Simulation and evaluation of stratified discharging and charging devices in combined solar thermal systems

► TRNSYS simulation study investigates different discharging and charging strategies. ► Energy savings due to better stratification increase with increasing solar fraction. ► Stratified discharging leads to the same or higher energy savings than stratified charging. ► Discharging with 4-way valve has higher energy savings than charging with 3-way valve. ► Discharging with two tapping points has 80% of advantage with seven tapping points.