future events (Palmgren et al., 2004). A reliable quantitative assessment of future costs of storage would emphasize, at least qualitatively, the uncertainty arising from such attitudes, so quantitative estimates based on engineering analysis may represent a lower bound on future costs.
Storage entails a health risk associated with acute leaks and exposure of workers or populations to hazardous concentrations of CO2 near facilities, an ecological risk to soils and groundwater due to chronic leakage, and a warming risk associated with sudden or chronic leaks that may partially or entirely vitiate the climatic value of a storage site (Anderson and Newell, 2004; Socolow, 2005). The likelihood of such acute or chronic leaks is discussed elsewhere in this report. The public and policy makers are likely to anticipate those risks and require that they be taken into account in the design, monitoring, and carbon-accounting procedures and in associated regulatory frameworks that would be part and parcel of storage (Wilson et al., 2007). Cost estimates therefore need to anticipate delay in initiating demonstration projects due to time lags in conception and development of the overall regulatory regimen for storage, as well as regulatory delay in licensing of each specific project, both in the demonstration phase and beyond. Some issues, such as liability insurance for near-term operation and for long-term site maintenance, require political resolution that may introduce additional delays (IRGC, 2008). Uncertainty in the probability of long-term leaks could translate into regulations that require the purchase of allowances equivalent to a fraction of the carbon stored by sources that are planning to sequester carbon; this requirement would increase the net cost of carbon capture and storage (CCS) compared with other alternatives.
Although there is no a priori reason for extended licensing delays to occur beyond the demonstration phase, experience with siting of a variety of industrial facilities (Reiner and Herzog, 2004) suggests that delays of a year to several years would not be unusual.
Once CCS attains full commercial-scale operation, delays could arise because of accidents that cause or threaten releases. The technologies, monitoring, and regulation of storage are likely to be closely related or even identical among sites, so interruption of operations at one site could affect operations at other sites and broadly reduce or temporarily eliminate storage; undermine credibility of the technology among investors, regulators, policy makers, and the general population; and add a substantial risk premium to investment in CCS.