Feasibility Assessment of Aquifer Thermal Energy Storage: A Case Study in Riva del Garda, Italy

Aquifer Thermal Energy Storage (ATES) systems have emerged as a promising technology for balancing seasonal variations in energy supply and demand, particularly in heating and cooling applications. By acting as seasonal buffers, ATES systems in larger scales can contribute to the stability of heating networks and offer flexibility in the electricity market through power-to-heat technologies such as heat pumps and electric boilers, thereby facilitating the integration of renewable energy sources. However, their successful deployment depends on a comprehensive understanding of local subsurface conditions, especially hydrogeological characteristics. Present study investigates the feasibility of ATES systems in a shallow confined aquifer (less than 200 m depth) in Riva del Garda, Italy. A site-specific numerical model was developed to assess system performance with a focus on recovery efficiency including a sensitivity analysis to explore the influence of three key parameters: (i) variability in hydraulic conductivity, (ii) strength of hydraulic gradients, and (iii) temperature magnitude of injected water for storage. Numerical simulations were conducted in the FEFLOW© software environment, enabling a robust evaluation of thermal behavior under multiple operational conditions. Further developments using the Volsung toolkit aims to refine the simulation model and explore the impact of subsurface variability in greater details. The obtained results confirm potential of ATES systems as a viable solution in line with the targets of decarbonizing large heating networks in Riva del Garda, Italy. Our findings emphasize the significant importance of hydraulic gradient, hydraulic conductivity, well spacing, and injection water temperature in shaping thermal recovery efficiency and overall system effectiveness.