Techno-Economic Analysis of Gen3 Concentrated Solar Power With a Topology-Optimized Silicon Carbide Heat Exchanger

Abstract This paper considers a topology-optimized primary heat exchanger (PHX) manufactured from silicon carbide (SiC) using additive manufacturing technology for integration into a Gen3 concentrated solar power (CSP) plant, which facilitates heat transfer between particles and supercritical carbon dioxide (sCO2). This primary heat exchanger technology provides the possibility of both reducing the cost per conductance in the primary heat exchanger due to the advanced heat transfer surfaces that can be achieved as well as increasing the turbine inlet temperature of the cycle due to the high temperature capability of SiC. Preliminary findings suggest that a 10% decrease in the cost per unit of conductance in the primary heat exchanger will result in a 1 $/MWh decrease in the levelized cost of energy, and the power block has a cost-optimal thermal efficiency of around 47% for a turbine inlet temperature of 680°C. The optimization methods presented in this research have also identified gains in the tradeoff between the cost of the PHX and the thermal performance of the power cycle, further reducing the levelized cost of energy. Performance of the primary heat exchanger — including cost per unit conductance, operating temperature, and lifetime — can be a strong determinant of where capital should be allocated in a concentrated solar power system. Such an indicator is helpful for the future design and techno-economic analysis of these systems. The presented results indicate the importance of carefully considering PHX design in meeting DOE cost targets for concentrated solar power.