Project Name: Liquid-Phase Pathway to SunShot
Funding Opportunity: Generation 3 Concentrating Solar Power Systems
SETO Subprogram: Concentrating Solar Power
Location: Golden, CO
SETO Award Amount: $8,067,655
Awardee Cost Share:  $5,432,401
Principal Investigator: Craig Turchi

Download the Executive Summary for this project.

This project team will design, develop, test, and validate a two-megawatt integrated concentrating solar-thermal power (CSP) system that uses a liquid heat-transfer fluid (HTF) to supply solar-thermal energy to a simulated power system. The team will test the system’s ability to monitor and control corrosion, operate a high-temperature solar receiver, efficiently store thermal energy, and transfer heat to supercritical carbon dioxide, the working fluid of an advanced power cycle. For the HTF, the team will consider a three-component chloride salt and a liquid sodium metal. After the team evaluates the materials and components, they will choose an integrated system design to be further developed and then proposed for construction and testing as part of the Topic 1 liquids pathway. 


The research team will validate the physical properties of two HTF—a three-component chloride salt and a liquid sodium metal—and test their material compatibility. They will then design and model the receiver, thermal storage unit, and primary heat exchanger based on the HTF properties. The team plans to use this system alongside insulated tanks that can withstand the extremely hot temperatures needed for thermal energy storage. The team will then model the full system to illustrate its efficiency and estimate the cost of constructing a commercial-scale CSP plant.


This project will evaluate two liquids that could potentially replace the molten nitrate salt traditionally used in CSP plants, which currently operate at a maximum temperature of 565° Celsius. The liquids investigated in this project are stable at temperatures greater than 800°C and will be tested with several strategies to prevent corrosion at those temperatures. CSP plants that operate at higher temperatures increase overall solar-to-electric conversion efficiency and hold the promise of decreasing the levelized cost of energy of CSP electricity. This work will inform the design and development of high-temperature, low-cost CSP plants.