Environmental changes and related public policies require an energy-focused sustainable industrial transformation (SIT) that reconciles economic, environmental, and social objectives. Local energy clusters are conducive to these transformative processes since they represent institutional structures that link key actors and factors in territorial communities to form niches for the green transition. However, SIT policies at the local level are in a nascent stage, and empirical evidence on these processes remains scarce. Furthermore, it is necessary to advance a conceptual background for SIT and identify the development conditions for territorial energy communities. In response to these theory- and policy-related challenges, this monograph aims to conceptualize the role of energy cluster policies in SIT using an institutional approach, as well as to identify the progress of the energy cluster policies and the development stages, drivers, and obstacles of local energy clusters. The author’s empirical basis will be Polish energy clusters analyzed against international policies and experience in territorial energy communities. This book provides unique value by developing an institutional analytical framework for energy cluster policies, identifying the conditions for the development of energy clusters, and proposing actionable policy recommendations in this area. The Open Access version of this book, available at http://www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives (CC BY-NC-ND) 4.0 license.