There are quite a few institutional wood chip boilers installed around northern New England. I believe Tarm biomass has a few models and there are several manufacturers. I used to work on occasion on the larger bomasss power plants installed around the region that are slowly dying. The hassle with burning chips is chip uniformity, the smaller the boiler the harder it is to meter the fuel flow to the boiler. Most folks think of nice uniform chips that look like square charcoal briquettes. When I went to the biomass shows and saw the small demo units running in the parking lot I would take a look at the chips and wonder where they got them as they were definitely not what I saw in the plants I worked on.
Unfortunately unless someone pays a premium for uniform chips what they get are whole tree chips which include sticks and leaves plus the typical chipper used in the woods tends to shred the wood instead of chip it. Ideally to make a nice uniform chip the chips should be made from the trunks (bole) the same stuff we want for firewood. The uniform chips are great to deal with and flow almost like water, the whole tree chips are nightmare, they get tangled up and clog things. Many a small biomass system owner has learned early on that who and where they get their chips is the most important thing in keeping the systems running. All sort of stories of having to having to have someone stand there 24/7 trying to keep the chips flowing in a supposedly non attended systems. At least one firm in the region got smart and they take make premium chips and handle the fuel supply for a lot of the institutional burners. They owners pay a premium but it cuts the hassle way down.
The problems with non uniform chips is why wood pellets were invented. They are the ultimate uniform wood chip, they are dry so the storage volume is low and no sticks or leaves. Obviously they cost more but they are the way to go for small unattended home systems.
The pulp mill I worked for had a 6 story chip screening facility that could sort chips from a chipper or purchased chips so that the chips going to the pulping process were uniform. It was a Weyerhaeuser licensed system that put out a very uniform chip. Any over sized chips were sorted out and resized, things like sticks and leaves went to our bark boiler. We went through 1100 tons of green wood chips a day so we didnt want clogs in our storage and conveying systems.
The one I tended had what Hurst calls a 'Clairifier' on it. It 'cleans' the chips before they get to the feed auger. Pulls out all the trash, sticks, big chunks, rocks, chainsaw parts, you name it. We even got stuff like rakes, brooms, stopsign posts and lots of gloves. too.
No such thing as 'clean chips' bulk delivered.