Explaining (Non) compliance and customization in European infrastructure planning

National administrations are key actors when it comes to the implementation of EU policies. At the same time, they are deeply entrenched in national institutions that may prevent that EU policy objectives are reached. Research on the Europeanisation of national administrations has therefore sought to investigate if and to what extent EU policies lead to administrative change and whether that leads to convergence of administrative structures and processes over time. In this paper we present an explanatory approach for explaining differences and similarities in the national implementation of the Trans-European Networks – Energy (TEN-E) Regulation. The TEN-E Regulation seeks to reform and especially accelerate the permit procedures for energy infrastructure projects that are of a strategic European interest. These projects of common interest (PCIs) are crucial for enhancing energy security, competitiveness and for the integration of renewable energies. To reach the goal of planning acceleration, the Regulation is one of the very few pieces of European legislation that entails detailed rules for national administrative procedures, in particular deadlines for the planning process. However, in practice member states meet these deadlines to varying degrees. We therefore, first, want to explain why some member states plan energy infrastructures faster than others (being more compliant), and second, why the member states differ or converge in the institutional design and speediness of their planning procedures. In our explanatory model, we take into account a set of factors derived from the compliance and customization literature. To explain the compliance (i.e. to what extent the deadlines are met) we elaborate on potential effects of capacity of the national administration, legitimacy of the energy transition, number of actors/veto-players involved in the procedure and perceptions of these actors. To explain divergence/convergence, we build upon the assumptions of the administrative traditions approach, and assume that countries of similar traditions will also adopt similar reforms. With this model, we hope to prepare the ground for fruitful future research: First, on this basis we can extend the literature on customisation by investigating the customisation of administrative procedures – a research area that has so far not received much attention. Second, it hopes to provide insights into the conditions under which customisation can be a problem-solving strategy (in this particular case leading to faster planning procedures). Third, on this basis we can extend the focus of previous research on the Europeanisation of national administrations by including all geographical regions. Fourth, we can contribute to the literature on convergence by investigating if, to what extent and why administrative procedures converge or diverge. While convergence research has hitherto focused mostly on convergence on the outcome, we still know very little about institutional convergence, especially concerning administrative procedures.