This contribution studies the usability of aquifer thermal energy storage (ATES) for seasonal solar heat storage by means of thermo-hydraulic modeling. The geological setting refers to the North East German Basin (NEGB), specifically a site approx. 50 km west of Berlin, Germany. The considered storage formation is located in Jurassic sandstones at about 270 m depth below surface, showing an in-situ (undisturbed) formation temperature of around 17 degrees C and appropriate hydraulic storage properties. The paper considers idealised doublet systems in faulted as well as unfaulted reservoir domains and studies the energy-and mass transport of simulated ATES systems. Five perennial loading/unloading series of solar thermal energy are investigated, assumed to be harvested by a hectare-sized flat plate collector field which is modeled employing climate data of the considered region. The simulation results exemplarily show how the storage system develops temperature-conserving recovery fractions of up to 80% heat recovery during the first years of operation. (C) 2016 Elsevier Ltd. All rights reserved.