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Electricity From Salty Water

kdawson posted about 5 years ago | from the foaming-brine dept.

Power 301

BuzzSkyline writes "It's possible to produce energy by simply mixing fresh and salty water. Although chemists and physicists have long known about the untapped energy available where fresh water rivers pour into salty oceans — it's equivalent to 'each river in the world ending at its mouth in a waterfall 225 meters [739 feet] high' — the technology for exploiting the effect has been lacking. An Italian physicist seems to have solved the problem with the experimental demonstration of a 'salination cell' that creates power given nothing more than input sources of salty and fresh water. The researcher believes that this renewable, environmentally friendly energy source could be deployed in coastal areas and could provide another addition to the green-tech roster. A paper describing the technology is due to be published in an upcoming issue of the journal Physical Review Letters."

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Quick! Grab all your salt shakers and run to the b (5, Funny)

WolphFang (1077109) | about 5 years ago | (#28809621)

Quick! Grab all your salt shakers and run to the bathtub!

Re:Quick! Grab all your salt shakers and run to th (-1, Offtopic)

Anonymous Coward | about 5 years ago | (#28809837)

If only the professor knew. (4, Funny)

0100010001010011 (652467) | about 5 years ago | (#28809643)

he key ingredient in a salt-water capacitor is "activated carbon," extremely porous carbon made from wood, coal, or coconut shells.

Gilligan could have lived well on that island.

Re:If only the professor knew. (0, Offtopic)

Bandman (86149) | about 5 years ago | (#28810401)

Really???

You chose to make a coconut joke on slashdot, and DIDN'T include the phrase "it could grip it by the husk"???

You silly 8-digit UIDs...

Your mother was a hamster

Re:If only the professor knew. (0)

Anonymous Coward | about 5 years ago | (#28810575)

he key ingredient in a salt-water capacitor is "activated carbon," extremely porous carbon made from wood, coal, or coconut shells.

Gilligan could have lived well on that island.

The professor made a device to recharge the batteries in the radio they had...

Do I get get peak or off-peak rates... (2, Funny)

Anonymous Coward | about 5 years ago | (#28809655)

...for pissing in a swimming pool?

Re:Do I get get peak or off-peak rates... (1)

Frosty Piss (770223) | about 5 years ago | (#28809883)

Many people have told me that I have a shocking personality...

Double Duty? (4, Interesting)

drrck (959788) | about 5 years ago | (#28809657)

So can we expect this to work in parallel with existing hydro power generation techniques?

Re:Double Duty? (5, Informative)

localman57 (1340533) | about 5 years ago | (#28809815)

Only if the waterfall is on the edge of the ocean...

Re:Double Duty? (0)

Anonymous Coward | about 5 years ago | (#28809941)

I seem to have missed the day in school where they taught us that rivers end immediately after hydroelectric dams.

Re:Double Duty? (0)

Anonymous Coward | about 5 years ago | (#28810211)

Or, we can add salt to the clouds.

Re:Double Duty? (0)

Anonymous Coward | about 5 years ago | (#28810265)

What if we had a man-made dam & waterfall at the edge of the ocean? Double dip on the energy production?

Re:Double Duty? (2, Insightful)

Bandman (86149) | about 5 years ago | (#28810413)

How do you propose to get the water high enough at that point to fall into the ocean?

Re:Double Duty? (2, Insightful)

AP31R0N (723649) | about 5 years ago | (#28810387)

Since the Earth is flat (with the Sun orbiting around it), this should be a cinch.

When we find the edge of the Earth we can push all the Darwinists off!

Re:Double Duty? (1)

H0p313ss (811249) | about 5 years ago | (#28810523)

When we find the edge of the Earth we can push all the Darwinists off!

Should be a cinch to spot from orbit! ... oh wait ...

Re:Double Duty? (1, Interesting)

mcgrew (92797) | about 5 years ago | (#28810105)

At first I thought "probably not". Hydroelectric is actually gravity and solar power; you need a waterfall, or a place where the river is channelled into a smaller space (like a dam). Hoover Dam and Tom Sauk come to mind.

Then I realized that not every river is as big as the Mississippi; Even though most damns are far inland, perhaps you could dam small streams or rivers flowng into the ocean. They dam the big ones bacause the bigger the river, the more power you can get from it.

What I'd like more explanation of is how this technique works - TFA doesn't say. I got the impression that the writer didn't understand, either. Can any of you chemists/physicists explain this phenomena in layman's terms for us?

Re:Double Duty? (2, Funny)

Anonymous Coward | about 5 years ago | (#28810199)

in a car analogy please.

