Geothermal energy is gaining attention as a reliable source of clean, firm power for the U.S. power sector, spurred by advancements in enhanced geothermal systems (EGS) and drilling techniques. To address its underrepresentation in capacity expansion models, EPRI and the National Renewable Energy Laboratory, with funding from the Department of Energy’s Geothermal Technologies Office collaborate in this project to enhance the representation of geothermal technologies and resources in EPRI’s US-REGEN model and to derive general guidelines for improving the representation in other capacity expansion models. To this end, hydrothermal, near-field and deep EGS resources are integrated following NREL’s ReEDS model temperature-based resource supply curves and cost assumptions. Six scenarios are analyzed with the improved geothermal representation, two economy-wide net-zero pathways—differentiated by the availability of carbon capture and storage (CCS)—across three geothermal cost scenarios (conservative, moderate and advanced). In the advanced cost scenario, geothermal, particularly deep EGS, could reach 36 GW of capacity nationally by 2050 in the pathway with CCS and 59 GW in the pathway without CCS, contributing up to 8.5% of total electricity generation. However, deployment remains limited under conservative and moderate cost assumptions. These findings underscore the relevance of incorporating EGS into capacity expansion models and offer guidelines for better technology integration. These guidelines emphasize consistent resource definitions, temperature-based classifications, regional disaggregation, and addressing cost uncertainty, while tailoring the technology representation to the model’s structure and complexity to ensure accurate and informed utility planning and policy development.
Authors Anahi Molar Cruz and Nils Johnson