Better Batteries for Future Energy Demands

We often take for granted the fact that when we flick a switch a light turns on. In reality, the seemingly simple act of turning on a light is a complicated process that requires a precise balance between generation and transmission of energy as demand varies throughout the day. With consumers increasingly interested in getting their energy from renewable sources like solar and wind, which produce energy intermittently, energy storage has become an incredibly important topic in cleantech. Developing cheap, high-performance storage technology to enable more solar and wind energy would represent real progress towards goals of cutting carbon emissions.

The major challenge of figuring out how to retrofit our current means of distributing power with next generation battery technology is an issue of national importance that requires intellectual contributions from a wide variety of sectors. Finding conduits between academic research, venture capital, public utilities, policy makers from local government, and early adopters to take a chance on emerging innovations is key to producing market-ready technology that customers need at a reasonable price. However, it is often difficult to find a way to bring these many viewpoints to the same table.

This was the goal of the Pacific Northwest Energy Storage Symposium at the University of Washington last month. The event brought together more than 100 people from both the private and public sector to understand and advance the state of energy storage, particularly in the Pacific Northwest.

A common theme throughout the symposium was the need to lower the cost of next generation battery technologies. The Joint Center for Energy Storage Research (JCESR), a research partnership between government, academia, and industry groups has a mission of creating batteries capable of “delivering five times the energy density at one-fifth the cost of the commercial batteries available at its launch in 2012.” That would mean a battery costing around $100 per kilowatt hour (kWh). As a point of comparison, the much publicized Powerwall unit by Tesla has been priced at $350 per kWh, not including installation or an inverter.

Another important aspect of advancing energy storage innovation is figuring out how to move technology from the lab to the field faster than pervious commercialized batteries. One example of a successfully commercialized storage system, the lithium ion battery, took over 20 years to make it into the hands of consumers. George Crabtree, director of JCESR, explained how public-private partnerships can cut down the time to market for nascent technologies. Dan Schwartz, director of the UW Clean Energy Institute (where the author is a graduate fellow), stressed that 20 years is not a time constant in nature for commercialization of a technology. Commercial development can move faster in the future.

One way to accelerate the leap from basic science to application is through novel characterization tools that could detect subtle changes in battery chemistry at early stages of cycling, Schwartz said. While computer models can capture most of the variance in battery chemistries, there are still some very rare interactions that can ultimately make a good idea fail. Being able to capture the complete range of side chemistries will help make better predictive models for researchers and eliminate technologies that will fail before spending money to build a prototype.

Jerry Siedler, a professor of physics at UW and founder of easyXAFS, is working on making these types of instruments available outside the sphere of academic research. He is developing a table top X-ray system that can perform tests now confined to the most powerful beam lines in the world. Costs and wait times for these machines make them ill-suited for the rapid prototyping needed by battery researchers in industry and academia. The easyXAFS instrument promises an accessible way for industry and other battery developers to monitor the degradation of new battery materials in real time under a variety of conditions. “Fail fast” is a mantra in the world of software startups. Battery developers need to fail fast, too, so they can fix fast.

Another technology making the leap from lab science to market is the flow battery. Also known as a redox flow battery, this state-of-the-art rechargeable battery system uses the ion exchange of chemicals dissolved in a solution to provide electrical current. An added benefit is that this technology does not have the issues of degradation from which solid state devices suffer and can be cycled without loss in performance. Several different chemistries were discussed during the symposium including zinc bromide, vanadium (the chemistry in the batteries from UniEnergy Technologies, based in Mukilteo, WA), and iron. In addition, researchers also discussed metal/air, sodium and potassium ion, divalent materials (such as magnesium) and all solid-state battery technologies. Indeed, energy storage, and batteries specifically, continues to grow as an important field of study in clean energy research.

On the commercialization side, UniEnergy’s CEO Z. Gary Yang discussed the recent installation of a vanadium flow battery on the Schweitzer Engineering Laboratories campus in Pullman, WA. A UniEnergy system with a maximum energy storage capacity of 4 megawatt hours was installed with the help of a $3.2 million dollar grant from the Washington State Clean Energy Fund and are run with the help of Avista Utilities. The original chemistry for the batteries was refined at the Pacific Northwest National Laboratory, underscoring the need for public-private partnerships to advance these technologies. [Editor’s note: UniEnergy Technologies CEO Z. Gary Yang will speak at Xconomy’s upcoming Seattle 2035 conference.]

Tom Rankin, president and CEO of the Washington CleanTech Alliance, lent an air of optimism to the event by concluding that major improvements in battery technology were going to happen because there are just “too many benefits to resist.” That is good news not only for researchers and industry but also the investors who may have been hesitant to invest in cleantech. In the end, customers will benefit the most from having a larger variety of options for storage at a manageable price.

Author: Sarah Vorpahl

Sarah Vorpahl is a Clean Energy Institute Graduate Fellow at the University of Washington. Her research interests include the characterization and development of new materials for solar energy and energy storage, as well as an interest in energy policy and public affairs.