Wood pellets a low-carbon fuel
No discussion about pellet heating is complete without talking relative carbon footprints – in fact it’s often the main reason to consider switching from more carbon intensive fuels. You may have heard that wood pellets are “carbon neutral,” but that is not entirely correct. All fuels currently require the use of some fossil fuels in at least the processing and transport phases. More accurately, wood pellets are a low-carbon fuel, especially when compared to common alternatives.
Most Canadian wood pellets are made from sawmill residuals, meaning they are leftovers of trees harvested for lumber, itself a low-carbon construction material. As forestry is a regulated sustainable industry in Canada, wood pellets are part of a renewable carbon cycle, where growing trees capture the carbon released by wood pellet combustion. That makes for a pretty small footprint.
How much smaller?
The graph below shows the relative carbon footprint of heating your home with wood pellets versus alternatives. The conversion efficiency of each fuel using modern appliances is factored in. Distance from factory to your home can be a factor in calculating the carbon footprint of wood pellets, but there are wood pellet production facilities in almost every part of Canada, and the impact of transport is typically minimal.
What about hydro?
Electricity is the wild card in most regions, as its carbon footprint depends on how it’s generated on your grid. If it’s principally hydro-power, as is the case in provinces like Quebec, B.C. and Manitoba, the footprint will be very low. If it’s coal-fired or gas-fired as it can be in other parts of Canada… Well have a look at the chart above for an idea of the relatively large footprint.
Throw another log?
Similarly firewood can potentially rival wood pellets in carbon footprint, but only if the wood is well-seasoned and a modern, high-efficiency wood stove is used. In the best-case scenario of modern pellet and firewood stoves, the pellet stove will still be more efficient and will produce two to five times fewer particulates.
In cases where poor wood or poor appliances are used, the health effects of particulate emissions should be factored in, especially in suburban or urban neighborhoods. Wood quality controls are inconsistent and older models or open fireplaces lack the conversion efficiency to be a reasonable low-footprint alternative.