Subsurface Thermal Impacts of Standing Column Well Operation: Insights from Operational Data

Ground source heat pump (GSHP) systems are increasingly adopted as renewable energy contributing to global decarbonization efforts. Standing column wells (SCWs) circulate groundwater directly within a single borehole, thereby leveraging the advantages of both closed-loop and open-loop GSHP systems. Owing to their reduced installation area requirements and cost efficiency, SCWs have been widely implemented in urban environments. However, comprehensive studies on SCWs remain limited, particularly with respect to the environmental impact of SCW operation based on actual operational data. This study characterized the thermal behavior of an SCW system installed at a university library in South Korea. System loads were derived from the operational data and correlated with degree-days, an indicator of energy demand, to quantify their relationships. A numerical model was then developed incorporating this relationship to simulate the spatial and temporal distribution of thermal plumes under different operational conditions. Furthermore, thermal plume evolution was evaluated under future climate scenarios by applying projected degree-days that account for global warming effects. Through this approach, the environmental impacts of SCW operation were evaluated in a more realistic manner, providing insights from a representative case of SCW applications in public institutions. Collectively, these findings are expected to contribute to the enhanced efficiency and long-term sustainability of SCW systems.