## 4 Discussion
### Further Application Examples  
The mosaik co-simulation framework has already been applied by different institutions in a variety of CPES test cases [39; 40; 41], demonstrating features like interoperability with real-time laboratories [21], the possibility of simulator exchange [20], or distributed coordination of heterogeneous simulation components [42].  
In the project NEDS, mosaik has been used to simulate different parts of a smart grid in energy scenarios of the years 2050 and transition years. In this setting, ISAAC was coupled with a smart home model, optimizing the flexibility usage of domestic loads with regard to congestion avoidance and cost minimization. For the development of the energy scenarios and their evaluation of sustainability, the SEP has been developed [23]. Supported by an information model, the scenarios have been modeled in this interdisciplinary project with partners from different domains, like electrical engineering, computer science, business administration, economics, and psychology.  
In the project Smart Nord ([[http://smartnord.de/](http://smartnord.de/)]([http://smartnord.de/](http://smartnord.de/)) (only available in German)), mosaik has been used for different purposes [43]. One major task has been the testing of agent-based distributed optimization strategies with different objectives along the value chain of a dynamic VPP [33]. Aside from that, market-based re-dispatch solutions have been evaluated with mosaik to test whether the associated products can help to prevent congestions in the system [44].  
Another approach for congestion management was developed in the project Designetz ([[https://www.designetz.de/](https://www.designetz.de/)]([https://www.designetz.de/](https://www.designetz.de/))) where a system cockpit (SC) was developed as an intelligent user interface for distribution system operators. It allows to identify congestions and initiate mitigation actions using various flexible units. For testing the functioning, the process of congestion management implemented in the SC architecture with many heterogeneous components mosaik is used as a connecting middleware. Those simulators include a flexibility optimizing heuristic (ISAAC), a database encapsulating real-world units, and a planning tool for determining the power system status. For details, see [35].  
The project LarGo! ([[http://www.largo-project.eu/](http://www.largo-project.eu/)]([http://www.largo-project.eu/](http://www.largo-project.eu/))) is focused on the large-scale roll-out of CPES solutions [45]. Mosaik is used to couple simulators for testing the roll-out and deployment process of smart grid applications. This includes power system simulation and ICT simulation.  
While most of the project mentioned so far are focused on purely software based CPES testing, the mosaik environment is also employed in the hardware-related European projects uGrip ([[http://www.ugrip.eu/](http://www.ugrip.eu/)]([http://www.ugrip.eu/](http://www.ugrip.eu/))) and ERIGrid ([[https://ergrid.eu/](https://ergrid.eu/)]([https://ergrid.eu/](https://ergrid.eu/))). The former is focused on the hardware integrated testing of microgrid solutions while the latter is contributing to the improvement of laboratory and co-simulation platforms for CPES testing.