Background: Various monitoring approaches have shown that urban areas and their energy systems are major contributors to climate change. Corresponding observations have mostly been based on physical data. However, text data is an untapped source of information that can be analyzed by text mining methods. Taking the example of the German Energy Transition, an interpretation network analysis was used to assess local transition patterns in 16 municipal climate action plans of regional centers in the State of Lower Saxony. Based on the holistic concept of social-ecological systems, three analytical perspectives were introduced, the social system, the energy system, and the three principles of strong sustainability, which inspired three questions: What is the “horizon of attention” regarding the stages of the energy system? What potential, in terms of coordination or collaboration, can be identified on basis of network links between societal sub-systems and the energy system? Are strong sustainability principles adequately linked to the energy system to support a transition towards sustainability? Methods: A computer-aided interpretation network analysis was used. The (co-)occurrence of indicative words representing pre-defined categories was checked in the measures proposed in the plans to analyze the importance and connectedness of these categories. For this purpose, three thesauri were created as fixed literature-based categorization schemes. Results: Municipalities had a nuanced understanding of climate protection focusing on energy conversion and end-use. Public administrations were closely connected role models, economic stakeholders seemed only partly interlinked. The plans referred to all three sustainability principles. However, their implementation might not fully acknowledge the ecological carrying capacity, because, e.g., the strategy of setting limits could not be clearly identified. Conclusions: To advance municipal climate protection, current cross-sectoral multilevel governance approaches should be improved with emphasis on capacity of local administrations, electricity grids, or renewables in the sectors heat and mobility. Also, more emphasis on sustainability communication and education based on all three sustainability principles will be crucial for a transition towards sustainability. From a methodological viewpoint, the text mining approach could confirm and complement recent studies. Considering its limitations and prospects, it can be advanced to useful tool sets for semantic sustainability assessments.