Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post - How to use TEGs to create power with your exhaust heat

California98Civic · 07-21-2017, 02:52 PM

Thanks for continuing the thread. That's a lot of TEGs at $20-$25 each!

I think this description so far suggests significant complexity in using TEGs to replace an alternator entirely. A much simpler set up would contribute to reducing alternator need. It could be smaller and cheaper.

To tvago's good points, I assume we'd use cooling fins if we put a TEG unit into the under car airstream. Daox is talking about a lot of TEGs, and I think they would not easily fit around the manifold. Better to be lined-up along the straight middle sections of exhaust piping. Some sort of forced airflow seems possible under the car, along the piping, quite easily. Personally, I would sacrifice temp differential for system simplicity. Coolant circulation makes for complexity.

Any system would need some kind of controller, yes? And there would be a need for a way to prevent the TEGs from drawing power when the car is cool, maybe? There might be situations in which ambient air is warmer than exhaust piping, no?

07-21-2017, 02:52 PM	#8 (permalink)
California98Civic Cyborg ECU Join Date: Mar 2011 Location: Coastal Southern California Posts: 6,299 Black and Green - '98 Honda Civic DX Coupe Team Honda 90 day: 66.42 mpg (US) Black and Red - '00 Nashbar Custom built eBike 90 day: 3671.43 mpg (US) Thanks: 2,373 Thanked 2,174 Times in 1,470 Posts	Thanks for continuing the thread. That's a lot of TEGs at $20-$25 each! I think this description so far suggests significant complexity in using TEGs to replace an alternator entirely. A much simpler set up would contribute to reducing alternator need. It could be smaller and cheaper. To tvago's good points, I assume we'd use cooling fins if we put a TEG unit into the under car airstream. Daox is talking about a lot of TEGs, and I think they would not easily fit around the manifold. Better to be lined-up along the straight middle sections of exhaust piping. Some sort of forced airflow seems possible under the car, along the piping, quite easily. Personally, I would sacrifice temp differential for system simplicity. Coolant circulation makes for complexity. Any system would need some kind of controller, yes? And there would be a need for a way to prevent the TEGs from drawing power when the car is cool, maybe? There might be situations in which ambient air is warmer than exhaust piping, no? __________________ See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread.