Unfortunately, most pellet stoves depend on electricity for the fan and controller and stop if the power goes out.

Gravity fed pellet stoves exist but have problems with consistency (and avoiding backdraft fires).

I've thought about building a pellet stove with an integrated Stirling engine generator, but it's a bigger project than I have time for. It should be more efficient than thermoelectric.

Wood has the slight disadvantage that it grows slower than it burns. Wood stoves still need active input for the "supply chain", you have to deal with some additional complexity, maintenance, and extra safety concerns. The forced draft stove in the article needs an electric fan to work.

A solar panel on the other hand is passive, with no maintenance, or safety concerns.

The setup in the article is OK if you already had the stove for heating and a lot of additional parts lying around to build the thermoelectric generator. In theory any electricity it generates is "free electricity" but the complexity is high, efficiency is low, and a bit of the little electricity it produces may be needed to just keep the whole thing going.