Comparison of promising materials for filling thermocline tanks as thermal energy storage of a CSP plant applying air as HTF

This work focuses on the comparison between different filler materials which can be used in the thermal storage system of an air CSP plant. In order to carry out this analysis, a packed-bed model of filler material has been developed, this model has been successfully validated against experimental data provided by external bibliography. Then, this model has been used to size the storage system for the different filler materials stated in this study. An iterative process has been carried out, varying the size of the storage system until the discharge time of the storage when the convergence solution has been reached is equal to the 11 hours of storage required by the plant. Once the storage system has been sized for the different filler materials, an estimation of the cost for each solution has been done. The results suggest than the steel-making slag is the filler material which leads to the cheapest thermal storage system.