Thesis (Master's)--University of Washington, 2017-09 ; Instream tidal energy is a form of renewable energy that is at an early stage of development compared to other forms of energy generation. A comparative multiple-case study was conducted to evaluate stakeholder group perceived concerns and benefits about the siting of commercial instream tidal energy projects. Based on their history of experience with instream tidal energy and their dissimilarity of population and grid connectivity Puget Sound, Washington State and Igiugig, Alaska were chosen. Interviews were conducted with key stakeholders in both locations to understand perceptions of project development. Perceived concerns and benefits were ranked; interviews were transcribed and coded to extract themes about project development. Providing local renewable energy, advancing science and technology, and environmental awareness were some of the top perceived benefits of the technology, while negative environmental impacts, conflicts with other uses, and unintended consequences were some of the top perceived concerns of the technology. The two locations varied in the type, number, and complexities of stakeholders involved in project development. Support or opposition about a project was justified by promoting the wellbeing of the affected stakeholders. There was overall more support in smaller communities isolated from municipal power sources, that had a demonstrated need for energy.