5 liters of water a day per panel. This would be really good for water resupply points on long trails. A tank, a couple panels, and you have a permanent water supply. That is, if you can keep jerks from shooting it...
In a hypothetical situation where energy is not a limitation, would it be possible to generate the same amount of water that we currently use in the world only from atmospheric water generators?
If energy is not limitation, you can do almost anything you want, like making diamond, water and microprocessors from grass clippings. The water we currently use in the world IS coming in from air, it's called rain. There are rivers and lakes full of it. Precipitating it would just make it rain a little less.