Provide every house on the planet with an artificial
leaf and we could satisfy our 14 terrawatt need with
just one gallon of water a day.
In case you haven't noticed, there are regions in this world with a freshwater deficiency (precisely those third world countries which would benefit from something like this), and one gallon of water per day is enough for 3, even 4 people to drink per day.
The article doesn't make it clear if this can function with salt-water, which would be more difficult. And if it cannot, this is not bio-friendly or cheap for that matter.