It doesn't sound like it. It just harvests the charge off the water particles. Imo this is interesting, but I'd expect there should be diminishing returns to

It doesn't sound like it. It just harvests the charge off the water particles. Imo this is interesting, but I'd expect there should be diminishing returns to more layers of this in any one place - subject to airflow and current humidity at the least - there can only be so much charge on any particular set of water particles, and even if natural processes restore it they won't do so instantly. The big question is, in a more optimized form of the device, whether the economics of such power generation are useful - how many $$ has to be spent to produce what sort of power output. It's an interesting proof of concept but without competitive economics for some use case, it is unlikely to see any notable adoption.