The Energy systems combine physical domains related directly to the processes of generation, storage, distribution, and consumption, in addition to communication technologies and software infrastructure for data and control purposes. The complexity of these heterogeneous systems makes it difficult to study them since tools of different domains must interact. In recent years, emerge a new enabling technique where global simulation of a complex system can be achieved by composing the simulations of its parts called Co-simulation. This research has the purpose of making a comparison between two of these co-simulation frameworks, MOSAIK and HELICS. To this aim, the comparison is divided into two components theoretical and performance.