Environmental Design and Optimization of Modular Hydropower Plants

This research aimed to understand the pathways to cost-effective and sustainable low-head hydropower. Designing viable hydropower projects requires optimization across many economic, environmental, and social outcomes. However, existing run-of-river hydropower design models often focus on economic performance and customizing technologies for high-head diversion schemes. Standard modular hydropower is a new design approach that uses standardized rather than custom-designed technologies to achieve economies of scale. Oak Ridge National Laboratory established a conceptual outline for module classes based on functions, such as generation modules and fish passage modules, but further research was needed to identify how modules should be selected and operated for a site. Therefore, a new hydropower design model, called the waterSHED model, was created to incorporate multi-objective optimization strategies and design considerations specific to standard modular hydropower. The waterSHED model uses an object-oriented approach, heuristic optimization techniques, and a system of inter-disciplinary models to assess project feasibility and design tradeoffs. The model quantifies the non-power benefits of fish passage, sediment passage, and recreation passage by integrating existing and novel modeling approaches into an operation simulation. Two case studies were conducted to validate the model and help answer research questions related to 1) the cost-benefit tradeoffs of non-power modules, 2) the economic drivers of modular designs, and 3) the value of fish-safe designs. These case studies highlighted the potential of several technologies, such as fish-safe turbines and sediment sluice gates, to improve the environmental performance of projects with minimal impacts on generation. However, cost reductions are needed to overcome the economic and regulatory challenges of low-head projects, particularly for foundation and generation technologies. The object-oriented approach facilitates rapid integration of the innovations that will emerge to meet these challenges. This research helped modernize hydropower design thinking and provided valuable tools to the industry that will enable communities to meet clean electricity goals and protect riverine ecosystems.