Project Name: Supercritical Carbon Dioxide Loop in Support of the Gen3 CSP Solid, Liquid, and Gas Pathways
Funding Opportunity: Generation 3 Concentrating Solar Power Systems Lab Call
SETO Subprogram: Concentrating Solar-Thermal Power
Location: Albuquerque, NM
SETO Award Amount: $3,600,000
Awardee Cost Share:  N/A

To achieve higher efficiencies, concentrating solar power (CSP) plants can use the Brayton power cycle, an engine design that uses supercritical carbon dioxide (sCO2) as a fluid to transfer heat. Current CSP plants use steam Rankine cycles, in which 35% to 42% of the collected heat is converted to electricity. Brayton power cycles that use sCO2 as the working fluid could increase this efficiency to 50% or above. This project will develop a sCO2 support loop to cool the main heat exchanger in a pilot plant project in Topic 1 of the Generation 3 (Gen3) CSP funding program.


The project team will discuss and develop their design in coordination with the three teams in this funding program that are developing Gen3 pilot plants, to ensure it will work in each one. Then they will construct and test the support-loop components to verify that they have all the necessary capabilities. Finally, the loop will be integrated with the pilot plant to create a complete thermal power system.


Brayton cycles based on sCO2 can use much smaller components than Rankine cycles do, saving construction, installation, and operation costs. The sCO2 Brayton cycle also could significantly lower the cost of CSP electricity by increasing plant efficiency, allowing more power to be produced from the same amount of collected solar energy.