The challenge with batteries is to come up with something big enough to provide electricity in useful amounts at a cost that’s competitive with traditional sources of generation. Zhenguo “Gary” Yang believes he has that technology: the vanadium redox flow battery.
To commercialize it, Yang has set up UniEnergy Technologies (UET) with investment from backers in China and Australia. UET has leased a 27,000-square-foot facility in Mukilteo and is hiring engineers to move the technology to demonstration and commercialization. The company hopes to have working models to show off to potential customers by the end of the year.
Yang was one of the scientists at Pacific Northwest National Laboratory (PNNL) who did research on the technology, which UET is licensing from PNNL. The battery works through the chemical interaction of differently charged electrolytes (electricity-conducting liquids) across a membrane. Multiple layers of membrane are assembled into a cell stack. In vanadium redox batteries, the electrolytes consist of vanadium ions in different charged states. The electrolyte material is stored in tanks and pumped into the stack to produce an electrical current. To recharge the battery, current from a source such as a wind turbine is introduced to restore the original charge of the ions in the electrolytes, which flow back to the storage tanks where they’re held until called upon again to produce electricity.
By tweaking the chemistry of the electrolytes, PNNL researchers found they could improve the temperature range in which the battery can operate while also increasing its capacity to store potential energy. It’s good for hundreds of thousands of cycles (charges and discharges) and can be easily scaled up to produce the amount of power—in the tens of megawatts—that would interest utilities and other customers with large demand.
As utilities move more toward time-of-day pricing (customers pay more for electricity in peak-demand hours), the owner of a big commercial building could download electricity at off hours into a battery for use later. Battery stacks could also be placed in remote locations, such as islands that can’t be connected to the grid. Yang notes that unlike pumped hydro, vanadium redox flow batteries don’t need a specific site to operate in and don’t require extensive lead times to deploy.
“There’s a lot of pent-up demand in the market,” says Russ Weed, an attorney with Graham & Dunn who has been working with Yang in setting up UET. “There’s a lot of competition, too.”
PNNL is licensing the technology to one other undisclosed group, and Yang acknowledges the United States trails other countries in electrochemical battery commercialization.
“Our purpose is to enhance U.S. competitiveness in this field,” he says. “We believe we have the leading team.”