Simulation and Performance Analysis of a Solar-Charged Desalination Salt Thermal Energy Storage System with Bypass Discharge

Thermal energy storage (TES) is a key enabling technology for renewable energy systems, particularly solar, where resource variability necessitates flexible and dispatchable energy delivery. This study presents a simulation model for a desalination salt-based TES system, employing a bypass discharge configuration to enhance outlet temperature stability. The present work incorporates a time-dependent Gaussian solar irradiance profile to represent realistic charging conditions. The TES unit, modeled as a packed salt bed, was charged for six hours using a solar collector area of 500 m2. Results show that the storage medium absorbed 1221 kWhth, raising its temperature from 20.4 ℃ to 550 ℃. During discharge, the bypass configuration maintained a nearly constant process outlet temperature of 61.8 ℃ for 4.48 h, extending useful operation before transitioning to direct discharge. Sensitivity analyses revealed that oversizing the TES without adequate solar input reduced charging efficiency, while oversized solar fields led to underutilized capacity. These results highlight the importance of balancing system design and demonstrate the potential of repurposed desalination salt as a cost-effective, sustainable TES medium for renewable integration.