Optimizing cord pyramid solar distillers: A comprehensive study on square baffles, reflectors, and phase transition materials

Limited access to safe drinking water is a critical global issue, particularly in areas with inadequate infrastructure. Solar stills offer a promising alternative for such regions. This study investigates the influence of square baffles within a modified solar still design on its overall efficiency. Additionally, the integration of reflectors is explored to enhance both evaporation and condensation rates. Furthermore, the effectiveness of a paraffin wax phase change material (PCM) combined with silver nanoparticles is assessed within the modified still. Thermo-economic analyses are conducted to evaluate the economic feasibility of the proposed system. The findings demonstrate a significant improvement in distillation yield. The modified still with square baffles achieved a yield of 9800 mL/m².day compared to 3550 mL/m².day for the reference still, representing a 193 % increase. Moreover, incorporating the nano-PCM at an optimal configuration (25 cords) resulted in a further 265 % productivity increase for the modified still with both square baffles and reflectors. This configuration also achieved an efficiency of 63 %. Economic analysis revealed a minimal cost difference between the reference still (0.014 $/L) and the modified still with square baffles and nano-PCM (0.01 $/L). In terms of environmental impact, the modified still exhibited a lower annual CO₂ emission of 28.8 tons.