UniEnergy Technologies Goes from Molecules to Megawatts
Vanadium, in the eyes of energy storage innovators, is a lovely, generous element, even though it’s often found in some dirty places. It is named for a Norse goddess of beauty. Its color, when dissolved in an electrolyte solution, changes from lilac to green to blue to yellow as it easily gives and takes electrons, creating the current inside a battery.
Vanadium is also increasingly sought both for its traditional use as an alloy to strengthen steel, and as the key ingredient in a battery chemistry that could form part of the solution to one of the biggest challenges the world faces—climate change. Electricity storage systems such as vanadium batteries can help add large amounts of solar and wind energy to the power grid, providing a consistent supply at times when the sun doesn’t shine and the wind doesn’t blow. Utilities and their regulators see such large-scale energy storage as a key enabling technology for smart grids, distributed energy systems, and meaningful levels of reliable carbon-free electricity from solar and wind to replace coal and gas-fired power plants.
The growing demand for energy storage, in turn, has spawned lots of companies pursuing a wide array of technologies. One of the contenders is UniEnergy Technologies (UET), based near Seattle. UET is going to market with its vanadium redox flow battery, incorporating refinements to the four-decade-old technology made by the company’s co-founders when they were at the Department of Energy’s Pacific Northwest National Laboratory. The company has an experienced team, a series of innovations in vanadium electrolyte chemistry and system design, several initial customers, and ambitious plans to scale up production in the next two years.
UET, and the broader energy storage industry, is about to get an important boost from the state. Washington Gov. Jay Inslee is scheduled to visit UET on Tuesday, and the company is expected to win two significant deployments with Washington utilities, supported by state funding, as the state positions itself as a leading test bed for new energy storage technologies.
And UET has another potential edge in the large-scale energy storage market expected to blossom over the next five years: One of its main investors, Dalian Bolong Holding Co., Ltd., of China, also happens to own one of the largest suppliers of vanadium and the maker of a central part of the battery hardware.
The origins of UET go back to the early 2000s, when co-founders Liyu Li and Z. Gary Yang had stable, stimulating positions as top research scientists at the DOE laboratory in Richland, WA, working on a range of materials science problems related to energy storage, carbon capture, and other technologies.
“In PNNL, the culture is you work in as many possible directions as you can, doing all kinds of stuff,” says Li, UET’s chief technology officer.
In 2009, they started working together on energy storage systems. Li recalls being captivated by the vanadium redox flow battery concept, invented in the mid-1980s by Maria Skyllas-Kazacos, a professor at the University of New South Wales, Australia, and based on earlier work on flow batteries by NASA researcher Lawrence Thaller in the 1970s.
“One of the prettiest elements in the whole world,” Li says of the active ingredient, vanadium.
Li, Yang, and other researchers began experimenting with new chemistries to address some of the shortcomings of the technology: At the time, its energy density was low—redox flow batteries require an enormous amount of electrolyte to store a meaningful amount of electricity. In addition, it could only operate in narrow range of temperatures, requiring energy-sapping cooling equipment that made the technology economically infeasible.
Their relative lack of familiarity with this specific battery technology freed them up to experiment, Li says.
“We just kept trying all kinds of stuff because we didn’t have any kind of previous experience, so there was no limitations for us,” he says.
Between 2009 and mid-2012, some $2 million in federal funding went into research at PNNL that would lead to the technology UET is bringing to market. Considerably more money went into the technology from other Department of Energy offices, as well as the broader energy storage problems researchers tackled at the lab.
“This is a good example of commercialized technology initially developed by spending tax dollars,” says Yang, who, like Li, immigrated to the U.S. from China, and is UET’s CEO. Both men are U.S. citizens.
They hit upon using a mixture of hydrochloric acid and sulfuric acid in the vanadium electrolyte, as opposed to the status quo of just sulfuric acid. This mixed acid formula allows for an increased concentration of vanadium in the electrolyte, unlocking significantly higher energy density and a broader range of operating temperatures. Their approach enabled the battery to work at temperatures between -40 degrees and more than 50 degrees Celsius, making it usable in most parts of the world, and with drastically reduced heating and cooling costs.
Gordon Graff, who worked closely with Li and Yang as manager of a broader grid energy storage initiative at Pacific Northwest National Laboratory (PNNL), says as their results were made public, it generated a great deal of interest from the energy storage industry, including battery makers and utilities.
