Evaluation of single slope solar still with different cabin depths with the minimum basin water level

The conversion of saline water into pure water by employing passive solar still (PSS) is a big challenge due to its low productivity. One of the methods to enhance productivity is decreasing the volumetric heat capacity of the cabin. The productivity from the PSS surges with minimum water depths and the maximum temperature gradient between the glass cover and unprocessed water. This work signifies a comparative study of PSS having three different cabin depths. First, the production of normal PSS is recorded and then the cabin depth is modified by the step provided in the cabin itself by placing the water tray on it. Lastly, the cabin depth is adjusted by providing detachable supports inside the cabin. The experiments were carried out in the location of Nagercoil, Tamil Nādu, India (8.1833° N, 77.4119° E). The variation in still production is analyzed. The experimental data shows that the production of PSS with a 40 mm height water tray is more than the other two cabin depths. The maximum distilled water output obtained is 2360 ml/m² per day for a 40 mm height water tray, 2000 ml/m² per day for the normal cabin, and 1600 ml/m² per day for a 70 mm height water tray. Energy payback time and distilled water production cost of the 40 mm height water tray were around 1.43 years and Rs. 2.75/m³, respectively.