Abstract

Heat is one of the basic constituents of energy which can be stored as well as extracted from solar ponds. Different types of solar ponds are available but main focus in this paper is on salinity gradient solar pond which is one of the emerging technologies. It can recover energy from brine water sources present in Pakistan with minimum land utilization and capturing maximum solar radiations. Numerous renewable technological sources are currently under use all across the world. However, inadequate research has been done upon salinity gradient solar ponds, which are cheaper and easy to operate and maintain. The salinity gradient solar ponds constitutes of three layers or zones: the lower convective zone with maximum brine concentration, non- convective zone with highest salinity gradient and the upper convective zone which has minimum concentration of brine. The brine water can be sourced from post reverse osmosis or through any other saline water source. Solar pond technologies may have numerous feasible applications including brine management, electricity production and providing heat for different industrial processes. The paper reviews different ways to optimize the efficiency of solar ponds while making it cost effective at the same time. Most of the research on salinity gradient solar ponds has experimented on external heat exchangers in which the heat is usually extracted from lower convective zone. Heat extracted is studied on independent variables such as brine load, height of solar pond, conductivity of heat exchanger, temperature and pH of the water. The heat extracted was further considered for steam generation. The steam could be utilized as a driving force for electricity generation and workability of industrial power plants. The economic feasibility based on the current conditions of Pakistan is also discussed.