A supplemental report to the U.S. Energy Information Administration’s (EIA) Annual Energy Outlook 2021 (AEO2021) describes how EIA uses a ratio of a power plant’s revenue to its cost (or value-cost ratio) as a simple metric to explain the economic competitiveness and, in turn, the types of power plants most likely to be built in EIA’s long-term model for the U.S. energy sector.