Laura, have you ever on a warm day noticed faint water droppings on leaves of some of your plants. Where has this water come from? It might have come from the leaf itself or alternatively it might have come from the atmosphere. The atmosphere/air around us can hold an immense amount of water in its vapour form. For example a parcel of 1 cubic meter of air at 30 degrees centigrade could contain 28g ( or 28 cc) of water. There is therefore a good chance that those drips on the leaf came from the atmosphere.
The fog fence provides a surface that is colder* than the air around it and therefore a place where water vapour can condense and the water collected. The water can then be used for irrigation of plant life AND the plant life itself generates it’s own water vapour so it is possible to use a fog fence , in a desert like area to collect water, feed it to plants and begin the process of creating a self sustaining green environment.
I am happy for suggested revisions to the above arguments.
*Sorry Laura,I have given you a completely wrong bit of information. It is very unlikely that the fence would be at a different temperature from the air around us. So how does it aid condensation? It’s made of metal. What do you feel when you touch a metal object that has been lying around on your table?.
It feels cold. Why? It should be at the same temperature as the rest of the objects on the table. It feels cold because metal is a good conductor of heat and as your fingers are quite warm it conducts the heat away from them and they feel cold. Maybe the metal in the fence is conducting heat away from the water vapour and because it loses heat it changes from the vapour form to the liquid form …..condensation.
Para added 15/10/17
link added 15/01/18