At the edge of the Atacama Desert, one of the driest places on earth, Lima, Peru, receives almost no rainfall. About 700,000 people have no access to clean water for drinking or bathing. Another 600,000 of the city’s 7.5 million residents rely on cisterns for their water, which must be filled by pumps or by hand and cleaned regularly.

But Lima’s Pacific Coast location experiences humidity of more than 90 percent on summer days, from December to February. So engineers from Peru’s University of Engineering and Technology (UTEC) have devised a way to turn that humid air into usable water. Last December, they erected a billboard in the Bujama District of Lima that by early March had produced 9450 liters (about 2500 gallons) of water.

More details can be found here:

http://www.popularmechanics.com/science/environment/water/a-billboard-that-condenses-water-from-humidity-15393050