Southwest Research Institute has received a $2 million grant from the United States Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E) to develop an advanced pumped heat electricity storage (PHES) system. This system offers twice the energy density of a lithium ion battery and is based on an innovative thermodynamic cycle to store energy in hot and cold fluids.
"It's important, now more than ever, to invest in innovative solutions that can help deliver on the promise of effective, renewable energy," said Danny Deffenbaugh, vice president of SwRI's Mechanical Engineering Division. "This new energy storage system is a wonderful example of research that benefits the world we live in, which SwRI engineers are committed to pursuing."
To implement renewables such as solar or wind energy on a larger scale, new energy storage technology is critical to match intermittent supplies with customer demand. In recent years, the energy industry as well as the Department of Energy have been investing in new energy storage methods to support on-demand availability of renewable energy that can be stored for longer periods of time. The SwRI team, led by research engineer Brittany Tom, plans to build the new grid-scale energy storage system over the next two years.
"Grid-scale energy storage technologies like this one can provide more than 10 hours of electricity at full power and address a critical need for renewables on electricity grids worldwide," Tom said. "To make renewables a viable energy solution, you have to invest in new methods of energy storage."
In this new system, electric energy from the grid is converted into thermal energy and stored as a thermal potential. At full capacity, the system can store energy for hours or up to several weeks before converting it back to electrical energy. The system can then provide greater than 10 hours of electricity at rated power. Tom adds that the capacity of the system can be easily extended by increasing the volume of the storage tanks.
Additionally, this form of storage offers a low-cost solution when compared to the costs of operations like "peaker" plants, which generate and provide electricity during the peak demand hours of the morning, later afternoon and evening. Because it's capable of storing energy for longer periods, the PHES system can provide electricity when needed.
A system like this is ideal for an intermittent resource like solar energy. Solar energy can offer plenty of supply in the daytime, but depending on the time of day or weather may not be as reliable as other energy resources. The PHES system's capacity for long-term storage makes renewable energy a much more practical option.
Additionally, unlike pumped-storage hydroelectricity, which requires a specific topography to take advantage of the gravitational potential energy of water, this new storage method can fit into most rooms, allowing it to be installed basically anywhere.
"This grant will further SwRI's efforts in developing a small-scale demonstration that can be scaled up to include renewable energy sources into the broader grid. I know that SwRI has been a leader in energy technology, and I'm glad to see San Antonio lead the way in helping Americans improve the ways we obtain, store and use our energy overall," commented U.S. Representative Joaquin Castro on the project.
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