Since wood pellets are consumed closer to their production site than fossil fuels less greenhouse gas is generated in their transportation.
The wood pellets used for residential heating are often manufactured from sawdust and shavings from other wood products manufacturing processes, although as such manufacturing has declined regionally many pellets are manufactured from whole round wood harvested for that purpose. The wood pellets are a pure refined wood product; nothing is added to the wood feed stock as they are manufactured. The heat of compression as the fine woody material is forced through a die heats the natural lignin in the wood binding the material into a durable pellet.
Virtually all of the wood pellets produced in the Maine market are made from wood which is certified as sustainably harvested by a third-party agency.