Innovative integration: Enhancing solar distillation efficiency with modified spherical solar stills

This study addresses the pressing need for eco-friendly potable water production, exploring the promising avenue of solar distillation. To overcome limitations in traditional systems, the author introduces the modified spherical solar still (MSSS), featuring a rotating ball within the design. A comprehensive experimental investigation compared MSSS performance with reference spherical distiller (CSSS) across energetic, exergetic, economic, and environmental (4E) dimensions. Key factors explored included: rotation speeds (0.2-1.2 rpm), wick material on the rotating ball, and thermal storage material (PCM) beneath the ball (desert sand, copper grits, or their mixture). The optimal MSSS configuration was identified: Rotation speed: 0.8 rpm (40 % yield increase), wick material: 57 % distillate enhancement at 0.8 rpm, and combined, these conditions yielded a remarkable 103 % distillate improvement compared to CSSS (7160 vs. 3525 mL/m2.day) and an efficiency of 59.5 %. Exergy efficiency also surpassed CSSS: 4.2 % for MSSS with PCM vs. 3.1 % for CSSS. Notably, the cost per liter of distilled water dropped significantly: $0.024 for MSSS with PCM compared to $0.066 for CSSS. Environmentally, MSSS with PCM saved 27.7 tons of CO2 annually. Lastly, the enviroeconomic parameter (Z ') rose from 335 for CSSS to 365 for MSSS with PCM.