Lessons Learned from Two Open Loop Geothermal Systems Using Shallow Aquifers for Heating and Cooling in Geneva, Switzerland

Conférence Chapitre d'actes Lessons Learned from Two Open Loop Geothermal Systems Using Shallow Aquifers for Heating and Cooling in Geneva, Switzerland eng 2025-10 author Faÿ Sylvie author Brixel Bernard 583062 author Quiquerez Loic 645337 author Soureillat Nicolas author Bel Alexandra https://europeangeothermalcongress.eu/wp-content/uploads/2025/11/Fay-et-al.pdf <p>This paper presents a retrospective analysis of two projects undertaken by the Services Industriels de Genève, focusing on the sustainable use of shallow Quaternary aquifers (<60m depth) in Geneva, Switzerland, for geothermal heating and cooling. Given the relatively slow groundwater flow velocities of these aquifers, the development, in collaboration with the State of Geneva through the Geothermies program, of hydrogeological models for long-term temperature variations prediction of these aquifers is essential for ensuring their sustainable exploitation. A central aspect of these projects was the establishment of a comprehensive monitoring system to track temperature variations over time within the aquifers. Through numerical modelling and operational data, the study highlights key challenges such as thermal short-circuit within the aquifer and seasonal imbalance between heating and cooling demands. The paper outlines mitigation strategies including installation of air-coolers or heaters, solar thermal recharge and integration with district heating/cooling networks. These case studies underscore the importance of flexible system design, continuous monitoring, and balanced thermal loads to ensure the long-term sustainability of shallow geothermal resources in urban settings.</p> Open-Loop geothermal systems Shallow aquifers Thermal short-circuit Urban geothermal energy Sustainable heating and cooling District heating/cooling networks Aquifer thermal recharge Geneva Canton GEothermies program Dewey 550 Dewey 333.7-333.9 18 Institut des sciences de l'environnement 0DB 41 Département F.-A. Forel des sciences de l'environnement et de l'eau 153 false 938 ISE Pôle Sciences 945 ISE Energie 659 Systèmes énergétiques European Geothermal Congress 7-9 Octobre 2025 Zürich (Switzerland) 0f560e5d-7ceb-4f8f-9c48-c39093e9e936 Proceedings chapter (Published version) Public EGEC2025_OpenLoopGeothermalSystems_.pdf 1231955 application/pdf 9406772c8cd37594a64e07b0488ebff5e1da2e21cfd0b6d2cc9ebab4cb4de0df openAccess Centres et instituts / Institut des sciences de l'environnement Faculté des sciences / Section des sciences de la Terre et de l'Environnement / Département F.-A. Forel des sciences de l'environnement et de l'eau

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Lessons Learned from Two Open Loop Geothermal Systems Using Shallow Aquifers for Heating and Cooling in Geneva, Switzerland	European Geothermal Congress			2025	50	94

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Brixel, Bernard