This paper documents the approach taken to characterize and represent an updated assessment of U.S. geothermal supply for use in forecasting the penetration of geothermal electrical generation in the National Energy Modeling System (NEMS). This work is motivated by several factors: The supply characterization used as the basis of several recent U.S. Department of Energy (DOE) forecasts of geothermal capacity is outdated; additional geothermal resource assessments have been published; and a new costing tool that incorporates current technology, engineering practices, and associated costs has been released
