My father has a pellet boiler and burns 12 ton a year. When we did the math on making our own pellets, it just did not work. By the time we got the
chipper, hammer mill and edge runner, we would be deep in hock, and production would be incredibly slow.
The problem with burning wood chips is uniformity to size and drying the wood. Industrial boilers can dry the wood before it is fed into the boiler, but it would be cost prohibitive on a home unit.
The school my kids go to has a wood chip boiler to heat their complex, including the sidewalks and parking lots outside. Even then they have saved 1/2 the cost over the old school and their oil boiler. BUT with smart boards and stuff, their electricity costs doubled.