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Help! Thermo Electric Generator Answered

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Just wondering if any of you knowledgable folk can help me out. Of late I have experimenting with solar cells and energy production. I have been calculating some interesting results, many of which due to the use of lenses, magnification and mirrors etc. Alas this has led to more that on fried solar cell due to the temperatures im dealing with. Is there any practical way to obtain/construct a Thermo electric generator as pictured? I have spent some time with my friend Google, leaving me with little more than the notion that perhaps this technology is out of reach of the home experimentor. Think giant light cannon that can melt pennies. How can I harness this heat directly as apposed to, going the boiler/steam powered engine method?

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WilliamB3 (author)2014-09-29

I should mention that to get the mineral oil up to a specific temperature, but no hotter, you should put a thermometer in the oil, then remove oil from the heat source once it reaches the desired temperature. In this way, heat sources that are far too hot for a Peltier module can still be safely used to power the module. Rocket stoves are also far too hot for a standard Peltier module, but they'll heat a batch of mineral oil up to the Peltier's maximum working temperature just fine.

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WilliamB3 (author)2014-09-29

No problem. Make 2 square metal reservoirs to hold liquid. Sandwich your TEG or Peltier module between them. Put cool water in the cold side.

Use your sun-laser (Fresnel lens) to heat up mineral oil ONLY to the module's maximum working temperature. Pour hot mineral oil into hot-side reservoir.

Should work without frying your module.

Store excess hot oil in a thermos & refill reservoir once initial batch of oil cools off.

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Kiteman (author)2008-11-06

Focussed sunlight seems to be a promising heat-source for stirling engines.

If you're after direct thermo-electricity, try googling for Peltier and/or Seebeck effects.

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kelseymh (author)Kiteman2008-11-17

Hey, wasn't Thermopile what the movie 300 was about? ...Oh, wait, that was Thermopylae. Never mind...

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Lftndbt (author)Kiteman2008-11-16

Any theories? Logged a bug report. But not sure if it showed up. Whom should I contact as I don't want to bug ewilhem.

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Kiteman (author)Lftndbt2008-11-17

Rachel is your best bet - I've had similar problems. If you can give her times of postings vs time of appearance / urls etc, her job will be easier.

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Lftndbt (author)Kiteman2008-11-06
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likewho (author)2010-09-22

I’ve tried standard peltier modules with limited success and very short service life. They cannot hold up to the higher temperatures necessary for good power generation performance. I found a terrific supplier with both standard temperature and high temperature TEG modules designed specifically for power generation. They sell a lot of devices on eBay and you can also buy from them direct. The company is Thermal Enterprises and here is are links to a couple of their eBay items.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310148993913&ssPageName=STRK:MESELX:IT


http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=310209561834&ssPageName=STRK:MESELX:IT

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moffett8 (author)likewho2011-10-26

Their 5 times the price of other companies who sell the same thing :-(

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GerardTV (author)likewho2011-09-25

You require high Temperature modules , if you use Standard Modules off of E-bay they cannot handle the heat.High Temperature Seebeck Modules.... TEG modules can handle the heat much better than peltier modules

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steveastrouk (author)likewho2010-09-23

I use Marlow cells for professional work, and they match the temperatures in your link. Why are these "special " ?

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likewho (author)steveastrouk2010-09-23

They are better than Marlow in several respects. The basic design itself is more robust. They are not the more fragile "porch" design that Marlow uses (where the base ceramic plate has an overhang just asking to be broken). Both the bottom and top ceramic are the same size. The thermal material used is formulated for optimum Seebeck (Power Generation) and from my experience are more efficient than Marlow material. They are also built for higher temperature service just as Marlow however these come with the perimeter sealed protecting against moisture. Another huge bonus is the price which is less than half of what Marlow charges.

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steveastrouk (author)likewho2010-09-23

It doesn't say it, and it doesn't back it up with any numbers. The overhanging ceramic is a great benefit for alignment in our application, and in several hundred cells, I've never broken one. I suspect it means that the terminations are stronger, because theyhave a substantical pad under the wire to fasten to.

ALL my Marlow cells have been edgesealed. I've tried cheaper cells, but the ceramics aren't anything LIKE flat enough for efficient operation, and that is where a lot of the cost difference is.

What justification do you have for saying it is formulated for optimum power generation, and how does it compare to Marlow, who are probably the commercial gold standard ?

I am inclined to suspect you are gently spamming Instructables, since your entire history of comments is pushing These Marvellous TEGS, with no proper justification but hearsay.

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likewho (author)steveastrouk2010-09-23

If you are happy with the expensive Marlow TEGS you should stick with them I suppose. I was just offering a reliable, efficient and very affordable alternative.

BTW, these are tolerance flat similar to the ones from Marlow so this has nothing to do with the cost difference.

I do not agree with your comment regarding Marlow being the commercial gold standard. In my opinion the first commercial manufacture of peltier modules (Melcor) has always been recognized as being the gold standard in thermoelectrics.

Again, if you are happy with Marlow I'd say you should stick with them.

