# Questions tagged [thermoelectricity]

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### What is the energy in a circuit with a temperature difference and no potential difference

Suppose I have some kind of thermoelectric effect, where there is an electric current flowing from a hot to a cold electrode. If there is no bias voltage $V$ and there is a current $I$, the energy ...
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### Calculating Peltier efficiency

This is half Skeptics SE , half here. Please help me proving this Kickstarter is baloney. Besides the stupid marketing claims what we have here is a neck band shaped portable device of 180x177x45mm ...
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### Thermoelectric Thomson effect as generator

In thomson effect we need an electrical current and a temperature difference at the same time. So it is possible use Thomson effect to generate an electric current? That is, how I generete an electric ...
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### Seebeck and Peltier effect vs Thomson effect - conductors difference

Both Seebeck effect and Peltier effect we have the need of two dissimilar conductors to break the symmetry of the system to produce a current. But, why in the Thomson effect we just need one conductor,...
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### How might the hypothetical "Dyson sphere" convert the energy from the sun to usable electricity?

I have tried to find the answer but it appears that this question was never asked. I consulted my teachers but they do not have any knowledge of this either.
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### Absolute Seebeck-Coefficient of Metals

Note: In litterature, the Seebeck-Coefficient is most often given to Platinum as a reference point, because it is challenging to measure the absolute Seebeck-Coefficient. It is however possible, this ...
1 vote
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### Using simple logic instead of the thermoelectric series

A thermocouple is made from two metals, Antimony and Bismuth. If one junction of the couple is kept hot and the other is kept cold then, an electric current will The answer is - Flow from Antimony to ...
1 vote
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### Efficiency of thermoelectric material and Carnot

Is Carnot efficiency also relevant for "open systems"? Example - If we take a thermoelectric material with the hot side connected to a stable heat source and the cold side to an infinite ...
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### Thermal power station powered by temperature difference between high and low altitude air

Would it be feasible to build a system where warm air from sea level is pumped to the top of a mountain to power a thermal power station? With a lapse rate of ~ 1°C / 100 m there should be plenty of ...
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### How to define and explain power factor in thermoelectric materials?

The power factor in thermoelectric materials is (seebeck coefficient squared)*Electrical conductivity. How do i define it in words to explain it?
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### The opposite of thermionic emission

"Thermionic emission is the liberation of electrons from an electrode by virtue of its temperature (releasing of energy supplied by heat). This occurs because the thermal energy given to the ...
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### Is my understanding of Seebeck effect correct?

I'm not sure whether I understand thermoelectric voltages (Seebeck effect). In the following image I show a simple thermo-couple consisting of materials A and B. On the left side there is a ...
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### Is Seebeck coefficient for a metal related to Fermi level as it is the case for contact potential?

When putting together two different metals a so called "contact potential" will be built up. So far I understand this is because the combined system wants to reach an equilibrium where free ...
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### Is there a theoretical efficiency limit for thermoelectric generators?

Typical Thermoelectric/Seebeck generators operate at 5-8% efficiency. Is there an upper limit to the conversion of heat flux (temperature differences) directly into electrical energy?
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### Joule heater physics

Why does a joule heater element heat up from the middle outwards to the ends? In the picture below, the kanthal mesh heating element is shown heating up from the middle outwards. I'm looking for an ...
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### Will withdrawing electricity via a thermoeletric device cool a whole closed system?

If a hot and a cold container are placed thermo sealed system, and a thermoelectric device is used between them and electricity is withdrawn that way, will the resulting entropic temperature in both ...
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### Is it theoretically possible transfer thermal energy to electrical?

I was searching web trying to find answer, but all I found are thermoelectrical generators which work on principle flowing electrons from heat to cold material and efficient is very low. I am ...
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### How can I experimentally check that the voltage in a thermocouple is generated be the gradient in the wires and not by the junction themselves?

I just found out on Wikipedia (also here and there) that the voltage in a thermocouple in not generated by the cold & hot junctions, but by the temperature gradient in the wires which generates a ...
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### What is the best way to generate electricity using fresnel lens? [closed]

I have a fresnel lens which I want to put to use for generating electricity. My house receives ample sunlight. What is the best way of going about it? Stirling engines, steam driven turbines are some ...
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### Why did my peltier modules stay warm inside vacuum?

My problem is a bit more complex, but I will do my best to describe it. I have assembled the following setup: I want to acheve the lowest possible temperature in vacuum on top of my stacked Peltier ...
1 vote
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### Could you electrically charge a liquid or granules to refuel EVs with it?

Is there a physical law that would make an electrically charged liquid or granules impossible to produce? Theoretically it should be possible to refuel an EV by adding two different liquids to it in ...
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### Formula for Temperature Gradient due to Joule Heating [closed]

I was wondering how to calculate how much the temperature will increase in a cylindrical wire due to current passing through it, I did some googling didn't find anything so I came up with the ...
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### Peltier, measure cooling effiency

I am wondering how to calculate the cooling efficiency of a Peltier device by having plots of the evolution of temperature of both side. Anyone has any idea?
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### Polarity definition of thermoelectric effect

After a brief search of the internet the polarity definition for thermoelectric voltage is not found. Let conductor X cross a temperature gradient where temperature A is higher than temperature B. ...
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### Can waste heat in specific environments be collected into photons and converted to electricity? [closed]

Crossposted on Engineering SE Here and here show possibility to combine photons of lower energy to one higher. Thinking of an application, it could be used to dissipate heat from laptop. Liquid ...
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### What does a voltmeter real measure in case of a pn junction?

