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Harnessing Slow Water Currents For Renewable Energy
Posted by
Soulskill
on Sat Nov 22, 2008 10:16 AM
from the hydroelectric-for-those-who-won't-give-a-dam dept.
from the hydroelectric-for-those-who-won't-give-a-dam dept.
Julie188 writes "Slow-moving ocean and river currents could be a new, reliable and affordable alternative energy source. A University of Michigan engineer, Michael Bernitsas, has made a machine that works like a fish to turn potentially destructive vibrations in fluid flows into clean, renewable power. This is is the first known device that could harness energy from most of the water currents around the globe because it works in flows moving slower than 2 knots (about 2.3 miles per hour). Most of the Earth's currents are slower than 3 knots. Turbines and water mills need an average of 5 or 6 knots to operate efficiently. Further details and a few brief movies of the technology are available, as well as a video explanation by Professor Bernitsas himself."
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Harnessing my leaky faucet? (Score:3, Funny)
I wanna harness the slow water current of my leaky faucet to trickle-charge my laptop; can I do that? If that works, I'll move on to trying to harness my *other* leaky faucet.
Re: (Score:2, Funny)
Have you tried this? [4flomax.com]
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Secondary effects? (Score:5, Interesting)
I'm not a fluid mechanic, but I wonder what the effects would be of slowing down already slow moving river water. Increased silt deposits? More flooding upstream? Anyone with more knowledge about river flows care to comment?
Re:Secondary effects? (Score:4, Insightful)
Parent
Headlines. (Score:5, Funny)
- for example, groins have been constructed on parts of the Thames to slow the water near the banks, encouraging scour of the main shipping channel
Has there been any ship collisions with those. If so was there a headline like this?
Ship hits Thames in groin.
Parent
Re:Secondary effects? (Score:4, Funny)
Erect a vortex generator instead of groins and you can control flow and generate electricity.
Yes, but you completely ignore the benefits of erecting groins.
Parent
Re: (Score:2, Insightful)
From the look of the system, there wouldn't appear to be too much slow down. Probably about on par with tossing a reasonably sized rock into a stream.
Of course, it's a matter of scale. One rock? not much impact, but throw to many in, and you have a dam. So I think the impact this system would have depends most on how much power it generates and how many can be fit on a given body of water before having a damming effect.
Re: (Score:3, Insightful)
"A damming effect" would never be a problem, the slower the water is moving the less energy available for extraction, so you would stop installing them long before the water stopped moving. I would guess that capital return rates would convince investors to stop installing them long before environmental impact became a significant problem.
Re: (Score:3, Insightful)
Are we all forgetting what caused the water to move in the first place? I mean the last couple of comments sort of act like this is a car on flat land coasting and we are talking about hitting the brakes every once in a while or introducing obstacles to slow it down. Imagine the same but with the car constantly coasting down hill.
Gravity is forcing the waters motion. It is going from one place that is higher to another that is lower in elevation. You have other factors like force and so on to consider but s
Re:Secondary effects? (Score:5, Interesting)
If it works (both technologically and financially) , it's brilliant - harnessing energy that would be lost anyway.
Parent
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There is no such thing as lost energy. The vortices are only manifestations of the symptoms, and not the end results.
If the energy isn't used to give the water momentum, it will increase the temperature of the water.
By tapping into the energy of the water, you will either make it move slower, become colder, or both. This may, depending on where it is tapped, be perfectly safe. But then again, it may not be. The question is whether there are any politicians who would stop a multi-billion dollar project b
Re: (Score:3, Informative)
The Colorado River at Phantom Ranch averages 80,000 ft3 of water per second, or 2.4 x 10^9 cc. The energy that would have to be extracted to cool that water by 0.001 degrees C would be 2.4 x 10^6 calories.
2.4 x 10^6 calories = 10^9 joules.
watts = joules/second, so that would be 10^9 watts, or 1 million kilowatts/second would be extracted. Now that's a lot of power for a 1/1000 degree temperature drop.
Another way to look at it is that it would take a million kilowatts to heat 80,000 ft3 of water 0.001 degre
Re: (Score:2)
The only way to live green is to lay down and die, after having demolished the last city and killed the last human being.
I call sophistry... you're using the fallacy of the excluded middle [wikipedia.org], not to mention constructing a hell of a straw man. In reality, there are a spectrum of option between the two extremes ("humanity commits suicide" and "humanity does nothing to avoid damaging the environment", but you choose to ignore them because your goal is to paint your political opponents as unreasonable.
Why not pu
Re: (Score:2)
I did not say there were no middle roads. Merely that greenies will never accept them.
I'm a greenie, and I accept them, so that's clearly untrue. Or perhaps your definition of "greenie" is "anyone who doesn't accept them"? In that case your argument is tautological and pointless [wikipedia.org].
Nuclear power expansion is the ideal middle road today after all. Barely needs any space. Lots of power. Cheap. Fuel many times recyclable. 1 kg fuel powers new york for a year. Few, tiny mines ... what else could you ask for ?
Wel
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Sounds like the energy is taken from eddy
... and this is sofa is it?
