Devil is always in the details. If solar power is all you need, are there any other maintenance or running costs and how high are they? How much does it cost to

Devil is always in the details. If solar power is all you need, are there any other maintenance or running costs and how high are they? How much does it cost to make this medium (hydrogel membrane) that is used to draw out the water? Also, based on the paper it looks like this would be more efficient and have greater utility somewhere like the Persian Gulf states, Northern Australia or other places that are consistently sunny and have high humidity.