Design and modeling of a high temperature solar thermal energy storage unit based on molten soda lime silica glass

•The design of a high temperature silica glass based thermal energy storage unit is presented.•The development of a quasi-bidimensional thermal model is discussed.•The performance of the 126kWhth TES is assessed through the transient model.•An in-depth exergy analysis of the behavior of the TES unit is performed, obtaining an exergy efficiency of 59%.