Pellet stoves are “carbon neutral” (for anyone who cares) & environmentally sound. They don't smoke like a cord wood stove & they consume waste wood.
You can also get pellet stoves that burn corn, or switch-grass pellets, etc. The corn burners are particularly good, as there's a lot of heat content and little ash in corn.
my parents’ wood furnace consumes waste wood without the need to peeltize it...
dad gets his wood from in the dumpster at work, from cleaning out line fences in farm fields, from my brother’s various activities...he even burned up the remains of our old home that was lost in a fire in the furnace
and no, the fire was not caused by the wood furnace - it was an electrical fire
I looked into getting a pellet stove for my wood-shop when I lived up North (1995). At that time pellets made from peanut shells were available.
It seems to me you could pelletize everyday trash. I bet there is a LOT of energy in the wax coated paper cups and containers that most fast food places use.