Economical Thermal Transfer Media for Generation 3 Concentrating Solar Power System with High Durability

The Department of Energy seeks a solution the improve the thermal transfer fluid for particle-based concentrating solar power (CSP) system. While ceramic proppants have been widely used for thermal transfer media, their high cost (>$1,000/ton) is a significant hurdle for further reduction of the Levelized cost of energy (LCOE). If the invented media or particles show excellent solar absorptivity and storage capabilities at a low price, the media can be used in both thermal energy transfer vehicles and storage, which creates a significant reduction of LCOE. Advanced Materials Scientia LLC (AMS) is developing multifunctional thermal energy media at a low price. The particle is a silica-based material, economical material with a high thermal storage capability, and iron oxide will be added to the silica sand for high solar absorptivity. In Phase I, AMS demonstrated the proof of concept that the hematite-coated silica sand particles with heat treatment produced the highest solar absorptivity in current markets. The particles were highly durable at ultra-high temperatures. Moreover, the sales price of our product is estimated 12 times lower ($82/ton) than ceramic proppants (>$1,000/ton), which are currently used in many industries and research institutions. We filed a U.S. provisional patent. We obtained a positive impact from the potential end-user, and the potential strategic partner has shown interest in our technology. We are currently speaking to the partner for future collaboration. In Phase II, AMS will optimize the physical properties of thermal erosion/corrosion resistance and flowability at high temperatures. We will perform the field test at Sandia National Laboratory. Then, we will test the prototype manufacturing. The product's sales price will remain $82/ton or less. Once the project is carried over into Phase III and beyond, the application is the media for the thermal energy storage and transfer vehicle. The multifunctional thermal media transfer the concentrated sunlight from the particle receiver to the thermal storage system. The transferred media produce high-temperature energy in the storage, generating electricity by running turbine engines. Because the developed media have high thermal energy capabilities at a meager price, the estimated LCOE is 0.059 $/kW-hr or less from 0.065 $/kW- hr. The reduced LCOE is close to SETO's 2030 goal (0.05 $/kW-hr). The technology contributes not only to create jobs but a zero-carbon mission. The media fabrication system is simple and does not require an energy-consuming process such as a spray dryer. Compared to typical ceramic media production, the technology expects to reduce carbon emissions by 26%.