In Peru, it hardly ever rains and most water sources are polluted, but the humid air is full of water vapor. So the University of Engineering and Technology has rigged up a billboard to suck drinking water out of thin air.

Taking advantage of capital city Lima’s high humidity levels, engineers have created a system to gather the water through reverse osmosis, purify it, and send it down, clean, to families below.

[youtube http://youtu.be/35yeVwigQcc%5D

It’s already produced almost 2,500 gallons of water and is the only billboard we’ve ever seen that actually can justify its existence.