This research examined cooperation among core Thai government organizations involved in achieving the energy-from-waste (EFW) targets stipulated in the country’s 2015 Alternative Energy Development Plan (AEDP). To this end, we used the institutional analysis and development (IAD) framework to illuminate the intricacies of such collaboration, which reflects interactions that flow logically from the decisions and measures taken by actors as they deliberate over relevant situations. Data were obtained mainly from government documents and in-depth interviews with employees of the collaborators that are directly involved in the development and implementation of AEDP 2015. The concept of cooperation intensity was used to inquire into the cooperative interactions of the aforementioned government organizations and analyze the factors and conditions that influence these actors’ decision to work with one another. We focused on the effects of institutions on cooperation under the AEDP policy process. To strengthen the novelty of this work, we categorized cooperation intensity into five levels, which can serve as guidance in the evaluation and improvement of collaborative endeavors. These levels are reflected in collaboration through (1) the pursuit of common goals and mutual benefits, (2) the pooling of resources, (3) the sharing of responsibilities, (4) the synchronization of activities, and (5) the monitoring of partners. Using the proposed cooperation intensity levels, we identified the following causes of ineffective cooperation: Differences in perceptions of problems related to municipal solid waste (MSW) and the prioritization of solutions put forward by the individual actors; the actors’ commitment to different solutions; the inconsistency among responsibilities, actions, and control over the expected outcomes of the actors; the failure of the actors to clarify and synchronize related and duplicate policy activities; and the unwillingness of the actors to undergo checking and monitoring. Overcoming these problems necessitates the enhancement of communication, which would reinforce cooperation given that effective communication leads to perfect information and an improved understanding of other actors.