Evaluating thermal losses and storage capacity in high-temperature aquifer thermal energy storage (HT-ATES) systems with well operating limits: insights from a study-case in the Greater Geneva Basin, Switzerland

Abstract

High-temperature aquifer thermal energy storage (HT-ATES) may play a key role in the development of sustainable energies and thereby in the overall reduction of CO2 emission. To this end, a thorough understanding of the thermal losses associated with HT-ATES is crucial. We provide in this study a numerical investigation of the thermal performance of an HT-ATES system for a heterogeneous aquifer modelled after a well-defined region in the Greater Geneva Basin (Switzerland), where the excess heat produced by a nearby waste-to-energy plant is available for storage. We consider different aquifer properties and flow conditions, with complex injection strategies that respect maximum/minimum well pressures and temperatures, as well as legal regulations. Based on the results, we also draw conclusions on the economical feasibility (e.g., energy recovery factor vs. drilling costs) for the different strategies.Our results indicate that the true behaviour of HT-ATES systems may deviate significantly from theoretical performance derived from idealised cases. This is particularly true when the operational pressure and temperature ranges of the wells are restricted, and for heterogeneous aquifers.

3D Basin‐Scale Groundwater Flow Modeling as a Tool for Geothermal Exploration: Application to the Geneva Basin, Switzerland‐France

“…We investigate groundwater flow in the Geneva Basin using the geothermal module of MRST (Collignon et al., 2020). We consider a single‐phase H 2 O compressible Darcy flow.…”

“…The geothermal module also provides the necessary equations of state to account for density and viscosity changes. Further details about the geothermal module can be found in Collignon et al (2020).…”

“…In the model, they are set as hydrostatic pressure and constant geothermal gradient according to Chelle-Michou et al (2017). The fluid density and viscosity are computed following the Spivey et al (2004) formulation, implemented by default in the geothermal module of MRST (Collignon et al, 2020). Thermal fluid parameters are chosen in the range of appropriate literature values (Sharqawy, 2013).…”

“…In this framework, the Canton of Geneva is exploring geothermal opportunities in the Greater Geneva Basin (GGB, Figure 1) (Faessler et al., 2015) thanks to the GEothermie2020 program (https://www.geothermie2020.ch). Preliminary results have been encouraging (Carrier et al., 2019) and numerical models have already been used to evaluate the feasibility of heat storage in the Molasse and Malm formations of the GGB (Collignon et al., 2020). However, basin‐scale fluid flow processes remain poorly documented in the region.…”

“…Interpreted seismic lines are obtained from Allenbach et al (2017) and Clerc et al (2015). tested by Collignon et al (2020) to investigate low-to medium-enthalpy hydrothermal and groundwater systems (MRST geothermal module) (https://www.sintef.no/projectweb/mrst/modules/#geothermal).…”