Re:Double Duty? (4, Interesting)

Wrath0fb0b (302444) | about 5 years ago | (#28810421)

I got the impression that the writer didn't understand, either. Can any of you chemists/physicists explain this phenomena in layman's terms for us?

Intuitively, anything that happens spontaneously (e.g. water falling down in a gravitational field) must be downwards in free energy or else it wouldn't happen (with any significant probability). So you know that when you pour together your rum and coke into a glass, the final state (uniform mix) must be lower in free energy than the initial state (rum on the bottom, coke on top).

Slightly less intuitively, you can understand it very simply with a lattice model of solution under the assumption that there are no energetic effects (true to first order). Imagine the solvent as a lattice in which each square/cube (2D or 3D, your choice) can be occupied by solute or not -- now count up the configurations that correspond to a mixed solution versus an unmixed solution. That difference is configurational entropy and drives it to seek the macroscopic state with the most microscopic realizations since, in the absence of significant energetic effects, every microscopic state is equally likely.

Of course, it's on wikipedia: http://en.wikipedia.org/wiki/Entropy_of_mixing [wikipedia.org]

Re:Double Duty? (1)

markk (35828) | about 5 years ago | (#28810229)

Of course. This has nothing to do with dams or tidal power or anything like that. This is about estuaries and deltas. Think about installations in the Nile, or Amazon deltas. Wherever rivers run into the sea actually. That is where you find fresh and salt water together. It could be a limited but useful augment in some coastal areas. If the fresh water is running into the ocean anyhow we can use "concentration potential" to get some power at the end of the cycle. Ultimately this is solar power which came from evaporation which created the freshwater in the first place. It is an interesting idea. The devil will be in the construction details which will determine whether this is scalable.

Researcher! (1)

stevey (64018) | about 5 years ago | (#28809665)

Typo in the summary:

The reearcher believes that this renewable, environmentally friendly energy source could be deployed in coastal areas and could provide another addition to the green-tech roster

Obviously that should be "researcher"

Re:Researcher! (1)

socrplayr813 (1372733) | about 5 years ago | (#28809889)

No, he's clearly just become an archer multiple times. Re-archer. Duh.

Re:Researcher! (1)

SBrach (1073190) | about 5 years ago | (#28810593)

Now that I know what a re-archer is, can you give me the definition of a re-earcher?

What about the fishies? (1, Informative)

hargrand (1301911) | about 5 years ago | (#28809673)

"The reearcher believes that this renewable, environmentally friendly energy source..."

Don't bother. PETA and Greenpeace both called and said it'll kill too many endagered fish species.

Economy is a Subset of Ecology (4, Insightful)

weston (16146) | about 5 years ago | (#28809801)

Don't bother. PETA and Greenpeace both called and said it'll kill too many endagered fish species.

While PETA and Greenpeace may have different definitions of "too many" than you do, balancing concern about impacts on fish stocks with concerns about energy is a perfectly reasonable thing to do, given that fish are part of our food supply (and food chain).

There's also issues like whether or not a given fresh water supply might have better uses.

Re:Economy is a Subset of Ecology (4, Funny)

T Murphy (1054674) | about 5 years ago | (#28809943)

Maybe a good balance then is to develop solar-powered fish?

Re:Economy is a Subset of Ecology (5, Funny)

StikyPad (445176) | about 5 years ago | (#28810155)

I thought our food chain was Sun -> Corn -> Cows/Pigs/Chickens -> Cows/Pigs/Chickens -> Dinner.

Re:Economy is a Subset of Ecology (4, Funny)

DoofusOfDeath (636671) | about 5 years ago | (#28810419)

I thought our food chain was Sun -> Corn -> Cows/Pigs/Chickens -> Cows/Pigs/Chickens -> Dinner.

We have a backup system:

??? -> Taco Bell -> Dinner.

Re:Economy is a Subset of Ecology (0)

Anonymous Coward | about 5 years ago | (#28810185)

In a very general sense, I agree with your sentiment.

However, it should probably be pointed out that PETA do not consider fish a legitimate part of the food chain. To PETA it is unethical to not be a vegitarian.

Re:Economy is a Subset of Ecology (3, Interesting)

ShadowRangerRIT (1301549) | about 5 years ago | (#28810483)

Somewhat inaccurate. They have offered a reward to the first person to make in-vitro meat, where the meat is grown independent of the animal, economically viable. They oppose "unethical treatment," which is defined broadly enough to mean killing or confining an animal for virtually any reason. Bruce Friedrich, a spokesman for PETA, has said that if in-vitro meat were available, he'd eat it in a heartbeat. After all, no animal would have to suffer to provide it. It's a consistent position, which I respect.

