Performance analysis based on energy and exergy output of double slope passive and active solar still

This paper intends to explore double slope passive solar still (DSPSS) with the help of thermal modeling along with experimental validation. Further, a comparative study has been done for active (integrated with disc type concentrator and photovoltaic module) and passive solar still based on improved thermal modeling with suggestions about design. The average thermal efficiency for passive solar still (PSS) and active solar still (ASS) are 17.5% and 21.3%, respectively, which shows active solar still has a 21.71% better performance. The average exergy efficiency for passive solar still and active solar still found to be 2.4% and 3.5%, respectively. Further, optimization of solar concentrating disc diameter has been done for 0.5, 1, 1.5, and 2 m. The theoretical yield and maximum water temperature found to be 2.83, 3.64, 5.1, 7.3 kg/m2 and 70.02, 75.8, 85.2, and 98.2°C, respectively.