TEG power, anyone fooled around with TEG modules?

thehardway

I ran across ThermoElectric Generator (TEG) modules and wondered if anyone here was experimenting with them. Seems like they might be a good way to remove excess heat in solar thermal systems, useable in solar concentrators to lower temps etc. Should work very well if cooled by a stream or using stored runoff water in a mist system or trickle. Seem a little pricey though. All of the ones I have seen were built on a micro level. I wonder if the Seebeck effect is applicable on a macro level. I realize it is only 6% efficient at best but since it has no moving parts or maintenance and only requires a temp imbalance to produce power I could see some benefits to building one. I see where they have them for cars and woodstoves. supposedly 100-500 watt output is feasible by using multiple strings of the small modules. Why not build bigger modules? Is it a source problem or a physics problem?

inetdog

Re: TEG power, anyone fooled around with TEG modules?

thehardway wrote: »

I ran across ThermoElectric Generator (TEG) modules and wondered if anyone here was experimenting with them. Seems like they might be a good way to remove excess heat in solar thermal systems, useable in solar concentrators to lower temps etc. Why not build bigger modules? Is it a source problem or a physics problem?

There are many problems. First, it will only work with a concentrating system because of the power levels involved.
Second, it is very inefficient in terms of the electrical power compared to the heat transferred. But if the heat is just waste heat anyway, that is not necessarily a show stopper.
Third it is very inefficient in terms of the amount of power produced compared to the cost of the system. That is the big problem. You would be better off using straight cooling and putting the same amount of money into more panels instead of putting it into TEGs.
The Seebeck-Peltier effect operates on a macro level, but the costs become macro too. The limit to the voltage per junction is independent of the size of the system, but the current scales just fine.

It is an economics problem whose parameters are set by the underlying physics.

Some of the members use them for things like powering an air circulating fan for a space heating wood stove.

Cariboocoot

Re: TEG power, anyone fooled around with TEG modules?

Somewhere on the forum there's an evaluation of a commercial TEG generator. Let's just say it doesn't measure up.