According to MIT, this technology works even at small scale, with one the size of a suitcase able to desalinate 6 litres per hour, and only needing to be serviced every few years.

Here’s a video detailing how it works.

  • OP, you made a mistake in the title. This doesn’t scale down to suitcase size. It scales up to suitcase size. Which makes sense - water circulation powered by passive solar heating can only go so far.

    And if you notice, the device is fueled by sunlight - so it needs a 3x3 square of shallow water for each “suitcase”. The devices can’t stack on top of one another. If you start putting these down along the coast you quickly run out of space - and the coastal habitat where these devices would sit is extremely valuable to both humans and animals, and if you put them too close together you start having problems with salt runoff accumulating.

    This could supply fresh water for poor coastal villages or off grid homesteads. It doesn’t scale to cities.