Abstract
The Tanana River hydrokinetic characterization study started in 2009, when little was known about how river environments in Alaska would affect hydrokinetic power generating devices or how those devices might affect the state’s river environments. Few hydrokinetic devices were beyond the concept/design stage, and a first attempt at demonstrating a hydrokinetic device at Ruby, Alaska, had just concluded. The primary focus of previous paper studies of hydrokinetic power generation in Alaska involved determining the locations of highest average river currents and hydrokinetic power densities without regard to other aspects of river environments. This project took a broader approach by examining a range of river conditions that include sediment transport and riverbed conditions, river current velocity and turbulence and their seasonal variation, woody debris, fish stocks, and wintertime flow. As the project progressed, it became apparent that many of the river environmental factors identified in our study had the potential to significantly affect the deployment and operation of hydrokinetic power generating devices. For example, both the Ruby demonstration project and another demonstration at Eagle, Alaska, were ended due to problems with debris. To adequately characterize the most important river environmental factors, it was necessary to go beyond the project’s original scope of work to include river hydrodynamic modeling, more extensive fisheries measurements, and an expanded study of woody debris and its mitigation. The results from this expanded scope of work provide a solid basis for moving to the next stage of hydrokinetic technology development and testing needed for successful long-term deployment and operation of hydrokinetic devices in Alaska rivers.