The Electric Power Research Institute (EPRI) has been selected by the U.S. Department of Energy (DOE) and the National Energy Technology Laboratory (NETL) to lead a pilot project to test concrete thermal energy storage (CTES).

Participants in the $5 million project will design, construct, and test a CTES system to demonstrate the technology’s potential to store thermal energy for conversion to electricity when integrated with thermal power units. As designed, high-pressure steam from the power plant flows through tubes, heating the modules, which store the thermal energy until its returned to the power plant to generate electricity in response to grid demand. The pilot project will test modules similar in size to those expected to be used in larger-scale commercial applications.

The 10-MWh CTES system will be integrated into an existing coal power plant, providing a slipstream of high-temperature steam for testing.

Many coal power units in the United States are being pressed to operate more flexibly to provide grid stability and protection, which can reduce efficiency and operational life. The CTES system may enable a coal plant to run more consistently, providing stored heat when electricity is not needed. Such operating cycles better fit a thermal plant’s design and could improve its profitability. The technology also can be applied to natural gas, nuclear, or concentrating solar power.

EPRI will lead a team of Bright Generation Holdings, the CTES technology developer; AECOM, to perform engineering, procurement, and construction work; and Southern Company, to provide the field test site and operational support. This team will design and build a first-of-a-kind, pilot-scale field test facility for this thermal energy storage technology.

The testing will establish the capabilities of the CTES system in a real-world environment, demonstrating its efficiency and ability to handle flexible operating conditions. In addition, an analysis will be done to determine the costs and benefits of a full-scale application of CTES technology.

EPRI will also offer a program for key stakeholders, primarily power generating companies, to be part of the project, and learn about the technology firsthand.

“EPRI’s long history of advanced power systems research, our extensive collaboration with DOE and NETL on other projects, and our relationships with the power industry make us uniquely qualified to lead this important project,” said EPRI Vice President of Generation Tom Alley. “This technology has the potential to provide a number of important benefits for today’s rapidly changing energy network.”

“The growth of variable renewable energy requires grid protection provided by dispatchable sources, which largely comes from fossil-based units. Integrated CTES can support fossil plants in their mission to help keep the grid reliable. Concrete thermal energy storage has the potential to be significantly cheaper than batteries with a smaller footprint. It also has the potential for longer-duration storage, which will be critical as more wind and solar come on-line.»

Initial work on the project is scheduled to start in October 2019, with construction beginning within a year. The pilot project becomes operational in early 2021.

The Electric Power Research Institute, Inc. (EPRI, conducts research and development relating to the generation, delivery and use of electricity for the benefit of the public. An independent, nonprofit organization, EPRI brings together its scientists and engineers as well as experts from academia and industry to help address challenges in electricity, including reliability, efficiency, health, safety and the environment. EPRI’s members represent more than 90 percent of the electricity generated and delivered in the United States, and international participation extends to 40 countries. EPRI’s principal offices and laboratories are in Palo Alto, Calif.; Charlotte, N.C.; Knoxville, Tenn.; and Lenox, Mass.