Wave-Powered Desalination

dptalia writes, "Scientists think they've found a way to harness the energy of waves to desalinate salt water. Currently desalination is an energy-intensive process, but this new design harnesses the renewable energy of waves to produce fresh water. Many countries depend on desalinated water to support their populations, and this invention could lower the cost of water generation." Production versions of the "desalination ducks" would be about 10 meters in diameter and 20 meters long. Each would supply water for more than 20,000 people.

Comments

Engineer

[Rostin]

Stephen Salter is an engineer, not a "scientist." The distinction can be blurry, but I think this is pretty clearly an example of engineering rather than science.

The only reason I point that out is that I'm an engineer, and I'd like credit to go where it's due. :)

Re:Why not solar?

[will_die]

They are called solar stills.
While easy in design they are rather expensive, require huge areas of land to produce sizable quantities of water and weather dependant. Also you cannot have moving water since it needs time to heat up so that steam is produced

Re:cool

[cloricus]

Haha yeah...How about this for frighteningly low; in early 2008 my city runs out of water. There are no backup plans and no prospects in the pipe line at the moment, due to a rather stupid population voting on our water future based on popularity (the good looking one was the dumb one) not on science, so all 100,000 residence and twice that in the near by regions will be out of water. I hear the huge storms that hit Brisbane over the last three days are only adding a weeks worth of water to their supplies too - they'll be out of water in four years - just over 1.5 million people in the city alone. The whole Australian east coast will be out of water by 2015.

So as you can imagine most Australians are eagerly awaiting news of these projects and basically anything that will solve our water problem before, as is often quoted, the shit really hits the fan.

Re:Floating all your eggs in one basket?

[artecco]

I do not know what kind of platforms you reffering to, but I at least don't see any technical problems with build such plant. Within my industry (Norwegian oil&gas) we build offshore equipment and platforms, and the dimensioning of equipment are all well within what's technical achievable. Even in worst case scenarios

So since we already dimension Oil rigs and equipment for mammoth storms, freak waves and gas explosions (happening at the same time for your pleasure), I would guess it wouldn't be a problem to build one of these...technical at least. Economical I don't know^^

Re:Wow.

[finity]

The water that must be pre-heated is the "ballast" water. That water is already fresh water. The salt water doesn't have to be heated to 100 C, it's pulled to a low pressure with the ballast water, so it doesn't have to be heated as much.

Neither engineer nor scientist. An inventor.

[jetxee]

The author is an inventor or a designer. To become an engineer he needs to take into account all the practical aspects of the implementation. Not only technical questions. Cost, producibility and serviceability should also be addressed in engineering. Once we see working implementations used in production we may call him an engineer.

However, his invention is really interesting. And I really hope to see it in production.

According to Wikipedia:

The crucial and unique task of the engineer is to identify, understand, and interpret the constraints on a design in order to produce a successful result. It is usually not enough to build a technically successful product; it must also meet further requirements. Constraints may include available resources, physical or technical limitations, flexibility for future modifications and additions, and other factors, such as requirements for cost, marketability, producibility, and serviceability. By understanding the constraints, engineers derive specifications for the limits within which a viable object or system may be produced and operated.

Re:Solar Stills

[Noryungi]

Yes, I know there is more to a solar panel than painting a piece of glass black. Happy? ;-)

However, let me point out that there are two types of solar panels out there: photovoltaics and thermal solar. The design I was talking about is, of course, a "thermal solar" type of panel, that does not generate electricity (that's a photovoltaics) but that uses the heat radiated by the sun.

Of course, someone out there is going to say: "Aha! But thermal solar can also be used to generate electricity", to which I reply: yes, but these use a Stirling Engine, and not the simple fluid-heating mechanism that I described in my first post. See here for an example of a Solar Stirling engine used to generate electricity.

A lot of people who think solar panels are inefficient and/or too expensive think about photovoltaics, and not heat-transfer solar panels. The latter being, of course, much more simple in design and less expensive, while still providing important functions.