An important development in recent years has been increased interest in retrofitting CO2 capture at existing power plants. In parallel, it has also been suggested that flexible operation of power plants with CO2 capture could be important in at least some jurisdictions. It is likely that retrofitted power plants could have significant ‘built-in’ flexibility, but this potential is often not considered in studies of the economic performance of power plants with CO2 capture. This paper makes a contribution to filling this gap by developing methods for first order screening analysis of flexible operation of power plants with CO2 capture and applying them to the case study example of an appropriately integrated retrofit of post-combustion capture at a coal-fired power plant. The quantitative analysis suggests that rich solvent storage could be an attractive option on a short-run basis for some fuel, CO2 and electricity price combinations. Results from first order analysis can then be used to determine which operating modes should (and shouldn’t) be included in further, more detailed design studies.