A new report by a team of Oxford Net Zero researchers reviews the current state of knowledge on onshore geological carbon storage (GCS) and its feasibility in the UK.
The research examines the technological, economic, regulatory, and social aspects of onshore GCS, identifying key research and regulatory gaps. It was led by Laurent Chan, Molly James, Millicent Sutton, Dr Tom Kettlety and Prof Myles Allen.
Geological carbon storage is a storage process where CO2 is injected into deep geological rock formations for permanent storage. The CO2 can be sourced from industrial processes, biomass, or directly from the atmosphere. This term refers to one step in the process of Carbon Capture and Storage (CCS) or Carbon Dioxide Removal (CDR) with GCS. Effective GCS will likely play a key role in reaching net zero emissions.
Most research and regulation has focussed on offshore GCS. However, there is evidence to suggest that onshore GCS may be a necessary and more cost-effective storage option, and serve as a complement to offshore GCS in the UK, particularly if demand for CO2 storage were to greatly increase. However, significant knowledge gaps and obstacles exist for onshore storage.
Key findings of the report include:
- The addition of onshore GCS could improve access to CCS as an abatement option for dispersed or in-land point sources, by reducing the CO2 transport distance (by comparison with offshore GCS).
- There is little publicly available geological data on onshore CO2 reservoirs in the UK, and few studies have analysed their potential for GCS. This means that onshore CO2 storage capacity and injectivity remain uncertain and needs further research.
- Given that there has been widespread extraction of conventional oil and gas onshore in the UK, there is potential to repurpose depleted fields and deep well infrastructure for small-scale GCS projects. However, more work assessing the suitability of specific sites will have to be conducted to accurately assess this potential.
- In the UK, there is no regulatory framework for onshore GCS, with regulators solely focussing on offshore GCS. Thus, there are significant legal, regulatory, and policy hurdles that prevent the development of onshore GCS.
- There is a widely held assumption that gaining a social licence for onshore projects will be difficult, however the authors find that offshore GCS is not necessarily preferred to onshore GCS by the UK public. More specific public perceptions and social acceptance research on onshore and offshore GCS in relation to place history and social contexts is needed.
Overall, greater certainty on the potential of onshore GCS in the UK could be ensured by funding work to close research gaps highlighted in this report.
