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Old 07-26-2017, 06:39 AM   #28 (permalink)
serialk11r
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The Alphabet Energy TEGs are supposed to be cheaper because they're silicon based, but because the hot side temperature can be higher they are still effective. The only tidbit of info on cost I found was this:
https://www.alphabetenergy.com/alpha...gy-efficiency/

"Pricing for the PowerModule Developer Kit™ starts at $1,995."

That includes the TEGs, a stainless steel heat exchanger, coolant radiator, pump, and will generate >900W at higher temperature. That means the TEGs themselves are near the 1 dollar/watt range I believe, because that heat exchanger has got to be really expensive with all the little fins.

I think a good strategy would be to use only a few of them to generate say 90W so that you have just enough electrical power for most of the critical things like ignition/fuel pump, and cooling the generators with the heater circuit. That way the alternator isn't struggling at low engine speed, and you can underdrive the alternator for minor efficiency gains. The amount of extra heat going into the coolant is modest and the weight/complexity/cost would be very reasonable.

Engine exhaust at WOT is actually hotter than 700C, so temperature could still be a problem but given they advertise its use for truck exhaust, I am guessing it is probably capable of handling those temperatures. Then again they say 350C maximum continuous operation... I dunno.

I think this will be truly viable the day when someone comes out with a cheap 700C hot side capable TEG.

Last edited by serialk11r; 07-26-2017 at 07:01 AM..
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