Temperature differences converted to electric...

[Koen1]

@scotty1: You're just talking about a heat sink here. Even if we ignore the fact that we simply cannot build a huge metal heat sink that extends from the earths surface into space, it would still not be a good solution. We'd be better off using geothermal power plants.

@FreeEnergy: As far as I know thermocouples only work when there is actually HEAT that can dissipate accoring to the laws of thermodynamics. Heat is not the same as relative temperature difference. As far as I know, the Seebeck effect (thermionic emission) only occurs at certain temperatures, and not necessarily at certain temperature differences. It is similar to the phenomena of only seeing the Peltier effect (reverse of Seebeck effect: thermocouples cool the surrounding air when additional electrical energy is supplied) when electrical energy is put in, and not when more electricity is "sucked out". (excuse the laymens terminology here but I think what I mean is clear? It is the adding of the energy that causes the cooling effect, not the subtracting of the energy, even if the potential difference and the relative electron flow should be similar.)
Obviously it would be fantastic if we could simply make thermocouples that produce output on temp differences between -20 and zero degrees, as it would mean free power everywhere except on the poles, and it would probably mean huge amounts of output in hotter regions.
But as far as I know thermionic emission at those temperatures is simply not possible. Electrostatically stimulated emission as in "cold cathode" vacuum tubes is possible at those temperatures, but then we're talking about a whole different ballgame.

also, if we look at that Eneco thermocouple chip for example, we can see that although it is a really nice design and it operates in temperatures up to 600 degrees Celcius, it still only gives a maximum efficiency of 20 to 30%. So 70 to 80% of the heat energy still goes to waste. Which just shows that it's a "simple" thermocouple and not an actual heat-to-electricity convertor. 

[FreeEnergy]

Why not just reverse global warming...
Tesla wrote.....
I read some statements from Carnot and Lord Kelvin (then Sir William Thomson) which meant virtually that it is impossible for an inanimate mechanism or self-acting machine to cool a portion of the medium below the temperature of the surrounding, and operate by the heat abstracted. These statements interested me intensely. Evidently a living being could do this very thing, and since the experiences of my early life which I have related had convinced me that a living being is only an automaton, or, otherwise stated, a "self-acting-engine," I came to the conclusion that it was possible to construct a machine which would do the same. As the first step toward this realization I conceived the following mechanism. Imagine a thermopile consisting of a number of bars of metal extending from the earth to the outer space beyond the atmosphere. The heat from below, conducted upward along these metal bars, would cool the earth or the sea or the air, according to the location of the lower parts of the bars, and the result, as is well known, would be an electric current circulating in these bars. The two terminals of the thermopile could now be joined through an electric motor, and, theoretically, this motor would run on and on, until the media below would be cooled down to the temperature of the outer space. This would be an inanimate engine which, to all evidence, would be cooling a portion of the medium below the temperature of the surrounding, and operating by the heat abstracted.
Up there for thinkin' mate.....

thanks.

[FreeEnergy]

@scotty1: You're just talking about a heat sink here. Even if we ignore the fact that we simply cannot build a huge metal heat sink that extends from the earths surface into space, it would still not be a good solution. We'd be better off using geothermal power plants.

@FreeEnergy: As far as I know thermocouples only work when there is actually HEAT that can dissipate accoring to the laws of thermodynamics. Heat is not the same as relative temperature difference. As far as I know, the Seebeck effect (thermionic emission) only occurs at certain temperatures, and not necessarily at certain temperature differences. It is similar to the phenomena of only seeing the Peltier effect (reverse of Seebeck effect: thermocouples cool the surrounding air when additional electrical energy is supplied) when electrical energy is put in, and not when more electricity is "sucked out". (excuse the laymens terminology here but I think what I mean is clear? It is the adding of the energy that causes the cooling effect, not the subtracting of the energy, even if the potential difference and the relative electron flow should be similar.)
Obviously it would be fantastic if we could simply make thermocouples that produce output on temp differences between -20 and zero degrees, as it would mean free power everywhere except on the poles, and it would probably mean huge amounts of output in hotter regions.
But as far as I know thermionic emission at those temperatures is simply not possible. Electrostatically stimulated emission as in "cold cathode" vacuum tubes is possible at those temperatures, but then we're talking about a whole different ballgame.

also, if we look at that Eneco thermocouple chip for example, we can see that although it is a really nice design and it operates in temperatures up to 600 degrees Celcius, it still only gives a maximum efficiency of 20 to 30%. So 70 to 80% of the heat energy still goes to waste. Which just shows that it's a "simple" thermocouple and not an actual heat-to-electricity convertor. 

thanks

[hansvonlieven]

Why not just reverse global warming...
Tesla wrote.....
I read some statements from Carnot and Lord Kelvin (then Sir William Thomson) which meant virtually that it is impossible for an inanimate mechanism or self-acting machine to cool a portion of the medium below the temperature of the surrounding, and operate by the heat abstracted.

Not true! This is exactly what the dunking bird, also called the dippy drinking bird does.



The familiar Dunking Bird, invented by Miles Sullivan in 1946, is one of the most popular physics toys of all time.
For an explanation of how it works see: http://en.wikipedia.org/wiki/Drinking_bird

Hope this helps

Hans von Lieven

[FreeEnergy]

Why not just reverse global warming...
Tesla wrote.....
I read some statements from Carnot and Lord Kelvin (then Sir William Thomson) which meant virtually that it is impossible for an inanimate mechanism or self-acting machine to cool a portion of the medium below the temperature of the surrounding, and operate by the heat abstracted.

Not true! This is exactly what the dunking bird, also called the dippy drinking bird does.



The familiar Dunking Bird, invented by Miles Sullivan in 1946, is one of the most popular physics toys of all time.
For an explanation of how it works see: http://en.wikipedia.org/wiki/Drinking_bird

Hope this helps

Hans von Lieven

so this bird works below zero temperature?