Exergy analysis of the active solar distillation systems integrated with solar ponds

Active solar distillation system integrated with solar pond is the green energy system for desalination without negative environmental impact. This clean technology has potential to contribute a lot to water security, sustainable development, and world stability. In this article, results of the energy as well as exergy analysis performed on this novel system integrated with solar pond are presented. This theoretical analysis is carried out in the climatic conditions of New Delhi (India) during a typical summer day. The model and procedures can be helpful in the design, and performance investigation of the actual system anywhere in the world. The daily productivity, energy, and exergy efficiency of the passive solar still are found to be 5 L/m(2), 38.63 %, and 2.71 %, respectively, corresponding to a sum total of 24.436 MJ/m(2) day solar energy input in passive mode. With the integration of solar pond in the active solar still, the daily productivity, energy, and exergy efficiency rises to about 9.5 L/m(2), 46 %, and 14.81 % respectively, for thermal energy input from 100 to 500 W/m(2) during off-sunshine hours. The further improvement in the performance of the same system is observed if the thermal energy is supplied continuously (24 h) to the solar still in addition to incident solar radiation. The proposed system will meet the demand of freshwater in both rural and urban areas and help in reducing the load of CO2 emission on the environment, saving high grade energy consumed for desalination through conventional devices and technologies.