Russell,

I too am very interested in this. I have done a fair bit of research
last year. I'll try and dig it up....

Russell McMahon wrote:
> Peltier modules as Thermoelectric Generators.
>
> A Peltier Effect Device [PED] which has a temperature differential 
> applied across it produces a voltage at its terminals and may be used 
> as a Thermoelectric Generator [TMG] .
>
> There is quite a lot of material on the net re people using PEDs as 
> TMDs.
> Manufacturers who specialise in such things and presumably custom 
> build their cells fro optimum TEG use get efficiencies in the 2% - 5% 
> range.
>
> Sometime after Christmas and before we go on holiday on about January 
> 5th I hope to turn 10 x 68 Watt PEDs into a PED of whatever 
> performance may be achievable. Aim is to make something which can 
> charge a 12V battery for laptop and lighting use. TEG to be heated by 
> Propane.
>
> I rate the odds of producing a reasonably useful device in the time 
> available, given that much else must also be done, as rather low. 
> Worth a try though.
>
> Any input that anyone has on the subject would be most welcome. Please 
> retain the  two ::s in the subject line if replying.
>
> While these were not horrendously expensive I'd rather not turn them 
> into scrap by overheating. To get the efficiencies they do "real" 
> people run there PEDs at hot sides of several 100 degrees C (!!!). 
> Thje maximum temperature rating of these 'off the shelf' no name brand 
> cells is unknown.
>
> I considered using boiling water as the hot side but this is liable to 
> result in terribly low efficiencies.
>
> One thing that's unclear (but will be les so after 'playing') is the 
> heat flux that a given Peltier can actually be operated at. ie a 
> nominally 68 Watt PED will have a maximum rated heat flux in TMG mode 
> which is liable to be larger than occurs when used a a Peltier effect 
> device.
>
>
>
>
>         Russell McMahon
>
>   
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist