The aim of this book is to analyse and compare three European regions, which develop renewable energy technologies, in terms of their organization and functioning. The study is furthermore designed to develop policy recommendations to enhance the performance of regional innovation systems. The focus lies on regional collaboration in the form of networks and formal institutions. A cross-sectional study is conducted. The collected data is concentrated on the existing cooperation initiatives in the regions’ renewable energy sector, such as knowledge and institutional infrastructure, stimuli for innovation, or the influence of regional collaborators on each other. The comparison shows significant differences within the regions’ internal organization and functioning in terms of regional cooperation. It is concluded that the functioning of the triple helix has an impact on the innovation performance of an regional innovation system, while the organization of the region is not found to directly affect renewable energy innovation performance. Policy recommendations underline the importance of the entrepreneurial university and the government’s stimulation of bilateral networks.