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Seasonal Aquifer Thermal Energy Storage: MODFLOW-6 Modelling of a Campus-Scale Doublet System and Implications for Heat Network Scalability
Allegra GIBLIN TORLUCCI, Fleur LOVERIDGE, Simon REES, Arka DYUTI SARKAR, Joseph KELLY, Emma BRAMHAM, Nicholas SHAW, David BARNS
[, USA]
Aquifer thermal energy storage (ATES) offers a critical solution for decarbonizing heat networks by enabling long-duration energy storage that reduces grid demand peaks, minimizes renewable curtailment, and provides seasonal load balancing. However, widespread deployment requires robust site-specific modelling to quantify storage capacity and validate design approaches. This study presents a comprehensive evaluation of shallow ATES performance using a campus-scale "living lab" at the University of Leeds as a replicable model for heat network integration. Site characterization at the University of Leeds included a 2024 drilling campaign with thermal response testing (TRT) and multi-rate pumping tests to determine aquifer hydraulic properties and groundwater flow conditions. A dynamic three-dimensional model was developed in MODFLOW 6 incorporating campus data and assumed seasonal injection and extraction cycles over a ten-year simulation period to assess thermal plume stabilization and maximize storage capacity. Operational constraints included a maximum injection temperature of 25°C to limit environmental impacts and peak flow rates derived from pumping test data. Simulations indicate a viable conservative seasonal storage capacity of at least 2,000 MWh for a single doublet system—sufficient to meet approximately 66% of the heating demand for the northern cluster of engineering buildings and student accommodation on campus and significantly improve ground source heat pump efficiency by pre-conditioning inlet temperatures. Results showed good agreement with analytical solutions while providing spatial and temporal resolution of thermal plume evolution not captured by simplified methods. The campus model suggests scalability potential for urban heat networks, with preliminary analysis suggesting national deployment could provide at least 120 TWh of storage capacity. This work establishes a data-driven methodology for ATES feasibility assessment applicable to similar hydrogeological settings globally, addressing a key barrier to widespread adoption of geothermal seasonal storage.
Topic: Modeling