Enhanced Heat Capacity of Molten Salt Nano-Materials for Concentrated Solar Power Application

Abstract

Storage of thermal energy using molten salt materials has been widely explored for concentrating solar power. Since these power plants use thermodynamic cycle, the overall system cycle efficiency significantly relies on the thermal energy storage temperature. Therefore, increasing the thermal energy storage temperature and decreasing the amount of material needed can result in reducing the cost of solar energy. Molten salts are stable up to 700°C, relatively cheap, and safe to the environment. However, the heat capacity of the molten salts is typically low (∼1.5 J/gK) compared to other thermal storage materials. The low heat capacity of molten salts can be improved by dispersing nanoparticles. In this study, we synthesized molten salt nanomaterial by dispersing oxide nanoparticles into selected molten salts. Heat capacity measurements were performed using a modulated differential scanning calorimeter. Materials characterization studies were performed using a scanning electron microscopy. Hence, we evaluated the use of the molten salt nanomaterials as thermal energy storage media in concentrated solar power applications. Increase in the specific heat capacity of the molten salt is also demonstrated on addition with Nano materials of specific size and quantity.