Like a savings account for the electric grid, energy storage neatly balances electricity supply and demand. Renewable energy, like wind and solar, can at times exceed demand. Energy storage systems can store that excess energy until electricity production drops and the energy can be deposited back to the power grid. However, for widespread deployment of grid energy storage to occur, the research community must continue to investigate and improve ultra-low-cost materials and chemistries capable of long-term deployment.

Much of PNNL’s grid energy storage research is managed by the DOE’s Office of Electricity’s Energy Storage Program, whose mission is to perform R&D on a wide variety of energy storage technologies. Energy storage experts at PNNL are helping to accomplish this mission by developing energy storage technologies that integrate renewable energy into the grid. This reduces barriers like higher costs and limited storage capacity and provides more cost-effective power for consumers. PNNL also evaluates and analyzes pumped-storage hydropower (PSH) for DOE’s Water Power Technologies Office. PSH can generate electricity by pumping water from a lower reservoir to a higher one where it is stored until needed.

Achievements in the lab

Researchers developed a compound based on a pharmaceutical material that shows promise in replacing costly vanadium, a chemical element used in grid-scale batteries. Technologies developed in house are also catching the attention of industry. For example, a mixed acid electrolyte developed by PNNL researchers succeeded in cutting in half the cost of an advanced vanadium flow battery and doubling its energy density.

PNNL accelerates grid-scale energy storage research within its tens of thousands of square feet of lab space dedicated to technology research and development. An Advanced Battery Facility serves as the canvas for developing and validating new battery chemistries. The Redox Flow Battery Labs provide space for testing redox flow batteries on the bench and for large-scale demonstrations. And the Environmental Molecular Sciences Laboratory houses an environmental transmission electron microscope to evaluate battery structural and function materials, while a scanning transmission electron microscope and nuclear magnetic resonance spectroscopy allow probing of the materials’ microstructure and chemical compositions.

Beyond vanadium, a wide range of low-cost materials, such as sodium, zinc, manganese, are investigated for battery applications. As the research community perfects this complex chemical combination, widespread use will help pad the nation’s electricity “bank account” towards a more resilient, reliable power grid.