If you’ve been following climate news, you’ve probably seen a lot of references lately to something called carbon capture and storage (CCS).
In its Climate Change 2023 synthesis report, the Intergovernmental Panel on Climate Change (IPCC) mentions the “use of CCS in remaining fossil fuel systems” as one of the major changes we need to make to achieve net zero in our energy systems.
But what exactly is CCS? Carbon capture and storage consists of three stages: capture, transport, and the storage or use of that captured carbon. The capture stage can be carried out through three main methods: post-combustion, pre-combustion, or oxy-fuel combustion (burning a fuel with almost pure oxygen to produce carbon dioxide steam, and capturing the released carbon).
Once captured, the carbon can be stored underground – locking it out of the atmosphere – or sold in carbon markets. Controversially, it can also be bought by oil companies to pump more oil out of the ground in a process called enhanced oil recovery (EOR).
A green investment…
While it was first conceived as a way to reduce carbon emissions as early as the 1970s, investments in CCS have seen a sharp uptick lately. The U.S., for instance, will invest USD 2.5 billion in carbon capture technologies over the next five years.
But does carbon capture and storage simply give us a get-out-of-jail card to keep emitting? In July, the U.K. announced two new CCS projects as part of a GBP 20 billion funding package covering the next 20 years. The same announcement also featured the licensing of more than 100 new oil and gas projects in the North Sea.
For advocates of CCS, that funding is invaluable. “The IPCC says we need it – and when they say it, I know how much we need it,” says Beth Valiaho, vice president of policy, regulatory and stakeholder relations at the Canada-based International CCS Knowledge Centre, “It may be a smaller contribution than renewables, but that doesn’t mean we need it any less.”
The Boundary Dam coal power plant in Saskatchewan has used a post-combustion capture method since 2014. Valiaho describes it as “an entire huge chemical plant right next to the coal plant stack.” Once sulfur dioxide and other chemicals are separated out from the flue gas, a soap-like solution trickles down through a tower to clean and strip out the carbon dioxide, which is then compressed into a liquid-like state.
So far, the facility has captured over 5 million tons of carbon. But rather than being stored underground, about 90 percent of it has been bought by the oil industry for EOR.
…or an expensive techno-fix?
According to the Global CCS Institute, there were CCS 164 projects in development across the globe as of 2022, with 30 in operation. Once all of them are operational, they will have the capacity to capture more than 200 million tons of carbon a year. But those in operation today can only capture 42.6 million tons a year – less than 2 percent of the almost 37 billion tons emitted into the atmosphere every year, according to the International Energy Agency.
One major factor constraining the growth of CCS is its exorbitant installation costs – often reaching USD 500 million or more, says Chris Davies, director of CCS Europe, an organization that advocates the use of CCS primarily in industries.
While they have the expertise, he adds, “most companies are not going to build the transportation network and the storage facilities. It has to be facilitated by the public sector, so lots of bits have to join up.”
But once the infrastructure is in place, he adds, all kinds of entities doing CCS can then link into it, thus reducing costs.
High costs also explain why most of the captured carbon – 70 percent of it, according to various analyses – is used to extract more fossil fuels, rather than buried deep underground. It’s also why environmentalists tend to dismiss CCS as a genuine climate solution, especially as oil and gas exploration and production have both rapidly increased over the past two years.
Does carbon capture live up to the billing?
Often, if the price of carbon falls, or if oil prices fall, then it may no longer be cost-effective to continue with CCS. That was the case with the Petra Nova project in Texas, which was shut down in 2020 when oil prices fell significantly, meaning it could no longer cover the cost of capturing the carbon through additional oil sales.
Another problem with relying too much on CCS is that it only captures emissions at the source. “In the context of oil and gas production, CCS is used upstream, where about 20 percent of the emissions are created,” says Laura Cameron, a researcher with the International Institute for Sustainable Development (IISD). “The rest are created when that oil or gas is combusted. So for the bulk of emissions there, CCS isn’t doing anything.”
What’s more, projects don’t always achieve the target capture rate they set. This can be for a number of reasons, from shutdowns to equipment failures.
“The proponents claim that CCS will sequester 90 percent or more of the carbon from coal-fired power plant electric generation,” says Dennis Wamsted, an energy analyst at the International Energy Economics and Finance Agency (IEEFA). “We have not found that in the data, which is much more in the 65 to 70 percent range,” he says.
“Things just don’t work 100 percent of the time,” Wamsted emphasizes. “Developers need to be honest about that, but they’re not.”
Renewable energy may be a better bet
Cameron agrees that, so far, there are too few projects that have successfully captured the amounts of carbon that they promised – or that are reliably storing that carbon underground.
“The actual feasibility of storing carbon for thousands of years: how is that monitoring happening? How are we certain that that is going to hold up over time?” she asks.
For Davies, using CCS to support oil and gas extraction “fouls the pitch” for those who see it as a tool that can help curb climate change and that merits more public-sector backing. “It’s inevitable that people will be cynical about CCS when they hear of it being embraced by the very companies that profit most from our addiction to oil and gas,” he says.
According to Wamsted, two CCS facilities in Norway, which store carbon under the North Sea rather than using it for oil recovery, have also required a great deal of effort and money to make sure those storage units actually work. Renewable energy could be a much better investment, he believes.
“We have alternatives now that we need to be building as fast as we possibly can,” says Wamsted, “instead of retrofitting a coal-fired power plant that in five years potentially won’t work.”
Last year, wind and solar contributed 14 percent of total global energy production, according to the Energy Institute. These sources already provide 31 percent of the electricity generated in Europe and 21 percent in the United States.
“Renewables are already cheaper and better,” says Wamsted. “That reality isn’t a secret anymore.”