Sustainable potable water production from conventional solar still during the winter season at Algerian dry areas: energy and exergy analysis

The Algeria Sahara suffers from the scarcity of drinking water. Solar distillation is one of the simplest and generally inexpensive techniques to solve this problem. However, a second problem arises; this is low productivity in winter. The objective of this study is to overcome this difficulty by modifying the experimental setup by adding nanoparticles that compensate for the weak solar radiation in winter. The experimental results show that the daily productivity of conventional solar still in summer is 3.5 kg m⁻² and in winter is 2.2 kg m⁻². Similarly conventional solar still with CuO nanoparticles in winter is 3 kg/m² per day. The productivity of the conventional solar still without CuO nanoparticles in summer is best as compared to others. When comparing productivity during the winter season, it is found that the productivity of the modified distillery was 1.4 times better than the productivity of the unmodified distillery. The daily exergy efficiency of the conventional solar still in summer and winter is equal to 1.2 and 1.58%, respectively. The use of CuO nanoparticles in winter season has exergy efficiency equal to 2.41%. The daily exergy efficiency of the solar still was increased by 52.5% when using CuO nanoparticles in the winter season.