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steveastrouk (author)likewho2010-09-24

Again, show me the numbers, to justify the assertion that these are better than the competition, and I'll consider it, but "cheaper" isn't an advantage to me unless the reliability is there too.


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likewho (author)steveastrouk2010-09-24

If you want "numbers" go to the manufacturer. I simply posted information to inform others of what I believe to be a good option from my personal experience.

If your skeptical just pass on the information and stay with what you are happy with instead of ranting.

For those of you who care to consider what options are available here is another good source for TEGS: Custom Thermoelectrics in MD

Although I haven't tried their product myself I've talked with others who have and I'm told that they offer a quality device.

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Jayefuu (author)steveastrouk2010-09-23

I have a picture of just how non-flat cheapy TECs are. I will dig it out.

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nutsandbolts_64 (author)2011-01-24

From viewing some other comments (not in this forum) related to peltier units, they say that, unfortunately, the more the heat, the more inefficient they get.

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GerardTV (author)nutsandbolts_642011-09-25

We have been manufacturing Peltier and Seebeck modules with or venture company since 1999. If you interested in High Temperature we sell TEG modules that are rated up to 320C or about 650F. The main difference between
SeeBeck and Peltier Modules can be seen on You tube.

Part1
http://www.youtube.com/watch?/Difference between TEG and TEC modules
Part 2
http://www.youtube.com/watch/ Differences between TEG and TEC Modules

These two Videos should clear up any concerns about performance, temperature limitations, flatness, materials,construction, etc.....
if you need more answer, I've be mentored by a engineering Technologist that has been working with the technology for over 50 years (NASA days back in 1957). I've been working with it for 22 years.
If you need more answers email me at TecTeg@rogers.com

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howardhaimovitch (author)2011-01-20

Hello, I am looking for some help myself. I have an idea to use the back part of a solar panel and attach a seebeck type thermopile to capture the heat and produce electricity from the cells and from the heat. Anybody out there interested in helping me with my research?
howard@efficiencyanalysts.com;
text me at SHello, I am looking for some help myself. I have an idea to use the back part of a solar panel and attach a seebeck type thermopile to capture the heat and produce electricity from the cells and from the heat. Anybody out there interested in helping me with my research? Skype howard.haimovitch

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Big Bwana (author)2008-11-18

As pictured ?? It is possible firstly you need to find some n doped and p doped Bismuth Telluride ingots or pellets, these are a few companies that make the required products..

Global Thermoelectric, Calgary Alberta Canada
403-236-5556, FAX 403-236-5575 (12/07)
Manufactures Lead Tin-Telluride thermoelectric power generators.
tegsales@globalte.com
http://www.globalte.com

Hi-Z Technology, San Diego CA
858-695-6660, FAX 858-695-8870 (12/07)
Manufactures thermoelectric power generator modules.
info@hi-z.com
http://www.hi-z.com

Hui Mau Cooling Equipment, Bejing China
0086 13501215859, FAX 0086-10-60275767 (12/07)
Manufactures power generating and cooling modules.
info@huimao.com
http://www.huimao.com

Then you need to solder it between to ceramic plates, with very very low temperate solder or you'll melt the junctions and then you'll have a nice new pelter thermoelectric cooler / power generator ....

And if your light cannon melts pennies it will destroy a pelter type TEC I think the start to melt apart at 145 deg c .... (( I know soldering new leads to them has to be done faster then fast and you need to hold the lead with a pliers acting as a heatsink so they don't get to hot and melt ))

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thomasknow (author)Big Bwana2010-03-20

Hi Lftndbt, has it been done?

Find more infomation on the seebeck generater from pletier-info.com, it's true that a few company make the required products, and even in my company, it take fresh  man almost 2 months to practise the assembly and soldering, so why not buy directly the modules like bellow:

Picture from company: http://www.everredtronics.com/TEG.html

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Tool Using Animal (author)2008-11-17

I did some reading about thermoelectric generators after seeing this subject, the thing that stood out most was that 4% is considered high efficiency. :-(

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something to work on then. ;)

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Padlock (author)2008-11-17

I don't know about the one pictured, but a device called a peltier junction might do it. Just have to create a temperature difference between the two sides and it SHOULD generate electricity. I've never done it before, so I really don't know all to much about them.

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Lftndbt (author)Padlock2008-11-18

Hmmm, i'll look into that.

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killerjackalope (author)2008-11-17

Certain metals and alloys have a mush better seebeck coefficient, also I'm pretty sure the charge generated is proportional to the mass of heated material and the temperature too, granted at some temperature there would be a level off and possibly a drop eventually as the internal resistance of the material would rise exponentially with temperature, Ie: a less focused array on a much larger piece of material may yield better results.

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Kiteman (author)killerjackalope2008-11-17

The area of the contact-surface has an effect as well, I think.

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killerjackalope (author)Kiteman2008-11-17

Aye Less resistance over the couple and possibly other effects...

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Big Bwana (author)2008-11-17

I don't know if you can build one at home, they require specialized metals and equipment but they are fairly cheap to get from China... Either Google pelter devices or Thermoelectric coolers and a company called melcor is full of good info on using them as power generators and info like there maximum temp....

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