It's mentioned as the article as free from using waste wood.

so people are just delivering free wood to anyone who chooses to move out to the boonies? Seems like a bad assumption to be making

well, specific people are delivering free _waste_ wood to people specifically near them.

Kinda like those people that got free _waste_ oil from restaurants to run their vans. It's not something you can replicate literally anywhere but it does exist. Industrial waste has to be disposed of somehow and often people are happy for you to accept it for free.