Biogenic carbon capture, utilization, and storage (bio-CCUS) is technically feasible and strategically important for climate policy, yet deployment remains largely pre-commercial. While individual bio-CCUS technologies are increasingly well understood, the actor-level dynamics and governance conditions determining value chain formation are less studied. We address that gap through semi-structured interviews with representatives of 13 companies across bio-CCUS value chains and four forerunner municipalities in Finland, characterizing the decision-making environment facing both groups, complemented by an analysis of EU-level and national regulation. The findings reveal that investment in bio-CCUS is primarily constrained by system-level coordination failures: a chicken-and-egg dynamic persists between CO₂ producers waiting for stable demand and users waiting for reliable supply, while missing logistics infrastructure, spatial dependencies, and regulatory fragmentation across legal domains compound the challenge. Biogenic CO₂ is currently largely excluded from EU ETS compliance incentives, and strong policy support for RFNBOs contrasts with the near-absence of comparable incentives for other CCU applications. National policy instruments translate EU frameworks into concrete incentives, but their design may reinforce a focus on fuel-based pathways and limit participation of smaller actors. Municipalities can facilitate local value chain development through land-use zoning, and through linking actors, but cannot substitute for missing market-level incentives. We interpret these findings through the lens of coordination failure, organizing them around four interacting mechanisms – demand formation, complementary investment, infrastructure coordination, and multilevel intermediation – that jointly determine whether investment proceeds. Economic viability of bio-CCUS emerges as a systemic outcome that no single actor can bring about alone.
California’s 2045 net-zero goal relies heavily on carbon dioxide removal (CDR). Ninety-eight percent of CDR is expected to come from engineered systems such as direct air capture (DAC) and carbon storage. However, uncertainty in future DAC costs obscures its role in California’s decarbonization pathway. We address this gap by using the BRIDGES model, a multi-year sector-coupled gas-electricity capacity expansion model for California, to assess the deployment of two DAC technologies under varying cost assumptions. Specifically, we incorporate technology-specific data for liquid solvent and solid sorbent DAC like capital expenditures, operations and maintenance costs, and energy consumption. We develop scenarios that explore DAC upscaling and deployment. We find that 16 to 33 MtCO2/year of DAC capacity is part of a cost-optimal energy system in 2045 that abates emissions from electric power, buildings, and industry. While DAC deployment does not significantly impede the transition to a variable renewable energy-dominant system, it enables the continued use of natural gas for high-temperature industrial heat and natural gas-powered electricity generation. Even in scenarios with zero natural gas combustion, DAC is utilized to address persistent residual emissions, such as hydrofluorocarbon leaks in building appliances and uncaptured CO2 in industrial carbon capture and storage systems. These results position DAC as a critical complement to deep decarbonization, highlighting its role in managing residual emissions.
Carbon Capture, Utilization, and Storage (CCUS) is a critical pathway for mitigating the global greenhouse effect. Sub-seabed CO2 sequestration, particularly through hydrate-based methods, offers immense potential due to the vast storage capacity and favorable thermodynamic conditions of marine sediments. However, the complex phase transitions and associated geomechanical deformations pose significant challenges for in-situ monitoring of CO2 evolution and reservoir stability. This study utilizes a triaxial-resistivity apparatus to investigate the electrical response of silty-clayey sediments during CO2 hydrate formation and subsequent deformation under varying saturations and effective stresses. Key findings indicate that resistivity is highly sensitive to temperature and pore fluid content, with a 10 % difference in initial water saturation leading to an 88 % variation in resistivity. Furthermore, hydrate morphology and residual water distribution significantly influence electrical signals, resulting in resistivity fluctuations of up to 853 Ω·m at identical saturation levels. Beyond phase identification, resistivity effectively reflects sediment consolidation and pore structure evolution during the shearing stage, exhibiting a non-linear correlation with applied stress. These results demonstrate the feasibility of resistivity-based monitoring for tracking CO2 dynamics and assessing the mechanical integrity of sub-seabed reservoirs, providing essential theoretical support for large-scale sequestration in the future.
Carbon contracts for difference (CCfDs) have become a leading policy option in Europe for funding the deployment of carbon capture and storage (CCS) and other industrial decarbonisation projects. This mechanism aims to cover the gap between project costs and the prevailing carbon price over a given project duration. This paper assesses existing CCfD schemes in five European states, highlighting the design choices available to policy makers and their impact on CCS deployment. Design choices include parameters such as project eligibility and selection criteria, payment symmetry, price indexing, and performance criteria. Variation between these schemes is a result of different national contexts and policy visions for CCS development. Countries with weaker political support for CCS or a focus on industrial decarbonisation have tended to prefer CCfD programmes open to multiple decarbonisation technologies. Countries with a strategic vision to deploy CCS technology for multiple purposes have developed technology-targeted schemes. A fundamental challenge for CCS projects is a reliance on shared CO2 infrastructure, which creates co-dependencies with other projects and can increase cost uncertainty. Design features to address this challenge have included regional prioritisation, cross-chain risk mitigation, consortium bids, and flexibility to changing costs. Project selection and performance criteria can be tailored to promote goals such as near-term abatement, net-zero compatibility, and wider economic impact. As more countries develop CCfDs to meet their decarbonisation goals, this paper offers a structured comparison of the motivating factors and outcomes of key design choices for CCS, so as to inform the design of future schemes.
Fault zones are key structures controlling subsurface fluid migration and localization of deformations. Although faults have been extensively studied for decades, emerging CO₂ storage projects face challenges quantifying CO2 fault leakage risk as part of the overall containment risk assessment. This review first outlines the role of faults in CO2 containment risk with focus on fault zone mapping, architecture and models for fault seal integrity evaluation. Further, we emphasise the hydraulic and mechanical properties in mudrock faults and highlight advances in understanding hydromechanical coupling during fault reactivation based on insight from underground research laboratories. Finally, we discuss the implications for CO2 containment risk and summarize future research needs for mudrock faults.