“We knew what the jugular problems were and we focused on that,” Graff says, adding, “These were the things that have prevented these redox flow batteries from moving into the market.”
Battelle, the nonprofit research group that operates PNNL for the government, has licensed the technology to three companies including UET. The others are WattJoule, based in Lowell, MA, and a third company that has asked PNNL not to identify it, says Graff, who is now overseeing commercialization for PNNL’s entire energy storage portfolio.
“You don’t want to bet on just one horse,” he says, adding that this limited, non-exclusive licensing is common practice at the lab.
Yang says he never thought of trading in his government research job for the risk of a startup company until potential investors approached them. For he and Li, it meant uprooting their families and moving across the state. Li, 45, says his daughter asked him, “Who’s going to pay for my college?”
“It’s a hard decision,” Yang, 51, says, adding that he didn’t have as much gray hair when they started the company in 2012.
They’ve attracted several other gray-hairs of the energy storage business, something UET executives revel in.
“We must be the oldest startup company in the world,” says Rick Winter, 48, who joined UET as chief operating officer in 2013 after a quarter century in the energy storage industry.
Winter, a gregarious Australian, says the easiest description of a flow battery is “like a cross between a normal battery and a hot tub.”
The key ingredient is the vanadium, useful in energy storage because it can have four different levels of positive charge, or valence states, and changes among them easily. Vanadium ions remain in solution in the liquid electrolyte throughout the process—stored in two separate tanks—as opposed to the lead paste or lithium strut matrix at the heart of other common battery types. Winter says those battery technologies see their capacities fade over time in part because their solid active ingredients expand and contract with each cycle, causing cracking and fatigue.
The flow battery is “just a warm solution that gets circulated through this electrode stack, and that’s where the reactions occur,” Winter says. Current from the electricity grid charges the battery, adding electrons to push the valence states of the vanadium in the electrolyte farther apart, to +2 on one side of the stack and +5 on the other. This creates the electrical potential—stored as chemical energy—to be called upon when the battery discharges back to the grid. When the electrolyte passes again through the electrode stack, electrons go the other way. That creates a current flowing back onto the grid, returning the vanadium’s charge to +3 and +4, ready to be charged up again. As the vanadium passes through its four valence states, it changes to another of its four colors, which are represented in UET’s logo.
Unlike some other battery technologies, the vanadium flow battery can’t catch fire or fail because of a chemical reaction. It does pose health risks, of course, because of the corrosive acid in the electrolyte. But UET makes a point of emphasizing the safety and stability of this chemistry.
“You can charge it completely, you can leave it there, and come back a year later and you’ve got 98 percent of the capacity left in it—if you turn the pumps off. You physically separated your active species [in the two tanks]. So there’s first of all no mechanism for self-discharge,” Winter says.
That separation also provides a way to interrupt thermal runaway, an uncontrollable heat buildup that has plagued other batteries, by simply turning the system off.
UET can pack the tanks, plumbing, electrode stack, and control equipment into a standard 20-foot shipping container—making it easy to assemble, ship, and install the batteries. Speaking at a clean technology event on the Seattle waterfront last month, Winter looked out the window to the thousands of containers stacked at the port and described them as among “the least-appreciated high-tech things in the world.” (The 20-foot container is also the size preferred by the military, he adds.)
The company can fit a meaningful amount of energy storage into this relatively small package thanks to the advancements Li, Yang, and their colleagues made at PNNL, which doubled the energy density of the battery. The current design can store about 19.5 watt-hours of energy per liter of electrolyte, a mark UET believes it can continue improving on. (Imergy Power Systems, another vanadium flow battery maker profiled by Xconomy in December, says it can achieve 23 watt-hours per liter.)
On top of the containers, a small radiator—about the size of one for a truck—provides all the temperature regulation necessary, given the broad range of working temperatures.
“If I had to use a chiller or an air-conditioner [to maintain a narrow temperature range], it costs me 25 percent in system efficiency, because those things are incredibly inefficient,” Winter says. “They’re also unreliable and expensive.”
As it is, the battery is 65 to 70 percent efficient, with energy used to run the pumps and radiator, and lost through AC conversion during the round-trip from the electrical grid.
