Overview of molten salt storage systems and material development for solar thermal power plants

This paper gives an overview of thermal energy storage (TES) systems based on molten salts. It summarizes stateof-the-art molten salt TES systems. Storage systems in a research stage, such as the thermocline and floating barrier concepts, are also discussed. The paper summarizes previous work on molten salt material investigations at DLR. Experimental results of novel salt formulations with melting temperatures well below 100 °C are presented. An overview of temperature dependent thermophysical property values of Solar Salt is given. The thermal stability of nitrate/nitrite mixtures was examined by dynamic thermogravimetry and static measurements at constant temperature. We discuss in this paper the impact of the atmospheric conditions (partial oxygen pressure) and salt composition on the stability of nitrate salts. At DLR, a molten salt test loop is in the design stage. A scheme of the test loop and the options for experiments are presented.