Hello Allen, thanks for your reply. I hope, I can find the vid on youtube.
I am not a native speaker so I don't really get, what you mean by Rain Wall. And how this could be implemented.
What I want to use are peltier-elements, that are used to in 12V cool backs as source for cooling. But they also can produce energy, if they get a temperature difference.
Those peltiers used in cool backs are made to produce some cooling but don't use up too much energy. But there are peltiers elements that have like 60 or 80 watts if you manage to get the enough temprature difference between both sides.
As rocket stove mass heaters are quite large and those are very small, this could be a decent energy source. As I haven't yet build a mass heater, I lack the knowledge neccessary to find a good implementation.
My idea would be to mount them on a metal plate with good heat transportation on the hot side and link this also in metal to the smoke extract. And have some construction to get as much of the outside cold to the cold side of the peltiers. Maybe also a metal plate, that is linked to outside wall.
But I guess, I first have to build the mass heater then work out the temperatures and figure out how much energy a single hightecn peltier-element can produce, before buying a bunch of them.