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Science

New Method To Generate Electricity from Water 356

Posted by Hemos from the let's-see-how-it-really-works dept.
spaceling writes "The BBC reports reporting on research published in the Institute of Physics Journal of Micromechanics and Microengineering of the first new method of generating electricity in over 150 years. Larry Kostiuk and Daniel Kwok 'created a glass block, two centimetres in diameter and three millimetres thick, containing about 400,000 to 500,000 individual channels...[and] generated about 10 volts with a current of around a milliamp. This allowed the team to successfully power a lightbulb.'" This has also been covered all over the place.
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New Method To Generate Electricity from Water More

New Method To Generate Electricity from Water

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  • Liquid flow... (Score:3, Funny)

    by Webtommy88 ( 515386 ) on Monday October 20, 2003 @08:04AM (#7259353)
    From the article:


    While scientists have realized for decades that a flowing liquid could separate electron charges, no one appears to have linked the effect with a way of generating electricity.


    So... if these things end up becoming cell phone batteries and what not, where are you going to get the water flow needed to separate the charges?

    Shaking the phone or something? That just looks dumb :^)

    • Re:Liquid flow... (Score:4, Funny)

      by Anonymous Coward on Monday October 20, 2003 @08:09AM (#7259380)
      So now the bitch in the Volvo putting on eyeliner and talking on the phone will have something else to distract her as she runs me off the road.

    • electricity generator != energy source (Score:5, Insightful)

      by JulianOolian ( 683769 ) on Monday October 20, 2003 @08:25AM (#7259446)

      It's a new method of generating electricity, not a new way of storing energy or an energy source. The energy would have to come from somewhere else, and since the idea is pretty new, I doubt that anyone knows in much detail how (or if) it will work out in practice.

      I suppose you could either recharge a normal battery by pumping the handle your handy, portable water-generator for a few minutes, a bit like a baygen radio.

      Or, you could store the water under pressure and let it out through the device to get the energy back out.

  • Of course, it's not going to be valid... (Score:3, Insightful)

    by PatrickThomson ( 712694 ) on Monday October 20, 2003 @08:04AM (#7259354)
    In the humble opinion of the battery manufacturers
  • Or can sea water be used?
    • we already have plenty of water. arabs have none. that ends the wars because they cannot reach the USA or Europe very easily and terrorism doesn't occupy land.
      • There are lot of (more or less potential violent) wars over water. Turkey has build waterpowered electricity plants which use so much water that other surrounding countries saw their waterlevels drop. There are more examples besides this one from the Tigris: http://news.bbc.co.uk/1/hi/world/europe/943002.st m

        Yes.. I think it's entirely possible to have real wars in the future not to establisch democracy in a country, or to expand the territory of the aggressor but entirely focussed on the water.

        • Re:So now we end up fighting wars over water? (Score:5, Interesting)

          by Dun Malg ( 230075 ) on Monday October 20, 2003 @09:27AM (#7259794) Homepage
          There are lot of (more or less potential violent) wars over water.

          You make a very important point. Heck, look at how we fight over water in the US. We don't generally have "shootin' wars" over it anymore, but there's certainly a lot of acrimony. The various states arguing over how much water they can keep behind the dams and how much they can take out for irrigation on the Colorado river, for example. The California aqueduct taking most of the water in the Owens valley area and piping it down to Los Angeles caused a fair amount of strife too. I was driving around northern Nevada once about 10 years ago and I saw signs in store windows that said "Don't let Las Vegas take our water". Access to fresh water has been a central issue to civilization for eons. Heck, the first thing those monkey dudes in the beginning of "2001: A Space Oddessey" did after seeing the monolith and "gettin' wise" was grab bludgeons and chase off those other monkey dudes from the watering hole. Just a movie, but it makes an important point.

      • We had plenty of water. If you read the headlines [thespectrum.com], you'll see that our supply is becoming strained.

        And actually, the Arabs do have water. Or had. Iraq is blessed with an abundant supply of water, so much so in fact that some had speculated we did not go there for the oil as much as the water.

