With the ongoing emergence of smart and distributed grids, it becomes increasingly important to understand as well as improve legacy infrastructure while operating a much more interconnected and fragile architecture. To support this endeavor, a detailed simulation and real-life analysis are required. Leveraging advanced visualization and analytics methods can significantly improve and simplify tasks such as network analysis, maintenance, and planning, while also enabling operators to spot critical issues which are hard to detect otherwise. In this work, we work towards a comprehensive overview of the methods developed for the interactive visualization of power grids. We give an overview of the development of the field before motivating a range of comparison criteria and then evaluating the advantages and disadvantages of the single approaches. Finally, we derive a set of open research questions and possible further improvements to the field.