CO2 Capture and Storage with Leakage in an Energy-Climate Model

Abstract

Geological CO 2 capture and storage (CCS) is among the main near-term contenders for addressing the problem of global climate change. Even in a baseline scenario, with no comprehensive international climate policy, a moderate level of CCS technology is expected to be deployed, given the economic benefits associated with enhanced oil and gas recovery. With stringent climate change control, CCS technologies will probably be installed on an industrial scale. Geologically stored CO 2 , however, may leak back to the atmosphere, which could render CCS ineffective as climate change reduction option. This article presents a long-term energy scenario study for Europe, in which we assess the significance for climate policy making of leakage of CO 2 artificially stored in underground geological formations. A detailed sensitivity analysis is performed for the CO 2 leakage rate with the bottom-up energy systems model MARKAL, enriched for this purpose with a large set of CO 2 capture technologies (in the power sector, industry, and for the production of hydrogen) and storage options (among which enhanced oil and gas recovery, enhanced coal bed methane recovery, depleted fossil fuel fields, and aquifers). Through a series of model runs, we confirm that a leakage rate of 0.1%/year seems acceptable for CCS to constitute a meaningful climate change mitigation option, whereas one of 1%/year is not. CCS is essentially no option to achieve CO 2 emission reductions when the leakage rate is as high as 1%/year, so more reductions need to be achieved through the use of renewables or nuclear power, or in sectors like industry and transport. We calculate that under strict climate control policy, the cumulative captured and geologically stored CO 2 by 2100 in the electricity sector, when the leakage rate is 0.1%/year, amounts to about 45,000 MtCO 2 . Only a little over 10,000 MtCO 2 cumulative power-generation-related emissions are captured and stored underground by the end of the century when the leakage rate is 1%/year. Overall marginal CO 2 abatement costs increase from a few €/tCO 2 today to well over 150 €/tCO 2 in 2100, under an atmospheric CO 2 concentration constraint of 550 ppmv. Carbon costs in 2100 turn out to be about 40 €/tCO 2 higher when the annual leakage rate is 1%/year in comparison to when there is no CO 2 leakage. Irrespective of whether CCS deployment is affected by gradual CO 2 seepage, the annual welfare loss in Europe induced by the implementation of policies preventing "dangerous anthropogenic interference with the climate system" (under our assumption, implying a climate stabilisation target of 550 ppmv CO 2 concentration) remains below 0.5% of GDP during the entire century.

Leakage risks of geologic CO2 storage and the impacts on the global energy system and climate change mitigation

“…Specifically, IAMs have been used to analyze CCS deployment for various scenarios of technological availability and options for regulatory control (Bosetti et al 2012;Griffin et al 2014;Kalkuhl et al 2015;Kanudia et al 2014;Koelbl et al 2014;Muratori et al 2016Muratori et al , 2017Smith et al 2015;Gerlagh 2009, 2016;van der Zwaan and Smekens 2009). In most of these analyses, CCS technologies are used for 20-80% of primary energy production under various scenarios.…”

“…The economic implications of leakage have been investigated, some using integrated assessment models, by considering the economic burden that would fall on future generations or lost carbon credits when leaked CO 2 returns to the atmosphere (Gerlagh and van der Zwaan 2012;Ha-Duong and Keith 2003;Keller et al 2008;Teng and Tondeur 2007;Gerlagh 2009, 2016;van der Zwaan and Smekens 2009). While these normative studies provide valuable insights on Bacceptable^rates of leakage to the atmosphere, they do not consider the geophysical processes that control the outcomes and economic consequences of leakage.…”

Evaluating Uncertain CO2 Abatement over the Very Long Term

“…It has been argued that 1%/year CO 2 leakage is unacceptable from a global climate point of view, while a 0.1%/year leakage rate may perhaps be permissible (see e.g. [35] and references therein). At a 1%/year CO 2 leakage rate a given quantity of geologically stored CO 2 will have reduced to 37% of that amount after 100 years, whereas 90% of that quantity is still stored underground after a century for a storage medium characterized by a 0.1%/year leakage rate.…”

Bearing the Cost of Stored Carbon Leakage

“…In particular, the prospect of leakage could hinder the mitigation potential of fossil fuel CCS, hampering its future deployment. Consequently, it would lead to an increase in climate policy costs (van der Zwaan and Smekens, 2009). For this reason it is important to understand the magnitude of leakage, which is captured typically through the leakage rate, that is, the rate at which CO 2 leakage occurs at a specific storage site per year in terms of the stored carbon.…”

“…This low deployment can be associated with the absence of adequate incentives, lack of public acceptance, and to technological uncertainties associated with CCS (IEA, 2016;Lipponen et al, 2017). Among these barriers, carbon leakage from stored CO 2 could counteract the usefulness of carbon sequestration to help limiting global temperature increase (van der Zwaan and Smekens, 2009). In this paper, we analyze the impact of CO 2 leakage on the propsects of CCS in the power sector and the economic costs of mitigation 1 .…”