19. Performance Comparison of Sodium and Magnesium Chloride-Saturated Solar Ponds

This chapter deals with an experimental investigation of energy efficiency of sodium and magnesium chloride-saturated solar ponds. The solar pond systems are filled with varying-density sodium and magnesium chloride water in order to form gradient layers. A solar pond generally consists of three zones. The density of the zones increases toward the bottom. Solar radiation is absorbed by salty water and the temperature rises. The high-temperature salty water at the bottom of the solar pond remains denser than less salty water above it. Thus, the convective heat losses are prevented by gradient layers. The temperature distributions of the solar pond are obtained by using thermocouples from August to November. The density of the layers was also measured and analyzed by taking samples from the same point of the temperature sensors. The efficiencies of the solar pond are defined in terms of temperatures as the average representative solar energy. As a result, the maximum energy efficiencies of the heat storage zone for the sodium and magnesium chloride-saturated solar ponds are found as 25.41 % and 27.40 % for August, respectively.