Utilities are under increasing pressure to reduce power plant CO2 emissions. If the US and world follow through on their long-term commitment to dramatically reduce emissions, this pressure will become significant over the coming decades. It is in the face of these concerns that the future of US fossil-fired power plants is examined. There are over 1337 operational fossil-fired power generating units of at least 100 MW in capacity that began operating between the early 1940s and today in the continental US. Together these units provide some 453 GW of electric power. Rapidly retiring this still valuable capital stock or undertaking large-scale immediate redevelopment with advanced power cycles as a means of addressing their greenhouse gas emissions will not be a sensible option for all of these units. Considering a conservative 40-year operating life, there are over 667 existing fossil-fired power plants, representing a capacity of over 291 GW, that have at least a decade's worth of productive life remaining. Applying Battelle's specialized analysis tools, relationships between these 667 plants and their technology type, location, emissions, and vintage have been explored. Based on these factors and the proximity of these plants to geologic reservoirs with potential for sequestering large volumes of CO2, the average costs for retrofitting these newer-vintage plants with capture technology and sequestering their CO2 into such reservoirs are presented. A discussion of a set of planned US fossil-fired power projects within the context of a carbon-constrained world is also included. (C) 2004 Elsevier Ltd. All rights reserved.