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

The Department of Energy seeks a solution for the improved components for the next generation of Concentrating Solar Thermal Power (CSP) generation technologies. While there are many CSP system components, the thermal transfer fluid can be an excellent cost reduction candidate. The current state-of-art of the thermal transfer solid in the CSP system's particle receiver is the ceramic proppant. The proppant has high solar absorptivity and durability at high temperature. However, its high cost (1-2 $/kg) is a major hurdle to be continuously used as the transfer media. Due to this high cost, the proppant has limited use as only transfer, not for thermal energy storage. To overcome the problem, we propose a novel thermal particle that is economical and highly durable at 1,000oC. The particle has a multifunction that can be a thermal energy transferrable vehicle from the sunlight receiver tower and a direct storable medium in a thermal energy storage (TES) system. The particle is a silica-based material, which is an economical material and has the high thermal storage capability, and iron oxide will be added to the silica sand. The added iron oxide will enhance the solar absorptivity to transfer the thermal energy. We project the new technology will decrease LCOE to 0.059 $/kW-hr. This reduction LCOE is extremely close to the Department of Energy Solar Energy Technologies Office (SETO) goal by 2030 (0.050 $/kW-hr). In Phase I, we will develop the low-cost thermal particle around 0.05 $/kg, demonstrate its high durability at 1,000℃ as well as its durability, and outline the preliminary design and cost of installation of the prototype in the CSP-TES system. Once the project is carried over into Phase II or Phase III and beyond, the application will target the thermal energy storage market. This multifunctional thermal particle will transfer the concentrated sunlight from the particle receiver to the thermal storage system. The particle will be used as the storage media. Since the proposed particle has low-cost and high durability, the levelized cost of energy (LCOE) will be reduced to <0.059 $/kW-hr from 0.065 $/kW-hr. The reduction of LCOE will be close to the SETO’s 2030 goal (0.05 $/kW-hr). This technology will demonstrate the synergetic effect by combining the concentrating solar power components.