To attract fresh applicants, the UTEC (University of Engineering and Technology) in Peru sets its students an annual challenge. This time they were asked to find a way of irrigating plants with fresh water in an area where polluted waterways make this impossible. Their solution: The Air Orchard, a billboard that generates fresh water. The system works by converting airborne moisture into pure water using ten dehumidifiers hidden behind the poster. An irrigation system then streams the water to rows of lettuces. So far, more than 2,800 pollution-free lettuces have been given away to local people.