Before anyone starts, I'm aware of hypocrisy in other areas (PETA pet shelters), but I'm addressing only their views on vegetarianism.

Re:What about the fishies? (1)

vodevil (856500) | about 5 years ago | (#28809921)

Would this have a huge impact on fish species? If this is occurring in a natural estuary, there should be minimal environmental impact.

Re:What about the fishies? (4, Funny)

localman57 (1340533) | about 5 years ago | (#28809929)

PETA and Greenpeace both called and said it'll kill too many endagered fish species.

Dang it! I warned these people. Last month I sent them a letter:
Dear PETA,
While I love animals as much as the next guy, I'm sick and tired of your stupid press releases. You do more harm than good by making animal lovers seem rediculous to the general public.

Therefore, I have no choice but to make you reconsider your PR tactics. Starting next week, any time you issue a press release that does animals more harm than good, I'm going to the pet store, and buying a hampster. Then I'm going to take it out in the parking lot and hit it with a shovel.
Sincerely,
LocalMan57

Re:What about the fishies? (1)

Tanktalus (794810) | about 5 years ago | (#28810111)

That may not work. You might have to ramp it up over time. Start with hamsters, sure. Work your way up through cats, dogs, and eventually you can work your way up to seals [wikipedia.org] .

Personally, I'm going to eat another steak every time they issue a press release. Not sure how effective it'll be, but it's sure tasty.

Re:What about the fishies? (1)

vodevil (856500) | about 5 years ago | (#28810497)

That may not work. You might have to ramp it up over time. Start with hamsters, sure. Work your way up through cats, dogs, and eventually you can work your way up to seals [wikipedia.org] .

Personally, I'm going to eat another steak every time they issue a press release. Not sure how effective it'll be, but it's sure tasty.

I read this wrong as ramp it over time, so you start by using a shovel, then later on you put down cinder blocks and some plywood, and start jumping a row of hamsters with your monster truck.

Re:What about the fishies? (1)

Muad'Dave (255648) | about 5 years ago | (#28810607)

I love to see people wince when I use the phrase "I clubbed that thing like a baby seal!"

Re:What about the fishies? (1)

Chris Burke (6130) | about 5 years ago | (#28810191)

Oh, dude, I could have told you that would backfire! You need to read PETA's website, and on the page where they describe their mission to ensure that all animals are treated ethically, with repsect, and neither harmed nor exploited by humans, go to the bottom and read the fine print where it says "*except for hamsters, because they're dicks."

Seriously, nobody likes hamsters. They're going to keep issuing these press releases and you're going to be stuck buying a lot of hamsters!

Re:What about the fishies? (1, Funny)

Anonymous Coward | about 5 years ago | (#28810479)

Well, he tried gerbils, but every time he swung the shovel he hit Richard Gere.

Re:What about the fishies? (2, Insightful)

man_who_was_thursday (1289874) | about 5 years ago | (#28809957)

I suspect this could have a profound effect on environments where salt and fresh water mix gradually and where the mix changes with tidal flow. I live in Virginia, and I can't imagine this would work without significant environmental challenges to the coastal waterways like those that flow into the Chesapeake Bay.

Re:What about the fishies? (0)

Anonymous Coward | about 5 years ago | (#28810343)

Ok so we shouldn't put any of these power plants near the Chesapeake Bay. But just because we can't use it there doesn't mean we can't use it on any estuary system! Also according to TFA, the output water doesn't have ocean level salinity; instead it is, to use TFA's terms, "slightly brackish". Therefore it should be similar to water found in at least some natural estuaries.

Re:What about the fishies? (1)

Lumpy (12016) | about 5 years ago | (#28810047)

Then we put giant blenders at the openings of each intake pipe.

"we are not killing any fish, we don't see any fish entering our pipelines."

see simple solution. and the amount of chum flowing out will make the fish populations thrive.

Re:What about the fishies? (1)

BlackSnake112 (912158) | about 5 years ago | (#28810101)

I guess PETA forgot that rivers have been dumping fresh water into the oceans for millions (if not billions) of years now. Maybe their lawyers told PETA that suing a river for damages is sort of difficult.

Setting up a bunch of energy 'stations' where there is brackish water sounds like a win. The article didn't say anything about damming up the river, or needing to be in deep water. So set these up along the shore where water river cannot go anyway, less blocking of the river, less or no blocking of river traffic, power sent to the people. Really sounds like a win. Lets see what is said when the other shoe drops.

Re:What about the fishies? (0, Troll)

mcgrew (92797) | about 5 years ago | (#28810149)

Not every river mouth harbors endangered species.

