Improving the performance of a greenhouse-type solar distiller through absorber enhancement: an experimental and comparative study

This experimental and comparative study analyzes the performance improvements of a solar still. By enhancing the thermal properties of this component, the research aims to maximize radiation capture and energy transfer efficiency. Rigorous practical tests highlight the direct impact of these modifications on the evaporation rate and overall yield. Solar distillation is a particularly economical approach for freshwater production, especially in regions with high solar potential such as Morocco. Therefore, the main objectives of this study are to develop a greenhouse-type solar distiller, experimentally compare the performance of two different absorbers, conduct a techno-economic assessment of the more productive configuration, and evaluate the physicochemical characteristics of the distilled water produced by the system in comparison with that obtained through reverse osmosis. The experimental comparison showed that Absorber 2, featuring larger corrugations, achieved higher productivity than Absorber 1, featuring smaller corrugations, under similar experimental conditions. Specifically, freshwater production increased from 3 to 5.6 L/day, while the maximum internal temperature increased from 63 to 84 °C, and the daily energy efficiency increased from 39 to 46%. In addition, the physicochemical analysis of the specific water samples tested showed lower conductivity and bicarbonate concentrations in the solar-distilled water than in the corresponding reverse-osmosis water sample. Finally, the techno-economic assessment estimated a freshwater production cost of approximately 0.025 USD/L under the assumptions and operating conditions considered in this study.