        Water is going to become increasingly scarce as time goes by. Even power production using it may not be economically feasable... unless, again, you can use sea water.
      • I don't know if you should be flagged offtopic or a troll, maybe both but thanks for the brain fart keep up the good work.
    • So now we end up fighting wars over water?

      As if to imply that wars aren't already being fought over water...just look at Israel, which diverted the River Jordan away from Syria.

      Or, for something closer to home, try reading the Milagro Beanfield War, about a poor farmer who dares to use enough water for his field so he can eat. Rich cattle rancher/farmer gets all the water because he's in bed with the state officials..

    • Re:So now we end up fighting wars over water? (Score:5, Insightful)

      by Spy Hunter ( 317220 ) on Monday October 20, 2003 @08:45AM (#7259543) Journal
      The article title is misleading. This appears to be a new way to generate electricity from a pressure difference, using water flowing through small channels. It is not a method of generating electricity "from water," it is a method of generating electricity with water. The BBC article is guilty too, they misleadingly call it a "power source" when it is clearly a power storage technology (unless you have pre-pressurized water, maybe from geothermal activity or something). These few sentences from the article reveal the true nature of this discovery:

      What Professor Kostiuk and his team have achieved is create a kind of turbine device that does not have moving parts. "Efficiency is a fraction of 1% and right now we are trying to fully understand the characteristics of such devices. The real goal is to find ways of improving its efficiency to around four to 16% to compete with other energy sources."
  • ... the energy required to pressurize the water?
    Is it more or less the electricity produced by that method?

    Of course you can always build underwater and take advantage of gravity to make water flow through your channels...

    Guess we can also always get back to getting water in the well to wash, err, power out electronic devices!
    • if you build underwater, where does the water that has flown through your apparatus go? probably a storage tank of some type, that by definition has to have lower pressure than the bottom of the water source.

      at some point you have to transfer it back to a location of higher potential energy, and will waste even more of your 'produced' electricity.
      (unless of course you are simply going to drain your entire source into another location, and harness energy as a one-time thing).

      if you try to connect the appar
      • but one would have to wonder about the rate of corrosion of the electrodes, particularly in saltwater applications - they being submerged in water and all.

        Not to mention how clogged up those micro-pores are probably going to get with contaminants.

  • generating electricity (Score:2, Informative)

    by Speedy8 ( 594486 )
    BTW, nuclear reactors are not a new way of generating energy that was discovered in the last hundred and fifty years.

    • Re:generating electricity (Score:5, Informative)

      by EricTheRed ( 5613 ) on Monday October 20, 2003 @08:13AM (#7259404) Homepage
      True except that Nuclear Reactors don't generate electricity directly - they do so by converting water into steam which powers turbines, and the base technology for that is 150years old or so.
    • BTW, nuclear reactors are not a new way of generating energy that was discovered in the last hundred and fifty years.

      Nuclear reactors are just a new(ish) way of heating water.
      Spinning turbines with steam to generate electricity is as old as your hat.
      • Nuclear reactors are just a new(ish) way of heating water. Spinning turbines with steam to generate electricity is as old as your hat.

        However, there is the method used in the Cassini probe, which basically converts the heat of the nuclear decay directly into electricity. Ah, which are called 'radioisotope thermoelectric generators' (according to here [nasa.gov]). I can't remember how these worked (I took a class in nuclear engineering ~6 years ago and at one point they explained it, but I'm forgetful), but I'm rea

  • A hype? (Score:5, Insightful)

    by hankwang ( 413283 ) * on Monday October 20, 2003 @08:07AM (#7259369) Homepage
    This story looks like it's hyped. The device converts a flow of particles caused by a pressure difference into an electrical current. The paper itself (PDF [iop.org], you probably need to be a subscriber, but the abstract [iop.org] should be accessible for everyone) shows efficiencies between 0.0001 and 0.04. The higher number is only obtained if the external load is matched to the device within a factor 10, i.e., the device looses the pressure difference if you don't use the current.

