Carbon Capture & Storage (CCS/CCUS) — Technology, Projects, Costs & the Path to Gigaton Scale
Carbon Capture, Utilisation and Storage (CCUS) encompasses a family of technologies that capture CO₂ from point-source industrial emissions — power plants, cement kilns, steel furnaces, hydrogen production facilities — and either store it permanently underground in geological formations or utilise it in products and fuels. CCUS is consistently cited in IPCC scenarios as essential for reaching net zero: in virtually all 1.5°C pathways modelled by the IPCC, CCUS contributes 4–8 Gt CO₂/yr of abatement by 2050, particularly in hard-to-abate sectors where emissions cannot be eliminated through electrification alone. The technology is proven — Sleipner in Norway has stored CO₂ since 1996. The challenge is cost ($50–120/t CO₂ for industrial applications), scale (current operational capacity is ~50 Mt/yr — roughly 0.14% of what's needed), and political economy: CCS has faced sustained opposition from environmental groups who view it as enabling prolonged fossil fuel use. The IRA (2022) dramatically improved US economics via 45Q tax credits, and a pipeline of >500 Mt/yr capacity is now in development globally.
~50 Mt CO₂/yr
Current operational CCS capture capacity globally (2023); ~45 operating facilities; Global CCS Institute 2023 — up from 27 Mt in 2017; still <0.15% of annual global emissions
~5–8 Gt CO₂/yr
CCS/CCUS contribution needed in IPCC 1.5°C scenarios by 2050; 100–160× scale-up required from today; represents ~12–18% of 2020 global emissions
$50–120/t CO₂
Typical cost range for point-source CCS (post-combustion chemical absorption); power sector ~$80–120; industrial (cement, steel) ~$100–180; natural gas processing ~$30–60 (highest purity)
$85/t CO₂ (Class II) + $180 (Class VI)
US 45Q tax credit (IRA 2022) for CO₂ stored in geological formations; most significant CCS policy globally; triggered >$70B in US CCUS investment announcements in 2022–2024
~10,000 Gt CO₂
Estimated global geological CO₂ storage capacity; saline aquifers dominant (~98%); depleted oil/gas fields (~2%); capacity not a constraint — availability of suitable geology near emission sources is
~500 Mt/yr pipeline
CCS projects under development or in advanced planning (2023); if all proceed: 10× current capacity; uncertainty on execution; financing and permitting remain bottlenecks
CCS Capture Technology Comparison — TRL & Cost Range
Source: IEA 2020 (CCUS in Clean Energy Transitions); IPCC CCS Special Report 2005 (updated assessments in AR6); Bui et al. 2018 (Energy & Environmental Science — CCS review); Global CCS Institute 2023 Status Report; Boot-Handford et al. 2014 (Energy Environ. Sci.).
The Three Capture Approaches
Post-combustion capture: CO₂ is scrubbed from flue gas after combustion using liquid amine solvents (MEA — monoethanolamine is most common). The solvent absorbs CO₂, is then heated to release it, and is recycled. Mature technology; can retrofit existing plants. Energy penalty ~15–25% of plant output (to heat solvent). CO₂ in flue gas is typically 4–15% (power plants 10–15%, cement 15–25%).
Oxyfuel combustion: Fuel is burned in pure oxygen (not air), producing a near-pure CO₂ exhaust that requires minimal purification. The air separation unit to produce pure O₂ is costly and energy-intensive. Suited to new builds; Schwarze Pumpe (Germany) was the only oxyfuel pilot at large scale.
Pre-combustion capture: Fuel is converted to H₂ + CO₂ before combustion (via reforming or gasification + water-gas shift). H₂ is used as a clean fuel; CO₂ is captured from a concentrated stream (easier/cheaper to capture). Integrated Gasification Combined Cycle (IGCC) is the primary application.
Source: IPCC CCS Special Report 2005; Bui et al. 2018; IEA 2020; Boot-Handford et al. 2014.
The energy penalty — why CCS is costly: Every CCS system imposes an "energy penalty" — the parasitic energy consumed to capture, compress, transport, and store CO₂. For post-combustion amine capture on a coal power plant, this penalty is typically 15–25% of the plant's gross output — meaning a 1,000 MW plant with CCS produces only 750–850 MW of net electricity. The plant must burn ~20–30% more fuel to produce the same net power output, partially undermining the emissions benefit. This energy penalty is the primary driver of the high cost of CCS. Next-generation capture materials — solid sorbents, ionic liquids, metal-organic frameworks (MOFs) — are targeting much lower regeneration energies and energy penalties of 5–12%, potentially halving costs by 2035.
