Regulatory sandboxes are generally seen as an important tool to make policy and regulation evolve with the changes in our energy system and to create an equal playing field for new technologies and business models that arise with the energy transition. Although an increasing number of legal frameworks on regulatory sandboxes are being implemented in Europe, the pioneers in the Netherlands decided to close their sandbox program. These contradictory events lead to questions about the potential of regulatory sandboxes to bring innovation to the European energy sector. This paper contributes to this discussion by examining the experiences with regulatory sandboxes in Austria, Belgium, France, Germany, Great Britain, the Netherlands, Norway and Spain. We compare approved sandbox projects based on their scope and regulatory derogations to identify areas of innovation and regulatory learning brought by regulatory sandboxes. We also examine the legal frameworks of the concerned countries to evaluate the interaction between the implementation of the framework and its potential to bring innovation. In this way, we develop best practices on the topics of regulatory sandboxes and their imple[1]mentation frameworks.