Productivity enhancement of solar still through heat transfer enhancement techniques in latent heat storage system: a review

Solar still is one of the sustainable and renewable technology which converts brackish or salty water into fresh water. The technology helps in CO2 mitigation, global warming effect, and the use of solar desalination contributes towards decarbonization, mitigation of CO2 and other adverse global warming effect, and it contributes to the sustainable development goals (SDG). However, due to the low production rate of the distillate, the performance of solar still gets affected. The phase change materials (PCMs) as latent heat storage systems can enhance the thermal performance of solar still (SS). Further, techniques like increasing the area of contact and thermal conductivity can be practiced to enhance the heat transfer in PCM-SS. The article reviewed the performance of various designs of solar still integrated with PCM. Furthermore, the effect of nanoparticles enhanced PCM-integrated solar still with different absorber designs and configurations was seen. Compared to conventional solar still (CSS), the heat transfer techniques in PCM's SS can significantly improve the overall distillate productivity of Tubular SS by 218%, followed by single basin single slope SS 149%, pyramidal 125%, hemispherical 94%, and stepped 68%, respectively. In addition, the night time productivity was increased by 235%. Also, it was observed that in comparison to tubular PCM-SS, the nanodisbanded tubular PCM-SS increases the productivity by 68%, whereas in stepped solar still by using external condenser arrangement the productivity was increased by 48%. In single basin single slope, the nanoparticle disbanded PCMSS increases the productivity from 11 to 33%.