The water battery: now a reality! (3, Funny)

Drakkenmensch (1255800) | about 5 years ago | (#28809675)

I hope the Energizer Bunny owns water fins and a snorkel!

neat (0)

Sir_Real (179104) | about 5 years ago | (#28809695)

So does this mean the process produces as much electricity as it takes to de-salinate water? Or is it not a two reaction like that?

Re:neat (1)

davegravy (1019182) | about 5 years ago | (#28809727)

Are you looking to build a perpetual motion machine?

Re:neat (1)

John Hasler (414242) | about 5 years ago | (#28809751)

Only if both processes are 100% efficient. Neither can be.

Re:neat (1)

BitZtream (692029) | about 5 years ago | (#28809871)

Technically, they don't have to be for our purposes.

The fresh water streams exist due to an external power source, Sol.

Re:neat (4, Informative)

Anonymous Coward | about 5 years ago | (#28809769)

Keep in mind desalination is

salt_water -> salt + water

whereas this reaction is

water + salt_water -> less_salty_water

You'll note that they're not exactly inverses of each other.

Re:neat (1)

RKThoadan (89437) | about 5 years ago | (#28810023)

It certainly seems like it would work just fine to run it on straight salt instead of saltwater though, so the equations still mostly work. The water in saltwater is just serving as a handy salt transport mechanism. I can't imagine a practical application for running it on pure salt, although I suppose some survivalists might be a fan of it for a home generator. It's certainly easier to store salt than most typical fuels.

Re:neat (0)

Anonymous Coward | about 5 years ago | (#28810045)

add a little water to both sides:
salt_water -> salt + water
(salt_water + water) -> (salt + water) + water
less_salty_water -> salt_water + water

Re:neat (3, Informative)

4181 (551316) | about 5 years ago | (#28810277)

Keep in mind desalination is

salt_water -> salt + water

Show me a single commercial example where this is the case.

Desalination is:

lots of salt_water -> lots of slightly_saliter_water + a little fresh_water

High rejection ratios help reduce the energy requirements as greater temperatures or pressures (depending on the method) are required for greater salt concentrations.

Re:neat (4, Insightful)

jbeaupre (752124) | about 5 years ago | (#28809817)

It produces less (laws of thermodynamics are a bitch). But you point out an interesting way to describe it to people. i.e. It takes energy to desalinate sea water, this process is sort of like running desalination in reverse to generate energy.

Re:neat (4, Funny)

Rayban (13436) | about 5 years ago | (#28810131)

This would be a great way to power all those desalinization plants on the coast!

Re:neat (1)

jbeaupre (752124) | about 5 years ago | (#28810173)

Weirdly, it could power some. Take their example of mixing brackish and salt water to get electricity (or salty with very salty). Use the electricity to desalinate.

Re:neat (0, Troll)

mcgrew (92797) | about 5 years ago | (#28810219)

The best way to desalinate water is to let it evaporate from the ocean, then catch it when it falls from the sky.

Urine Powered Society (5, Funny)

davegravy (1019182) | about 5 years ago | (#28809749)

A device that gleans usable energy from the mixing of salty and fresh waters has been developed by University of Milan-Bicocca physicist Doriano Brogioli. If scaled up, the technology could potentially power coastal homes, though some scientists caution that such an idea might not be realistic.

Forget scaling it up. Put one such device in every fresh water toilet bowl.

Re:Urine Powered Society (1)

NatasRevol (731260) | about 5 years ago | (#28810271)

And tell everyone to drink less water!

More yellow == more lights!

Brilliant, Holmes, brilliant! (0, Troll)

Un pobre guey (593801) | about 5 years ago | (#28809753)

In a time where there is a huge and rapidly growing potable water crisis, some bozo creates an economic incentive to salinate what precious fresh water there is! By Jove, Holmes, you've done it again!

Like the whole corn-based ethanol disaster never happened. Jesus H. Christ...

Re:Brilliant, Holmes, brilliant! (0, Flamebait)

Anonymous Coward | about 5 years ago | (#28809847)

Hey retard!! Yes, I'm talking to you "Un pobre guey" *MORON*

You see the rivers going into the oceans? There you go. I'm not even going to try connecting these two dots for you. A drooling moron with single digit IQ probably can do it.

Re:Brilliant, Holmes, brilliant! (0, Offtopic)

Un pobre guey (593801) | about 5 years ago | (#28810091)

I guess you don't know about estuaries and their intimate relation with water use, wildlife habitat, etc. I would speculate that you are precisely 17 years old, the age at which a person knows and understands absolutely everything in the world.

