Can a Billboard Serve Any Purpose besides Advertising?

The area around Lima, Peru, is one of the driest places on Earth. Very little rain falls there, on the cusp of the Atacama Desert, and hundreds of thousands of people have limited access to clean water. But in the summer months, it is oppressively humid in Peru, so engineers at the University of Engineering and Technology (UTEC) in Lima had an idea about how to help -- both their neighbors and themselves. Facing a shortfall in enrollment, the university erected a billboard touting its program, and the school’s engineering students incorporated five condensing units into the sign, to convert the humidity in the air into water. In the first four months of operation, they had produced 9,450 liters (about 2,500 gallons) for their water-deprived neighbors.

Creating water out of thin air:

• In the summer, from December to February, humidity in Peru can be as high as 90 percent. Like a condenser in an air conditioner, water vapor in the air can be easily converted into liquid.
• The newly-created water is purified by reverse osmosis, and stored in a tank at the base of the billboard. Since the billboard went up, the university has seen a 28 percent increase in enrollment.
• Worldwide, about a billion people don't have access to safe drinking water, the World Health Organization says. A lack of clean water can lead to cholera and other diseases.