The National 5G Energy Hub is a research association between the TU Dresden and the RWTH Aachen as well as companies from the information technology sector. The project scope can be seen in the context of the digitalization of the energy sector. The key points are therefore sector coupling in the domain of thermal and electrical energy, wireless communicaton technologies for a scalable sensor and actuator pool and a flexible cloud infrastructure with respect to data privacy awareness. The paper presents selected use cases as an intersection of the main features of the 5G mobile radio standard and the requirements of future-oriented smart grid and smart building concepts. In the following, the cloud architecture designed for reliable and scalable information exchange is presented. Finally, the resulting services are highlighted and an outlook is given for the operation of a demonstrator.