Wow, I was under the impression that atmospheric water harvesting (AWH) was extremely inefficient. I don't have any numbers but things like [1][2] seem to indicate that AWH is currently not very useful.

The paper doesn't seem to (if I read it correctly) actually address this directly, instead it talks about how much energy is needed to extract water at different relative humidity levels and factors in the potential energy generated through solar panels. It also looks at the usefulness of this process given factors such as existing access to clean water (or lack thereof) and population. I didn't looking beyond the 'Methods' section, I hope I didn't miss anything here.

[1]: https://www.youtube.com/watch?v=aPvXnmBIO7o and/or https://www.youtube.com/watch?v=BhnoSREmWVY (talk about same silly product)

[2]: https://www.youtube.com/watch?v=vc7WqVMCABg