Interesting, but as always, the issue is scale. A suitcase-sized device that can produce 4-6 liters a day 'cheaper than tap water' is promising, but I'm skeptical because the infrastructure for tap water already largely exists. If you can either hook it up to the pipes localized to a dwelling, or if it scales up to the size of a plant that can distribute it along the pipes in place, maybe. Even then, it relies on sunlight and evaporation to work, which means variable, possibly insufficient output in the colder wetter months.