    If we take one liter (1 kg) of water at a pressure of 30 cm, then the energy contained is 2.94 J, of which 0.12 J will be available as electrical output. By comparison, a 1500 mAh NiMH battery can store 6500 J. The efficiency of the water battery can probably be improved, but let's face it, for small volumes and reasonable pressures, the stored energy density will never be very high.

    • Re:A hype? (Score:4, Interesting)

      by GospelHead821 ( 466923 ) on Monday October 20, 2003 @05:45PM (#7264151)
      According to the paper, itself, they seem to be interested more in powering MEMS. I can imagine many situations in which a chip designed to analyze a fluid wouldn't require a battery because the chip's sensors will be powered by electricity generated as the pressurized fluid traverses an "electrokinetic microchannel battery" at the front end of the chip. If they can increase the efficiency and insure that a thumb-operated pump (like the primer on your lawnmower) would provide sufficient pressure to drive the battery, this could be a really useful innovation.

  • Sounds like a van der Graaf (Score:5, Interesting)

    by panurge ( 573432 ) on Monday October 20, 2003 @08:07AM (#7259371)
    In fact, I've seen van der Graafs that work by using a flow of dielectric fluid rather than the rubber belt of the school versions. Admittedly they generate megavolts rather than volts - but isn't the basic method the same? i.e. charge separation.

    Also, the electricity isn't generated from the water. It's generated using the kinetic energy of flowing water - just like a turbine or waterwheel, and something needs to produce the kinetic energy in the first place...excuse me while I go and check my cold fusion plant, the room temperature seems a bit low.

    • Re:Sounds like a van der Graaf (Score:3, Funny)

      by Anonymous Coward
      Your room is cold because cold fusion doesn't generate heat, but uses it up. That's why it's called cold fusion.

      With normal fusion you can simply use the heat to boil water and send the steam trough a turbine, which will turn a generator; with cold fusion you need to put the reactor in a high place and use it to turn air into liquid, which will then fall down and turn the turbine like a watermill. You can then let the liquid air to either reheat and boil away, or sell it for a profit.

      Obviously, this power
    • No it is not.

      For anyone with university level knowledge of chemistry this is extremely fascinating because it harnesses the biggest pest in electrolysis and battery design. The so called dual layer phenomena.

      So even if it never ever makes it to become a decent generator the reseach may still give insight in making existing devices and fuel cells more efficient
  • I read one of the articles on this and mabey I missed something but where is this energy coming from? If there is no input of energy then how is there an output. Or have they figured out a loop-hole in the law of thermo-dynamics by finaly creating a perpetual motion machine.

    • Re:Laws of thermo-dynamics (Score:4, Informative)

      by BillFarber ( 641417 ) on Monday October 20, 2003 @08:14AM (#7259408)
      The energy comes from the water pressure requiredd to force the water to flow through the channels.
    • I read this elsewhere, not sure where I found the link, but I was thinking something along those lines as well.

      What I'm most curious about is how efficent such a system is in contrast to a typical generator. If so I can think of a few normal run of the mill sources of engery.

      1. Heat water to produce steem as with traditional power plants
      2. gravity fed as with rain and rivers as with traditional hydro plants
      3. Wave / Tidal forces

      Steem power seems a touch impractical for this system, except to provide

      • The few system i've seen for tidal generations were basicly underwater windmills, which do indeed get the job done. It seems to me that one could use a large holding tank which would fill at high tide, and flow out at low tide.

        I think I saw something like that in a documentary some years back. The proposed (or actual) generator used regular tide power as the tide flowed in and out, but at low tide supplemented the outflow with water from a holding tank. During times of low electricity use, water was pum

  • Must have missed geometry class that day. (Score:3, Funny)

    by ronmon ( 95471 ) on Monday October 20, 2003 @08:11AM (#7259395)
    I guess that means that pi really are squared.

  • Remote controls, watches, etc. (Score:3, Insightful)

    by Captain Kirk ( 148843 ) on Monday October 20, 2003 @08:16AM (#7259414) Homepage Journal
    This produces a tiny amount of power but it could be ideal for things like TV remotes, wireless mice, garage door controls, etc.

