Abstract Integrating flexibly-operated carbon capture and storage (CCS) into the existing power plants has operational benefits for the future low carbon power systems. This paper proposes an improved formulation for flexible operation of carbon capture power plants (CCPPs) within the conventional economic dispatch (ED) problem. The main contribution of this work is the simplification and the practicality of the variables used for the flexible operation control of the facility. The optimal ED problem of thermal power generation portfolio with CCPPs within the mix are computed using a chaos-enhanced Cuckoo Search optimization algorithm. To test the proposed formulations, an IEEE 30 bus test system was used. The impact of varying carbon prices on the system dispatch was investigated. The results reveal the potentiality of decoupling the generation and emission outputs of the thermal power plants.