Comparison of sizing calculations based on exergy and electric power production for molten salt thermal energy storage systems

Abstract

In this work a fast numerical model for sizing calculations of thermocline with filler storage systems, implemented in Matlab®, is presented. With this model, two sizing approaches are used. The first approach is considered as the classic approach, based on regained exergy after a full storage cycle, whilst for the second approach, the storage model is coupled with a simplified solar field and power block model. In the latter case, produced electric power after a full storage cycle is used for the rating of the storage configurations. Both approaches show a high efficiency of the thermocline with filler system. The comparison of both approaches show the influence of fluctuating boundary conditions on the cyclic behavior of the storage system and eventually, its sizing results.