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So you are not harvesting energy that would be lost energy; you are harvesting the energy of the flow.
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Now harness the energy of the water coming down my gutters.
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Where does that energy go normally? Into heat? I mean, energy can't really be lost so it must go somewhere.
Oceans, Not Rivers (Score:5, Insightful)
This device targets ocean currents, not rivers. Ocean currents already have too much energy (by historical comparison), accumulated in twistier undersea currents from the decades and centuries of escalating Greenhouse effects.
River current power is what is captured by hydroelectric dams. Which have their own problems, but we're already stuck with them. More ocean hydroelectric could allow us to release some dams that have too high a cost (environmentally or operationally) to justify their power output. Though application of these generators in rivers might just be a low-impact replacement for dams. However, the dams also deliver irrigation and drinking water, so we're probably stuck with them for the long haul.
Parent
Re: (Score:3, Insightful)
while you're probably right in that this technology will be most useful by extracting the vast amounts of energy contained in the ocean (absorbed solar energy) it will likely be deployed in a lot of rivers as well. in fact, the video mentions that the pilot project is being built on the Detroit River. so it's not just coastal cities who are going to benefit from this technology.
i think it's interesting that this technology is expected to be much more cost-effective than conventional solar power. and the abi
Re: (Score:3, Informative)
That may be the case where you live but here in the the western U.S., the majority of dams have been built for water storage purposes, followed in number by dams built for generation of hydropower. Relatively few have been built exclusively for flood control; I can think of a couple in the Los Angeles area and that's about it.
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Nooo. Many are, but a lot of dams are built for energy production. The TVA system being the prefet example.
Less of everything really (Score:2)
Less flow, less oxygen and less other nutrients (and therefore less life) in the water seem like obvious side-effects.
Re:Secondary effects? (Score:4, Informative)
Water runs down hill due to gravity, once it is passed the device
it will return to its prior speed.
The water does not get and keep its speed from its headwaters.
It varies based on the grade as it moves downstream.
In an ocean, it is not due to grades is more about thermal
differential due to the ocean heating the water.
It might have an impact there, but some of the current
contain flows that are many times the flow of all the rivers
in the world.
Like the Antarctic Circumpolar current:
http://en.wikipedia.org/wiki/Antarctic_Circumpolar_Current [wikipedia.org]
Parent
Doubling the Global Warming Reduction (Score:5, Interesting)
Replacing petrofuels (and even their waste heat) with this alternative generator would help slow climate change from the eliminated petrofuel waste.
But there's a vast amount of energy already retained in the Earth's oceano-atmospheric system. Vast rivers of undersea currents now store truly huge amounts of energy newly accumulated since industry's byproducts started the Earth retaining more energy. Undersea currents have grown much twistier in their paths around the globe. When that energy cycles through the interconnected systems on its own rhythms, the energy is sometimes transmitted into other media than seawater, that is much more disturbed by it. This is what the El Nino / La Nina cycle is an instance of: energy from heavy sea currents periodically enters the much lighter air, pushing it around much more. That kind of cycle, in a myriad of other such interactions, contributes to larger and more frequent storms.
If we harvested some of that energy from these currents with these new devices, we would be reducing the energy in those currents. The currents would return to their previous less twisty tracks. They would have less energy to transmit to the atmosphere and other climate engines. It would take a very large scale deployment, over a substantial period of time. But the double benefit would be well worth it.
Re: (Score:3, Informative)
hmm except that I'm reading it now and it says Interesting... so I'd say the moderation system works just fine - only not on a short timeline. It's like looking at an election vote too early... maybe only the no votes happened to be counted first... doesn't mean the voted on item won't pass later.
The Æolian Harp (Score:4, Interesting)
This technology works the same way as Davinci's "aeolian harp", as immortalized in The Æolian Harp [virginia.edu] by Samuel Taylor Coleridge:
Re: (Score:2)
First, I was wondering if fish ought to file a class-action lawsuit if the inventor tries to patent it. After seeing this, though, it might be more effective to bring a lawsuit by resurrecting Davinci as a zombie.
That acronym is so 1980's... (Score:5, Interesting)
FTFA: "VIVACE stands for Vortex Induced Vibrations for Aquatic Clean Energy"
There was a time when creating an acronym that made a real word was considered cute. Those were the days of the "ESPRIT" (Estimation of Signal Parameters via Rotational Invariance Techniques) and "MUSIC" (MUltiple SIgnal Classification) algorithms.
All that is in the past. These days, acronyms should Google well. Google for VIVACE, MUSIC, or ESPRIT and you'll get page after page of irrelevant sites. Scientists should try to name their projects with unique names, names that will let interested people search the web and *find* their projects.
Re:That acronym is so 1980's... (Score:5, Insightful)
No. No. No. Scientists, and anyone, should name things what they want, and Google should make a considerably higher effort to make search work MUCH better than it currently does. This just shows you how bad search is, and far it has to go. Google needs more competition.
