Electricity from Exhaust info - Seebeck cells
 

Just thought I'd throw this link up on a company that actually supplies thermo electric generators, they are planning to release one for auto exhausts in 2012, at bottom of page.
Thermoelectric Generators Wholesale (All Products)

There is another company out there two, I occassionally look them up to see how they are progressing with their products.
Still think a practical affordable unit will be a few years away, but it is moving forward, which is good.

I've seen their site before, but that looks like a new product. I'm kind of curious about that system's specs, though.

What's the weight, exhaust restriction, and (obviously) price? I'm also a bit leery because it's only 350 watts. I'm not sure that one unit alone would allow me to fully delete the alternator.

I'm not trying to sell it, just people are talking about it so thought I'd put it up.
The 200W fluid transfer one above it requires a 250C temp gradient and is $2,000, so the 350W exhaust unit will probably be circa $3,000.
you get a whole car for that price.

Oh, yeah, I wasn't asking you, specifically. I'm just saying that those are some of the questions I'm curious to know the answers to. Considering how new and innovative the technology is, that price ($3,000) wouldn't be terrible (my stock alternator costs ~ $500 as a replacement part). I'm sure an OEM could get these units for much cheaper than the listed, retail price.

I initially looked at these things as part of a renewable power supply system, so using a wood stove for heat,having the units mounted on it to get some electricity, and using water to take the heat away, hence a hot water supply.
There must be a heat transfer for them to generate electricity, so you need a hot and cold side.
Once they get efficiency up & cost down, then there are heaps of applications, the radiator would be ideal as this is where you really want to get rid of heat, but the differential wouldn't be much more than 50C, but if all the cooling tubes were covered with them you could probably still pull 200-300W from your radiator, that's 20amps.
There is also research going on incorporating them with solar cells, to get more power out per sq metre.
Still on the horizon though.

We need higher temperature ones that can go right on/after the cat (which can hit 800C+ under heavy load), and an efficiency bump wouldn't hurt, as that would improve the mass efficiency as well. Once they get that up though, the car will generate much more electricity than it actually needs from the exhaust, so we need mild hybrid drivetrains to really use waste heat recovery to the fullest.

However, I wonder how much power an ignition system takes...for say, a racecar, getting an extra few hundred watts at a weight penalty of a few pounds (running off the main coolant system with perhaps a secondary radiator) is pretty good.

And for people who want to DIY, these cells are a bit expensive at 80 dollars for a 3x3 :/

EDIT: oh there are some higher efficiency units that are 56mm x 56mm, 19W with 270C delta...nevermind even more expensive.

well how about this one

wayy cheaper

http://www.ebay.com/itm/THERMOELECTR...item2a197cbb00

and heres a real cheapo just over $5 for 136 watts

http://www.ebay.com/itm/POWER-GENERA...item35b97cd82a

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.

I just ordered some of the $5 ones.
any advice on a good way to test them for electricity production?

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heres' another, 300 degrees farenheiheit. am not sure why its being said that these are useless.
also, like mentioned above, I purchased some of of the cheaper ones to see what they are good for. what would be a good way to perform tests?