Biomass district energy in North America

The advantages of district heating plants, fueled by sustainably produced biomass are reviewed, and numerous successful examples in Canada and the United States are described. Canadian systems include the Trigen PEI system in Charlottetown, systems in the First Nations communities of Ouje-Bougoumou and Grassy Narrows, and systems serving public facilities in New Brunswick and Nova Scotia. In the United States, District Energy St. Paul has recently announced a 25 MW CHP plant fired with municipal tree thinnings and other wood wastes. There are two large state office complexes in Vermont that have been fired with sawmill residues and whole-tree chips for the last 15 years. There are also mini-district heating systems serving small communities, or just a few buildings, that have been pioneered in Vermont, Prince Edward Island and elsewhere. Other systems described include biomass thermal energy plants developed in Vermont ('the Vermont Model') to serve public schools, a 300 KW waste wood boiler developed by a PEI manufacturer and installed in several multi-building settings on farms and greenhouses, and the hand-fired high efficiency cordwood boiler produced by a Minnesota firm that have been used in a number of multi-building applications in native American villages in Alaska. It has been estimated that compared to building energy retrofits and efficiency improvements which might reduce fossil fuel consumption by 10 to 30 per cent, connecting buildings to a biomass-fired district energy system can reduce fossil fuel use and net CO2 emissions by as much as 80 to 90 per cent. 12 refs