Parent
Re: (Score:2)
Ppl can use boolean expressions to help find what
they need so they do not need to code
for lack of knowledge in searching.
see ... AND, OR, NOR, etc etc
A good portion is built right into their advanced
search features:
http://www.google.com/advanced_search?hl=en [google.com]
Re: (Score:3, Interesting)
And how is Google going to do a better job of searching? Magically discern your intent from the keywords you typed in? Keywords is all we have. Make your keywords better.
Suppose "what you want" is to name your project "The". Is there some way Google is going to find that when someone wants to learn about "The"? A search for the project's name would be completely useless, and no UI change or smarter algorithm is going to fix that as long as you search by typing into a text field. What a searcher would
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I think the worst example of this is probably ".NET". How do you search for that? "dotnet"? "microsoft.net" works pretty well for their own site, but most references to ".NET" are standalone, and you have to try mixing in other keywords like "windows".
At least with "There" you can search for their domain "there.com", because people seem to refer to it that way in self-defense.
Re: (Score:2)
> in self-defense
True dat. There are lots of reasons for that self-defense, too, not just ambiguity in language.
People are acutely aware of what constitutes a good name and what doesn't, even if they don't really think about it. "Gimp" ain't it. "there" ain't it. "string of unpronounceable consonants" ain't it. "FCKEditor" ain't it. Since we have this problem in meatspace, I see nothing inherently broken about the fact that we also have it on the Internet.
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Yah, but if a company's named "Bland" you're still going to be able to find it in the Yellow Pages. It's when you want to find who's having problems with "Bland" in Google that you're in trouble. Doesn't matter whether Bland's a brand of muffler or mp3 encoder.
The Internet turns all the knobs to 11.
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The Internet turns all the knobs to 11.
Except for the ones it turns to 0.
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Suppose "what you want" is to name your project "The".
Reminds me when I was googling for an eatery called "This and That" a few years ago...
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I think an easy solution in this case is to give capitalization some weight. Is it fully capitalized? Then treat it like an acronym. Is it partially capitalized? Give business or project names more priority than if it wasn't capitalized. Nobody I know is going to capitalize a simple noun, like "music", so "MUSIC" shouldn't be treated the same way.
Then again, I got mad when I switched my web page from a Windows server to a Linux server, and none of my links worked because I used to capitalize all my ima
"The" as a keyword. (Score:2)
Is there some way Google is going to find that when someone wants to learn about "The"?
Yes: a much better page analysis engine, which could understand a little bit of language structure(*), just enough to be able do detect from the context when "the" is just this very frenquently occuring english word (and doesn't need to be taken into consideration), and when the structure of other words around it tend to say that it is a different word which is important (an acronym).
Note that currently Google is able to somewhat do this already. Type in "who" and you get relevant answers (Wolrd Health Orga
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Google should be case sensitive.
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Yes, I know. Those two other algorithms that I mentioned, MUSIC and ESPRIT, were very important in a work I was doing once on digital signal processing. I spent a lot of time inventing new combinations of words to get just the DSP related links I wanted on MUSIC and ESPRIT. Trying to separate the junk links from the relevant results was no fun at all...
Re: (Score:3, Insightful)
Hey I agree with you. I've been trying to get someone to do a weighted search for a long time... no takers... I'll have to do it myself. Works like so:
Put in two words... tell the search engine that the second word is WAY more important, ie: Bass (+0) + Fish (+10)
What you should get back is a whole lot of pages about Fish where Bass is the actual keyword within that subset. Almost works like a category. Really it's multiple searches... first a search for the highest rated keyword, then a second search withi
Aquanator came first. (Score:2)
I believe the Aquanator came first.
http://www.smh.com.au/articles/2004/09/26/1096137100758.html?oneclick=true [smh.com.au]
geeze (Score:2)
Haven't we done enough damage without slowing down the earth's oceans?
Could the windbelt work as well? (Score:2)
I'd wondered before if something like the windbelt (http://hardware.slashdot.org/article.pl?sid=08/09/11/2257228) would work in a small stream or river. You would have the same constant flow over the belt, and I'd guess it would create the same oscillations (though probably not as much). I'm not an engineer, just curious.
A few alternatives (Score:3, Interesting)
Self rectifying water turbine, always turns the same way even if the water flow reverses
http://www.cetusenergy.com.au/action.php [cetusenergy.com.au]
and if you really want fishy like motion then
http://www.biopowersystems.com/biostream.php [biopowersystems.com]
The thing is enormous - 50 feet high, generating 300 hp. Full size proto is under construction.
Re: (Score:2)
We "must" have higher levels of CO2? Really? And desert irrigation is the only way to cool the planet? I am skeptical.
Solar panels warm the planet how? By increasing the amount of sunlight striking the Earth's surface? I think you may be mistaken there.
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What better way to cool the planet than to green the deserts?
Yes, that's what you should have said. It's a good question, and outside my ability to answer. However, to say that it is the only way to cool the planet is highly misleading.
We don't currently produce enough food for the whole planet.
That appears to be incorrect. [agassessment.org]
Your arguments run counter to themselves. "If we green the deserts..." "Darker colors retain heat." So by that logic, we should leave them as deserts so to better reflect the sun's heat.
Solar cells are designed to convert sunlight to electricity, not heat. An efficient solar cell will not add heat to the