# New Alloy Turns Waste Heat Into Electricity for Free



## lotuseclat79 (Sep 12, 2003)

New Alloy Turns Waste Heat Into Electricity for Free (w/ very short Video: 0.04).



> *Using a multiferroic alloy of nickel, cobalt, manganese, and tin, researchers at the University of Minnesota have discovered a method of creating green electricity from waste heat sources. This alloy could be placed near your cars exhaust to create electricity  or in the cooling towers of power stations to convert wasted heat into electricity. Beyond creating the alloy itself, which is made from common and abundant elements, there are no extra costs  and no additional pollution, either.*
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-- Tom


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## Ent (Apr 11, 2009)

Brilliant. But how? 
You can already generate an electric current simply by heating one end of the wire (while the other remains cold), but that doesn't provide for power generation simply because there's no way to get the wire back to its cold state without using even more energy. Surely the same issue would plague this technology. You can heat it, change the magnetic field, and cause a current in the surrounding coil but then you're stuck, at least until you turn off the heat source and let it cool down.


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## lotuseclat79 (Sep 12, 2003)

Hi Ent,

As I understand it, your wire does not have the properties of combining elastic, magnetic, and electric properties of its constitute elements - because your wire is not made of Ni45Co5Mn40Sn10, i.e. the new alloy.

A wire of the new alloy would detect the heat and then become strongly magnetic which would create an electric current in a surrounding coil. You don't need to heat it, just get it near enough to a heat source such that heat can be detected by the alloy effectively heating it. With regard to getting the wire back to its "cold" state, that is already subsumed by its multiferroicity which grants it two distinct physical states: in its base state, it is non-magnetic,

-- Tom


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## Ent (Apr 11, 2009)

I know that the technology is different, but the problem itself still remains. It will change to highly magnetic when heated, and a coil around it would then have a current induced by the new magnetic field. But Current is only caused by changes in magnetic field, not a steady one. So you don't get any more current until it either heats or cools past that critical temperature. Most systems where you have waste heat don't cycle it on or off to allow the technology enough time to cool.


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## lotuseclat79 (Sep 12, 2003)

Why wouldn't time to cool of the new alloy be instantaneous, just like a switch, due to its unique properties?

Turn off the engine, no more exhaust, hence no more heat and no more electricity generation.

Turn the engine back on, get exhaust heat which alloy detects, get electricity generation.

It sounds to simple to be true, but the combination of materials creates a unique set of properties that are quite different than normally observed, so it doesn't make enough sense to analyze it and expect it to behave as conventional materials would normally behave.

-- Tom


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## jiml8 (Jul 3, 2005)

lotuseclat79 said:


> Why wouldn't time to cool of the new alloy be instantaneous, just like a switch, due to its unique properties?


Because its thermal conductivity is not infinite. Takes time to dissipate the heat.



> Turn off the engine, no more exhaust, hence no more heat and no more electricity generation.
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> Turn the engine back on, get exhaust heat which alloy detects, get electricity generation.
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You should study Lenz's law. What you propose won't work. As Ent says, only the change in a magnetic field gives rise to the current. When the change stops, the current stops also.

I did some work for DARPA some years back investigating the thermal responses of high temperature superconductors when the current in the superconductor was driven past a critical point, beyond which the superconductor switched to normal state with all the implications of magnetic field changes and energy dissipation that went with that.

That wasn't the same problem as the one described here, but there are some rather startling similarities and we came up with no useful way to exploit the high temp superconductor's ability to change state. Many reasons, which I won't detail.

Looking at this particular thermal mechanism, I suspect it will have some commercial applications but will mostly be a curiousity or a way to generate miniscule quantities of electricity to power small electronic devices in odd locations. I would be very surprised if it proves possible to generate large quantities of electricity; it seems to me the mechanism just has to be too slow.


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## Elvandil (Aug 1, 2003)

Definitely a lot of questions to answer about this material. Can it be used for cooling? Does it work in reverse, i.e., does it produce heat if a magnetic field is imposed?

But what I don't understand is how the process can be repeating. Only accelerating magnetic fields produce electricity, so just "being a magnet" and sitting there means it produces nothing. So it would have to cycle somehow between magnetic/non-magnetic in order to produce any current. And then what happens to the heat? Does the material need to be cooled before it undergoes another transition?

I know I need to read a lot more about this to fully undertstand its implications. But I really would need to be dragged kicking and screaming to the idea that in a year or so we will have some thin film that we can wrap around a heat source and get any kind of usable electricity from it.  As *jiml8* says, maybe enough to light a watch-face. But then, that depends somewhat on how thin and layered the material can become.

I would love for it to be true and useful. I really do believe in "free" energy. Just not the kind of "over-unity" free that some people talk about. In relativity theory, all "forces" are fictitious, just as centrifugal force is in Newtonian mechanics. With the forces go kinetic energy and momentum as well which then become simply matters of how you look at things. There may well be another perch from which these things look entirely different.


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