Is 30% humidity really arid?
Any way to get clean drinking water to the world is always a good plan.
According to the NCESC, humidity in the Arabian Deserts ranges from 5% to 95%. A post from the same site states that humidity in the Atacama Desert ranges from 15-40%. According to a friend who lives in the Sonoran Desert of Arizona, the humidity range is similar to that of the Arabian Desert, with high humidity occurring primarily during the rainy season (intermittently July through September).
So no, in the desertthe device would work poorly or not at all during big chunks of the year.
As I write this, it is 96F and 11% humidity in Tucson, Az.
Story is pie-in-the-sky, at best.