A Critical Review on Solar Pond Technology

This paper reviews the basic principle of solar pond and problems encountered in their operation and maintenance. A solar pond is a shallow body of water which acts as a solar collector with integral heat storage for supplying thermal energy. Solar ponds are mainly two types: convective solar ponds and non-convective solar ponds. The shallow solar pond and the deep salt less pond are the examples of convective type. There are three types of non-convective solar ponds: salinity gradient solar pond (SGSP), membrane solar pond and polymer gel layers solar pond. A SGSP is a pool of water about 1-5 m deep, which contains dissolved salts to establish a stable density gradient. There are three layers in a SGSP: upper convective zone (UCZ), lower convective zone (LCZ) and salinity gradient non-convective zone (NCZ) in the middle. The Solar Gradient Solar Pond is the most eco-friendly and environment-friendly among all the solar energy systems for electricity generation, desalination, hot water applications in agriculture, green house heating, domestic hot water production and space heating and cooling of buildings.