“Inefficient as existing thermoelectric units are, they’re still cheaper than solar photovoltaics. I just don’t know of many who have commercialized the things yet, not for specific use in generating residential electricity. They’re chiefly known from those camp stoves as I mentioned. Outside of that, you’ve got inventors and tinkerers who appear not to be well funded selling them to order in low volume.”
They are used in remote locations where reliable generation is required.
I’ve played around with the idea of an “array” like a sleeve over a flue from a wood stove. You’d need a ventilated cavity within a chimney surrounding the flue and “array” in order to create the necessary temperature differential. The stove would need to be fired up at all times for electricity. That led to wood cookstove and an area that could be converted into a “summer kitchen” on a screened porch of sorts. Retractable walls could be as simple as insulated garage doors. If the heat could come from concentrated sunlight in warmer months, that problem goes away, but the flue would get *way* fancier, lol.