Need help for Peltier modules

[johan07]

Hello everybody

First, I know very well that the subject has been debated many times over all forums of France to draw the conclusion that it was not worth it.

I'm launching this topic because I need help following some experiments.

My basic problem: I just bought a house. Unfortunately this one is not sunny during 3 months of the year.
Which implies that photovoltaic panels will only serve me 9 months of the year.
Being in search of energy autonomy, I must find a solution to recharge batteries in winter (mid November to mid-February).

As of today, I made a prototype Peltier or Seebeck generator including 4 TEC-12706 modules. These are very common modules that I bought on a well known auction site.

The results are that I managed to produce 6 volts by putting this prototype on my wood stove. But it was the maximum voltage I could produce. Let's say that I leave 3 volts with 4 modules because by producing the 6 volts a module to grill because the stove (wood precise) was too hot.
To produce 3 volts, the stove was at about 100 degrees.
So eventually I will create another prototype of 16 modules that should produce 12 volts.

The intensity that generates my prototype, and ridiculous: 50 mA for 4 modules mounted in series producing 3 volts.
I made another measurement at 5 volts and the intensity is 70 mA.

And that's where I need help.

To add up the intensity of the modules, I would have to mount them in parallel. Unfortunately, it would reduce the tension.

Knowing that the yield is 1% how can I calculate the theoretical intensity of a module?
Is it enough to divide the power given in watts by the manufacturer by 12 or 24 volts to find this theoretical intensity?
Then it is enough to relate these results with the measurements that I made on my prototype.

I think I need to buy higher performance modules to be productive.

Will buying 24 Volts modules produce more voltage?

I'm stubborn is my bullshit obliges me to continue these experiments which according to most forums are doomed to failure.
I am not an expert in electricity so do not hesitate to edit your answers as you answer to a kid! (You know the example of the watercourse to explain the intensity and the tension).

Here I am waiting for your answer.

Thank you in advance.

FYI: A system similar to what I would like to create exists. I contacted them by email but I did not get an answer: http://thermoelectrics.de/de/product/mo ... d73d5&ref=

[dirk pitt]

the problem is not a story of failure or not, it's just physics.
you always have to do a big table calculation before you get into something.
therefore: the yield of a commercial peltier in seebeck mode (electricity production) is at best 2%
therefore to produce 100W it takes about a heat flow of 5000W. by working well the heat exchanges on a boiler of 15kw, it is perhaps what one could recover: 100W
there is a portable charger for hikers who walk on a camp stove that is about 4W on a stove that produces about 3000W. we are in the same ratios.
so for energy independence, I think it's a bit fair.

[Petrus]

I made a similar assembly (4 TEC-12706 modules in series) that I use to turn a fan over my wood stove, I also did some measurements that I posted here:
consume less-car / stirling-rocket-stove-generator-t14484-30.html

[Valou.saez]

Hello everyone I am a econologist largely beginner nevertheless I have already worked quite a lot with the pelts and what I can advise is to integrate these modules as intermediaries and not as a goal.
Let me explain: if you have a heat source and you use it to heat water, place your modules between the two, liquid cooling is the top to get the best out of each module and this allows the " heat transport rather than air cooling which requires close proximity.
Thanks to that I get about 2w per module and it's the same: 12706 (2 € on eBay)
So with just 1 module I can already load a phone (5v)
But do not imagine producing electricity, think about saving it ...
I am currently on a self-supporting oil burner thanks to these small modules with even a delta of ten watt for small needs.
Despite all the harm I have read about the pelts, I find them remarkable for their simplicity, no moving parts, and if you do not exceed the 200 ° and you do not shock them their longevity turns out theoretically Unlimited ... So why not go ?!
The key is the compilation of small means combined with savings of unnecessary expenses! Finally ... it's just me huh

[johan07]

Hello,

Thanks to all three for answering me.

@Dirk Pitt, I hear what you're saying to me. However when I spoke about energy independence, I did not mean at all costs with that Peltier modules.
But if it allows me to feed my lighting it will be good. After that, once I managed to create a generator worthy of the name, nothing prevents me to put several on my stove wood. Because there is a lot of hot surface (top, side, back, and face).

@Petrus and Valou.Saez, Your montages look pretty productive compared to mine. It must be said that I did that with recovery.
Would you be so kind as to describe your editing to get results like yours?

If not for the questions of my first post, would there be someone who could guide me to choose other modules to be more productive.

FYI, being married without children, we consume 55 € electricity per quarter. If I subtract the subscription, it makes us a consumption of 2400 Wh / day. I know that this consumption and very low and that is why I think that Peltier modules can allow me to produce some of the energy we need.

Thanks again.

[Petrus]

If you have a photo of your montage I could tell you what could improve it.
Otherwise, in general, it is necessary to maximize the heat flow through the modules, so put thermal paste, provide a large sink or better, as recommended by Valou.Saez use water to cool the cold part .

[Christophe]

the performance of a commercial peltier in seebeck mode (electricity production) is at best 2%
therefore to produce 100W it takes about a heat flow of 5000W. by working well the heat exchanges on a boiler of 15kw, it is perhaps what one could recover: 100W

No more than 2%? I thought that the efficiency of a peltier module was better, around 10% ... I must confuse with the efficiency in "cold" mode?

The idea evoked here by Camel1: electricity-electronics-informatics / effect-Peltier-Seebeck-en-generator-t2630-60.html # p39950 which I have taken up here: solar-photovoltaic / solar-thermoelectric-Hub-and-effect-peltier-t14596.html so is not really interesting ...

[johan07]

Hello,

Here I found the prices of the generators of my first post. I was expecting a lot more. http://www.tegmart.com/wood-stove/

[izentrop]

Hello,

Here I found the prices of the generators of my first post. I was expecting a lot more. http://www.tegmart.com/wood-stove/

At this price, better invest in solar, at least we do not waste entropy

[Gaston]

I was expecting a lot more. http://www.tegmart.com/wood-stove/

$ 750 for an 100W generator.
By running 24h / 24 for one year, it will produce 876 kWh ... about 120 € of electricity.

It takes more than 6 years of uninterrupted operation to make it profitable not to mention the cost of fuel (and it must be heated to 270 ° C so that it produces 100W), nor the cooling water (the water must return to less than 30 ° C) ...