EPRI, in collaboration with Southern Company and Storworks, has recently completed testing of a pilot concrete thermal energy storage (CTES) system at Alabama Power’s Ernest C. Gaston Electric Generating plant (Gaston), which the companies are calling the largest such pilot in the world.
The 10-MW-hour electric (MWhe) energy storage solution, developed by Storworks, is charged using heat from supercritical steam generated by Gaston’s Unit 5. As designed, high-pressure steam from the power plant flows through tubes, heating the concrete, which stores the thermal energy until it is returned to the power plant by converting feedwater into steam to generate electricity in response to grid demand. The project received funding from the U.S. Department of Energy under award DE-FE0031761.
The technology can be applied to existing or new thermal power plants, including coal, natural gas, nuclear, or concentrating solar power, the companies said, and the core technology can go beyond electric power to applications including decarbonizing industrial heat.
“Advancements in long-duration energy storage are key to unlocking the full potential of variable renewable energy resources on the path to net-zero,” said Neva Espinoza, EPRI vice president of Energy Supply and Low-Carbon Resources. “As the power sector navigates a highly complex transition, CTES could play an important role in efficiently delivering the reliable and affordable electricity society depends on.”
The companies said the original goals of the project were exceeded, as steam production at several pressure levels was demonstrated. More than 80 energy charge and discharge cycles were also successfully performed over 700 hours of total operation.
“We appreciate the vision and support from our partners that made this pilot demonstration possible,” said Scott Frazer, co-founder of Storworks. “Low-cost long-duration energy storage is increasingly critical in the shift to low-cost intermittent renewable energy, and the Gaston project represents an important milestone in advancing the commercialization of our technology. With industry-leading low cost, Storworks’ modular system can be tailored to a range of applications for both power plants and industrial decarbonization solutions.”
