Abstract The technological and economic impact of design changes in thermal energy storage of concentrated solar power (CSP) systems is assessed. It is shown that the system costs change with the types of storage tanks and also that the operation temperature is limited by the thermal properties of the thermal storage medium. In addition, the cost of energy can be substantially reduced by replacing the conventional power cycle with more advanced power cycles, such as a supercritical carbon dioxide power cycle. Using two types of thermal storage tanks and two thermal storage media, cases are generated incorporating combinations of the design options. A sensitivity analysis is used to investigate the impacts of each technological improvement. The results of this work will contribute to predicting the impact of research and improving the economics of the CSP system.