The setup of a shell-and-tube type LTS is shown in Figure 1. Within a container (shell), several storage elements are consistently distributed. The main component of the storage elements is a tube with heat transfer fluid (HTF) on the inside and PCM on the outside. For charging and discharging, the HTF flows through the pipes. The temperature difference between the HTF and the other parts of the storage elements causes charging or discharging of the storage system. Typically, the PCM changes its phase during these processes. On charging, the PCM melts and solidifies on discharging. Since the PCM has a comparatively low heat conductivity, fins can be included into the storage unit to improve the charge and discharge power. In the following, several different types of fin allocations and their effects on the storage performance during discharge will be examined with numerical simulations, examples of which are pictured in Figure 2. The types of analyzed fin allocations can be categorized into five groups. Each allocation consisted of a storage element with 100 fins. Mostly, the fin density (fins per axial distance) increased towards the storage unit outlet in order to adapt the fin density to the temperature difference between HTF and PCM.