Yellowknife banks on a controversial climate solution

The Northwest Territories' biggest city is using a biomass boiler to lower its emissions — but critics argue it's not as environmentally friendly as it’s made out to be.

Over the last six months, Canada's National Observer has been looking into what's working and what's failing in cities across Canada as they rise to the challenge of fighting climate change. In a 13-part series, we will be taking you across the country, province by province, for a look at how cities are meeting the climate emergency with sustainable solutions.

August 23rd 2021
  • Yellowknife, capital of the Northwest Territories, has invested in a biomass boiler that burns wood pellets instead of oil to heat municipal buildings — so far, the boiler has cut 1,477 tons of greenhouse gas emissions, according to the city.
  • But critics argue biomass fuel isn’t as environmentally friendly as it’s made out to be — and that the city’s numbers don’t account for the whole process of collecting that fuel, from harvest to production to transportation.
  • Most of Yellowknife’s wood pellets come from sawmill waste that would otherwise be incinerated. Companies claim this waste wood is carbon-neutral. Critics, on the other hand, call this an “accounting convention” that assumes a new tree is planted for every tree that’s cut down.

On the evening of Feb. 6, 2018, Mike Auge, then manager of sustainability and solid waste for the City of Yellowknife, walked onto the conference room stage at the Westin Hotel in Ottawa.

He was there to collect an award from the Federation of Canadian Municipalities (FCM), honouring the city’s latest environmental innovation: a biomass boiler that would burn sustainably sourced wood pellets instead of oil to heat five separate municipal buildings.

Northwest Territories aims to reduce its greenhouse gas emissions by 30% below 2005 levels by 2030.

Efficient heating systems are something of a holy grail in the Northwest Territories, where winter temperatures can drop to -30 C. Space heating accounts for over a third of all emissions in the territories, split down the middle between public and privately owned buildings. The Northwest Territories aims to reduce its greenhouse gas emissions by 30 per cent below 2005 levels by 2030. To get there will require focusing on cleaner methods of electrical generation, space heating, transportation and more efficient industrial processes.

In the Northwest Territories, where temperatures can drop to -30 C during winter, government is always looking for sustainable ways to heat buildings. Photo by Emily Hon / Unsplash

Not surprisingly, sustainable options are a perennial topic. In 2010, the territorial government officially adopted biomass as its favoured energy-generation alternative.

Biomass boilers burn organic matter — usually sawmill waste processed into pellets — to produce energy. If done correctly, it has the potential to be carbon-neutral since wood and other organics can be replaced in a shorter amount of time than fossil fuels.

“Biomass has proven to be a really cost-effective and environmentally sustainable solution in the Northwest Territories for several decades now,” said Yellowknife Coun. Shauna Morgan. “It's a pretty mainstream thing now up here.”

According to the city, the biomass boiler reduced emissions by 1,477 tons during 2019 and 2020, and has saved the city between $140,000 and $160,000 a year in oil bills.

Yellowknife's biomass boiler burns wood pellets instead of oil to heat several municipal buildings. Photo by Hannah Eden

A simplified biofuel diagram might look like this: two arrows form a circle between a forest of green trees and the sky above. The trees pull CO2 out of the atmosphere and store it as they grow. If a tree is cut down and burned, its CO2 is released back into the atmosphere. In the perfect world of this diagram, there are no deficits on either side: for every tree harvested, another tree is planted in its place. The cycle is “neutral” and continues forever.

Biomass is almost uniformly sold as being better than fossil fuels because of this idea that it's carbon-neutral.

Mary S. Booth, an ecologist and founder of the Partnership for Policy Integrity

However, environmental experts argue the biomass industry very rarely works in such perfect harmony.

“Biomass is almost uniformly sold as being better than fossil fuels because of this idea that it's carbon-neutral,” says Mary S. Booth, an ecologist and founder of the Partnership for Policy Integrity in Massachusetts. “So people make decisions about whether to burn wood or not based on false information.”

For an accurate calculation of emissions, Booth argues, every stage in the production cycle must be included, from harvest to production to transportation.

Several of these stages were specifically excluded from Yellowknife’s emissions calculation, and Canada’s National Observer was therefore unable to confirm the accuracy of its published reductions.

FPInnovations, the organization that provided the wood pellet emission rates used in Yellowknife, did not include any supply chain emissions from producing and transporting the wood pellets from Alberta to Yellowknife, or the emissions from producing or transporting the diesel.

The City of Yellowknife says its biomass boiler has helped reduce greenhouse gas emissions and save between $140,000 and $160,000 a year. Photo by Hannah Eden

Biomass is being portrayed as instantaneously carbon-neutral, but wood doesn’t grow back overnight.

Mary S. Booth, ecologist and founder of the Partnership for Policy Integrity

Most of Yellowknife’s wood pellets come from La Crete, Alta., where pellets are made from sawmill waste that would otherwise be incinerated. Since pellets are not the primary reason for the timber harvest, FPInnovations considers the waste wood carbon-neutral.

“Biomass is being portrayed as instantaneously carbon-neutral, but wood doesn’t grow back overnight,” says Booth.

Alberta does require timber companies above a certain size to replant trees, but the decades-long delay between the cutting and replenishing of trees creates a steadily increasing carbon load in the atmosphere.

