YELLOWKNIFE, Northwest Territories — Many buildings throughout the Northwest Territories already burn wood pellets for heat, but backers of biomass district heating say we need to think bigger. …Lachlan MacLean stood outside Yellowknife’s Explorer hotel. …The city’s core has the highest-density heating load in the Northwest Territories yet most of the buildings still use heating oil. Although several Yellowknife building owners have installed systems that burn biomass (such as wood pellets) instead of oil, in an effort to reduce costs and carbon emissions, space in the heart of downtown is limited. District heating – where heat produced at a central location is piped to several buildings – might provide an answer, he said. …“This has promise,” MacLean said of a biomass district heating system downtown. …In the North, biomass heating systems have a proven track record, according to MacLean.