The European Union has some of the most ambitious targets to decarbonise its energy system in the coming decades. To do so, it is likely that many countries will depend on intermittent renewable energy sources such as wind and solar power. There is still a lot of uncertainty in relation to the integration of these resources, since the current energy system is not designed to handle intermittency on the supply side. The Smart Energy System concept is one approach which can accommodate very large penetrations of these intermittent resources, with some analysis demonstrating how penetration levels in excess of 80% are possible in the electricity sector. Hence, this approach is one potential solution that will enable the European energy system to significantly reduce its carbon emissions. In this study, the Smart Energy System approach is applied to Europe, which achieves two key objectives: firstly, it demonstrates the type of technical changes required in the EU energy system by presenting the technologies and their synergies in the Smart Energy System approach and secondly, this study quantifies the scale of each technology required to achieve a 100% renewable energy system in Europe. The results indicate that a 100% renewable energy system is technically feasible in Europe using the Smart Energy System approach, assuming technologies develop according to industry’s current expectations. Furthermore, the results show that the 100% renewable Smart Energy System will have similar costs as a fossil fuel alternative in Europe, but even more significant, the 100% renewable energy system will consist of much more investments instead of fuel imports. A conservative estimate suggests that this will result in the creation of approximately 10 million additional jobs in the EU. These results important in the context of decarbonising energy systems, since they indicate that 100% renewable energy can be technically achieved at an economic gain.