Impact assessment can play an important role in global energy transition, delivering knowledge to identify and manage the impacts of renewable energy projects. Yet, there are enduring concerns about IA’s efficacy for renewable energy development. Based on content analysis of IA applications for wind energy development in Canada, this paper examines the environmental and social impacts typically assessed across wind energy projects and the mitigation solutions proposed. Results indicate considerable imbalance between biophysical versus social impacts, including mitigation solutions. IAs include far more solutions for managing biophysical impacts than social ones, with impact-to-mitigation ratios of 1:4.3 and 1:1.3 respectively. Most mitigations focus on impact minimisation, followed by avoidance, and are often vague and imprecise regarding the timing, methods of implementation, and responsibility. Notwithstanding common impacts, mitigation actions that were common across projects were too vague or imprecise to support transferable practice to find efficiencies in assessment. Improved understanding the impacts of renewable energy projects and mitigation solutions, and learning from one project to the next, are foundational to advancing the role of IA the transition to renewable energy.