Re:Brilliant, Holmes, brilliant! (3, Insightful)

Andy Dodd (701) | about 5 years ago | (#28809895)

There are serious transportation issues with piping potable water from places where it is plentiful to places where it is needed. That's WHY we have a potable water crisis in some areas (especially the American Southwest) while we have no problem whatsoever in others (like the Northeast or the mouth of the Missisippi). In those places there's already huge amounts of water flowing into the ocean. This technology would allow that water that is already being mixed with ocean water to generate electricity in the process.

Also there are situations where water is not potable due to issues other than salinity, and for the purposes of this process might be considered "fresh" compared to saline water.

An interesting thing would be if this could be used to provide for cheap solar power - Some of the largest "solar power" we use today are salt concentration ponds - they don't provide electrical power BUT they do provide the function of separating salt from water in large solar ponds. It would be horrendously inefficient per unit of surface area, but the cost is so low that large surface areas could be achieved.

Re:Brilliant, Holmes, brilliant! (3, Insightful)

mrisaacs (59875) | about 5 years ago | (#28809969)

If you RTFA (pardon me, I forgot this is SlashDot) the same effect can be gotten by mixing salt water with more highly salinated water (made by evaporating sea water - say, using a solar evaporation pool) or lightly polluted water (non-potable).

I could also venture a guess, based on the fact this is a solution postulated for coastal locations, that the process could also be sited at or near the mouth of a river - say one the empties into the sea or ocean? In that case only fresh water that was destined to end up mixed into salt water would be used.

Re:Brilliant, Holmes, brilliant! (0, Flamebait)

mcgrew (92797) | about 5 years ago | (#28810347)

There's no water shortage where I live. Fresh, drinkable water falls from the sky and it's free! The "water shortage" is caused by people stupidly moving to deserts and expecting rain. It isn't a water problem, it's a stupid people problem.

Re:Brilliant, Holmes, brilliant! (0)

Anonymous Coward | about 5 years ago | (#28810531)

Would you like all the desert dweller to move into your back garden though? That might work for e.g. the SW united states moving to Oregon, but if China gets a drought this century, or the monsoon fails and India has to move, you may not like having a billion new neighbours.

Re:Brilliant, Holmes, brilliant! (1)

FooAtWFU (699187) | about 5 years ago | (#28810583)

Hey, that's not entirely true! Water shortages in the US are also caused by people farming on the prairies and pumping out the aquifers. Water shortages in the Third World typically aren't half so much water-shortages as potable water shortages.

Where does the fresh water come from? (0)

Anonymous Coward | about 5 years ago | (#28809811)

Given the shortage of fresh water I hope the push will be for using river water already lost to the sea. There's still problems there because you are effectively having to yet again damn rivers for energy which has already caused major environmental problems. It sounds interesting but there may be no practical way to exploit it in any volume to make it worth the problems it will cause.

Re:Where does the fresh water come from? (1)

localman57 (1340533) | about 5 years ago | (#28809851)

You're only thinking in terms of the United States, you insensitive clod! Think about someplace like Bangladesh. They have a hell of a rainy season, and a seacoast. Last I checked, a fresh water shortage wasn't a big problem for them. At least during the rainy season. Potable water? Yes. Unsalted water? No.

Re:Where does the fresh water come from? (0, Offtopic)

ivan256 (17499) | about 5 years ago | (#28809919)

He's thinking in terms of the southwestern United States. There are plenty of other areas in the US that have more than enough fresh water. People from the southwest tend to be pretty self-centered when it comes to regional issues, and assume everybody has the same problems. The rest of us tend to ignore them.

Re:Where does the fresh water come from? (1)

rtrickey (1080719) | about 5 years ago | (#28810009)

I hope you're joking about the people from the southwest being self-centered thing, cause otherwise, wow, you need to fucking get out and meet people more.

Re:Where does the fresh water come from? (1)

pixelpusher220 (529617) | about 5 years ago | (#28810287)

that's the thing, most everyplace as 'regional issues'. Though most don't involve basic necessities of life like, ahem, water.

Having grown up in the Northeast, I'm amazed at the lack of 'natural issues' the Northeast has. Extremely rare tornados, hurricanes and earthquakes. No appreciable landslide risks, forest fires hardly ever happen (i.e. it's wet), no active volcanoes. There's the acid rain thing, but that's manmade.

Build your house away from trees, with a high sloping roof (snow) and a supply of firewood and there aren't many natural disasters likely to even phase you.

And yes I've lived in other parts of the US, it's only then that you learn to appreciate the things you took for granted.

