Carbon Capture and Storage (CCS)

Key Takeaways

• Carbon capture and storage (CCS) is a process that captures CO₂ from industrial facilities before it reaches the atmosphere, then stores it permanently underground.
• CCS is different from direct air capture (DAC). CCS captures emissions at source; DAC removes CO₂ already in the atmosphere.
• The technology is essential for hard-to-abate sectors like cement, steel, and chemicals where emissions can't be fully eliminated through electrification.
• As of 2025, 77 CCS projects are operating globally, capturing around 50 million tonnes of CO₂ per year — roughly 0.1% of global emissions.
• CCS is a targeted tool for specific industrial emissions, not a substitute for reducing emissions in the first place.

What Is Carbon Capture and Storage?

Carbon capture and storage (CCS) is a three-step process: capturing carbon dioxide from industrial exhaust streams, transporting it, and storing it permanently underground in geological formations.

The CO₂ is captured from large point sources — places like cement plants, steel mills, chemical facilities, and refineries — where emissions are concentrated. Once captured, the CO₂ is compressed, moved via pipeline or ship, and injected deep underground into rock formations that can hold it for thousands of years.

CCS is not the same as planting trees or other nature-based approaches. It's an engineered solution designed specifically for industrial emissions that are difficult or impossible to eliminate through other means.

How Does Carbon Capture Work?

Step 1: Capturing CO₂

Most CCS systems use chemical solvents (typically amines) to separate CO₂ from industrial exhaust gases. The flue gas passes through a solution that binds the CO₂. The solution is then heated to release a concentrated stream of pure CO₂.

Industrial CCS systems are designed to capture around 90% of the CO₂ from flue gas. Higher capture rates are technically possible but require more energy and equipment.

There are three main capture approaches:

Step 2: Transporting CO₂

Once captured, the CO₂ is compressed into a dense, liquid-like state and transported to a storage site. Pipelines are the most common method for onshore transport. For cross-border or offshore storage, ships are increasingly used.

The Northern Lights project in Norway, for example, accepts CO₂ by ship from industrial emitters across Europe and stores it beneath the North Sea.

Step 3: Storing CO₂ Underground

The final step is injecting CO₂ deep underground — typically more than 800 metres down — into geological formations. Two main types of formations are used:

• Depleted oil and gas reservoirs: These have porous rock that held hydrocarbons for millions of years, with cap rock above that prevents upward migration.
• Deep saline aquifers: Porous rock formations saturated with brine, found deep underground in many regions.

The IPCC concludes that well-selected and properly managed storage sites can retain more than 99% of injected CO₂ over 1,000 years.

Storage sites are monitored continuously using seismic surveys, pressure monitoring, and geochemical sampling to track the CO₂ and detect any potential issues.

CCS vs Direct Air Capture: What's the Difference?

These terms are often confused, but they're fundamentally different:

This distinction matters for climate strategy. Under frameworks like the Science Based Targets initiative (SBTi), emission reductions and carbon removals are counted separately. CCS reduces your reported emissions; DAC (when paired with storage) generates removal credits that can neutralise residual emissions.

When someone talks about "carbon capture credits" in the voluntary carbon market, they're usually referring to DAC with storage (DACCS), not industrial CCS.

Does Carbon Capture Actually Work?

This is the question everyone asks — and it deserves an honest answer.

The Numbers

As of 2025, there are 77 CCS projects operating globally, with another 47 under construction. Together, operational projects capture around 50 million tonnes of CO₂ per year.

That sounds like a lot, but global CO₂ emissions are around 37 billion tonnes per year. CCS currently captures roughly 0.1% of global emissions.

The project pipeline is growing — capture capacity has increased at a compound annual rate above 30% since 2017. But deployment is still far below what's needed to meet climate targets.

Successes

• Sleipner (Norway): Operating since 1996, storing around 1 million tonnes of CO₂ per year in a saline aquifer beneath the North Sea. Decades of monitoring show secure containment.
• Northern Lights (Norway): The world's first open-source CO₂ transport and storage infrastructure, receiving its first shipment in 2025 from Heidelberg Materials' cement plant.
• Quest (Canada): Captures CO₂ from hydrogen production, storing over 8 million tonnes since 2015.

