The United States Environmental Protection Agency (US EPA) conducts extensive research to enhance the scientific foundation for national environmental decision-making. In this context, US EPA has developed COMET (City-based Optimization Model for Energy Technologies) to capture the whole energy system at the city level over a user-defined analyses timeline, from the extraction of primary resources to conversion into useful energy to meet end-use service demands. COMET accounts for the investment and operation costs, as well as greenhouse gas (GHG) emissions and other air pollutants, of alternative technology pathways meeting long-term energy demands in the buildings, transportation, and waste sectors. In this way, COMET enables users to explore, compare, and optimize energy technology solutions over the coming decades, especially for medium- and large-sized cities working to achieve energy optimization objectives and emissions reduction targets. Model results reveal how the energy system can be balanced under different scenarios and assumptions, as well as how system costs and emissions change with respect to those scenarios. With this information, city officials and their stakeholders working to pursue energy planning within their borders are positioned to make more informed policy and program decisions.

An open-source version of COMET designed for use by local planning, energy, or environmental agencies in any city is developed – will be called “Generative COMET”. The Generative COMET model incorporates innovative features that streamline the calibration process to align with official energy or GHG inventories, based on the level of detail available in city-level data. It provides cities with a versatile framework for analyzing energy and GHG emission scenarios, with different levels of data granularity and city-specific conditions. Its modular and adaptable structure enables cities of all sizes to explore customized strategies for meeting energy demands and achieving GHG reduction targets effectively.

This dataset is associated with the following publication: Kaplan, O., K. Vaillancourt, M. Pied, R. Chaffanjon, F. Pedroli, D. Cooley, and N. Dietsch. Generative City-based Optimization Model for Energy Technologies: COMET Documentation and User Guide. U.S. Environmental Protection Agency, Washington, DC, USA, 2025.