Augmenting Distillate Output of Single-Basin Solar Still Using Cement Blocks as Sensible Heat Energy Storage

Solar still is a green energy product. It uses heat energy of the sun to purify muddy or salty water. Single-basin passive solar still is the best choice for drinking water-prone remote areas. Investigations show its limitation because of its lower performance in terms of distillate output. Several attempts were made by different researchers for improving the performance of conventional solar still. One of the proven methods to improve the output of solar still is to incorporate sensible heat energy storage material. In this experimental work, prime focus is to enhance the output of the single-basin conventional solar still by putting cylindrical cement blocks as a heat storage material in basin water. A comparative study between the modified still (with cement blocks) and conventional still (without cement blocks) of the same size was carried out for the same experimental condition of Jabalpur, India (23° 10′ N, 79° 59′E), with different depth of water ranging from 2 to 5 cm. Result recorded indicates that the output depends on the water depth and mass of sensible energy storage material. The maximum yield was obtained for least water depth of 2 cm. The daylight yield was found enhanced up to 67% in the modified still as compared to conventional still, while decreased performance is observed in overnight productivity. The overall yield increased by 17% considering 24 h. of output. Uncertainty and error analysis have also been carried out.