Water harvester keeps solar cells cool
S. Himmelstein | November 19, 2024
The expanded deployment of solar energy technology in Saudi Arabia has highlighted the need to keep these systems from overheating in the high temperatures common to the region. A novel solution has been engineered by combining atmospheric water harvesting technology and a lubricant coating. The approach relies on passive radiative cooling in a gravity-assisted design that requires no electricity.
The coating composed of a polydimethylsiloxane elastomer lubricated with silicone oil is applied to the condenser face of a vertical double-sided architecture. This system was originally designed to reflect thermal heat and keep solar cells cool but not to capture the water produced. With the addition of the lubricant, condensate is easily collected by gravitational forces
Field tests demonstrated that this arrangement could almost double the rate of water collection compared with alternative atmospheric water harvesting technologies. As reported in Advanced Materials, the passive water collection rate of the lubricated system, which doubled the local cooling power, was 21 g/m2/hour. This far surpassed that of the 10 g/m2/hour harvested by a superhydrophobic surface.
Researchers from Saudi Arabia’s King Abdullah University of Science and Technology (KAUST), Stanford University, King Fahd University of Petroleum and Minerals (Saudi Arabia) and the University of Pennsylvania contributed to this study.