Editing IPCC:AR6/SR15/Chapter-4 (section)

==== 4.3.1.6 Carbon dioxide capture and storage in the power sector ====

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The AR5 (IPCC, 2014b) <sup>[[#fn:r168|168]]</sup> as well as Chapter 2, Section 2.4.2, assign significant emission reductions over the course of this century to CO <sub>2</sub> capture and storage (CCS) in the power sector. This section focuses on CCS in the fossil-fuelled power sector; Section 4.3.4 discusses CCS in non-power industry, and Section 4.3.7 discusses bioenergy with CCS (BECCS). Section 2.4.2 puts the cumulative CO <sub>2</sub> stored from fossil-fuelled power at 410 (199–470 interquartile range) GtCO <sub>2</sub> over this century. Such modelling suggests that CCS in the power sector can contribute to cost-effective achievement of emission reduction requirements for limiting warming to 1.5°C. CCS may also offer employment and political advantages for fossil fuel-dependent economies (Kern et al., 2016) <sup>[[#fn:r169|169]]</sup> , but may entail more limited co-benefits than other mitigation options (that, e.g., generate power) and therefore relies on climate policy incentives for its business case and economic feasibility. Since 2017, two CCS projects in the power sector capture 2.4 MtCO <sub>2</sub> annually, while 30 MtCO <sub>2</sub> is captured annually in all CCS projects (Global CCS Institute, 2017) <sup>[[#fn:r170|170]]</sup> .

The technological maturity of CO <sub>2</sub> capture options in the power sectors has improved considerably (Abanades et al., 2015; Bui et al., 2018) <sup>[[#fn:r171|171]]</sup> , but costs have not come down between 2005 and 2015 due to limited learning in commercial settings and increased energy and resources costs (Rubin et al., 2015) <sup>[[#fn:r172|172]]</sup> . Storage capacity estimates vary greatly, but Section 2.4.2 as well as literature (V. Scott et al., 2015) <sup>[[#fn:r173|173]]</sup> indicate that perhaps 10,000 GtCO <sub>2</sub> could be stored in underground reservoirs. Regional availability of this may not be sufficient, and it requires efforts to have this storage and the corresponding infrastructure available at the necessary rates and times (de Coninck and Benson, 2014) <sup>[[#fn:r174|174]]</sup> . CO <sub>2</sub> retention in the storage reservoir was recently assessed as 98% over 10,000 years for well-managed reservoirs, and 78% for poorly regulated ones (Alcalde et al., 2018) <sup>[[#fn:r175|175]]</sup> .  A paper reviewing 42 studies on public perception of CCS (Seigo et al., 2014) <sup>[[#fn:r176|176]]</sup> found that social acceptance of CCS is predicted by trust, perceived risks and benefits. The technology itself mattered less than the social context of the project. Though insights on communication of CCS projects to the general public and inhabitants of the area around the CO <sub>2</sub> storage sites have been documented over the years, project stakeholders are not consistently implementing these lessons, although some projects have observed good practices (Ashworth et al., 2015) <sup>[[#fn:r177|177]]</sup> .

CCS in the power sector is hardly being realized at scale, mainly because the incremental costs of capture, and the development of transport and storage infrastructures are not sufficiently compensated by market or government incentives (IEA, 2017c) <sup>[[#fn:r178|178]]</sup> . In the two full-scale projects in the power sector mentioned above, part of the capture costs are compensated for by revenues from enhanced oil recovery (EOR) (Global CCS Institute, 2017) <sup>[[#fn:r179|179]]</sup> , demonstrating that EOR helps developing CCS further. EOR is a technique that uses CO <sub>2</sub> to mobilize more oil out of depleting oil fields, leading to additional CO <sub>2</sub> emissions by combusting the additionally recovered oil (Cooney et al., 2015) <sup>[[#fn:r180|180]]</sup> .

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