usage typically peaks middle of the day, more so than residential users who get home and crank it up in the early evening. Solar on their rooftops thus have a potentially better impact on both energy offset and demand charges. Combine that with a little bit of battery storage — and get tax credits for both — “and all of a sudden the benefits get even better,” he said. And for energy storage suppliers that subsidy helps too.

Lead image: Symbol for the chemical element Vanadium, via Shutterstock

Previous articleREC Solar Sheds Residential Solar PV Business Unit and Sunrun Scoops It Up
Next articleNordex Sees Wind Installs Climbing in Germany Even as State Aid Is Cut
Jim is Contributing Editor for, covering the solar and wind beats. He previously was associate editor for Solid State Technology and Photovoltaics World, and has covered semiconductor manufacturing and related industries, renewable energy and industrial lasers since 2003. His work has earned both internal awards and an Azbee Award from the American Society of Business Press Editors. Jim has 17 years of experience in producing websites and e-Newsletters in various technology markets.

No posts to display