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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.
The inventor's name is Stephen Salter. Heh.
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.
Or you could just heavily fine the water companies 'til they fix their pipes, rather than letting such huge amounts of water leak away.
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.
While that is strictly speaking accurate, it is of course not the full story. The vast majority of that water is in parts of the country where it is not able to be used. Perhaps a huge canal down the middle of the country might solve it - but nothing short of that would.
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.
desalination ducks... Wonder if they'll use the salt to make saltine quackers...