Molten-Salt Closed-Loop Geothermal Systems for Super-Hot Rock Resources: Thermal Drawdown Mitigation and Dispatchable Power Through Thermal Buffering

Abstract

This paper presents a molten-salt closed-loop geothermal system developed primarily for super-hot rock environments, where subsurface temperatures exceed those typically accessible to conventional hydrothermal technologies. By operating at ultra-high temperatures and employing molten salt as both the subsurface heat-transfer fluid and the surface thermal storage medium, the system enables efficient, dispatchable geothermal power generation without formation fluid production or reservoir pressure depletion. The paper focuses on the thermodynamic advantages of super-hot rock operation, engineering strategies for mitigating thermal drawdown, and the role of molten-salt thermal buffering in improving system longevity and project economics. Secondary deployment pathways, including retrofits of existing geothermal wells and selected orphaned oil and gas wells, are discussed as complementary but non-primary applications.