Montreal-based organizations working on carbon removal

A rendering of a Deep Sky carbon capture facility that will extract carbon from the atmosphere. (Deep Sky)

The Canadian government is keen on achieving net-zero carbon emissions by 2050, and many in Montreal are taking it seriously.

Experts believe that simply achieving net zero will not be enough. The damage that has already been done needs to be reversed.

One Montreal-based company, Deep Sky, is working on carbon removal to extract carbon from the atmosphere and store it underground.

According to the Deep Sky website, humans have released 819 billion tons of carbon dioxide into the atmosphere in the past 150 years. The website adds that once carbon dioxide has been emitted, it takes 10 to 50 years before impacting the environment, meaning that today's climate change-related environmental consequences are due to emissions from generations ago.

"Carbon removal is not the answer to all the world's climate problems. However, I'm 100 per cent sure that carbon removal has to be part of any answer because stopping what we're doing isn't good enough. We've passed that point," said CEO Damien Steel.

The carbon removal industry is still in its infancy, so there are currently some major roadblocks. Another caveat is that any carbon removal technology must use renewable energy to serve a purpose.

The cost of electricity is also a huge consideration. This is a big reason why Deep Sky wants to build a carbon storage facility in the Bécancour region of Quebec, which is also known for its abundant renewable power and underground space for sequestration. The region is already getting significant investment from the Quebec government for electric vehicle battery production.

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"When you look at the price of electricity and renewable power around the world, it varies quite widely," Steel said. "One of the advantages we have in Canada is that we have three provinces in Canada, which are basically hydro grids (B.C., Manitoba, Quebec), and those hydro grids today produce renewable power at some of the cheapest rates on the planet."

Steel is adamant that figuring out the technology is not the issue but rather the energy efficiency of air capture units to make them cost-effective.

He hopes that removing one ton of carbon from the atmosphere will eventually only require 1,000 kilowatt-hours of energy.

"The best [units] in the market today are probably around 2,000 to 3,000 kilowatt-hours per ton," Steel said.

One kilowatt-hour cost 7.6 cents in Quebec in 2023. Removing one million tons of carbon per year at 2,000 kilowatt-hours per ton leaves an electric bill of $152 million. The cost is cut in half to $76 million if removing one ton uses merely 1,000 kilowatt-hours.

Efficiency in carbon capture

Normand Mousseau is the scientific director at the Trottier Energy Institute at Polytechnique Montréal and a physics professor at Université de Montréal.

He is not as worried about the energy efficiency of air capture units but more about their efficiency in terms of how much carbon they can remove at the source. He says that currently, carbon capture machines do not use exclusively renewable energy.

"Most of the plants that do capture carbon dioxide were not designed to be highly efficient in the proportion of capture," he said. "Essentially those are places where you want some carbon dioxide to reinject underground to extract more oil and gas... These setups were never made to say, 'I want to capture all the carbon to remove it so that it does not escape.'"

These plants emit more carbon dioxide than they remove, which means that extra work--and money--must go into removing the excess carbon dioxide.

He says, in theory, carbon capture units should be able to remove at least 95 per cent at the source.

However, removing carbon is very expensive because, according to Mousseau, carbon dioxide is only present in the air at 400 parts per million, equivalent to 0.04 per cent, so it becomes more complicated.

"The idea is that today, the efficiency we have is very much theoretical," he said, emphasizing that test facilities need to get off the ground as soon as possible to work out any kinks. "Once you get to reality, it's much more complicated. And the only way to learn this is to do it."

Like Steel, Mousseau is sure that carbon removal is not the only solution and that carbon emissions must also be reduced. However, he calls on all government levels to take carbon removal seriously due to the excessive costs and time associated with it.

"We're no longer in a time where we have to say, 'Let's try this, and if it doesn't work, let's do this.' Let's invest. We'll need some of this direct air capture anyway," he said.