Novel design of tubular solar still using lightweight star-wick evaporator with graphite nanoparticles

Clean water is a matter of human life, and solar energy is a promising clean energy resource for future clean water production, helping to combat the severe impacts of climate change. However, the primary barrier to disseminating techniques using solar energy is their high cost compared to conventional technologies. Therefore, the economic development of solar water desalination technologies to lower production costs is a pivotal research trend for the future development of the solar energy water nexus. This study introduced a novel design of a half-tubular solar still with a lightweight rotating star-wick evaporator aided by graphite nanomaterial. The results of the novel design showed significant enhancement compared to the conventional design of the same device without the star-wick facility. The location of all experiments is 30 o N, 32.5 o E (Suez University, Suez, Egypt). The productivity of the novel design reached 6.32 L/m 2 day and the average thermal efficiency reached 55.27%, with a water production cost of 7.47 $/m 3 . Using the novel rotating star-wick enhanced the yield and thermal efficiency by 94.22% and 94.5%, respectively, with a 21.62% reduction in the water production cost. • A nano-star-wick rotating evaporator was developed for a novel half-tubular solar still. • The novel system produced 6.32 L/m2day of freshwater with an efficiency of 55.27%. • The novel system enhanced water production and efficiency by 94.22% and 94.5%. • The novel system reduced water costs by 21.62%, achieving a very low cost of $7.47/ton.