Exergo‐enviro‐economic‐based investigations of novel solar stills enhanced by nanoparticles and PCM combinations

Abstract Many regions of the world still struggle to access fresh and clean water. Water‐borne diseases are affecting 42 million people and killing about 2.5 million children per year. Among the several methods for converting salty, tainted, and brackish water into pure water, desalination is one of the most energy‐efficient methods. Another energy‐efficient option is solar still for gaining pure and drinkable water. In the present study stearic acid (CH 3 (CH 2 ) 16 COOH), paraffin wax (C 31 H 64 ), lauric acid (CH 3 (CH 2 ) 10 COOH) as PCM and copper oxide (CuO), titanium dioxide (TiO 2 ) as nanoparticles is used in solar still, which are connected and linked with solar water heater. Further, several experimental models have been developed to analyses experimentally to exercise productivity and performance gains. It is found that the maximum output occurs at about 2.30 p.m. Compared with CH 3 (CH 2 ) 16 COOH, C 31 H 64 , CH 3 (CH 2 ) 10 COOH in basic solar still, the productivity increases by 40.8%, 19.5%, and 31.6%, respectively. The copper oxide, titanium dioxide (nanoparticle) and stearic acid, paraffin wax and lauric acid (PCM's) mixtures have the daytime energy efficiency of 25.23%, 40.12%, and 36.81%, respectively, while the conventional solar still's energy efficiency is only 28.2%.