The main research question addressed in this work is how energy clusters can be evaluated and what general conclusions can be drawn out of their activities. Traditional innovation cluster analysis approaches chiefly rely on surveys, interviews, open publications, and patents—lack of using updated activities of innovation clusters. Therefore, preceding cluster analysis methodologies always lack of providing up-to-date information. In this sense, analyzing energy cluster activities is an obvious interest for policymakers, investors, companies, etc. Moreover, such assessment help to track the development of new technologies, participation of different actors in an innovation ecosystem, and emerging topics in the energy sector. This work presents the research outcomes on the leading energy-innovation clusters in Germany. To this end, this paper exploits the publicly available website data from the clusters and member’s web-pages to investigate their geographical distribution, key focus areas, cluster, and member activities. In the course of the project, a web-scraping tool has been developed to crawl the clusters and member’s websites and scrape their text data. The tool performs systematic and guided web-scraping for searching a keyword presence on a particular web-page. In addition to this, data from commercially available company databases are used to complement the missing information from the website data. A total of 44 energy clusters along with 4524 members are taken into account in this study. The proposed methodology has shown that unstructured web-data is a valuable source for analyzing the clusters and their member’s innovation activities. Results have also indicated that there is a strong correlation (r=0.85) between Research and Development (R&D) expenditure and cluster count in individual federal states. The overall results have indicated that the majority of energy clusters are very specialized in certain topics, nevertheless, topics such as hydrogen, carbon, and bioenergy are getting notable attention from various stakeholders. Simultaneously, various cross-sectoral topics are also emerging due to the coupling between different sectors. Findings could help policymakers and federal innovation agencies to understand the ongoing progress in cleantech innovation activities. From the methodological point of the view, it provides an underlying ground to access the impact of cluster policies.