Electricty from heat

Discussions about solar, wind and radiant energy. Electronics and projects dealing with energy savings.
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Electricty from heat

Post by happyhippy » Sun Mar 22, 2015 4:51 am

Hi again Troy - glad to see you are still pumping out the videos, so thanks for that. I am only halfway through the February ones but stillenjoying every single one of them and learning a lot.

Anyway, considering you have your fire on all day, have you looked at the heat to electricity method of alternative energy. Okay you have to depend on chips to do it, but I think its about $15 of parts tops, probably lower considering the US Ebay seems to be cheaper than the UK one!

Here is a link to how to build something: http://www.instructables.com/id/Charge- ... -a-Candle/

Like I said, if you have your fire on during the colder months, then this looks like a near enough 'free source' of energy for at least your phone. Not sure if you could get the full 12v from the Peltier cooler with the temperature you get out of your burner but as they get enough for a constant 5v output with a candle, it may be worth a go!

Doubt it will pump out a lot of energy, but maybe enough on those no solar days to keep your phone going :)

Keep safe,


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Re: Electricty from heat

Post by dawa3100 » Sun Mar 22, 2015 11:20 am

Interesting concept. I wander how many of them can's can be stacked on top of one another before the heat gets to low to generate power?

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Re: Electricty from heat

Post by happyhippy » Sun Mar 22, 2015 11:39 am

Not sure - I have ordered a couple of the Peltiers to play with from Ebay, so hopefully tell you soon :D
I wonder how hot they can get before they go pop, there surely has to be a cut off point when it gets too hot and the semiconductors just give up the ghost?

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Re: Electricty from heat

Post by hi_tech_guy_18 » Thu Mar 26, 2015 12:02 am

You can stack them in 3's but you are pushing it with 4+

Better & Bigger ones http://www.customthermoelectric.com/

These devices utilize the Seebeck effect (the opposite of the Peltier effect) to generate electrical energy. The only requirement is that each face of the device must be exposed to different temperatures; a "hot" side and a "cold" side. The greater the temperature difference, the more power generated. While all of our thermoelectric devices will generate some power, the following devices are the most efficient and capable of operating at 320°C (608 °F) on the hot side. Power generation efficiency can reach 6% with 300°C (572 °F) hot side and 25C (77 °F) or cooler cold side.
The 56x56 mm TEG 2411G-7L31-15CX1 - $52.00
Watts 21.6 - 3.0 Amps - 7.2 Volts
320°C (608 °F )on the hot side

You use a DC DC Step Up Regulator converter to make 12V

You wire them in layer series strings groups to get upto A Max of 150V (20 in a string is 144V @3Amps)

Then use 3x 60A MPPT Controllers to Convert the 144V Voltage into 12V With Extra amps (Each time it goes over 12V you gain more 12V amps)

with 3 Stings Layers
320°C on the hot side
- HOT Side layer
- Mid layer
- COLD layer
25°C cold side

the combined total 144V @ 9 Amps from the 3 strings in parallel

144V fits into 12 12x Times
3 Amps becomes 36 Amps per string to the 3x MPPTs
9 amps (combined would be too much for a single 60A MPPT = 108A)

For the aria you would need to make a 5 Second Water to Steam 320°C (608 °F ) Coiled Pipe Heat exchanger for the fire and Capture every BTU from the flame to rapidly flash boil water Were the Volume of water is less than the Contact surface yet there more surface for it to travel across

good example Coiled Pipe Heat exchanger

Cyclone Waste Heat Engine


It there Cyclone boilers / Coiled Pipe Heat exchanger you want to pay attention too

and feed this Steam 320°C (608 °F ) in to a long Square pipe so you can have Seebeck coving every part of it in 3D
You have the 4 side to attach stacks too Top Bottom left and right and slope it at 3° so water collects and ready to go back to the coil for boiling under gravity You could pass this water thow a few Car Matix fan heaters to lose some heat (But put this heat to other uses Heat the home + Dry Wood + Keep a green house warm

You can also recover the heat form the otherside of the Seebeck and use to give you a contant supply of hot water
Surplus hot water can go under the floor of the green house to store heat in thermal mass and cool the return water ready to go though the water cooling blocks on the Seebecks

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Re: Electricty from heat

Post by techman » Mon Mar 30, 2015 11:08 am

On average these devices put out about half an amp. Higher priced (higher quality) ones can produce more power.

You also need very good heat sinks for them to work well.

I hope to experiment with them one day

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Re: Electricty from heat

Post by GaiaLight » Sun Jan 03, 2016 11:51 am

Oh my, $52.00 for each piece of TE module? :o For sake of experimenting, why don't you just go for cheaper one.
Like the one made in China. You can find a quality low price by contacting manufacturer directly.
But still, wow! That's a great project. Will be listed in my-to-do list for this year perhaps. :roll:
Learn more about thermoelectric at http://thermoelectricbasic.com

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Re: Electricty from heat

Post by techman » Mon Jan 04, 2016 9:38 am

You get what you pay for. There are cheaper models on ebay but they are not manufactured as TEG devices. These are simply heating and cooling elements used to make a little bit of power.

The cheap ones will work for experimentation and to show proof of concept though but they will not generate much power

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