The other problem that I've heard about with respect to TEG's (thermo electric generators or cells) is durability. A camp stove/pack stove type of stove is gonna get knocked around a bit. Comes with the territory. The TEG is an excellent idea -- if they can make it practical.

Like I say, the Biolite stove has been up on the web for some time. I first read about them in this 2009 article. There's got to be something that's making them difficult to bring to market.

HJ