Researchers at the University of California, Berkeley and MIT have created a solar-powered device that can condense up to 2.8 liters of water out of the air daily:
The system Wang and her students designed consists of a kilogram of dust-sized MOF crystals pressed into a thin sheet of porous copper metal. That sheet is placed between a solar absorber and a condenser plate and positioned inside a chamber. At night the chamber is opened, allowing ambient air to diffuse through the porous MOF and water molecules to stick to its interior surfaces, gathering in groups of eight to form tiny cubic droplets. In the morning, the chamber is closed, and sunlight entering through a window on top of the device then heats up the MOF, which liberates the water droplets and drives them—as vapor—toward the cooler condenser. The temperature difference, as well as the high humidity inside the chamber, causes the vapor to condense as liquid water, which drips into a collector. The setup works so well that it pulls 2.8 liters of water out of the air per day [DOI: 10.1126/science.aam8743] [DX] when run continuously, the Berkeley and MIT team reports today in Science.
(Score: 0) by Anonymous Coward on Saturday April 15 2017, @08:07AM
Or its physical dimensions. Or its rate of degradation.
Depending on those factors you can start calculating out the required device volume to provide adequate water, as well as the lifetime and potential material waste at the end of the usable lifetime, all of which are important factors in determining if these devices make sense outside of a science lab.