New Method To Generate Electricity from Water

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.

Comments

Of course, it's not going to be valid...

[PatrickThomson]

In the humble opinion of the battery manufacturers

So now we end up fighting wars over water?

[corebreech]

Or can sea water be used?

Re:So now we end up fighting wars over water?

[corebreech]

We had plenty of water. If you read the headlines, 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.

Re:So now we end up fighting wars over water?

[Spy Hunter]

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."

A hype?

[hankwang]

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.

Laws of thermo-dynamics

[Yawgm8th]

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.

Remote controls, watches, etc.

[Captain Kirk]

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.

electricity generator != energy source

[JulianOolian]

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.

medical uses

[shrubsky]

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:Not an energy source

[Anonymous Coward]

No-one said it's a new energy source. It's a new way of generating electricity (RTFA). Up to now you had to turn a turbine to produce electricity. That's what happens in a hydroelectric, coal burning and nuclear power plant. They all make a turbine turn by passing steam or water over it. This is something new, because it doesn't use a turning magnet (like in a turbine) to cause induction in a coil and then produce elctricity. It uses a completely different way of producing electricity. No-one claimed to produce energy out of nothing, it's just a way of converting energy to another form (electricity).

What a piss-poor set of comments.

[Fantastic Lad]

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

Re:What a piss-poor set of comments.

[Anonymous Coward]

What category do you fall in?

Is this really anything new?

[guygee]

I read the actual paper, (available, with registration required, here), 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" exists due to the flow of water through sermipermable layers of rock and clay. A bibliography 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.

There are much better ways

[poelzi]

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."

Re:Personal electric generation.... My shoes!

[MrScience]

Why not use Piezoelectrics? :)