The amount of energy-related data is increasing: Smart meters, smart plugs, and even household appliances themselves create detailed records of energy data. This kind of data can be used to gain valuable insights into the status of the energy grid. Furthermore, energy data can serve as a basis for elaborate optimization and for additional services, leading to a significant commercial value. But at the same time, energy data often is highly sensitive data that can affect residents’ privacy. Therefore, an energy data management system is needed which satisfies both technical as well as user-driven requirements. This paper presents a concept for such a user-oriented energy data management system. During the design phase, a detailed requirements analysis was performed. An initial data life cycle analysis focussed on technical aspects. Ensuing this step, an analysis from a user’s perspective was performed. The resulting requirements form a list of specifications which were used to create a modular concept called Data Custodian Service. This system has also been implemented in form of a demonstrator.