The European Union as a whole is dependent on the imports of primary energy sources, mostly due to politically or economically unstable regions, and their dependence is constantly increasing. Since a new millennium, the EU started to adopting strategies focusing mainly on energy efficiency and the usage of renewable energy sources as their potential is not negligible. There are a big differences in the usage of the renewable energy sources among the member states. The main purpose of this thesis is to discover barriers of renewable energy sources implementation. The relevant concepts of Path Dependence, Intergenerational Change and Multi-Level Perspective are tested with the data of chosen study case, Denmark and Slovakia, in order to analyze barriers which are standing in the way of implementation of renewable sources. As a result, six main barriers are illustrated.