Material aspects of Solar Salt for sensible heat storage

Molten salt composition and composites for improved latent heat thermal energy storage

“…Variations constantly occur in the results of the same properties of materials which in theory should be almost identical taking into consider the variations in the purity of the materials used [3,7,9,14]. Bauera [8] and his team found a ±7% and ±15% variation in data for heat capacity, and thermal diffusivity and conductivity of solar salt respectively compared to previously calculated values revealing inconsistency with tested results. For example, the maximum thermal stability in the aforementioned study was discovered to be significantly lower than that of the solar two project in Albuquerque [17].…”

“…A primary reason for this being the salts moderately low thermal conductivity at the optimum hot salt temperature of concentrated solar plants 565°C, which is (0.470±0.3) /mK for Employing alternate eutectic salt material composition and composite materials, however, could be the answer. The efficiency of the molten salt LHTES is characterised by a range of thermo-physical properties most importantly thermal stability, heat capacity, thermal conductivity and melting point, these properties directly effecting heat storage capacity and transfer rates [8]. Standard solar salts exhibit low thermal conductivity, therefore altering the material's thermo-physical properties to increase this, may prove to be very beneficial for various commercial applications including CSP technology [9].…”

Characterization of desert sand as a sensible thermal energy storage medium

“…This is lower than the heat capacity of common molten salts (1.5 kJ kg -1 K -1 for Solar Salt [14]), although the effect may be compensated with the large temperature range over which the sand may be operated (maximum of 800-1000 °C compared to 565 °C for Solar Salt) or larger quantity of this inexpensive material. The specific heat capacity reported here is comparable to that of other granular TES materials such as proppants or silicon carbide [15], [4].…”

Effect of sand and moisture on molten salt properties for open direct absorption solar receiver/storage system

“…Putting the solar salt under real conditions of air and humidity has an advantage in increasing the upper temperature limit for both cases with and without sand compared to the above results with nitrogen gas atmosphere. This could be explained by equation (1) where the oxygen helps to keep nitrate more stable than with nitrogen 9 . Also, there was an increase by 1 % of salt mass with 2 % of sand and that may be because of interaction between sand and air and or humidity (still under investigation).…”