Slashdot Mirror

← Back to Stories (view on slashdot.org)

New Method To Generate Electricity from Water

Posted by Hemos on 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.

3 of 356 comments (clear)

  1. A hype? by hankwang · · Score: 5, Insightful
    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, you probably need to be a subscriber, but the abstract 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.

    --
    Avantslash: low-bandwidth mobile slashdot.
  2. Re:generating electricity by EricTheRed · · Score: 5, Informative

    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.

    --
    Java gaming nut - http://www.retep.org/ or for the rail http://uktra.in/
  3. electricity generator != energy source by JulianOolian · · Score: 5, Insightful

    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.