This paper studies the cost of energy (COE) for several emerging, fossil fuel power plants such as an integrated gasification combined cycle (IGCC) power plant, a natural gas combined cycle (NGCC) power plant, and a pulverized coal (PC) power plant under three different scenarios defined by the International Energy Agency (IEA). In order to compare the COE for each power plant more realistically, the concept of the 20-year levelized cost of energy (LCOE) was used. Since previous LCOE analyses did not consider the changes in fuel price and CO2 prices, the reliability of previous LCOE results is not good enough to be acceptable for future energy planning. In this study, modified LCOEs, which consider the changes in fuel and CO2 prices with respect to the different scenarios were suggested in order to increase the reliability of the economic comparisons of emerging, fossil power plants. In addition, energy planning was done in order to present the applicability of the proposed calculation method for the COE. (C) 2011 Elsevier Ltd. All rights reserved.