Global Operating CCS Capacity by Sector (Mt CO₂/yr, 2023)
Source: Global CCS Institute 2023 Global Status of CCS Report; IEA CCUS Projects Database 2023; individual project operator reports; GCCSI facility database (gccsinstitute.com/resources/global-status-report).
Key Operating Projects
Sleipner (Norway, 1996)World's first commercial offshore CO₂ storage; Equinor; 1 Mt/yr CO₂ from natural gas processing stored in Utsira sandstone formation; 27+ years of monitoring — no leakage detected
Quest (Canada, 2015)Shell, oil sands hydrogen plant; 1.1 Mt/yr; demonstrated reliable industrial CCS; deep saline aquifer storage Alberta
Boundary Dam (Canada, 2014)SaskPower; world's first post-combustion CCS on coal power; 1.0 Mt/yr design; struggled operationally; underperformed vs. design; important lessons for power sector CCS
Petra Nova (USA, 2017)Largest US power CCS; 1.4 Mt/yr design; mothballed 2020 (low oil prices reduced EOR revenue); restarted 2023 under 45Q; illustrates EOR dependency risk
Northern Lights (Norway, 2024)Equinor + Shell + TotalEnergies; Europe's first CO₂ transport + storage open-access infrastructure; 1.5 Mt/yr Phase 1; designed to receive CO₂ from cement, waste-to-energy, steel across Europe; receives from Brevik cement plant
Quest for Ammonia (various)Natural gas + SMR hydrogen production with CCS now accounts for ~30% of operating CCS capacity globally; cheapest CCS application (high CO₂ purity from syngas); used by fertiliser, methanol producers
Source: Global CCS Institute 2023; Equinor Sleipner project data; SaskPower Boundary Dam reports; NRG/JX Nippon Petra Nova 2023; Longship/Northern Lights project reports.
Geological CO₂ Storage — Global Capacity Estimate by Type (Gt CO₂)
Source: IPCC CCS Special Report 2005; Metz et al. 2005; Global Atlas of CO₂ Storage (USGS/BGS/Geoscience Australia 2023); Ringrose et al. 2021 (Elements — CO₂ storage); Ehlig-Economides & Economides 2009 (Journal of Petroleum Science — storage critique and response); Bachu 2015 (Progress in Energy and Combustion Science — CO₂ storage in geological media).
Storage Mechanisms & Safety
CO₂ injected into deep geological formations (>800m depth, where it becomes supercritical — dense liquid-like) is trapped by four mechanisms:
Structural trappingCO₂ rises until it hits an impermeable caprock (shale, salt); same mechanism traps natural gas for millions of years; primary initial trapping; requires good caprock integrity
Residual trappingCO₂ bubbles trapped in pore spaces by capillary forces; becomes immobile quickly; highly effective; accounts for 10–40% of injected CO₂
Solubility trappingCO₂ dissolves into brine; CO₂-rich brine is denser and sinks; permanent over centuries; convective mixing accelerates this; major long-term security mechanism
Mineral trappingCO₂ reacts with reservoir minerals to form carbonates (calcite, siderite); effectively permanent over millennia; Iceland CarbFix project shows this can happen in 2 years in basalt
Sleipner 27-year safety record28 Mt CO₂ stored since 1996; regular seismic monitoring; no leakage detected; most important safety data point for the technology; referenced in every regulatory discussion
Source: IPCC CCS 2005; Ringrose et al. 2021; Bachu 2015; Equinor Sleipner monitoring data 2023; Snæbjörnsdóttir et al. 2020 (Nature Geoscience — CarbFix basalt mineralisation).
CCS Cost by Application & Source ($/t CO₂ avoided, 2023)
Source: IEA 2020; IPCC AR6 WG3 2022 (Annex III — technology costs); Fasihi et al. 2019 (Joule — techno-economic assessment); Budinis et al. 2018 (Energy Strategy Reviews — CCS assessment); Global CCS Institute 2021 (economic modelling); NRDC 2022 (45Q analysis).
Economics — What Makes or Breaks CCS
Natural gas processing (sweetening)~$20–30/t CO₂; already captured to meet gas quality specs; CCS = cheap incremental step; most economical application; Sleipner, Quest use this
Hydrogen (SMR/ATR + CCS)~$30–50/t CO₂; high-purity CO₂ stream from reformer; "Blue hydrogen" value chain; Shell Quest, Air Products are examples
Coal/gas power + CCS~$80–130/t CO₂; dilute flue gas; large energy penalty; Boundary Dam lesson; uneconomic without policy support; increasingly less relevant as renewables dominate new builds
Cement kiln CCS~$100–180/t CO₂; more favourable CO₂ concentration in flue gas vs. power; but smaller-scale, no existing CO₂ infrastructure at most sites; Brevik = frontier project
45Q tax credit impact (USA IRA)$85/t CO₂ for geological storage; $60/t for EOR; makes most hydrogen + industrial CCS economic; triggered $70B+ in US announcements; most transformative CCS policy globally
Carbon price needed for unsubsidised CCS~$80–150/t CO₂ EU ETS equivalent for most applications; EU ETS currently €60–80/t (2024); CCS becoming viable at margin for highest-concentration sources
Source: IEA 2020; Global CCS Institute 2021; IPCC AR6 WG3 2022; IRA (P.L. 117-169) 45Q provisions; NRDC 2022.
