This work assesses the retrofit potential of existing Portuguese fossil fuel power plants with post-combustion CO2 capture and storage (CCS) technology. The Integrated Environmental Control Model (IECM) was used to provide a systematic techno-economic analysis of the cost of emission control equipment, the reduction in greenhouse gas emissions, and other key parameters which may change when CCS is implemented at a fossil fuel power plant. The results indicate that CCS requires a large capital investment and significantly increases the levelized cost of electricity. However, the economic viability of CCS increases with higher CO2 prices. The breakeven CO2 price for plants with and without CCS was estimated at $85-$140/t of CO2 depending on the technical parameters of the individual plants. (C) 2012 Elsevier Ltd. All rights reserved.