So in ideal conditions one could expect to provide about 12 to 15 people with drinking water per square meter. For me this is an impressive number.
If I calculate one unit with 300 dollars this would mean 5.5 cents per person per day for one year for fresh drinking water. And after that only a little bit for maintenance probably.
From the article "The team estimates that a system with a roughly 1-square-meter solar collecting area could meet the daily drinking water needs of one person.", which sounds very different.
On this Q&A page [1] Zhang is quoted "Our current strategy, for example, is to use an assembly of 100 of these devices to achieve an area of 1 m2, which will increase the total production by 100 times to create 10-20 liters of clean water per day."
I don't want to sound too negative, but something doesn't add up here. Still, enough water for one person per square meter of desalination plant is an impressive result I think. The oceans are big.