Application of Advanced Techniques in Double Slope Solar Stills: An Experimental Study in Iraqi Climates

ABSTRACT The increasing global demand for freshwater, driven by human activities and population growth, coupled with the environmental impacts of conventional water production methods relying on polluting energy sources, highlights the urgent need for sustainable alternatives such as solar energy. This study focuses on enhancing the performance of double‐slope solar stills (DSSS) by integrating five rotating cylinders and four photovoltaic (PV)‐powered electric heaters. The primary goal is to increase the evaporative surface area and reduce the water film depth. The tests were carried out at six distinct speeds (0.1, 0.2, 0.4, 0.6, 1, and 1.5 rpm) between April 8 and 26, allowing for a thorough analysis of how rotational speed influences distillation efficiency. Experimental trials revealed that the integration of rotating cylinders resulted in a 95% increase in the evaporative surface area, leading to enhanced productivity even in the absence of electric heaters. At a rotational speed of 0.4 rpm, the solar still achieved a daily output of 3169 mL/day across different speeds. Moreover, the use of PV‐powered heaters resulted in a substantial 221.33% increase in overall productivity, raising the daily output to 6008 mL/day. These results highlight the synergistic benefits of combining rotating cylinders with PV‐powered heating systems, contributing to a significant optimization of DSSS performance. This integrated approach not only proves to be cost‐effective but also offers a sustainable solution for producing potable water, especially in remote areas where access to clean water is a challenge.