One of the challenges in the area of photovoltaic electricity production is the intermittent production and the required electricity demand. Depending on the actual scenario the use of electrical energy storage systems can extend the utilization of PV based distributed energy production systems. The new requirements of current and future electricity networks based on Distributed Energy Resources (DER) in particular for Renewable Energy (REN) lead to system architectures with a combination of technologies to improve performance and efficiency of distributed generation. Energy storage technologies can deliver stored electricity to an end-user or the electric grid. They can be used as uninterruptible power supply (UPS), or for improving the power quality. Since these energy devices are located usually near the point of use, they are included in the distributed energy resources category. Especially with local energy production such as photovoltaic systems or wind turbines they form a simple hybrid system where it is important to design cost effective optimum system based on the specific needs in on grid and off grid scenarios. This thesis looks into the typical use-cases and related scenarios in order to categorize the usefulness of electrical storage systems. The main focus is on the combination of photovoltaic electricity production and batteries as a storage system and the different system combinations in on grid and off grid scenarios. The goal is to categorize the results in order to determine the optimal storage size. The combination with photovoltaic electricity production allows the use of existing data for a wide variety of use-cases. The integration of the electricity output of non-predictable sources requires the balancing of production and load. Understanding the different scenarios and the impact of the storage design parameters will allow for the design of better systems in the context of Distributed Energy Resources.