Thermal Energy Storage (TES) is a key component for an efficient energy supply and for achieving a low-carbon energy balance. TES allows flexible storage volumes and periods, and it represents a cross-sector technology as it couples heat, cooling energy, and electricity. This session is dedicated to Underground Thermal Energy Storage (UTES) technologies, their performance and engineering, as well as new insights into related heat transport processes in the subsurface. In particular, the focus is on Aquifer Thermal Energy Storage (ATES), Borehole Thermal Energy Storage (BTES), Mine Thermal Energy Storage (MTES) and related ground-based variants such as pit storage, cavern storage and artificial water-gravel storage basins. The aim of this session is to overcome technical obstacles concerning the design and sustainable operation of TES. We want to improve our understanding of any UTES-related thermal, hydraulic and other environmental effects.
In a broader context, we invite contributions that show how to enhance the societal perceptions and engagement in UTES developments and how to integrate UTES technologies in wider energy system. Both in research and in practice, accurate characterization of subsurface flow and heat transport based on observations of induced or natural variations of the thermal regime is essential. Thus, we invite contributions that reveal new insight into advances in experimental design, report novel field observations, as well as demonstrate new sequential or coupled modelling concepts. The seasonal and long-term development of thermal and mechanical conditions in aquifers and heat transfer across aquifer boundaries are focus points. This also includes the role of groundwater and geothermal energy in the context of UTES for predicting the long-term performance of storage and production of thermal energy (heating and cooling), as well as integration into urban planning and policy making. We also invite hydrogeological studies that examine heat as a natural or anthropogenic tracer with the aim of enhancing thermal response testing or improving our understanding of relevant transport processes in the underground.