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Anyone actually ordered a TEG system online?

oldmancharlie

oldmancharlie

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Hello,

Does anyone have 1st or quality 2nd hand experience ordering a TEG unit online and putting it to the test? Solar is virtually useless during our winter (same latitude as Anchorage, AK), our electricity consumption is VERY low, our woodstove is always hot and I can pipe in air as cold as -50 C in the depths of winter; I'm thinking that my set-up is a good candidate for something like this unit:


Or this sold out 45W version from a different company:


Thing is, all the websites look dodgy, two are awkward clones of each other, and I tried searching the forums but can't find anyone's solid, first hand experience with ordering and using a pre-fab generator.

Anyone know anything useful?!

My plan is to use it to charge a Bluetti AC200P, which might be a whole other discussion, hahaha...

Thanks everyone!
 
oldmancharlie said:
Hello,

Does anyone have 1st or quality 2nd hand experience ordering a TEG unit online and putting it to the test? Solar is virtually useless during our winter (same latitude as Anchorage, AK)
Click to expand...
Damn Southerners! :ROFLMAO:

I don't have any first hand experience to offer on those TEG generators either but I have been looking at same problem.
1. Output power rating is at maximum hot side temperature: in practice you can't push the modules to max limit, 50% to 75% of maximum output might be possible on wood stove.
2. cooling fan eats substantial part of the maximum output

Kryotherm has thermoelectric generators up to 1kW in case you need to heat aircraft hanger:

Thermoelectric generators operating on gas fuel

kryothermtec.com kryothermtec.com
 
They work, the higher the temp differenc3 the better. Pipe outside air across it and attach it to your stove heat shield, but if you open a door the draft quits and it can overheat and break. Perhaps with a minimum air flow switch and a fan.
 
Looks like tec makes a 60watt version. Thermoelectric modules can be had on the bay, and such places, for <$10. Wonder how hard it would be to buy a bunch of the modules and diy a thermoelectric generator?
 
Kornbread said:
Looks like tec makes a 60watt version. Thermoelectric modules can be had on aaaathe bay, and such places, for <$10. Wonder how hard it would be to buy a bunch of the modules and diy a thermoelectric generator?
Click to expand...
Cheap modules are for cooling use and have limited max temperature. Proper TEG modules can withstand much higher temperatures. Something like 120 cel vs. 400cel.
You can use the cooling modules also for generating power mut efficiency really sucks and its hard to generate enough electricity just to power the cooling fan.
 
Kornbread said:
Looks like tec makes a 60watt version. Thermoelectric modules can be had on the bay, and such places, for <$10. Wonder how hard it would be to buy a bunch of the modules and diy a thermoelectric generator?
Click to expand...
Do you have a link? 60W air cooled?
 
From looking at a whole bunch of websites, it seems like the supply is more geared towards DIY builds. And for that the individuals modules are certainly not all created equal. Different materials of different conductivity, and the cooling vs heating modules are designed differently.

I think this is a super cool article about their use:

solar.lowtechmagazine.com

Thermoelectric Stoves: Ditch the Solar Panels?

Wood stoves equipped with thermoelectric generators can produce electricity that is more sustainable, more reliable, and less costly than power from solar PV panels.
solar.lowtechmagazine.com solar.lowtechmagazine.com

The article certainly shows a bit more of their potential, especially if you went to town on how many modules you use. It also shows what the options of complete units show; air cooled produces the least power, when you start adding liquid cooled and then liquid heated and cooled you can start to make more power. This company in China makes a wider range of complete units using liquid, oil, hot gas even, a few available on alibaba, but I don't know any of the prices:

江西纳米克热电电子股份有限公司--Thermoelectric Generators

江西纳米克热电电子股份有限公司
thermonamic.com.cn

And again, hesitant to be the first person to roll the dice with ordering a unit but might just have to give it a shot.

Finally, a cold-climate consideration; with a liquid cooled unit you could use glycol, pump it outside and let it fall through a car radiator before bringing it back into the system. If you're in the subarctic like me that has to help with keeping that temperature differential high.
 
Ive been pondering this very question for a while.

