Solar ponds are of two kinds one which is convective and the other is non-convective shallow ponds, the most important non-convective pond is the salt gradient pond. A solar pond is a low price solar collector for both storing and collecting the thermal energy for long duration of time. The salinity gradient solar pond is a steady reproduction pond of salted water where the concentration gradient of the salt rises with increasing depth. The salinity gradient solar pond consists of three layers. The upper convective zone is the first layer (UCZ) it has a homogenous salt concentration and a convective heat transfer, it has a temperature equal to the ambient temperature and a close salinity to the sea water (3.3 wt%). The non-convective zone (NCV) also has conductive heat transfer, its salinity density and temperature increases quasi-linear to attain the maximum level, hence convection is not possible. The lower convective zone (LCZ) it is the storage layer with the densest and uniform salinity close to brine saturation thickness is flexible, the LCZ depends on factors such as the thickness of the LCZ and NCZ layers, radiation intensity, ambient temperature and solidity of salt gradient.
Protections and improvements of the performance of the solar ponds was by mainly using the first law of thermodynamics. Energy analysis are the calculations of energy transfer and losses. The second law of thermodynamics was used for the energy analysis, it is proposed as a useful tool for designing an energy system with high efficiency that also reduced the irreversibility in the system and processes. There was a notice in reflection back to the sky from the solar radiation defecting from the pond. Due to the heat loss through the evaporation, convection and radiation from the pond’s surface the UCZ layer has the highest wasted energy, then falls under it the LCZ and this is due to the high temperature difference with the ambient temperature because of the insulation, hence greater stored energy in the LCZ.