Many people have never cared much for billboards. So the idea that a billboard could produce potable water sounds like a hoax or a cheap trick.
But it's neither: The billboard pictured is real, it is located in Lima, Peru, and it produces around 100 liters of water a day (about 26 gallons) from nothing more than humidity, a basic filtration system and a little scientific and engineering creativity.
Lima, Peru is the fifth largest in all of the Americas, with some 7.6 million people (closer to 9 million when you factor in the surrounding metro area). Because it sits along the southern Pacific Ocean, the humidity in the city averages 83% (it's actually closer to 100% in the mornings). But Lima lies at the northern edge of the Atacama, the driest desert in the world, meaning the city sees perhaps half an inch of precipitation annually—making it the second largest desert city in the world after Cairo. Lima depends on drainage from the Andes as well as runoff from glacier melt—both sources on the decline because of climate change.
Enter the University of Engineering and Technology of Peru (UTEC), which was looking for a splashy campaign to kick off its 2013 enrollment period. It turned to ad agency Mayo DraftFCB, which struck on the idea of a billboard that would convert Lima's H2O-saturated air into potable water. And then they actually built one.
It's not entirely self-sufficient, requiring electricity (it's not clear how much) to power the five devices that comprise the billboard's inverse osmosis filtration system, each device responsible for generating up to 20 liters. The water is then transported through small ducts to a central holding tank at the billboard's base, where you'll find—what else?—a water faucet. According to Mayo DraftFCB, the billboard produced 9,450 liters of water (about 2,500 gallons) in just three months, which equals the water consumption of "hundreds of families per month."
Just imagine what dozens, hundreds or even thousands of these things, strategically placed in the city itself or outlying villages, might do. And imagine what you could accomplish in any number of troubled spots around the world that need potable water with a solution like this.