/sci/ - Science & Math

[Anonymous No.7941577]

Why don't we use thermocouplings for energy production?

A thermopile costs next to nothing to produce. It's pieces of wires welded together and can produce energy from any temperature difference. A heated home in Alaska with some thermopile blocks could probably power everything in the house besides the heater and stove. Same could be said for recovering energy from an A/C cooled home in Florida.

More practically, why are high-temp coolant lines and engine blocks not entirely lined with thermopiles to generate electricity from the waste heat? For that matter, steam turbines in power plants on the main... It's basically free energy, right?

[Anonymous No.7941586]

>>7941577
>free energy
nigga please

[Anonymous No.7941614]

>>7941586
Holup. Hol up. Smhtbth senpai. Dude. But yeah, A thermocouple generates electricity from nothing but a temperature difference. There are plenty of instances in the a energy-producing system where a thermocoupling can use waste-heat to generate electricity.

Also, I wonder why photovoltics are used when thermopiles could do the same thing better if the ambient tempt was high

[Anonymous No.7941641]

>>7941577
horribly inefficient, expensive, dangerous, and heavy.

they are niche energy sources. things like satellites, remote light houses, rovers, space ships, etc.

[Anonymous No.7942028]

>>7941641
I don't think of is talking about radioisotope thermal generators. More thermocouples used to generate power from ordinary waste heat.

IIRC, they arnt efficient enough to bother with.

[Anonymous No.7942060]

>>7941577
>>It's pieces of wires welded together
are the shittiest fucking way to generate power thermoelectrically. We only use thermocouples for sensors now, because it is much much more efficient to use bismuth telluride.
>>A heated home in Alaska with some thermopile blocks could probably power everything in the house besides the heater and stove. Same could be said for recovering energy from an A/C cooled home in Florida.
The temperature difference in both those cases is fucking low, like 15 fucking degrees. Second, we insulate houses so they don't lose heat.
>> It's basically free energy, right?
it's not enough to be worth it. Especially if it's just wires welded together. Wires welded together would probably not generate enough electricity to pay for themselves.

[Anonymous No.7942676]

>>7941577
>Why don't we use thermocouplings for energy production?
We do but only for certain niches that are known for
- cost no issue
- extreme reliability
- no vibrations

Otherwise it is too expensive and Stirling engines are better, easier and cheaper.

>A thermopile costs next to nothing to produce.
Check the price of Peltier elements (Seebeck in reverse, same principle). Please let us all know if you find any that are cheap and good.

>It's pieces of wires welded together
You are thinking of thermocouples. A good practical thermocouple is rather a lot more tyhan that.

> and can produce energy from any temperature difference. A heated home in Alaska with some thermopile blocks could probably power everything in the house besides the heater and stove.
Back in the 60's people planned to put sealed blocks of nuclear waste in the foundation of new homes for use as heat sources with thermopile possibilities. Then terrorisme became a problem. You need a heat source and tmperatures should not vary too much or cracks will appear. Placing it on a stove is not a good idea.

>Same could be said for recovering energy from an A/C cooled home in Florida.
To some extent, yes. To avoid too much loss in A/C efficiency you would need a larger outdoor unit for dissipating more heat.

>More practically, why are high-temp coolant lines and engine blocks not entirely lined with thermopiles to generate electricity from the waste heat?
First reason is that car manufacturers are really backwards and will rather invest in defeat devices than recovery devices. Also in this case there are better alternatives to thermopiles such as closed circuit steam turbines and Stirling engines. A quick back of the envelope calculation suggests you can recover 10 percent extra useful energy. Cost will be added complexity.

>For that matter, steam turbines in power plants on the main... It's basically free energy, right?
Steam turbines are already very efficient.

[Anonymous No.7942699]

>>7941586
>being under the delusion that every time someone mentions "free energy" they are talking specially about breaking laws of thermodynamics

Or you know, energy that doesn't cost significant $$$ to create.

[Anonymous No.7942719]

>>7942676
>Check the price of Peltier elements (Seebeck in reverse, same principle). Please let us all know if you find any that are cheap and good.

Not, OP, but you can get them fucking dirt cheap online now. Of course they will be dropped shipped from fucking Asia and take god damn forever to arrive on the cargo ship. Oddly enough, they are a solid product. (TEC1-12706) However, if you want an ass load of power from them you'll need a lot of them which can be expensive.

You can also make your own if you have the time and skills.

I do agree that a Stirling engine would be better for most things so long as the pros you listed for thermocouplings are not required. Like the OP said about using them on AC units. Solid use for a Stirling engine.

>First reason is that car manufacturers are really backwards and will rather invest in defeat devices than recovery devices.

So much this. Vehicle engines are so terribly designed that most of their design is based around how to fix the initial faulty design using what amounts to as a bandage.