Environmental conflicts arising from concerns of local residents and environmental protection groups pose a significant barrier to the further development of wind farms in Japan, as in other countries. There has been increasing discussion about countermeasures to address the concerns and ease conflicts. In order to design a smooth and adequate planning system of wind farm developments, this study aims to demonstrate factors that determine the success and failure of conflict resolution at the project stage. To do so, this study focuses on public participation at the project stage, and analyzes its function in light of the site-specific difficulties determined by the characteristics of the project. Through eight in-depth case studies, the results demonstrate that the projects with a high level of site-specific difficulties are much more likely to be unsuccessful regardless of the levels of public participation; therefore it indicates the limitation of practice to ease conflicts at the project stage. Barriers discovered to hinder developments include “designated areas regulated by the Natural Parks Act” and “the disclosed 10km grid habitat for Golden Eagle.” On the other hand, the projects with a low level of site-specific difficulties are more likely to be successful with a high level of public participation at the project stage.