Analysis of high-temperature aquifer thermal energy storage system performances with heterogeneous permeability distribution, insights from a case study in Burgwedel, Germany

Abstract

A high-temperature aquifer thermal energy storage (HT-ATES) system has the potential to balance the seasonal mismatch of energy supply and energy demand. Reservoir permeability heterogeneity is generally not considered in the investigation and design of ATES projects. In this case, this study investigated the influence of heterogeneous permeability fields on the performance of target HT-ATES, i.e., pressure, terminal production temperature, energy recovery rate, and levelized cost of heat. Results show that the heterogeneous permeability distribution slightly influences the terminal production temperature and energy recovery rate with the constant injection and production rate. However, the injection and production pressures are highly related to the standard deviation of unevenly distributed permeability but demonstrated to be independent of the correlation length. Compared to the heterogeneity of the permeability field, the reservoir energy recovery rate and terminal production temperature are more sensitive to the well spacing. In addition, energy loss due to the surrounding rocks only matters during the early times of the operation period and becomes less significant as the operation proceeds. Furthermore, the growth in injection/production pressures due to the permeability heterogeneity considerably increase the system levelized cost of heat by more than 25 % compared to the current operating ATES systems.