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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.
2,000 cubic meters per day of desalinated water from each unit. That's over 350 gallons per minute. Impressive!
Oh, you're not stuck, you're just unable to let go of the onion rings.
And Australias salination problems are solved.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
This could be really useful in the UK, we are getting frightening low on water during the summer months to the point where we thought that we might have to go back to stand pipes. We would have the money to build something like this and the energy to heat the water (it needs to be pretty hot to do it) - I do wonder though if it would be practical for the very poor countries because of the requirements on the heat (although maybe solar could take care of that) and the cost of building them... I wonder if it will be prohibitavely high
also "One unit should be able to produce around 2000 cubic metres a day", that's pretty amazing.
*''I can't believe it's not a hyperlink.''
The inventor's name is Stephen Salter. Heh.
I've often wondered why solar power isn't harnessed to distill seawater. It ought to be a simple matter to hook up a glass-topped insulated-on-the-bottom pyramid or somesuch with an inlet that lets seawater in (and the concentrated result back out for that matter) whenever a larger-than-average wave passes, set it up so the seawater passes over a metal plate, add some mirrors and/or lenses to heat the thing enough to create some steam, and pipe the steam out the top and over to a shaded receptacle with a non-insulated bottom (so it's heatsinked to the ocean basically) for the condensing. With a good design, it ought to be possible to do something like this so that it runs more-or-less unattended and requires only enough energy input to keep the mirrors and lenses aimed correctly as the sun moves across the sky at one cycle per day.
Cut that out, or I will ship you to Norilsk in a box.
All floating platforms are subject to damage or loss during storms. You don't want interruptions in your fresh water supply, ever, and you especially don't want to lose it after a big storm, exactly when you need it most. This looks like a good idea in theory, but you don't base risk management on best case scenarios.
If you were blocking sigs, you wouldn't have to read this.
This particular type of technology could be extremely important in countries with few water sources. Say such as much of the Middle East. Israel has a single fresh water source for the entire country, the Kinnert (Or Galilee) This same freshwater sea is the water source for a great part of Jordan. Both countries have coasts on the Red Sea- and already there are massive desalinization plants there, on the Israeli side. But, what about Egypt? All the African Countries on the coast that are still pretty dry. This particular technology could also be of great use in the first world, as someone else stated, in places like England. I'm sure they aren't the only country with a water problem.
A sensible installation would accompany the floating platforms with a large reservoir to act as a buffer and prevent such interruptions.
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.
have a spare one or two on land, ready to deploy? This is a good idea anyway, since one of the ducks could fail for any other reason, leaving people thirsty. If you lose a duck to a storm, you replace it with one stored on land.
It ain't perfect, but it ain't bad either. Combine that with reservoirs (either big lake, or lots of 1 gallon jugs of freshwater at homes), and it's much better than the status quo.
Support a few technologists in Washington.
In general, it's not feasible to capture wave power. The stuff is too diffuse-- it takes too much infrastructure to capture too little energy to even pay back the cost of building the contraption.
It doesnt matter whether you use the mechanical energy to generate electricity, desalinate water, or make tea. You can't build a wave energy capture device that's rugged enough to survicve the storm, corrosion and other hazards at a reasonable cost.
As a starting point, let's take their (unsubstantiated) estimate of 2,000 cubic meters per day. A quick google shows that's worth about $1,000 to $3,000. Assuming the waves are active 75% of the time we could expect maybe $2,000 a day from this device. That's about $700,000 a year. Kinda impressive at first glance. But will that be enough to even pay for the gadget over time? Let's estimate, generously, that the device will last ten years. And that we can borrow money to build it at 5% interest. If it and the pipeline to shore can be built for $10 million, we need to pay at least approx $1.5 mil a year to make headway on the principal and interest. Plus the cost of staff and maintenance. We're still a factor of more than two away from breaking-even. And that's assuming no risks due to weather or unanticipated problems with new technology.
the renewable energy of waves
Come on, this is supposed to be a science/engineering summary of a science/engineering article. The term "renewable" should at least mean something. Bio-fuel crops are arguably "renewable." Waves simply are. Nobody needs to re-plant our gravitational interaction with the moon once we've harvested it. Swine waste methane is not the same as tidal activity. It's the article summary, for cryin' out loud. At least get the fundamental concepts behind the word choice straight. "Renewable" isn't the same as "something other than oil."
Don't disappoint your bird dog. Go to the range.
As an added bonus, this could all be funded by selling the extracted salt to crisp companies.
It is too early for costs. If you consider reality costs are variable based upon manufacturing techniques, materials used, supply, economies of scale, administrative costs, delays by regulatory groups and other things that are not immediately apparent even after construction of the first prototype. First you find out if it can be done - then you work out how to do it well for as little as possible based on better assumptions than those given above (only ten years of operating life when even desktop computers are designed to last longer?). I would certainly even question your assumption of the value of water in remote areas becuase it enables other activities that could generate money or other benefits by saving on transport costs for water.
It may be possible that is true but it is a pretty wild claim to make - what do you have to back this up? Why don't you think it is likely that the designer has considered existing structures that are built to survive for decades in waters with very powerful storms?
However, his invention is really interesting. And I really hope to see it in production.
According to Wikipedia:
desalination ducks... Wonder if they'll use the salt to make saltine quackers...
I think you have bad information, his name is Stephen D. Salter.
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Unmentioned so far: what to do with the leftover salt. Unless you wait for 100% of the water to evaporate, you end up with highly salinized waste water. IIRC there are some desalinization plants in the Middle East or India, and significant "dead zones" in the ocean nearby. None of the indigenous aquatic life can tolerate raised salt levels.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
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.
The right to offend is far more important than the right not to be offended. (Rowan Atkinson)