Assessment of the overall energy and exergy efficiencies of the salinity gradient solar pond with shading effect

In this paper, the energy and exergy distributions and efficiencies in the square solar ponds have been investigated numerically and experimentally. For this purpose, a small scale solar pond with square cross-section was built and tested at Urmia University in Urmia-Iran with a height and area of 1.1 m and 4 m2, respectively. In the small solar ponds, shading by the side walls affects the accumulation of solar energy and thermal energy storage. Therefore, a shading model is also developed for achieving a complete understanding of the energy performance of the small solar ponds. So, by using the proper relations and considering the shading effect, energy and exergy efficiencies were analyzed in the pond. Maximum energy efficiency of the pond with and without shading effect were 3.27% and 3.65%, respectively, the values for maximum exergy efficiencies were also 0.19% and 0.27%, respectively. The results confirmed that by applying the correct relations for energy and exergy efficiencies, the ponds' performance can be properly investigated.