Southern Research Institute has signed a jointly funded cooperative agreement with the U.S. Department of Energy as part of the DOE's new "Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage" funding program, part of the SunShot Initiative. CSP: ELEMENTS supports the development of high-temperature thermochemical energy storage (TCES) systems that enable concentrating solar power plants to produce electricity in the evenings and even overnight when the sun is no longer shining.
CSP technology employs mirrors that concentrate reflected sunlight onto receivers containing heat transfer fluids. From there, the fluids are used to heat water, which in turn generates steam that is used to power turbines and produce electricity. By adding thermal storage to these facilities they are able to operate at significantly higher capacity factors and produce approximately double the energy for the same size power facility. Furthermore, the production of electricity can be shifted to occur at the same time as peak power demand, making the electricity much more valuable.
The Southern Research Institute project will develop a TCES system that uses a low-cost calcium-based sorbent in a reversible closed-loop endothermic-exothermic chemical reaction cycle. The system stores energy during mid-day when sunlight is plentiful in the endothermic step, and then releases energy when the sun is no longer shining during the exothermic step, allowing for electricity to be produced in a more stable and consistent fashion. This TCES system is projected to cost about one-quarter as much as current state-of-the-art molten salt storage systems, and will be able to store the same amount of energy in a system about one-sixth the size.
"Utilizing these low-cost regenerative calcium-based sorbents, researched for carbon dioxide capture in coal-based power generation facilities, leverages existing knowledge bases and is an innovative transfer of technology," said Dr. Santosh Gangwal, project Principal Investigator. "Through rigorous material development we can refine these sorbents to perform successfully in this environment throughout the entire 30 year life of a CSP plant."
Furthermore, while molten salt storage systems can only operate up to about 550 degrees Celsius, the Southern Research Institute TCES system can operate sustainably up to 900 degrees. "As the next generation of CSP plants moves towards higher operating temperatures to achieve higher conversion efficiencies, a new generation of high-temperature storage needs to be developed to allow these facilities to continue to provide power in a cost-effective and dispatchable manner," said Ryan Melsert, co-Principal Investigator of the project.
The U.S. Department of Energy (DOE) SunShot Initiative is a collaborative national effort that aggressively drives innovation to make solar energy fully cost-competitive with traditional energy sources before the end of the decade. Through SunShot, DOE supports efforts by private companies, academia, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour.
Southern Research Institute is a not-for-profit 501(c)(3) scientific research organization founded in 1941 that conducts preclinical drug discovery and development, advanced engineering research in materials, systems development, and environment and energy research. Approximately 500 scientific and engineering team members support clients and partners in the pharmaceutical, biotechnology, defense, aerospace, environmental and energy industries. Southern Research is headquartered in Birmingham, AL, with additional laboratories and offices in Wilsonville and Huntsville, AL, Frederick, MD, Durham, NC, Houston, TX, and Cartersville, GA.
SunShot's Ranga Pitchumani and awardee Cliff Ho discuss how the innovative, state-of-the-art, concentrated solar power plants currently coming online safely utilize the suns energy to generate heat and the ability to store energy in a cost effective manner.