Carbon capture and storage (CCS)
Also known as: CCS, CCUS, carbon capture, utilization, and storage
Carbon capture and storage (CCS) catches carbon dioxide from smokestacks at power plants, cement kilns, refineries, or other industrial sites, compresses it, and pumps it deep underground into rock formations for permanent storage.
It's seen as important for industries that are hard to electrify. While CCS has worked at some projects for decades, its record is mixed: several flagship plants captured less than promised, and critics worry it extends fossil fuel use.
Carbon capture and storage (CCS), explained at three levels
At home
Think of a range hood over a stove that catches grease before it coats your kitchen. Carbon capture works like a chemical filter on a factory chimney: it pulls carbon dioxide out of the exhaust before it escapes. The captured gas is squeezed into a dense fluid, piped away, and pumped kilometres underground into porous rock sealed by solid layers above.
At work
Carbon capture and storage (CCS) separates carbon dioxide from an industrial plant's exhaust, transports it, and stores it permanently underground. It matters for heavy industries such as cement, fertilizer, and refining, whose emissions come partly from chemistry rather than fuel, so switching to clean electricity is not enough. Its economics usually depend on carbon pricing and government tax credits.
At home
CCS has three steps. Capture usually runs the exhaust through a chemical solvent, often an amine, that grabs CO2; heating the solvent later releases pure CO2 and lets the solvent be reused. Transport compresses the gas and sends it by pipeline. Storage injects it more than a kilometre underground into deep saline aquifers or depleted oil and gas fields, where a cap rock above traps it, much as it once trapped natural gas.
At work
Capture is easiest where CO2 is concentrated. Hydrogen production and natural gas processing produce nearly pure CO2 streams, while power plant flue gas is only about 4 to 15% CO2, which makes capture costlier. Post-combustion capture treats exhaust after burning, while pre-combustion and oxy-fuel designs change the process itself. CCUS adds utilization, such as using CO2 for enhanced oil recovery, which produces more oil and so complicates the climate benefit.
At home
Capturing CO2 costs energy, mainly the heat needed to strip the CO2 back out of the solvent. On a coal plant, this 'energy penalty' can consume roughly a fifth or more of the plant's output, and the capture unit must run reliably every hour to hit its target. While the chemistry is well understood, in my view that penalty is why CCS on power plants struggles, while capture on concentrated industrial streams is far cheaper.
At work
Assess CCS on verified capture rates in operation, not design targets, and on full lifecycle emissions, including the energy the capture unit consumes. Storage needs site characterization plus measurement, monitoring, and verification over decades, and clear rules on who carries long-term liability; Alberta, for example, can take over liability after a site closes. Shared hubs that pool pipelines and storage across emitters cut costs. Public acceptance, pipeline safety, and Indigenous consultation shape approval in Canada.
Real-world examples
At home
Marcus grew up near Estevan, Saskatchewan, and took a school field trip to the Boundary Dam carbon capture plant. Years later, he followed news about its performance and was surprised how much harder the real project was than the brochures suggested.
At work
Nadia is a sustainability director at a cement company in Alberta. Since most cement emissions come from the chemistry of making clinker, not fuel, her team is studying CCS as one of the few ways to reach net zero, using federal tax credits to improve the economics.
How it compares
| feature | Carbon capture and storage (CCS) | Direct air capture (DAC) |
|---|---|---|
| Source of CO2 | Smokestacks and industrial processes | Ambient air |
| CO2 concentration | High | Very low, about 0.04% |
| Cost per tonne | Lower | Much higher |
| Climate effect | Reduces new emissions | Removes existing CO2 |
CCS prevents emissions at the source. DAC removes CO2 already in the air.
For analysts
When a company counts on CCS in its net-zero plan, I'd ask for evidence of actual capture rates from comparable projects, not design targets. The gap between the two has been the technology's biggest credibility problem.
History & origin
Oil companies have injected CO2 underground to push out more oil, called enhanced oil recovery, since the 1970s. Norway's Sleipner project began storing about a million tonnes of CO2 a year under the North Sea in 1996, partly to avoid a national carbon tax. Saskatchewan's Boundary Dam Unit 3 became the world's first commercial coal power plant with CCS in 2014, though it often ran below its capture target. Shell's Quest project in Alberta started in 2015 and has stored millions of tonnes from oil sands upgrading. Canada introduced a CCUS investment tax credit, and the Pathways Alliance of oil sands producers proposed a large carbon storage network, which Ottawa and Alberta backed in a 2026 memorandum of understanding with the producers. In my opinion, CCS makes the most sense where there's no other way to cut emissions, like cement, and the least sense as a reason to delay alternatives.