Coupled geophysical and technoeconomic growth constraints on geological carbon storage scaleup with an application to the UK

Iman R. Kivi , Xiaowei Gao, Sam Krevor

Geological carbon dioxide storage is central to meeting many national climate change commitments. Yet large-scale deployment remains poorly constrained by both techno-economic limits on how rapidly the technology can scale and physics-based constraints imposed by the behavior of the subsurface. We here develop a modelling framework to identify feasible CO2 storage scaleup trajectories constrained simultaneously by techno-economic growth and dynamic geophysical limits. We employ logistic and Gompertz models to represent policy-compliant deployment trajectories and simplified physics models to assess the resulting regional subsurface pressurisation. Applying the framework to the United Kingdom (UK), we find that offshore storage resources are sufficient to accommodate all government mid-century deployment rate targets up to 175 Mt yr-1. Cumulative storage of up to 78 Gt can be achieved under Gompertz growth trajectories. The more aggressive logistic trajectories are constrained by reservoir injectivity, limiting the achievable resource base to 69 Gt. Geological uncertainties further narrow feasible pathways, but does not eliminate many key scaleup targets. A tenfold reduction in reservoir permeability while maintaining mid-century injection rates decreases the achievable storage resource to ~40 Gt. We conclude that a large contribution from geological CO2 storage to rapid decarbonisation in the UK is attainable if supporting regulation, investment and industrial capacity expand in accordance with national climate ambitions.