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Put that waste-heat to use!

LewDude

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Saw an interesting article yesterday and thought of all the heat this forum generates when we aren't on-line talking about lasers (ie. when we are actually creating awesome light!)...

Thin film converts heat from electronics into energy | Berkeley News

Will this find its way into/onto our hosts some day?

Great time to be alive...and lasing ;)
 



paul1598419

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I don't see this as useful for laser pointers. It isn't even new technology as we have been able to produce current from PN junctions when heat is applied. If they can get a better efficiency than 19% it could be valuable in areas like large server networks that generate a lot of heat.
 

diachi

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I don't see this as useful for laser pointers. It isn't even new technology as we have been able to produce current from PN junctions when heat is applied. If they can get a better efficiency than 19% it could be valuable in areas like large server networks that generate a lot of heat.

Yup, it's really not worth it for what's going to amount to no more than a few watts, at most.

Apply it to something like a datacenter that's dumping out megawatts of heat and it becomes a lot more worth while.
 

LewDude

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I realize it's not much at all...thought it was neat, and they are talking about generating power from smaller, and cooler sources than what was previously possible. Not new technology, but advancing what's already pretty neat.

You guys are right about getting anything useful from our lasers. I was mentioning them in our pointers a bit tongue in cheek...but then again, never say never!! :)
 

Cyparagon

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The idea is fundamentally flawed, and here's why.

Electronics need to be cooled to prevent over-heating. For low-power devices, stagnant ambient air is sufficient, while high power devices might require chilled water cooling. Thermo-electric generators operate on a heat differential, and inherently pose a thermal resistance across them. All-else-equal, to put them on electronics means your cooling air/water needs to be colder (which requires energy, defeating the purpose of harvesting energy), or your electronics need to be hotter (which is bad for operations and reliability).
 

Benm

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Indeed, these things would add thermal resistance between diode and heatsinking, which is usually the last thing you want.

The only place i can see it having an application is in things that have huge overkill heatsinking, but in such situation the reason is often just that not much heat is generated to begin with, so there is little power to recover either.

It could be used in buildings where it both improves thermal isolation and recovers energy from the heat gradient. I don't see any application in consumer electronics of any kind for now.
 

paul1598419

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From the first law of thermodynamics, a generalization of the conservation of energy, I think if work is done by these devices and they are efficient enough, their work will provide the needed cooling for these devices that need cooling. At least, that is the direction I assumed they are going with this technology.
 
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paul1598419

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I suspect they will eventually work like a TEC, but won't produce more heat in the process of cooling. I'm sure this technology is no where near ready for that.
 

Cyparagon

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I suspect they will eventually work like a TEC, but won't produce more heat in the process of cooling.
They themselves don't produce more heat, but if you put a thermo-electric generator between a CPU and a heat sink and try to harvest power from that heat transfer, I promise you (or rather, physics promises you) the CPU will be way hotter as a result.

I use my lasers' waste heat as handwarmers ;)
Put them in your holster instead, and it becomes waist heat :whistle:
 
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paul1598419

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I don't see them working between a device and its heat sink. Rather as part of the heat sink to carry heat away from it. But, they are not anywhere near being able to do that yet. This is my suspicion of where the people working on this are trying to go.
 

RedCowboy

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Paul, don't you see how the heat harvesting wrap would also produce a restriction in the metal to air heat dissipation rate ? The wrap would turn 15% of the heat into electricity, but it would not pass the other 85% as if it wasn't there, it would reduce the normal metal surface area to air heat transfer causing your device to run hotter, it would be counter productive because the other 85% of the heat energy would be restricted from it's normal transfer into the air.

p.s. I'm not saying the other 85% would be completely blocked, but restricted causing heat buildup in the device at a faster than normal rate.
 
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paul1598419

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That is why I said in post #2, that once they get the efficiency up way above 19% that this might be a possible way to extract electricity from large server network facilities.
 
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