A study "C02 capture readiness of unit 6 in Thermal power plant ŠOštanj" prepared in June 2010 confirms that Unit 6 of Power plant Šoštanj fulfils technical and spatial requirements of capture readiness defined in European legislation. An addition to the study in greater detall analyzes availability of suitable CO2 storage sites ln Slovenia, nearby countries and North sea. Their availability and appropriate capadty are the condition of retrofitting CCS to the Unit 6 of Thermal power plant ŠOštanj. Carbon capture plant will capture from 70,2 to 76,2 Mlo.t carbon dioxide in the period from the year 2020 to 2054. Estimates demonstrate that Slovenia has sufficient storage capacity to store captured CO2 on Unit 6. The conservative storage capacity estirnate for aquifers amount about 92 MiO.t. Besides aquifers a potential additional storage site is represented by coal mine located just near the Power plant. Storage sites in nearby countries like Croatia and Italyhave large storage capacities and are in radius at maximum of 350 km. That Is c10se enough not to make high transport cost. Another possible solution offers port Koper at the Adriatic sea. From there it is possible to transport compressed CO2 to suitable locations in North sea or elsewhere by ships. Economical parameters of retrofitting carbon capture and storage technology to Unit 6 like investment cost, operational & rnaintenance cost, transport and storage cost are analyzed. Cost originating from Ioss of power production rs also considered. All of them are expressed in Euros per unit of generated electricity ( /MWh). When C02 is mainly stored in Slovenian deep onshore aquifers the total cost of CCS is in range from 28,1 to 39,1 /MWh andthe representative value is 30,6 /MWh. In the case when C~ has to be transported to locations about 250 km from the source and stared in onshore aquifers the cost is from 28,8 to 39,9 /MWh and the representative cost is 31,4 /MWh, Total carbon capture and storage cost could be even higher it the distances to storage sites are longer, the transport is carried out by offshore pipelines or by ships and the storing is dene in offshore aquifers.The cost of electrlcity generatiOn that originates from CCS is compared with the cost that is based on price of C02 aliowances. Considering the lowest CCS cost implementatiOn to Unit 6 of Therrnal power plant ŠOštanj (storage in Slovenian onshore aquifers) is in range of cost originating from emission trading when CO2 allowance costs more than 33 . In case of high est carbon capture and storage cost (storage in onshore aquifers 250 km from Unit 6) the point where CCS yields more than emission trading is at 46 per CO2 allowance. Additlon to the study "C02 capture readiness of unit 6 in Thermalpower plant ŠOštanj" shows that storage sites for permanent storage of carbon dioxide are available and have sufficient capacity. Cost analyzes confIrms that retrofitting carbon capture and storage technology to Unit 6 of Therrnal power plant ŠOštanj Is economically feasible and in range with cost induced by emisslon trading.