When asked about these calculations, a spokesperson for FPInnovations responded: “Determining carbon intensity or payback is an onerous and comprehensive task that must take into account forest ecosystem and carbon dynamics at the landscape level, forest harvesting systems, biomass supply sources, supply chain impacts such as biomass transportation and biofuel manufacturing, end-use, as well as other factors.”

Extremely low emission rates published by organizations like FPInnovations are only ever projections, says Booth.

“The fact is, when you burn wood, it emits more CO2 than fossil fuel per unit energy,” she says. When organizations say “carbon-neutral,” they’re assuming that there will be a one-to-one regrowth of trees in deforested areas, but “this is an accounting convention,” she says. “It does not reflect physical reality.”

Case in point: as the wood pellet industry continues to grow and the demand for pellets outstrips the amount of wood waste available, most Canadian manufacturers have begun sourcing up to 25 per cent of their pellet fibre directly from the forest.

Companies in British Columbia have even started harvesting trees from unique old-growth forests.

In the Northwest Territories, several pellet mills (including one in development in Hay River, near Yellowknife) use wood from a mix of dead and living trees to produce its products. As of 2016, the territorial government did not require that harvesters pay to replant trees, hoping instead for natural forest regeneration.

Despite these trends, the federal government has thrown its support behind the industry with zeal. The FCM — a federally funded organization — has funded 11 biomass projects across Canada since 2000. It didn’t provide any money for Yellowknife’s boiler, but the FCM gave the city a sustainability award for the project despite the fact that, at the time of Auge’s acceptance speech to the group in 2018, the boiler hadn’t even been installed yet. It was somewhere over the Atlantic, en route from a European manufacturer.

Aware of the environmental concerns around biomass fuel, Yellowknife is proceeding with caution but has plans to build a second boiler in the future. Photo by Hannah Eden

The presumption of reduced emissions — and eagerness to celebrate it — is endemic to the industry. You’ll find that simplified biomass diagram, with its two perfect arrows, printed on the first page of most industry pamphlets. Rarely do they elaborate on the emissions expended in the supply chain, or the 20 to 100 years it takes for the forests to regrow.

With all of this in mind, Yellowknife is proceeding with caution. “We are very aware from our efforts to do Community GHG Inventories, that even taking a snapshot of GHG emissions in our own community is extremely complicated, necessarily incomplete, and far from an exact science,” says Morgan, the Yellowknife councillor.

“It is not the perfect magic bullet solution or the only renewable energy solution we will ever need,” she asserts.

The city plans to put in a second biomass boiler for the Yellowknife Water Treatment Plant, which has the highest fuel consumption of any municipal building in the city. Its long-term goal is to switch to locally harvested wood chips, prioritizing waste wood (like pallets that end up in the city’s dump) and burnt wood from forest fires. Will biomass boilers truly help the Northwest Territories lower emissions? The jury is out. It all depends on sourcing the right feedstock and ensuring that forests, which are valuable carbon sinks, aren't sacrificed to produce power.

I wonder what the PM2.5 measurements and other potentially toxic chemical readings are from biomass burning? Seems it would be worth working those factors into any decisions about whether it is any sort of viable solution.

The article does not contain the word "methane", which most organics decompose into, if you don't burn them. It's a much more-powerful greenhouse gas.

The issue with replanting arises when the tree is cut down, not when the decision is made to burn or not-burn the leftover waste from the sawmill. If you're cutting down trees for lumber or paper without replanting, that's where the problem occurs.

As long as the decision to cut down for other reasons is already made, failing to use up all of the dead tree to eliminate as much fossil burning as possible, help shut down the whole fossil industry, find sustainable (at least, potentially sustainable) replacements for fossil, is just wrong.

In my view, the climate threat from burning wood is that wood is being given a blanket "carbon neutral" status regardless of whether it comes from mill waste (lower net-CO2) or from trees cut specifically to burn (potentially very high net CO2). This failure to distinguish is creating huge incentives to cut trees to burn...even when that results in huge amounts of CO2 accumulating in the atmosphere. In addition, National Resources Canada states in their annual State of the Forest report that climate change is happening 10 to 100 times faster than the forests can adapt. And they point out that seedlings are particularly vulnerable. Local seedlings will not be fit for climate they will need to grow up in. So it isn't just about replanting in the age of rapid climate changes.

Thanks for an interesting article on an increasingly critical topic of burning forests for energy. An additional problem with burning trees for energy is that Canada's managed forests are no longer growing back as fast as they are being cut down. In fact Canada's forests have been net emitters of CO2 in recent years. That means none emissions from burning the wood is being re-absorbed by the forests in recent years and is instead accumulating in the atmosphere...just like fossil fuel CO2. One of the two arrows in that simple closed loop graphic the author talks about in this article has gone missing. For more on this emerging climate threat:

Driving to Prince George along hwy 97, there are a number of mills that buy logs and convert them into pellets. Originally, pellets may have come from mill waste but that is no longer the only source. There's a risk that old growth interior temperate rainforest will be used to make wood pellets as BC NDP resists producing a forest policy.

Whatever happened to the plan to use the closed Giant mine for district heating? Surely more climate friendly?