Aquifer Thermal Energy Storage within a Groundwater Protection Area: Interactions under Seasonal Imbalanced Conditions

This study investigates the interactions between Aquifer Thermal Energy Storage (ATES) systems and groundwater extraction within protected drinking water zones, focusing on the effects of seasonal thermal imbalance. ATES systems store and recover thermal energy using aquifers, offering a sustainable alternative to fossil fuels for heating and cooling. However, their deployment is restricted in groundwater protection areas due to concerns about thermal and chemical interference with drinking water supplies.

Using a synthetic groundwater model based on the Grobbendonk extraction zone in Belgium, the study simulates 800 scenarios with varying degrees of seasonal imbalance—where summer heat injection exceeds winter extraction. The results show that such an imbalance increases annual temperature fluctuations at nearby groundwater wells from 1.2°C to 1.5°C. Sensitivity analysis identifies the imbalance and flow rates as the most influential factors, with geological conditions also playing a significant role.

The findings suggest that thermal disturbances increase under imbalance but stabilize over time without long-term cumulative effects. This research provides quantitative insights into safe ATES deployment near groundwater wells, supporting more flexible regulations and improved subsurface planning for sustainable energy use.