    Sure its being hyped a bit there is a lot of potential here.
    • it could be ideal for things like TV remotes

      And what would power the pump needed to move the water? Or would you have to shake your remote every time you wanted to change the channel?

      Sure its being hyped a bit there is a lot of potential here.

      No pun intended, right?
      • And what would power the pump needed to move the water? Or would you have to shake your remote every time you wanted to change the channel?

        Perhaps pressing a button could generate enough pressure to force water through the cell to power the device momentarily...

        It would be quite disappointing if your remote sprung a leak though =/
      • Well, unless it's glued to a couch or something you probably end up moving it rather a lot, and it could have a small battery or capasitor that would be charged whenever that happens.

        Not unlike the kinetic watches, etc. Though the traditional generation techniques in them are (for now at least) probably quite a bit more effective than this water filtering.
    • Someone could create an hourglass, with this device in the center to provide power to an LCD screen and a circuit which counts down seconds.

      Mostly a geeky concept, but at least you'll never worry about having to find new batteries if the existing ones have worn out...
    • Sure its being hyped a bit there is a lot of potential here.

      Hey, that's a good one! ;-)

  • Cool! (literally) (Score:4, Funny)

    by xyote ( 598794 ) on Monday October 20, 2003 @08:22AM (#7259433)
    We'll be able to water cool and water power cpu's at the same time.


    Heh! I noticed not a lot of RTFA in evidence. The researchers who discovered this stated where the energy comes from.

  • medical uses (Score:2, Insightful)

    by shrubsky ( 661474 )
    The article stated that this method is mainly only good at generating small amounts of electric power. This could still be useful for thing like pacemakers, however; I imagine people would rather have one of these powering their pacemakers than have surgery every few years to change batteries.

    I wonder -- would it work on blood? The channes are 10um thick; how wide is a red blood cell?

    • Re:medical uses (Score:3, Interesting)

      by WegianWarrior ( 649800 )

      According to this page [umn.edu], the avrage red bloodcell is about 9um in diameter, so pouring blood down a channel just 10um wide is asking for trouble. The downside is that - as far as I can understand the article - that the size of the channel is vital for the functioning of the generator.



      *ponders* Hmm... urine is mostly water, isn't it... ?

  • My 2 cents (Score:2, Informative)

    by asciimonster ( 305672 )
    As far as I understand it, The glass around the chaneels is charged; for easy let's say it's positively charged. When water with ions (read: salt) is pumped through the tubes the positive ions cannot pass: they are repelled and stay behind, whereas the negative ions can move freely through the tube and out the other end. Entrance is positive, exit is negative, hence the potential difference and current can be extracted. The energy comes from the pumping power and is converted to electrical power. I just do

    • Re:My 2 cents (Score:2, Interesting)

      by Robmonster ( 158873 )
      For my physics A-level practical some 7-8 years ago now I tried pumping salt water through a tube inside a magnetic field. Two electrodes on opposite sides of the tube measured the voltage across it. You could see that voltage generated was propotional to the speed of the water and the amount of salt it contained.
  • This isn't an energy source, you have to pressurize the water.
    Unless you have free pressurized water, it won't create a new source of energy.
    If you do, how is it different then your old fashioned water wheel? (or the newer hydro electric dams).

    Maybe this can generate small amounts of electricity on already moving parts, but I don't see the breakthrough.

  • Wouldn't a Van Der Graff generator be more efficient?
  • http://www.wired.com/wired/archive/6.11/coldfusion .html Remember how exciting it seemed? I'll wait for the other shoe to drop....
  • Now if they could find a way of generating power out of beer, that would be cool. A power keg, so to speak. Though as there's almost no way of telling Molson apart from water, it's qutie likely that the scientists were actually using beer.
  • I think that could, if the CO2 doesn't create a problem, solve the whole pressure deal. And plain ol' carbonated water is (comparatively) cheap to boot.
  • If you RTFA, it's 1% efficient (worse than a little turbine, for instance) and you need to pressurize the water first. Which means some kind of elastic vessel, since water isn't compressible. So you need a big balloon attached to your laptop...