Re:Where does the fresh water come from? (1)

ivan256 (17499) | about 5 years ago | (#28810315)

I hope you're joking about me being joking, 'cause otherwise, wow, you need to get out and experience more of the world.

Re:Where does the fresh water come from? (1)

Gizzmonic (412910) | about 5 years ago | (#28810079)

People from California tend to be pretty self-centered when it comes to regional issues

FTFY

This is a huge problem for Los Angeles. Ever seen "Chinatown"?

Re:Where does the fresh water come from? (1)

BitZtream (692029) | about 5 years ago | (#28809911)

... I understand people don't read the articles, but did you even bother to read the summary?

Although chemists and physicists have long known about the untapped energy available where fresh water rivers pour into salty oceans â" it's equivalent to 'each river in the world ending at its mouth in a waterfall 225 meters [739 feet] high'

It would be impractical to do it anywhere else.

Re:Where does the fresh water come from? (1)

Zerth (26112) | about 5 years ago | (#28810007)

Actually, it doesn't need fresh water, just a saline gradient. So one could easily use brackish->sea water or even sea water->higher salinity water from evaporation ponds.

Technically, you could even use the "waste" output of a desalination plant, but of course that wouldn't recover anywhere near the energy put in.

Not so new.. (5, Informative)

Anonymous Coward | about 5 years ago | (#28809831)

Actually the technology was already available, and is to be used to power most the majority of homes in the Netherlands, including mine, if the proposal is approved:

http://ecoworldly.com/2009/03/08/saltwater-power-could-supply-energy-for-most-dutch-homes/

Or the original publication:

http://pubs.acs.org/doi/full/10.1021/es9004224?cookieSet=1

Too late (3, Funny)

BrookHarty (9119) | about 5 years ago | (#28809857)

Too late, Exxon already bought the patent.

Re:Too late (1, Troll)

mcgrew (92797) | about 5 years ago | (#28810289)

Too late, Exxon already bought the planet

There, fixed that for ya...

Re:Too late (0)

Anonymous Coward | about 5 years ago | (#28810625)

Too late, Exxon already bought the planet

There, fixed that for ya...

not funny, hmm, not insightful... hmmm, not interesting that's for sure (reusing a lame meme), not underrated, what could it be?
oh -5, lame

Maybe someday PISSING in the WIND can become (-1)

davidsyes (765062) | about 5 years ago | (#28809955)

a very EXCITING form of DISCHARGE. The POTENTIAL might be SHOCKING if not staggering, resulting from IONIC water. Pissing on someone on a seesaw might be felt as a new form of "waterboarding". Such a new sport could ... UPEND other forms of dischage... someday, giving light to a (w)hole new form of en(d)tertainment....

Re:Maybe someday PISSING in the WIND can become (0)

Anonymous Coward | about 5 years ago | (#28810123)

RANDOM words are CAPITALIZED in your POST ... AWESOME

Re:Maybe someday PISSING in the WIND can become (2, Funny)

pixelpusher220 (529617) | about 5 years ago | (#28810325)

need new "Missed Funny(+1) By *That* Much" moderation....

This could be big for desalinization. (2, Interesting)

Lordplatypus (731338) | about 5 years ago | (#28809981)

It would be interesting if this could make desalinization more energy efficient. After you finish desalinization you end up with clean water and very salty water. If you mixed the less salty sea water with your now very salty water, could they recover part of the huge amounts of energy that desalinization requires?

Install these on Urinals (1)

StaticEngine (135635) | about 5 years ago | (#28809985)

Clearly, every time I take a leak, I could be generating power from the mixing of my salty urine with clean water during the flush. Also, I should be pissing onto a tiny waterwheel hooked up to an electric generator, and there should be a Francis Turbine on the flush release outflow.

Next, we'll poop right into a methane extracting farm, and we'll inject pine cones into each person's lungs to extract the exhaled CO2 directly.

It's perfect!

Logan's Run... (1)

Xin Jing (1587107) | about 5 years ago | (#28809989)

So that's how Farrah powered her blow dryer inside the dome! Identify Logan 5-thousand watts, baby!!

New option for solar power!!! (2, Interesting)

sliverstorm (942764) | about 5 years ago | (#28810003)

This is actually really interesting! Think about it. We've been limited to solar cells for a long time for producing electricity, and those have limitations we are constantly struggling against. But... Now, you can make a simple isolated enviroment consisting of water and salt. Design it such that fresh water runs down from a resivoir into a lower resivoir with salt. Expose the lower resivoir to sunlight, and use the greenhouse effect to speed up the evaporation of the water. Direct the vapors up to the upper reservoir, where they precipitate out, and flow back down! Thus, we generate electricity and use the sun to separate the two components to repeat the cycle. (plus if you want, you can capture the heat from the condenser, for even more energy) Not something you could put in your car, but on a large scale I bet this could work. Similar to large steam powered plants.

