Watercone.

Similar to the scheme for obtaining drinking water if stuck in the desert - all you need is a warm day, green leaves, a container, a sheet of plastic (strong cling-wrap will do) and soil soft enough to dig a small hole.

Put the container in the middle of the hole and place the leaves around it - cover the hole with the plastic using some stones to secure the edges, and place another stone in the middle of the plastic above the container, creating an inversed cone.

The moisture evaporating from the leaves collects on the inside of the plastic and runs down to the point made by the stone on top, and evetually drips into your drinking container.

I wonder, would a large scale system like this work as a seaside desalination plant? How big would it have to be to produce a sufficient amount of water to top up a city's water supply?

I think that Neatorama should link up to the main Watercone site since it has quite a bit of information about their product.

Well, I was relating the scarcity of water levels due to the rising nature of our Oceans and the rising population of our species which taxes the natural water supply in many countries, especially, those in the 3rd World. I would agree that we as a species aren't supposed to live in deserts, however, with the grim prospect of increasing droughts due to weather and mismanaged land/water resources (we can take a gander at the giant dust bowls being created in China for an example) we'll be seeing a lot of folks ending up in areas with creeping desert conditions going without potable water.

Either way, if we were to send a bunch of these to folks in countries suffering from a lack of potable water we can save many lives from dehydration, malnutrition, and diseases from unsanitary water.

Yeah, they are called "solar stills". As kids, we were big into trying out stuff we read about in Survival manuals purchased out of Soldier of Fortune Magazine. The solar still was one of the those. They don't exactly put out a lot of water and the effectiveness depends on weather conditions: nice hot days (to aid evaporation) and cool clear nights (to aid condensation) work best. N.B. In areas without a supply of saltwater, it is *possible* to erect one over urine-soaked ground to "recycle" the water. heh heh... I guess if you are thirsty, you do what works.

I have to laugh (grimly) about one thing ... the two previous posters alluded to "shrinking water supplies". This is a farce! Yes, water is scarce in parts of the world and notably parts of the US. But these places are called deserts AND PEOPLE AREN'T SUPPOSED TO LIVE THERE! It is absurd that the U.S. Federal government does all kinds of kooky things and spends tons of money bringing water to Las Vegas, Phoenix, LA, and other places that really aren't suited to supporting enormous populations. Meanwhile, people with plenty of water (like those of us in the Great Lakes area) pay taxes to finance the folly and make do with 1.6 gal/flush toilets that don't work. Stupid, stupid stupid.

Straight talk from Sid.

Aren't they called solar stills? I have a feeling that these have been around for a while. They sometimes put them in lifeboats.
But I have a feeling that they're going to become increasingly popular...