Enhancing solar still thermal performance: The role of surface coating and thermal energy storage in repurposed soda cans

Despite technical developments, fresh water remains a critical human need unmet in many distant regions. This research investigates a solution by enhancing a single slope solar still (SSSS) with paraffin wax as an energy storage medium in recycled soda cans. These cans were coated with a unique mixture of black paint and carbon soot nanoparticles gathered from automobile engine exhausts to boost thermal conductivity and heat absorption. These nanoparticles, averaging 50-60 nm in size, greatly enhanced the heat absorption efficiency of the cans. Morphological examination demonstrated a consistent distribution of nanoparticles across the surfaces of the cans. The experimental setup was kept at a constant water depth in three different configurations: SSSS without phase change material (PCM) cans, SSSS with uncoated PCM cans, and SSSS with coated PCM cans. The SSSS with coated PCM cans showed significant improvements in thermal performance and cumulative yield, with gains of around 75.7 % and 102.3 %, respectively, when compared to the SSSS with uncoated PCM cans and those without energy storage. These findings show the potential for better waste management and renewable energy usage in delivering readily available drinkable water.