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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.
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.''
I thought so too. So why do they always have to find some nay-sayer -- this Nidal dude, for instance -- who has an obvious axe to grind and is therefore completely blind to the possibilities? Scale has nothing to do with it; it's cost per unit fresh water produced that matters -- and in places where energy is scarce or infrastructure is lacking, the desalination ducks sound like an awesome solution.
:)
Plus -- they won't plug off the way RO membranes do.
licet differant, aequabitur
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.
Perhaps you could pull them a few metres underwater during a storm?
It would be more impressive if it didn't require the water to be pre-heated to 100C. I think it's safe to say, pour boiling seawater into just about anything with some condenser tubes setup, and you'll get fresh water out of the condenser. It appears to be insulated with Impossiblium, you know, the stuff that'll allow it to maintain internal temperature for a month while it works, with no heat input. I'm willing to bet, read the fine print in the marketing manuals, and you will find the Mark II version will have double the production if you power it with snake oil too....
10 years, Are you kidding? You can easily build it to last 75 or hundreds of years with proper maintenance. Take the word of a civil engineer. The moving parts may be more difficult, but I doubt it. We've got movable dams that are just about zero maintenance, that have been standing there for almost 40 years now. Of course, If you put multiple installations nearby, it saves the immense cost of laying another pipeline underwater (Probably costs more then the whole facility.) Also, funding for projects like this doesn't work like a bak loan. You simply take a percentage of the profit in eschange for providing funding.
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?