The use of information technology services is increasing and causes a rising energy demand of data centres. In order to cover the requirements linked to this effect and respond to the energetic and environmental goals, fossil fuels need to be replaced by renewable energy sources, and methods to increase the efficiency of the processes have to be developed. Regarding the energy supply of data centres, the complex integration of different energy systems into the technical infrastructure of the data centres is challenging. Within the RenewIT project [1], fourteen thermal and electrical power supply concepts for data centres have been investigated [2]. Regarding intermediate results of the project, the four concepts with combined heat and power production (CHP) provide the most promising solutions. One of the concepts with CHP, the system biogas-fed solid oxide fuel cell (SOFC), is presented to show the methodology of modelling and simulating the CHP subsystem including non-series products with EBSILON [3]. The complex part load behaviour of the subsystem is identified and the information is transferred into TRNSYS [4] to increase data processing and minimize computing time.