That is simply brilliant. Faux bricks which connect together to create a phased array antenna that create a mesh network between connected homes. Now if it was low enough power to run on the heat differential between the flue gases and the ambient air I would know I was in the future.
The canonical example of harvesting the heat differential is the biolite stove[1] it uses a thermoelectric generator[2] to provide up to 4 watts (peak) of power.
I'm on beer fuel atm and have only read it briefly, but isn't that pure, free energy? With a solid state device. Why do we not have some of these things around our fridge etc.
Because if it generates energy from your fridge it means you deeply failed at insulating your fridge, and you have to spend several times as much energy putting the cold back inside.
In most places you can use significantly more efficient devices to turn heat differences into electricity.
I think he is more talking about the heat that the fridge outputs to cool the inside, which is likely warmer than the ambient temperature in the room. Just a guess.