At a Glance
Most integrated assessment and other macro-scale energy system models find that widespread carbon capture and storage (CCS) at very large scales is crucial to achieve ambitious CO2 reduction goals. However, these models assume that abundant low-cost geological storage is available to meet all needs. This research presents the contrasting view that storage capacity uncertainty could seriously hamper the pace and scale of CCS deployment, especially in developing Asian economies. This storage capacity uncertainty leads to “chicken-or-egg” challenges that deter investment. The implications for emissions reduction goals and the role that CCS should play in a net-zero future warrant more attention.
Integrated assessment and other macro-scale energy systems optimization models (IAMs) for exploring decarbonization pathways are influential in shaping international, national, and subnational energy and climate policy. Most such models indicate very large-scale deployment of CCS in all major emitting nations. For example, in IAM scenarios which limit warming to 1.5 °C, median CCS deployment reaches 11Gt CO2/y by 2050 and around 13-23Gt CO2/y of CCS by 2100 (Huppmann et al., 2018). At a national scale, Princeton’s Net-Zero America study featured at least 1 Gt/y of CCS across all but one scenario that expressly precluded CO2 storage (Larson et al., 2021). Notwithstanding these modeling insights, there remains disagreement among academics, policymakers, and other stakeholders about the need for CCS.
In 2021, the researchers reviewed a range of decarbonization scenarios and assigned the value of CCS in time-bound netzero pathways to three levels: threshold value (without CCS, net-zero outcomes are likely to be implausible at a global scale); commercial value (where minimizing cost is a central goal of a net-zero transition); and option value (maintaining a credible CCS option mitigates the risk of other, for example, renewable heavy pathways, from faltering) (Greig and Uden, 2021). This value of CCS is driven by its versatility — providing firm low-carbon power, industrial decarbonization, low-carbon hydrogen production, and generating negative emissions via engineered removals.
The research is also examining the ongoing failure to deliver on these modeled scenarios and increasing calls to improve the feasibility of modeled pathways. CCS is just one example where real-world deployment has fallen short of the ambition in modeled scenarios.
In 2021, with Postdoctoral Researcher Joe Lane, the research challenged the prevailing supposition behind most IAMs, namely, that CCS capacity can be expanded rapidly to circa gigatonne-per-year levels by mid-century, in most major emitting regions. This supposition assumes that CO2 storage capacity is ubiquitous, especially in deep saline formations. This modeling perspective derives from discounted static estimates of subsurface spore volume. Investments in CCS, on the other hand, require confidence in accessible, dynamic (injection rate-based) capacity estimates. The latter is much more uncertain and heterogeneous within and across regions. Reducing these uncertainties requires serious site-based investment in characterization, exploration, and appraisal.
The researchers posited a conundrum for CCS (Lane et al., 2021) that creates a gap between ambitions and reality: despite the crucial value offered by CCS, its rate of expansion is constrained by a lack of investment confidence due to chicken-or-egg type challenges that are founded in uncertainties around storage capacity coupled with the threat of technology substitutes. The chicken-or-egg investment challenge is reflected in Figure 2.1. Failure to address this conundrum presents a risk to CCS deployment levels implied in net-zero targets, especially in fast-growing Asian economies with limited oil and gas production history. Figure 2.2 highlights the gap between historical oil and gas production and one International Energy Agency (IEA) scenario (IEA, 2017) for CCS in India and China.
The researchers are also working with collaborators at Imperial College London to evaluate the impact of regional CCS constraints on 1.5 °C-compatible scenarios using the TIAMGrantham IAM, a version of ETSAP-TIAM (Loulou and Labriet, 2008). This research considers the effects of constraining annual CO2 storage rates to the maximum historical annual oil and gas extraction rates in each region. The research suggests a need to rethink the allocation of CCS as a mitigation option across electricity, fuels, industrial, and negative emissions, with a significant shift in the optimal resource mix to 2050 (Grant et al., submitted 2021).
Looking forward, opportunities for further research include:
- methods to develop plausible regional assessments of dynamic CO2 storage capacity; and
- methods to inform the execution feasibility of modeled CCS scenarios based on:
- reverse-engineering the asset delivery sequence across CO2 storage, CO2 pipelines and CO2 capture facilities to meet those targets; and then
- reverse engineering the investment decision sequence implied by this asset delivery sequence.
Such research could help identify policy and critical infrastructure investments necessary to bridge the gap between CCS ambition and reality.
Huppmann, D., et al., 2018. IAMC 1.5°C Scenario Explorer and Data Hosted by IIASA v1.1. (https://doi.org/10.22022/SR15/08-2018.15429).
Larson, E., C. Greig, J. Jenkins, et al., 2021. Net-Zero America: Potential Pathways, Infrastructure, and Impacts – Final Report (Princeton University). (https://doi.org/10.5281/zenodo.6378139).
Greig, C., and S. Uden, 2021. The value of CCUS in transitions to net-zero emissions. The Electricity Journal 34(7):107004. (https://doi.org/10.1016/j.tej.2021.107004).
Lane, J.L., C. Greig, and A.J. Garnett, 2021. Uncertain storage prospects create a conundrum for carbon capture and storage ambitions. Nature Climate Change 11:925-936. (https://doi.org/10.1038/s41558-021-01175-7).
Loulou, R., and M. Labriet, 2008. ETSAP-TIAM: The TIMES integrated assessment model Part I: Model structure. Computational Management Science 5:7–40. (https://doi.org/10.1007/s10287-007-0046-z).
Grant, N., A. Gambhir, S. Mittal, C. Greig, and A. Koberle, Submitted 2021. The investable potential for CCS deployment and its impact on long-term mitigation pathways. Journal of Greenhouse Gas Control, in review.
Energy Technology Perspectives 2017 (IEA, 2017). (https://www. iea.org/reports/energy-technology-perspectives-2017).