Researchers at Oak Ridge National Laboratory (ORNL) developed the Cost Analysis of Hydropower Options at Non-Powered Dams Report to provide hydropower developers with better insights into the potential costs of adding hydropower generation capability or powering existing non-powered dam (NPD) projects and to explore ways to reduce these costs. Using available data and assisted by hydropower design experts from Small Hydro Consultants, researchers identified key characteristics of potential NPD hydropower projects and grouped them into classes that aligned similar projects with one another. Researchers then evaluated detailed design, initial construction costs, and hydropower generation for a representative project within each group. This report provides a critical update to cost estimates for NPD projects and insights into the site and design features that drive costs. Results for the representative sites will serve as templates to support more accurate estimates for thousands of prospective NPD projects, saving stakeholders time, effort, and millions of dollars when assessing sites for NPD hydropower development.