Electricity Generation with Wood Heat

[DevilsBrew]

[pa_friendly_guy]

I remember my neighbor telling me about a guy who studied air movement. He used a round tube and wanted to move air between floors for heating and cooling. He tried pulling it and he tried pushing it through the pipe to figure out which way worked best and which was more efficient. There was a difference, but for the life of me I can't tell you which way worked better. I think I must be getting that old timers thing.


PS Sorry Matt if we kind of hi jacked this thread. I liked the original topic of generating electric from heat. Sorry if we wondered a bit from the topic at hand.

[DevilsBrew]

Us drift? No! It is my middle name.

[4seasons]

[mannytheseacow]

Ha! TEGs are $3.95 with free shipping. Dang! 5 for $20.

[mannytheseacow]

So starting to dig into the TEG technology a little bit here... What is the optimum temp for those things to run at? Would the heat dissipation blocks be necessary if the TEG was encapsulated and held at the perfect temperature?

Matt, is there any way you IR thermometer can read the temp of the surface of the TEG when it's running? If not, approximate temp? Are we talking 100* or 350* ?

[matt walker]

My playing around with them leads me to believe that it's right about 250°-300°F that they work best. Keep in mind, we are saying TEG but really these are TECs, and as such are cheap and not optimized for this use. But cheap! I'm saying that because I think the limited useable range is a function of them being coolers rather than generators. Maybe. Anyway, I set it on a heat sink on a surface that's around 450°, that seems to do, until I really crank up the stove. Then I have to move it or lose it. Yep, if you can engineer constant heat and keep the cool side bleeding the heat fast enough, you will have constant power. I have been able to stabilize mine so I have light the whole time the stove is burning.

[mannytheseacow]

Hmmm. So if I'm understanding this right, it needs hot on one side but cool on the other? I guess there goes my idea. If it just had to be hot I was thinking it could be buried in the mass at an appropriate temp and it would work all the time. Wah, wah, wah.....

[matt walker]

Yeah, it's the delta T that makes it go, not just heat. That's the real challenge, although with your applications I can see putting a little pot of water on the "cool" side and running your circ pump through it. Double feature!

[matt walker]

Geez, terrible syntax up there. Sorry.