FTA: the real problem (4, Insightful)

lazn (202878) | about 5 years ago | (#28810085)

"Brogioli maintains that his salinity cell could be ramped up faster than other salination approaches and could be made as affordable as solar power in a decade or so."

As affordable as Solar in a decade? Solar's main problem now is it's cost!

Some ideas (3, Interesting)

drinkypoo (153816) | about 5 years ago | (#28810093)

One of the best places (potentially) to grow algae for biofuels is in the desert. You could pump seawater inland, and circulate it in pools. If you covered those pools with greenhouses (which could just be big clear balloons... or not-so-big ones, if you use arrays of small pools) and collected water they'd make you some fresh water, which could then be combined with incoming salt water to produce energy to help run the system, whether that would be the pumps, mixing devices which keep the pools circulating, or what ever else have you.

Another idea for the waste water produced from this process is to pump it inland and use it in the algae pools... so you can have coastal plants whose effluent is used to grow algae for carbon-neutral biofuels, and [optionally] to raise the water table in the desert.

that's all quite interesting butt... (0)

Anonymous Coward | about 5 years ago | (#28810153)

http://www.time.com/time/health/article/0,8599,1912448,00.html

there have been no (as in zero (0)) genuine clouds for several years now. kind of skews the projection about 100% or more.

sort of the same method used to inform US that we might not all be billyonerrors ever again, or we might not win the increasing # of wars.

I don't get it (1)

Esc7 (996317) | about 5 years ago | (#28810169)

I looked at the diagram and it showed that it needs to be hooked up to a charge and ground? It looks like they are just transferring the charge into capacitors while using the salt as an electrolyte?

I'm sure this works, otherwise we wouldn't be talking about it seriously, but my primitive mind can't see WHERE the net energy is coming from the salt water.

Could someone help me out and explain?

Thanks!

Re:I don't get it (1)

lenehey (920580) | about 5 years ago | (#28810353)

Conceptually, two substances that are mixed has more entropy than when they are separated, so you can see that energy is available to be extracted in the mixing of the fresh water with the salt water (thereby distributing the salts throughout the mixture).

Re:I don't get it (1)

DomNF15 (1529309) | about 5 years ago | (#28810629)

The diagram alone doesn't explain the whole story - the text it above helps...basically what is happening as a result of electrostatic forces and diffusion of the Sodium and Chlorine ions is that the capacitance of the carbon based electrodes is decreasing.

Since C = Q/V, or in layman's terms Capacitance = Charge/Voltage, it is easy to see that by reducing the Capacitance under a constant charge, the Voltage (work potential) increases. The net energy gain is the increase in voltage potential.

Whose energy are we stealing? (2, Insightful)

Marc_Hawke (130338) | about 5 years ago | (#28810187)

Windmills convert wind into electricity. The result...less wind on the far side. That changes climate I'm guessing. Not sure how wind affects things. Hotter animals because of less breeze? Smaller area of seed dispersal? Other things.

Solar panels take the heat energy out of the sunlight and convert it to electricity. I'd think that would cause the ground to heat up less, but that's probably insignificant compared to the direct change of 'being in the shade' for all the flora and fauna under the solar panels.

What do the hot/cold water exchange generators do? I would expect that pumping cold water from the ocean warms up the ocean...but that would be putting energy INTO the water instead of extracting it. So I'm a little confused. Lets just say it 'changes the ocean temperature'. That's enough to disrupt the ecosystem.

With this salty water thing. Whose energy are we stealing? If there's some sort of exothermic reaction going on in all river mouths, there's definitely something that's evolved to take advantage of that. Energy on the planet doesn't just SIT there doing nothing. (cept Oil...nobody uses Oil but us. :) ) What's the result of the environmental impact study? (I don't just mean habitat loss...I want to know who specifically was harvesting that energy.)

Misleading point in summary (1)

Weedhopper (168515) | about 5 years ago | (#28810213)

I read this summary extremely skeptical but after reading the article (which is pretty sparse on detail) it sounds simple enough to work. In principle.

The problem is this sentence:

Once he jump starts the cell with electric power, all that is required to produce electricity are sources of fresh and salty water and a pump to keep the water flowing.

Pumping water is a notoriously is a notoriously energy expensive process. That's why we try to use gravity as much as possible to move our water around. The question is if this process produces enough energy to offset the cost of moving in and out of the (presumably) mixing chamber. If the answer is no, then this grinds to a screeching halt right then and there.

