Experimental study of basin type vertical multiple effect diffusion solar still integrated with mini solar pond to generate nocturnal distillate

In present study, the conventional basin type vertical multiple effect diffusion (VMED) solar still has been modified to enhance the diurnal productivity of still and produce nocturnal distillate from the still. Multiple floating wicks were used in the basin to enhance the diurnal productivity of the still and mini solar pond was used to supply heat to basin water in batch mode during night to produce nocturnal distillate from the still. The performance of modified still was compared with conventional basin type VMED still under same weather and operating conditions by running both stills simultaneously. Both stills were constructed of same material and dimensions, and consisted of four effects. The diurnal, nocturnal and overall total productivity of modified still was found to be 49.87%, 71.21% and 56.92% respectively, more than the corresponding productivities of conventional still. The daily cumulative efficiency of modified and conventional still was found to be 80.29% and 59.6% respectively, when the total solar radiation on glass cover was 23.1 MJ/m2/day, average ambient temperature was 25.3 °C and feed rate was 0.13 g/m2/s.