This article studies the challenges of Thai energy-from-waste (EFW) development from an institutional perspective. Policy capacity, described as conditions for effective policy development and implementation, of the main government organizations involved in EFW development under the Alternative Energy Development Plan (AEDP) 2015 is examined. Adopting the variables used under the institutional analytical and development (IAD) approach, we modified the analytical framework for policy capacity by categorizing factors contributing to policy capacity into elements (skills, resources, and process) that affect the decisions and actions of actors of government organizations. Then, the results from the in-depth interview were interpreted through a modified analytical framework to examine policy capacity at the organizational and systemic level of government organizations involved in EFW development. We believe that a modified analytical framework for policy capacity is compatible with the IAD approach and can facilitate the utilization of policy capacity for further analysis under the IAD approach. Moreover, the modified framework can encourage a better understanding of current policy capacity and its impacts on other organizations, since an organization values its own policy capacity and others' policy capacity differently. Consequently, this understanding can benefit the improvement of cooperation among Thai government organizations involved in EFW development.