CCS Role by Sector in IEA Net Zero Scenario (Mt CO₂/yr captured, 2050)
Source: IEA Net Zero by 2050 Roadmap 2021 (updated 2023); IEA CCUS Roadmap 2020; IPCC AR6 WG3 2022; BlueScope 2023; CEMEX 2023; Ervia (Ireland) CCS strategy 2023.
CCUS vs. CCS — The "Utilisation" Pathway
Carbon Capture and Utilisation (CCU) converts captured CO₂ into products rather than storing it: synthetic fuels (e-fuels), chemicals (methanol, ethanol), building materials (CO₂-cured concrete), or food-grade CO₂ (for carbonated beverages, greenhouses). CCU is growing but faces a fundamental accounting challenge:
e-fuels (Power-to-Liquid)CO₂ + H₂ → synthetic aviation fuel or methanol; when burned, CO₂ is re-released; only carbon-neutral if H₂ is green and CO₂ from biogenic/air source; not permanent storage
CO₂ to methanol / ethanolCarbon Recycling International (Iceland); CO₂ + green H₂; "Carbon Methanol" for chemicals; permanent? No — oxidised on use; but reduces need for fossil methanol feedstock
CO₂-cured concrete (Solidia, CarbonCure)CO₂ mineralised into calcium carbonate during concrete curing; permanent storage in concrete structure; CarbonCure used in >900 concrete plants (2023); 5–8% CO₂ reduction per m³
Enhanced Oil Recovery (EOR)CO₂ injected into depleted oil fields to push out remaining oil; most existing US CCS uses this revenue model; controversy: extracted oil burned → net CO₂ benefit unclear; declining as model
Source: IEA CCU report 2019; CarbonCure Technologies 2023; Solidia Technologies 2023; Carbon Recycling International 2022.
Global CCS Capacity — Historical & Pipeline (Mt CO₂/yr)
Source: Global CCS Institute 2023 Global Status of CCS Report; IEA CCUS 2023 tracking report; Mitsubishi Heavy Industries 2022; SLB (Schlumberger) CCUS division 2023; US DOE Office of Fossil Energy 2023 (45Q-triggered project announcements).
The CCS Debate — Supporters & Critics
IPCC positionCCS essential in most 1.5°C pathways; particularly for hard-to-abate sectors (cement, steel, chemicals) and bioenergy with CCS (BECCS) for negative emissions; not optional in IPCC NZE
Greenpeace / NGO critiqueCCS "licence to pollute"; extends fossil fuel investment; high cost diverts from renewables; historical underperformance of projects (Boundary Dam); risks of leakage; false solution
IEA / industry positionCCS not in competition with renewables — it addresses emissions renewables can't; hard-to-abate sectors have no electrification pathway; CCS is essential part of the portfolio
EOR / oil industry involvementHistorical CCS development was tightly linked to EOR revenue stream; gave impression CCS = oil production tool; Northern Lights and industrial CCS represent a genuine decoupling from EOR
Performance vs. promiseBoundary Dam (2014) captured ~50% of designed volume in early years; Kemper County (coal gasification CCUS) cancelled $7.5B overrun; created credibility gap for the technology
Source: IPCC AR6 WG3 2022; Global CCS Institute 2023; SaskPower Boundary Dam performance data; MIT CCS Energy Laboratory (various); Global Witness 2022 (critique).
The US Inflation Reduction Act 45Q — the most important CCS policy in history: The IRA's enhancement of the 45Q tax credit to $85/t CO₂ for geological storage (from $50/t pre-IRA) has transformed the economics of CCS in the United States. The credit is technology-neutral, available for 12 years after the facility begins operating, and can be transferred (sold) to investors who can monetise the credit regardless of profitability — making it highly bankable for project finance. Within 12 months of the IRA's August 2022 passage, the US Department of Energy received project proposals representing over 500 Mt CO₂/yr of capture capacity. The credit has triggered the largest wave of CCS project development in history. The parallel $3.5B in DOE Regional Direct Air Capture (RDAC) hubs and $2.5B for carbon management demonstrations extends the policy to novel technologies. No other jurisdiction has come close to matching this policy lever for CCS deployment.