Failures

• Petra Nova (USA): A coal plant CCS project that consistently underperformed its targets and was shut down in 2020 after just three years. It restarted in 2023 but remains a cautionary example.
• Kemper County (USA): A gasification and CCS project that went billions over budget and was ultimately abandoned.

The track record is mixed. Many announced projects never materialise — around 70% of announced CCS projects historically have not been built. But the projects that do operate generally work as designed.

The Honest Assessment

CCS is not a silver bullet. It won't solve climate change on its own, and it's not a reason to delay phasing out fossil fuels.

But for certain industrial processes — particularly cement, steel, and chemicals — CCS may be one of the only ways to deeply reduce emissions. These sectors have "process emissions" that come from chemical reactions, not just burning fuel. You can't eliminate them by switching to renewable electricity.

The IPCC and IEA both conclude that CCS has a necessary but limited role in reaching net zero, particularly for hard-to-abate sectors.

Where Does CCS Make Sense?

CCS is most relevant for industries where emissions are hard to eliminate through other means:

Good fit for CCS:

• Cement production: About 60% of cement emissions come from the chemical process of heating limestone, not from fuel. CCS is one of the few options to address this.
• Steel production: Blast furnace steelmaking releases CO₂ from the chemical reduction of iron ore. CCS can capture these process emissions.
• Chemicals and refining: Hydrogen production, ammonia, and ethanol facilities produce concentrated CO₂ streams that are relatively cheap to capture.
• Waste-to-energy: Capturing CO₂ from burning waste can reduce emissions from facilities that handle materials that can't easily be recycled.

Less suited for CCS:

• Power generation: Renewable energy (solar, wind) is now cheaper than fossil fuel power plants with CCS in most regions. CCS on power plants made sense when it was first proposed; today, it's generally not cost-competitive.
• Transport: Electrification and efficiency are more practical solutions for most transport emissions.
• Buildings: Heat pumps and insulation are better approaches than trying to capture emissions from heating.

The key principle: use CCS where alternatives don't exist, not as an excuse to avoid switching to cleaner options. Both the IEA and IPCC emphasise this point in their net zero scenarios.

CCS in Europe

Europe has built a comprehensive regulatory framework for CCS and is developing shared infrastructure to make it accessible to countries without domestic storage options.

EU Framework

• CCS Directive (2009/31/EC): Establishes rules for site selection, permitting, monitoring, and long-term liability for geological CO₂ storage.
• EU Emissions Trading System (ETS): CO₂ captured and stored counts as avoided emissions, reducing a facility's compliance obligation.
• Net-Zero Industry Act: Sets a target of at least 50 million tonnes per year of CO₂ injection capacity in the EU by 2030.
• Carbon Removal Certification Framework (CRCF): Creates EU-wide certification for permanent carbon removals, including DACCS and BECCS. Note: fossil point-source CCS is not classified as a "removal" under this framework.

Key European Projects

• Northern Lights (Norway): Shared transport and storage infrastructure accepting CO₂ from emitters across Europe.
• Porthos (Netherlands): A hub connecting Rotterdam industrial emitters to offshore storage.
• Longship (Norway): Includes the Brevik cement plant CCS facility and connections to Northern Lights storage.

Country-Specific Approaches

How Much Does CCS Cost?

Costs vary significantly depending on the CO₂ source, technology, and distance to storage.

Key Cost Factors

• CO₂ concentration: Higher concentration = cheaper capture. Natural gas processing has ~50% CO₂; ambient air has 0.04%.
• Energy prices: CCS requires significant energy. Access to cheap, low-carbon energy improves economics.
• Distance to storage: Longer pipelines or ship transport add cost.
• Policy support: Carbon pricing (EU ETS), subsidies, and tax credits can make projects viable.

CCS-equipped plants use 13-44% more energy than unabated plants because of the energy needed to run the capture process. This "energy penalty" is a key consideration when evaluating net climate benefits.