Energy Systems and Technologies for the Coming Century ...

The main cost of CCS lies in the capture stage, both in the capital cost of the CCSequipment and especially the loss in efficiency of the power plant. The costs of transportand storage, while substantial, are smaller. The overall cost of CCS is estimated at € 60–90/t CO 2 during the demonstration phase, falling to € 35-50/t CO 2 during the earlycommercial phase (2020-2030) and to € 30-45/t CO 2 after 2030, once the technology iscommercially mature. All prices are per tonne of CO 2 abated. (Metz et al., 2005;McKinsey & Co., 2008). All these costs are on top of the original cost of electricity, andwhether CCS is economic depends on the future price of CO 2 . At present, low CO 2prices make CCS demonstration projects too expensive, so extra funding is required(Figure 1).Figure 1. Estimated development of the cost of CCS (McKinsey & Co., 2008)The technologies for the individual steps in CCS already exist and the geological storagecapacity for large-scale implementation exists. The International Energy Agencyestimates that CCS could reduce the worldwide emissions by 10 Gt CO 2 /y, and that thecost of achieving climate stability 1 by 2050 would be at least 70% higher without CCS(International Energy Agency, 2008). This number could be even larger as found inLüthje et al., 2011. In the future, CCS fitted to biomass-fired power and industrial plantscould be used to decrease the atmospheric concentration of CO 2 .3.2 CCS modelling in TIMESThe various TIMES models contain techno-economic parameters that quantifyexpectations on gradually increased efficiencies and lower costs during the next three tofour decades. The most critical parameter is the loss of thermal efficiency during carboncapture. For example, the efficiency of modern coal-fired steam turbines (pulverisedcoal, PC) will be reduced from 46 % to 36 %. Similar reductions apply to IntegratedGasification Combined Cycle (IGCC) and Natural Gas Combined Cycle (NGCC). Thiswill improve in the future for both with and without CCS, and for some of the variants ofCCS technologies the difference may be reduced. Table 1 shows the assumptions chosenfor quantitative modelling.1 50% reduction in CO 2 emissions, compared to 2005, by 2050.Risø International Energy Conference 2011 Proceedings Page 583