Can I replace an alternator with peltiers?

[EcoCivic]

Originally Posted by redpoint5

...and then the small matter of creating a 250 C temp differential. You'd have to get that off the exhaust header since 190 F coolant isn't enough of a temperature difference to maximize the potential.

I don't think creating a 250 degree C temp difference would be that hard. Just use the exhaust header for the hot side and engine coolant for the cool side.

[teoman]

Originally Posted by EcoCivic

I don't think creating a 250 degree C temp difference would be that hard. Just use the exhaust header for the hot side and engine coolant for the cool side.

It is not the absence of heat that worries me, it is the excess of heat.

If it goes above 250 deg C then you fry your peltier devices pretty quickly. Controlling the precise temperature can be a pita. Heatsink to the cold side would be a better idea in my opinion. Or its designated water or thermal pipe circuit.

[RedDevil]

Same problem as with Stirling generators; keeping the cool side cold requires much more effort than feeding heat to the hot side.
You don't want to add a heavy radiator, pump and everything just to be able to switch out the alternator when you've properly heated up the engine. A hybrid electric system or big battery & alternator delete would be cheaper and lighter.

[oil pan 4]

You know you could test it and see if it would be worth it.
Just do an alt delete and see where that gets you.

[EcoCivic]

[QUOTE=oil pan 4;545512]You know you could test it and see if it would be worth it.
Just do an alt delete and see where that gets you.[/QUOTE/] It's easy enough to take the alternator belt off and check MPG. Good idea.

[teoman]

And you could rig up a fan and a kettle to test how much energy the tec or teg modules produce.

That would be beneficial to all of us who have been pondering this.

[ar5boosted]

Cable tie one to the front of the radiator for testing.

See how much power you get.

An automotive alternator can generate up to 200A for aircon, headlights and all such things.

I personally think that a generator built into the muffler would be better. Because any normal muffler blocks flow and so would a generator. There'd be expired patents to look up from people that have got it working.

Hugely fuel efficient motors have little if any extra heat. That is, the engines don't really get hot enough.

Since I have a Peltier right on my desk now, I worry about the quality of the insulation on the joining wires in an automotive application. But please go ahead and try.

[California98Civic]

I saw a module on digikey.com that offered 14.5 volts and 6 amps. I bought a few lower power ones for experimenting with my daughter a few years ago. Those were just toys, for toy projects. It seems possible that you could build a system around the exhaust pipes or muffler more easily because less oil/grease and it is open to the wind for cooling one side. I wondered about using my aero diffuser under my rear bumper as a platform for tiles near the muffler. There is a lot of heat back there, but not the supper heat of the exhaust header and CAT. I thought of it after reading that BMW was experimenting with electricity generation using the muffler end of the exhaust system.

[California98Civic]

You got me hunting and I found this very interesting paper: https://energy.gov/sites/prod/files/...10/crane_0.pdf

(I better go back to my real work now, heh heh!)

[teoman]

Originally Posted by California98Civic

I saw a module on digikey.com that offered 14.5 volts and 6 amps. I bought a few lower power ones for experimenting with my daughter a few years ago. Those were just toys, for toy projects. It seems possible that you could build a system around the exhaust pipes or muffler more easily because less oil/grease and it is open to the wind for cooling one side. I wondered about using my aero diffuser under my rear bumper as a platform for tiles near the muffler. There is a lot of heat back there, but not the supper heat of the exhaust header and CAT. I thought of it after reading that BMW was experimenting with electricity generation using the muffler end of the exhaust system.

That is not the power generation capacity of the unit.

They are also pretty good coolers. Verry inefficient but very compact. For evey 5 Joules of energy you put in to it, it sucks 1 joule of energy from one side to the other side. So you have 1J of thermal energy sucked from one side and 6j of thermal energy pushed out the other side.