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Old 02-20-2012, 12:13 PM   #19 (permalink)
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Quote:
Originally Posted by mans View Post
do you believe that one of these devices rated at 136 watts is likely to be unable to deliver even 13.6 watts of electricity when at full operating temp?

i'm guessing it should put out at least 10% of its rated capacity, and with enough of them on an exhaust system at operating temp it should do the trick.... no?
I was going to write an answer, but I found Serialk11r has covered this question already

Quote:
Originally Posted by serialk11r View Post
That 136 watts is how much power you can pump into it to make it act as a horrendously bad heat pump. If you wired it in reverse, you'd probably see only a few watts come out.

The 62x62 one you linked is 180C max temperature, again, useless. It'll produce at best a few watts.

Like I said the commercially available ones that are any good at producing electricity are rated up to 300+ and cost a fortune.

They're working on developing better materials that should increase efficiency a good bit, but don't expect that to show up on the market anytime soon. There are TECs that can run at 700C or whatever but they're probably not for sale to the general public, and probably cost a crapload, not to mention still have poor efficiency. Efficiency is a concern because loading the cooling system significantly will be a problem.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

So $5 for a couple of Watts might not sound too bad on the face of it, but if these devices are even 1% electrically efficient that would mean that potentially 99% of the heat would have travelled across the device to the 'cold' side. That's alot of extra heat to get rid of and that is almost certainly going to mean indirect load on the engine itself - running cooling fans, pumps, etc.
Gut feeling is the net result would be a negative... unles I'm missing something.
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