This stuff about X process is equivalent to Y incredibly energetic phenomena is misleading. There's incredible amounts of energy locked up in just about anything. It's just that our technology is such that our extraction processes suck. We're terrible at it. Think about cars. Of all the ways we know of motivating four wheels, we choose to process processed hydrocarbons we dug up from the bottom of the ocean. There's basically an infinite amount of energy in the sky in the form of wind alone. We're just terrible at taking it out.

So some process that claims to potentially harness some percentage of the electrical energy of a 100 meter waterfall? I'd like to hear about it when they build the thing and it actually lights up a bulb. Till then, it's just a concept.

Re:Misleading point in summary (1)

savanik (1090193) | about 5 years ago | (#28810501)

In the "real world", the pump would be replaced by the river or other source of water. This would be powered by the water cycle, primarily sourced by the sun's evaporation of ocean salt water. Unlike a hydroelectric dam, you don't have to create a huge vertical gradient for it to work well, so building along a coastline with river access should be quite sufficient to create enough water pressure to keep the system moving around.

The biggest problem I can think of with this concept is the same problem most any coast-based energy generation system has - hurricanes. Experimental technology tends to stand up poorly to 75mph winds.

Re:Misleading point in summary (1)

c6gunner (950153) | about 5 years ago | (#28810585)

Exactly. The thing is supposed to work by diffusion. According to the article, the salt crystals are forced away by the inrush of fresh water, and this movement is what creates the extra voltage. But if your inrush of water is caused by a pump, I don't care how efficient the pump is, you're still not going to produce enough electricity to power the contraption, let alone to get any energy out of it.

I'm calling this myth BUSTED!

Now if we get a device to take salt out, (1)

ourcraft (874165) | about 5 years ago | (#28810245)

And Carbolic acid out too, while producing electricity, then we would have the utopia machine.

Environmental impact. (1)

Kaptain Kruton (854928) | about 5 years ago | (#28810407)

The article described these things as small environmentally friendly devices. They may not pollute the water and they may be small, but I cannot help but wonder what type of impact they could potentially have. The article states that one of these devices could power small house. However, a lot of homes and buildings exist in places near the joining of rivers to oceans. This would give reason to place a lot of these devices in these deltas. However, to my admittedly limit knowledge on the subject, some animals and plants live in the deltas and typically avoid other areas. If deltas are overrun with these devices, what will the environmental impact be? Are these devices going to greatly change the methods and ways of life for the delta-dwelling creatures when the devices are placed in great numbers throughout the delta? If so, they may not be as environmentally safe as the researcher wants people to believe. Also, if great numbers of these devices are placed in the mouths of rivers and deltas, is the movement of silt into and through the deltas going to be disrupted? I do not know the answers, but these are the questions I have when he claims to have what seems to be a perfect energy source (for certain areas) and then states it is environmentally safe.

My goodness! (1)

Steegest (1317083) | about 5 years ago | (#28810473)

This could spell the condemnation of every species that have evolved to live in brackish water...

Of course with better materials it'll get better (2, Informative)

marcosdumay (620877) | about 5 years ago | (#28810509)

Nice to see somebody talking about energy from water salinization once in a while, but that is not the first experiment to gather a few microjoules at lab. Up to now, no aparatus could be scaled up, all of them hit that "we just need better materials" barrier. There is a reason for that, because of the way difusion works, each device can create at most 100mV, and that will fall almost exponentially down to near 10mV once one starts gathering more than 5% of the available energy.

Just put that on the right perspective, there are just a few specialized diodes that will dissipate less than 100mV on the charge going through it. A normal silicon diode will dissipate 700mV, and there is simply no diode that will dissipate less than 10mV. Also, to get some sane amount of power at 10mV one needs quite a big current, the charge is available to extract that current, but the resistence of your circuit (and the capacitor's dieletric is a piece of the circuit) is a huge barrier. To create 1kW, one'd need a total current of 10^5A (of ions flowing into and out of the coal, if not electrons flowiong throug the circuit), with a total resistence of 10^-7 ohms. To reach such small reistences it is normaly needed lots and lots of material, or "just" better material.

Inaccurate story (5, Informative)

Otto (17870) | about 5 years ago | (#28810609)

There have been other ways to extract salinization energy: http://en.wikipedia.org/wiki/Reverse_electrodialysis [wikipedia.org]

These methods are even being used in test sites to generate power. Main problems are that there's a lot of crap in rivers that you need to filter out to get high efficiencies.

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