I recently learned, that a voltmeter doesn't measure difference of electrical potential but difference of electrochemical potential $\tilde{\mu} = \mu/e + \Phi$. My original question was about ...
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### What voltage is needed to ionize oxygen at the centre of this ball and would we hear any noise from thunder?

The outer ball is 10 metres in diameter (its surface is the Earth's atmosphere) and a vacuum separates the outer ball from a 1 metre ball of atmospheric air which exists at atmospheric pressure. The ...
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### Could this imaginary cooling solution work?

Imagine a perfectly insulated ideal closed cylinder. Inside, at the two ends there are two bodies, one with the temperature of T the other with temperature -T. Between the almost touching bodies with ...
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### Seebeck Coefficient variation with Fermi Energy at different Temperartures for the Same Material

So we have been recently introduced to the Seebeck Coefficient in thermoelectrics, however, I had some questions on it, and I kept finding contrasting information online, maybe because I don't know ...
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### Reaction to increase and diminish mass at will (forward and reverse reactions) [closed]

Non-professional question... Is there currently a method for converting mass to/from another form of energy? This would be like an exothermic reaction in that mass is consumed, but it would also have ...
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### Thermoelectric Seebeck Crystalline Structure

Recently reading about Crystalline Structure in metals and other forms of doping. Being that thermal energy has so called phonons could it be that crystals in metal having an effect like that for ex. ...
1 vote
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### Does a temperature gradient in a single metal rod generate an electric field?

Based on this question, I was trying to understand what happens with the electrons when there is a gradient of temperature between the ends of a metal rod. I put the contacts of a voltimeter at the ...
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### Is Joule's law of heat generated by electricity only applicable for ideal resistors?

I have learned about Joule's law of heat generated by electricity. It states that $H=VIt=I^2Rt$. But here's where I'm confused: if the whole electrical energy does not get converted into thermal ...
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### If there is no limit to $ZT$, why are there no materials with $ZT>3$?

It is well understood that the thermoelectric performance of a material (described by the parameter $ZT$ ) has no transport related upper theoretical bound. This means a material can exist that can ...
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### How can I understand Luttinger's theory of thermal transport coefficients?

I am trying to understand Luttinger's research paper Theory of Thermal Transport Coefficients, J. M. Luttinger Phys. Rev. 135, A1505 – Published 14 September 1964 While I am able to understand the ...
1 vote
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### Peltier Effect in Nature?

Are there examples of the Peltier effect occurring naturally, or has it only ever been artificially produced? Has there ever been what amounts to a 'natural refrigerator' discovered? And what would be ...
1 vote
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### Thermoelectric cooler's Qmax cites maximum heat transfer — how is it so close to rated wattage considering TEC's low efficiency?

Some background regarding my question: I'm thinking if making some sort of TEC-based ice cream maker. Considering the combined specific heat capacities, I calculated (possibly incorrectly) the value ...
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### (Fundamental) difference of Seebeck effect for metals and semiconductors

In which way is the Seebeck effect different for semiconductors from metals and why is it greater? What is the difference in the underlying physical principle? My knowledge so far is: Bring two ...
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### How does a thermoelectric generator at equilibrium get started?

Considering only the secondary steam turbine stage of a thermoelectric plant, if the system is shut down, and the pressure is at equilibrium throughout the system, how is a pressure differential ...
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### How does one calculate the voltage/wattage from Seeback Effect?

The Seeback Effect is a thermoelectric effect, where two different alloy wires are attached in a loop. One conjunction is heated while the other is cooled, creating a temprature gradient. As the wires ...
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### What is the basic explanation of a thermocouple?

What is the working principle of a thermocouple? Apparently, it isn't the contact voltage but, well, what is it? Finally it seems to be about the thermodiffusion but there is quite a lot going on so I ...
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### Question about how Ashcroft and Mermin came to Equation 1.56

I'm trying—unsuccessfully, as of yet—to follow how the second half of equation 1.56 is derived in Solid State Physics by Ashcroft and Mermin (equations below). Please keep in mind that I'm using this ...
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### Thermal Wheatstone Bridge

I am currently studying about the thermal conductivity of rods, as I am reading a Idea popped up in my mind that is , Is the concept of wheat stone bridge Valid to thermal resistors ?
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### How does a weather station temperature sensor work? (physics behind)

In an automatic weather station, a temperature-measuring electronic sensor (which is typically 1,5 m in the air above a grassy ground and covered from direct sunlight) is in a certain way coupled to ...
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### How would you measure the seebeck coefficient of some material?

Suppose you are given some materials that are viable to be used in a thermocouple. What is a procedure that could be used to measure the Seebeck coefficients of those materials? What apparatus is ...
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### What are the components of a Peltier cooler and what form factors can it be shaped to?

I am looking to build a cooling device of sorts, and reading about the different options it seems implementing the Peltier effect is the most logical way as it has no moving parts, doesn't require ...
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### Passive dissipator block between two peltier cells seemingly raising overall temperature differential

I am experimenting with stacked Peltier cells trying to build a simple diffusion cloud chamber. I noticed that when simply stacking two peltier cells the upper side reaches a temperature (around -15 C)...
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### Current from Internal Energy?

Internal energy in a conductor includes the collective vibration of the constituent particles including electrons and nuclei. If I place a heated conductor in a magnetic field, the charges will ...
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Consider a closed system consisting of a room surrounded by walls at temperature $T$ (infinitely big, so $T$ remains fixed). In this room, we place a power source with a wire of a particular material, ...