  • THIS IS NOT A NEW WAY OF GENERATING ELECTRICITY! (Score:3, Informative)

    by glomph ( 2644 ) on Monday October 20, 2003 @09:11AM (#7259703) Homepage Journal
    See, for instance, http://www.amasci.com/emotor/kelvin.html

    Which operates under a very similar principle, but with macrochannels. I built one of these when I was a kid, thirty-some years ago. It is so damn cool, your tongue sticks to it!
  • Just thought I'd drop a line and mention a quick thought. With the water battery, could you use a solar oven during the day to build the pressure? Then via cooling or some other mechanism (like venting one side) you would then harvest energy from the cell...
    Sunlight
    Water Input > Chamber 1 > Water Battery > Chamber 2 > Valve.

    (Chamber 1 and 2 being separated)

    1. Sunlight heats/pressurizes chamber 1 and 2 (like a solar oven)
    2. Valve is opened on Chamber 2 to create pressure
  • I wonder how well this would work for storing energy, say for a self-sufficient farm powered by a windmill, solar cells, or whatever. Currently such a setup would use a battery, not terribly efficient. With this, you could use the windmill or whatever to pump water upwards into a tank, then when generation falls off, the water flows downward through this gizmo.

  • Yup, I can see this now...

    • Hey, Bob -- can you hold for a sec? My phone's battery warning light is flashing. Thanks.
    • pump pump pump
    • Okay -- that's better!

    Yaz.

  • So it seems like there must have been a few new technologies for generating electricity in the last 150 years. Many people mentioned that nuclear power plants use steam driven turbines, an old method of producing electricity; however, I have read about some that heat a conducting liquid and then the energy is converted into electricity using magnets and the Lorentz force. This must be fairly new, since it probably couldn't even have been understood until the mid to late 17th century. I've certainly never

  • Personal electric generation.... My shoes! (Score:4, Interesting)

    by Wubby ( 56755 ) on Monday October 20, 2003 @10:15AM (#7260098) Homepage Journal
    Why not put a couple pumps (no pun intended) in the soles of shoes? As I walk around I could generate the power I need to recharge my phone/low power laptop.

    Hey, maybe it would force me to exercise more.

    *ring ring*
    ME: Hey... Bob... what's... up....[huff puff]
    BOB: Dude, why are you outta breath?
    ME: Phone... dying... needed... recharge...[cough]

    Kids wanna play thier Gameboy... make 'em walk the dog! (hmm, mini paw sized pumps)

  • What a piss-poor set of comments. (Score:3, Insightful)

    by Fantastic Lad ( 198284 ) on Monday October 20, 2003 @10:21AM (#7260138)
    Sorry. Time to judge.

    20% Stupid jokes
    10% "But you still need pressure!" redundant observation.
    30% "Electrostatics? Please. I'm too cool to be impressed."
    20% "I TOTALLY don't get it, and will prove as much by saying something asinine."
    18% Skeptical combination of the above.
    2% Genuinely insightful observation.

    It just goes to show; smart Slashdotters sleep in.


    -FL

  • Lets say we take this glass disk and put two large bags on it, one side filled with water, and the other side empty. You squeeze the water through the disk, providing the pressure difference to generate elecricity, until the other bag is full. Does squeezing the other bag and moving the water back through the disk the other way also generate electricity?

  • Is this really anything new? (Score:4, Insightful)

    by guygee ( 453727 ) on Monday October 20, 2003 @10:44AM (#7260306)
    I read the actual paper, (available, with registration required, here [iop.org]), and granted, these guys did a good job on the analysis and experimental verfication, and also should be commended for bringing attention to this phonemena, but the basis for their work has been know for quite some time. In the field of geophysics, it has long been known that "spontaneous potential [slb.com]" exists due to the flow of water through sermipermable layers of rock and clay. A bibliography [usgs.gov] on spontaneous potential in boreholes has been compiled by the USGS with some papers dating back to the 1940's.

