Seven scientists of the energy informatics groups in Oldenburg (Uni Oldenburg and OFFIS) visited the Carnegie Mellon University in Pittsburgh, PA, USA in order to explore cooperation possibilities. This was funded by the Deutsche Forschungsgemeinschaft (DFG) in form of an initial workshop. The focus of the visit was on intensive discussions about the topics “co-simulation” and “architecture development” – next to the active participation in the annual conference “Carnegie Mellon Conference on the Electricity Industry” on the topic “Testbeds for Smart Grids and Smart Cities: Means of Learning“. On the host side, which was supported by the U.S. National Science Foundation (NSF), ten experts from the working group of Prof. Marija Ilic participated in a very fruitful discussion. Different use cases for further cooperation could be identified, which have already been introduced and furthered by Prof. Sebastian Lehnhoff and Prof. Marija Ilic in the context of the DFG-JST-NSF workshop “Future Power System Architectures and Control Paradigms”, during 20-22 April 2015 in Arlington, VA, USA.