Thermoelectric generator?

[BioHazard]

I've always been fascinated by peltier elements used for heating and cooling. I've recently become more interested in their power generating potential. I have a creek behind my shop that runs at about 55 degrees F I could use for the cold side of the generator. I could also easily build a waste oil and/or biomass powered heater/boiler to create hot water to generate energy from.

I'm looking at thermoelectric generator panels such as this one:
http://cgi.ebay.com/THERMOELECTRIC-POWER-GENERATOR-TEG-MODULE-NEW-USA-/310230284381?pt=LH_DefaultDomain_0&hash=item483b2a785d
But the major question I have is just how much power can I generate with something like that? Is there some way to calculate power output based on temperature differential?

Ideally I would like to install a hydroelectric generator in my creek, as well as using it for cooling a thermoelectric generator, to each make a few hundred watts a peice. A couple hundred watts doesn't seem like much but if it's running 24/7 it adds up to a few hundred kilowatts/month....

[cschuerm]

I've used gas fired TEG's to supply micro-power telemetry devices along gas pipelines.  I think you'll find that they are close to useless as a power generation device for most typical applications.  Output impedance is very high, so you can't put much load at all on a TEG.  Efficiency is also terrible (5-10% if memory serves).  If you have an unlimited supply of heat and need only a few milliamps into a high impedance load, they can be just the ticket.

chris

[Apogee]

Looks like it could be interesting to play with.  For $16 one might pick up a couple and experiment and report back.

Would be a cool find if it could work.  I wonder what the output could be with 100 of them hooked together?

Steve

[Lloyd]

The Technology is changing fast.



http://www.huffingtonpost.com/2008/08/11/30-year-old-space-probe-t_n_118126.html

I can't find it now, ZF developed and tested a 1 kw exhaust as part of their diesel truck/bus hybred diesel electric program. The fleet numbered in the 100's if I recall.

I'll try to find the info.

Lloyd

[Ronmar]

I recall reading some articles about self powered pellet stoves, using thermogeneration to power the blowers/auger...

[BioHazard]

This is what really got me thinking about this stuff recently:
http://www.tegpower.com/products.html
Scroll down and they have a 50 watt module...at $500 I'm not interested, but, judging by the size of it there can't be too many peltier elements inside....

I'm hoping to make about 200 watts of hydro power from the creek, which doesn't sound like much, but that's 144 KWH/month. If I could generate another 200 watts or so with thermoelectric that would be really nice....

[PsycoBob]

Now that the heating season's here, I'm suddenly interested in a TEG to make enough juice to charge my cell phone from the kerosene heater in the living room. I'd love to put together something big enough to supply one of my 20k btu military heaters in the camper, but they're real power hogs. 13A at 28v. I had a vented salamander-looking heater that was designed to make enough power to keep itself running after a few minutes of juice to start it. Makes me wish I'd thought to write down the model # before selling it.

[rcavictim]

I've used Peltier modules in the past to cool or temperature stabilize electronics packages used in a radio telescope to improve sensitivity and baseline perforance.  When I recently saw them offered on ebay for much cheaper prices a couple of years ago out of China I got thinking about the possibilities of a TEG.  The major problem I think one has to deal with in those modules available on ebay from China is that the junctions are all held together with eutectic solder.  That stuff melts at just a couple of hundred degrees or so.  Fortunately for us they have become inexpensive enough to experiment with at home.