Determinants for the market diffusion of renewable energy technologies - An analysis of the framework conditions for non-residential photovoltaic and onshore wind energy deployment in Germany, Spain and the UK

The deployment of renewable energy (RE) technologies for electricity generation is a central element of the European energy and climate strategy and was laid down in binding targets on EU-level. The actual RE technology diffusion is, however, shaped by the framework conditions and support measures implemented in the individual EU Member States. This dissertation aims at contributing to a more integrated view of the influencing factors (determinants) for the deployment of RE technologies. To this end, a conceptual framework is drawn up to assess the boundary conditions for RE diffusion from the RE developer's perspective. The framework is operationalised using a composite indicator (CI) approach and applied in a diffusion model to allow the anticipation of possible future technology deployment. The thesis concentrates on two mainstream RE technologies, namely onshore wind and non-residential PV, and focuses on European countries. Within the analysis, particular emphasis is placed on providing a holistic assessment of the impact of economic and non-economic determinants on the diffusion of RE technologies at national level. The assessment aims at understanding RE developers' preferences and rationalities regarding the overall framework conditions for RE deployment in order to identify the drivers for and barriers to technological change and to facilitate efficient policy design and regulatory transformation. The most relevant diffusion determinants from the viewpoint of RE project developers are identified through literature research and moderated expert workshops. The relative relevance of the determinants in the diffusion process is then assessed based on an EU-wide questionnaire that resulted in the collection of >200 datasets. Building on this broad empirical basis, a composite indicator (CI) is developed for the diffusion of non-residential PV and wind onshore. The CI provides a transparent framework for the quantification of the diffusion determinants and allows an evaluation and benchmarking of national RE frameworks. In a further step, the CI is integrated in a diffusion model which enables projections of possible future market developments under different configurations of the national RE framework. This modelling approach applies and further develops established logistic models of technology diffusion. The overall approach is validated by applying it to three case study countries: Germany, Spain and the United Kingdom. Data collection in these case study countries involved, among others, semi-structured interviews with 31 RE experts. The different regulatory framework conditions in the three countries lead to 3 different CI results and projected technology diffusion. The results verify the robustness of the approach and the applicability of the concept to different national contexts. The findings of this thesis contribute to the methodological and empirical basis for understanding and modelling technology diffusion processes in general and RE technology diffusion in particular. The approach developed in this thesis further improves the scientific basis for the evaluation of RE support policies and can contribute to RE targets being achieved in an efficient and sustainable way.