    The real questions are how practical and economically viable this approach will be for medium to large-scale power generation. For natural sites (e.g. permeable rock layers), what type of electrodes can be used, how well will they resist corrosion, and how large must they be? The bottom line: how much will the power cost over the entire life cycle in terms of $ per KWH?

    For manufactured microchannel membranes or devices, added questions are the cost of manufacture and the lifespan of the device. How easily will the pores become clogged, what steps must be taken to prevent this, how long will it take for the pores to erode over time, and what is the expected lifetime of the microchannel device?

    One big difference between pure science and engineering is that engineers need to factor in economics.
  • "The BBC reports reporting on research ..... "
    So what you're saying then is that this is old news... I mean, if they're only reporting that they reported on it, then that means that it *WAS* reported some time previous.

  • There are much better ways (Score:3, Insightful)

    by poelzi ( 177615 ) <`gro.izleop' `ta' `gro.todhsals'> on Monday October 20, 2003 @11:20AM (#7260565) Homepage
    I began recently to work on high frequency eletrolyse and magnetic electrolyse which hase a much better efficacy.
    The Energie Problem is solved decades befor, but open your eys - Nobody can sell it without risking his life.

    For example:

    http://www.cheniere.org/books/excalibur/moray.ht m

    From "FUEL FROM WATER, Energy Independence with Hydrogen" Author Michael A.Peavey Publisher Merit, Inc., P.O. Box 694 Louisville, KY 40205 Library of Congress Number 88-188956 ISBN 0-945516-04-5 Page 22.

    " The smallest amount of energy needed to electrolyse one mole of water is 65.3 Wh at 25 degrees Celcius (77 degress F). When the Hydrogen and Oxygen are recombined into water during combustion 79.3 Wh of energy is released. 14 Wh more energy is released in burning Hydrogen and Oxygen than is required to split water. This excess must be absorbed from the surrounding media(environment) in the form of heat during electolysis." [...] "At 25 degrees celcius, for voltages of 1.23 to 1.47 V, the electrolysis reaction ABSORBS HEAT. At over 1.47 V at 25 degrees celcius, the reaction gives off heat."

  • Does it have to be a liquid? (Score:3, Interesting)

    by LWATCDR ( 28044 ) on Monday October 20, 2003 @11:21AM (#7260579) Homepage Journal
    Could a gas,like steam work as well?
    What about superheated air?
    This could be a replacement for turbins.
  • Most of the energy in pushing the water through the channels is lost as heat. Just a tiny fraction will end up dissociating atoms electrically.

    So efficiency will be fundamentally low. If you have something where in theory you can harvest all the energy, you have a good chance of achieving 50% in practise (e.g. fuel cells). And sometimes even better (e.g. turbines).

    As the efficiency is fundamentally low, I don't expect much from this "invention".

    People seem to misunderstand how you'd work this invention:
  • I wonder if a more mature version of this technology could find itself being used in hydro dams in the future....

  • A Practical Use (Score:3, Interesting)

    by Aidtopia ( 667351 ) on Monday October 20, 2003 @11:49AM (#7260829) Homepage Journal

    More and more public restrooms have those infrared detectors to flush toilets and run the faucets. I bet they all have batteries in them. Batteries run down, disposal of them is an environmental problem, etc.

    If this gizmo provides enough power to run the detector and the valve, it may be a perfect application. You already have water running through the device.

  • If this doesn't turn out to be practical as an energy source maybe it could be uses to measure water flow. It's solid state -- seems better than the stuff we have now.
  • Scientists in Germany invent a 'water wheel [waterwheelfactory.com]' capable of capturing the kinetic and potential energy of elevated water with efficiencies two orders of magnatude higher than this 'glass brick' method.

    Though still theoretical, applications could include milling wheat, generating hydrogen for Zero Emission vehicles, or powering the internet.
  • It's called electroosmosis. Just hit up google. What they did is scale it up.
  • Why are the energy claims that do not threaten the energy stranglehold that the most powerful entities on the planet have due to this stranglehold get attention in the form of Slashdot links and time/money spent investigating?

    Here [cheniere.org] and here [seaspower.com].

    Just seems rather silly... and obvious.

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