The role of deep closed-loop advanced geothermal systems in the future net-zero Swiss power system

Deep closed-loop Advanced Geothermal Systems (AGS) are a carbon-free electricity generation technology that can support the transition to net-zero power systems by 2050. Unlike conventional geothermal power plants, AGS do not require permeable geologic formations and are thus largely geology-independent, providing distributed, flexible, and dispatchable electricity. Although their resource potential and technological characterization are widely researched, investment costs remain uncertain, and their integration into national power systems has hardly been studied. This paper analyzes the integration of AGS in the 2050 net-zero Swiss power system, focusing on their techno-economic aspects and their contribution to power system security. The generation potential of AGS is computed and aggregated at each transmission grid node, and the conditions under which AGS become an economically competitive generation technology from a cost-minimization perspective are investigated. The interactions of AGS with other generation and storage technologies, as well as with overall system operations, are assessed. Finally, the grid nodes at which AGS are optimally deployed are identified, and AGS’ impact on power system reliability is investigated. The results suggest that AGS become economically competitive in Switzerland at overnight investment costs below 21,500 EUR/kWe when renewable generation subsidies are in place, and below 15,000 EUR/kWe when they are not. The deployment of AGS reduces the need for gas-fired power plants, battery storage, PV, and wind, and AGS installations can concentrate in areas of high demand, high demand-to-generation ratio, or frequent network congestions. Owing to their distributed and flexible nature, AGS also have the potential to enhance system reliability.