I think the best option is a CPU water cooler setup with a CPU water block attached to the "cold" side of the TEG and then a loop that runs to the outside with another PC (or larger) rad. Granted youll have to run glycol (antifreeze) in the cooling loop so it doesnt freeze at -50 but very doable.
Plus 2 small holes in the side of the house for hoses is a lot easier to manage than trying to pipe cold air inside for spot cooling

In theory with a custom water block you could stack several TEG together to form a larger surface area.

The thing i havnt worked out is how you manage high surface temps of cast iron stoves in terms of max temp for the TEG. like surface temps of the iron can easily hit 600-800+F so now you have to rig something to suspend the hot plate several inches off the cast iron in order to mange hot surface temp. This becomes an interesting material challenge as you need something that is non-conductive and also has a high temp tolerance and structural. Those materials are very far and few in between. limited to things like ceramics etc. some sort of stack of aluminum standoffs with silcone feet buffers may also work...

Again to design on paper is a real materials engineering challange. its likely best to just start building stuff and see what works kinda of solution. knowing that along the way your going to burn some stuff up so have spares
 
Last edited:
Kornbread said:
Looks like tec makes a 60watt version. Thermoelectric modules can be had on the bay, and such places, for <$10. Wonder how hard it would be to buy a bunch of the modules and diy a thermoelectric generator?
Click to expand...
That is what I am doing, I already have 10 Modules, 4 different styles of passive heat sinks, one of them can mount 6 TEG's, the smallest only 2. I have some high temperature thermal paste/glue and I already have the equipment to test the unregulated output and I am sorting through (made my own post) what the best charge controller or charge/power station to use. As I go through the process, I can share my finding via long winded soap box posts, like this one. My biggest challenge I suspect is generating enough heat and dissipating enough heat through the heat sinks to keep the delta temperature at it's most efficient value. For the moment, I intend to use a cast iron skillet that I sinned against and ruined and a simple stove top and see what happens. So far the cost is minimum so I can abort if I can't generate enough power, or can't generate enough power over the possibly needed cooling fans, if the fans are tied to the TEG output, the output should be enough to kick in the fans and help shunt the heat away.....let's I guess.
 
Kornbread said:
Me, being simple and such, was thinking silicone hockey pucks.
Click to expand...
schmism said:
Ive been pondering this very question for a while.

I think the best option is a CPU water cooler setup with a CPU water block attached to the "cold" side of the TEG and then a loop that runs to the outside with another PC (or larger) rad. Granted youll have to run glycol (antifreeze) in the cooling loop so it doesnt freeze at -50 but very doable.
Plus 2 small holes in the side of the house for hoses is a lot easier to manage than trying to pipe cold air inside for spot cooling

In theory with a custom water block you could stack several TEG together to form a larger surface area.

The thing i havnt worked out is how you manage high surface temps of cast iron stoves in terms of max temp for the TEG. like surface temps of the iron can easily hit 600-800+F so now you have to rig something to suspend the hot plate several inches off the cast iron in order to mange hot surface temp. This becomes an interesting material challenge as you need something that is non-conductive and also has a high temp tolerance and structural. Those materials are very far and few in between. limited to things like ceramics etc. some sort of stack of aluminum standoffs with silcone feet buffers may also work...

Again to design on paper is a real materials engineering challange. its likely best to just start building stuff and see what works kinda of solution. knowing that along the way your going to burn some stuff up so have spares
Click to expand...
I am hoping to give you guys some working numbers for a simple set up using passive cooling or fan cooling using the power from the TEG to send air across the fins.
 
Hello,
I have been asking Thermonamic for prices. This is the results:
Screenshot 2022-09-13 032902.pngScreenshot 2022-09-17 012903.pngScreenshot 2022-09-21 100551.png
If 5 or 10 people got together then the ready-built 100w generator is a very good option indeed! It would probably be cheapest in the end and hassle free. Otherwise getting 3 people together to get 10 40x40mm modules each is another good option, especially as it includes shipping. Anybody interested?
More discussion can be found here: https://diysolarforum.com/threads/d...-design-input-wanted.46999/page-2#post-600180
 
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