If you’re using electricity for that climate control, then that would be a waste of energy. I think the main appeal here is for places where wood is already burned for cooking and water heating. I imagine it could be a nice way to generate a bit of electricity during cold and dark winters when the sun isn’t shining all that much.
Edit: I have no clue why that one downvote came, but I guess I could elaborate on why it would be a waste of energy: The TEGs generate electricity from the movement of thermal energy from one side to the other. The article states their efficiency to be about 5-6%. That means that of the heat coming in from the outside, about that much is turned into electric power. The rest just heats up your indoors and the AC will have to work that much harder. The exact same goes if the outside is cold and inside is hot. It cools down the indoors and the AC will have to work that much harder. They can be practical in certain situations, when there’s lots of thermal energy but little electricity, like when wood is being burned. Burn a little more wood to get a bit of electricity. I’m sure there’s situations like what I described above where that tradeoff would be beneficial.
The bit about eliminating chimneys is that you can use a TEG to power a fan which gets the smoke out, instead of relying on convection, which needs a chimney, and many impoverished places lack the means to make holes in roofs. A properly designed chimney absorbs and stores a considerable portion of the heat flowing through it.
Also not sure about the max temperature these things can handle. They mention that the benefit of using these between a heat source and water that is being heated is that the water keeps the element from getting too hot.