UET buys standard containers from China International Marine Containers with a few customizations, including ports near the top to allow multiple containers to be connected together “like a pack of Duracells,” Winter says, and a full, solid steel floor that serves as a secondary containment mechanism for the battery.
“That makes a dramatic difference to the cost of deployment,” Winter says.
Site preparation and engineering can make up a third of a typical large-scale battery’s total cost, he says. “We want to reduce that to something like 5 to 10 percent of the deployed cost.”
The batteries can be built on a simple eight-inch concrete slab with grounding points, grid interconnection, and communications hookups. Enough containers can be packed together to store up to 20 megawatts of electricity per acre. They can also be stacked two or three high, multiplying the capacity per acre.
As a standard unit of international trade, the container can be easily shipped to locations around the world.
UET believes this standardization, as well as the ability to manufacture and test the batteries inside its facilities rather than in the field, will help it compete on price and reliability. Its current pricing is about $875 per kilowatt hour of storage, or about $3,500 per kilowatt of peak power capacity, but the company expects those numbers to come down substantially through economies of scale and product improvements as it ramps up manufacturing.
The company has another potential pricing advantage, too: There are about 23,000 liters of vanadium electrolyte in each shipping container, filling tanks that take up about three-quarters of their volume and constitute three-quarters of their total weight. This is where UET’s relationship with Bolong New Materials—owned by UET’s Chinese investor—comes in.
“The big issue with vanadium has been massively volatile pricing,” says Bill Radvak, CEO of American Vanadium, a Vancouver, Canada-based mining company aiming to build a vanadium mine in Nevada to serve the energy storage market. “I’m not talking 20 to 30 percent, but 400, 500 percent increased pricing in a month or two. When vanadium electrolyte is 40 percent of the cost of your batteries, any kind of volatility like that obviously means you’re losing a lot of money with each battery cell.”
(UET says the electrolyte represents about a third of the price of its battery, assuming the two components are purchased together. It also offers the option of leasing the electrolyte.)
“That’s why certain research firms that look at energy storage at the macro level aren’t very big proponents of vanadium flow batteries,” Radvak adds. “Not because of technology, but because they just don’t believe there’s enough vanadium supply there to keep the costs down and keep the batteries competitive.”
American Vanadium has partnered with Gildemeister to market the German company’s vanadium redox flow battery in North America. “What we’ve done really is insulated our partnership from that global issue by having our own supply,” Radvak says.
So too has UET with Bolong New Materials, which Radvak describes as “a top-three global provider of vanadium specialty alloys and chemicals.”
Winter says Bolong is capable of producing enough vanadium electrolyte annually to build batteries with the capacity to store 1.5 gigawatt hours of electricity. Russ Weed, UET’s vice president of business development, says since Bolong is an affiliate company, UET gets competitive pricing.
The vanadium retains its value throughout the expected 20-year life of a UET system, which the company says can handle unlimited charge and discharge cycles. “It justifies a no-cost disposal contract at the conclusion of the project,” Winter says.
In addition to the vanadium electrolyte, UET is sourcing the electrode stacks—which Winter calls “the heart of our technology”—from Rongke, another Chinese company owned by Dalian Bolong Holding, which is backing UET alongside KMG, an Australian iron mining company. Rongke has been working on this crucial component for 14 years, with nine years of field deployment, Winter says.
“There’s been $250 million of investment specifically in this technology, specifically this product,” Winter says, referring to Dalian Bolong’s investment in UET, Rongke, and Bolong New Materials.
“We’re the pointy end of the spear,” Winter adds.
UET plans to assemble and test its Uni.System batteries at its facility in Mukilteo, WA, about 30 minutes north of Seattle, taking advantage of engineering talent and production infrastructure amassed in the area to serve Boeing. The company plans to expand into a 67,000-square-foot facility with seven loading docks, where it aims to scale-up its capacity to assemble up to 100 megawatts of batteries—or 1,250 containers—in 2015. The containers would be backed up to the loading docks and stuffed with the components.
After Li and Yang founded the company in 2012, UET moved quickly through three design iterations. Inside a large room with a yellow gantry crane sits the first, completed in June 2013 and nicknamed Elviss, for “energy leveling vanadium integrated storage system.” The second, completed less than six months later, is called Angus—after Angus Young, the lead guitar player in AC/DC—in a nod to the power electronics that convert the electricity from the battery to electrical grid-ready alternating current, and Winter’s Australian roots.
