Carbon capture and storage (CCS)

“Capturing carbon at a source can reduce emissions. It does not make the underlying process impact-free. ”

Carbon capture and storage separates carbon dioxide from concentrated exhaust or process streams, compresses it, transports it and injects it into deep geological formations. It can reduce emissions from cement, chemicals, hydrogen production and some power or industrial facilities. CCS is not one technology but a chain.

Capture performance, energy penalty, transport integrity, storage capacity, monitoring and long-term containment all affect the result. A plant advertising 90 percent capture may achieve a lower system-level reduction once upstream fuel emissions, uncaptured periods and additional energy use are included.

The strongest case is often in industrial processes where carbon dioxide is inherent to chemistry and alternatives remain limited. In power generation, CCS competes with efficiency, renewables, storage and demand-side options whose cost and system implications differ.

Context matters more than the label. Storage quality is central. Geological formations must be characterised, injection monitored and leakage risk managed over long periods. Regulatory responsibility and financial assurance should remain clear after operations cease. CCS can also prolong fossil-fuel infrastructure if used to justify new extraction or delay cleaner alternatives.

That does not mean every project is invalid. It means project appraisal should compare the full opportunity cost and lock-in risk against credible alternatives. For practitioners, the reported metric should be net emissions avoided across the chain, not simply tonnes captured. Availability, capture rate, upstream emissions and storage permanence should all be visible.

Practical application

Assess the full capture-transport-storage chain and a credible no-project alternative. Report annual operating capture rate, utilisation, energy penalty, upstream emissions, net avoided emissions and storage monitoring rather than nameplate capacity alone.

Why it matters

CCS may be important for hard-to-abate industry, but weak system boundaries can overstate performance and hide dependence on continued fossil fuel use.

Common misconception

CCS removes historical carbon dioxide from the atmosphere. Conventional CCS usually prevents a portion of source emissions; it becomes removal only when capturing biogenic or atmospheric carbon with durable storage.

Connections

CCUS adds utilisation. Direct Air Capture supplies atmospheric carbon. Transition Risk tests whether CCS-dependent assets remain viable under changing technology and policy.

A question worth asking

What is the net emissions reduction after energy use, upstream supply and periods when capture is unavailable?

Selected references

International Energy Agency, Carbon Capture, Utilisation and Storage analysis. IPCC, Sixth Assessment Report, mitigation options. ISO 27914, geological storage of carbon dioxide.