This paper presents a fine-tuned coupling of four energy models in order to include important electricity system aspects. These are detailed modeling of electricity demand, agent-based market dispatch of generation units and long-term capacity investments as well as congestion management in the transmission grid. The approach is applied for Germany and its neighboring countries. First results illustrate a whole coupling loop. In addition, the application of generation and transmission adequacy indicators shows a significant increase in critical system states from 2035 onwards.