The third article they call Johnny Cash, because it’s the first system ready for commercial sale.
“It sounds a bit greedy,” Li says as Winter explains the names. (UET’s conference rooms are musically themed, too. I met the executives in Graceland and passed Folsom on the way to see Elvis and Angus—though the latter is in reference to the headquarters location of the California Independent System Operator, a recognition of the importance of the California market, rather than the famous Cash song.)
Five 20-foot containers sit together in a string on a concrete pad outside a UET loading dock. Four of the containers hold 100 kilowatt batteries—for 400 kilowatts total—and the fifth holds the power control system and transformer.
UET is competing in an energy storage market expected by several analysts to easily exceed $100 billion by 2020. Other companies making vanadium flow batteries include Gildemeister, Imergy, Prudent Energy, WattJoule, and Sumitomo Electric Industries. Still another set of companies is at work on flow batteries with different chemistries, and others approach energy storage with solid state batteries, flywheels, compressed air, pumped hydro, and other technologies.
Large-scale energy storage in general is a hot field. The Energy Storage Association, a trade group, had more than 700 people at its annual conference last month in Washington, D.C., an attendance record indicating interest in the industry.
UET is making progress in this highly competitive, global market. Through its European subsidiary Vanadis Power, the company made its first sale earlier this year to Bosch, which is supplying a community wind farm in northern Germany with a vanadium flow battery that can store up to 1 megawatt hour of electricity, as well as a second 2 megawatt hour lithium-ion system from Sony.
The Washington state deployments, to be supported by matching grants from the new Washington Clean Energy Fund, are expected to be a 1 megawatt system for Avista, an investor-owned utility in Spokane, and a 2 megawatt system for the Snohomish County Public Utility District. These offer the prospect of further validation for UET and other technology providers as companies eye a big prize in large-scale energy storage: California.
“Washington state is about to become a Petri dish of energy storage,” Weed, 51, says. “There’s going to be five or six systems installed here in the next 18 months of different kinds and technologies.”
In part, the growth is being driven by new mandates aimed at reducing greenhouse gas emissions by adding renewable power to the grid. Utilities regulators in California have required that the state’s investor owned utilities acquire 1,325 megawatts of energy storage capacity by 2024 as they adapt the electricity system to changing supply and demand patterns resulting from the state’s renewable portfolio standard (RPS). The RPS requires that utilities source a third of their electricity from renewable sources by 2020, a target they are well on their way to meeting, mostly by adding wind and increasingly solar. This influx of renewable power, plus the increasing use of smart meters and the growth in numbers of electric vehicles, is dramatically changing the patterns of electricity supply and demand in California, posing a challenge to grid operators.
The graph illustrating daily net electricity demand in California is starting to resemble a duck, and is referred to as the duck curve in utility circles. The net demand curve is high before sunrise, like a duck’s back. As solar power production peaks in the middle of the day, net demand drops (the duck’s belly). In fact, on sunny days, more power might be produced than there is demand for, according to the California Independent System Operator (PDF). The net demand climbs steeply again in the afternoon, rising like a duck’s neck, as solar production ends and people come home to turn on air conditioning and televisions, cook dinner, and charge up their cars.
The duck’s belly part of the curve is where the energy storage technologies of UET and its competitors could shine: The technologies would soak up that extra mid-day electricity, storing it until it’s needed for the evening peak.
“Long-duration batteries are particularly useful in this context,” Weed says.
Other promising markets include Hawaii, which has the nation’s highest electricity prices, and New York, where grid reliability and resiliency concerns have grown after Hurricane Sandy.
Despite UET’s success with its latest generation battery, Li and Yang aren’t standing still. Together with a half-dozen other PhDs on the 40-person staff of UET, they continue to tinker with the chemistry and engineering of the system. Labs and scaled-down systems spread across the far side of UET’s headquarters are devoted to optimizing controls and power electronics and testing and improving the electrolyte and electrode stacks.
“That’s my top-secret stuff,” Li says after being told a reporter was given a tour of the labs.
“We still need new invention, new technology,” Li says. “So we have a very big R&D team—seven, eight PhDs—working on new developments, new controls, new battery design, everything. We continue to improve the performance.”