Modelling of aquifer thermal energy storage connected to hospital buildings: A case study in Denmark

Aquifer thermal energy storage (ATES) is a type of un-derground seasonal thermal energy storage which uses underground water as the storage medium. Different modeling and simulation tools have been used to model ATES coupled with building and district energy systems.However, most of these methods use co-simulation techniques, which are computationally expensive, time consuming and complex to set up and debug. This paper illustrates a simplified cooling-mode operation of an ATES-based system model developed entirely using the Modelica language. Results indicate that Modelica is an appropriate tool for developing energy system models consisting of ATES to assess their performance. For the case study analyzed in this paper, we controlled the aquifer circulation pumps to supply a constant water temperature of 12 °C to the buildings. Furthermore, the model allowed us to predict the aquifer temperatures in the warm well over time at different distances.