PNNL

Abstract

Hydropower is the largest renewable energy resource in the world and the United States. However, Hydropower dams have adverse ecological impacts because migrating fish may be injured or killed when they pass through hydro turbines. In the Columbia and Snake River basins, dam operators and engineers are required to make these hydroelectric facilities more fish-friendly through changes in hydro-turbine design and operation after fish population declines and the subsequent listing of several species of Pacific salmon in the Endangered Species Act of 1973. Grant County Public Utility District (Grant PUD) requested authorization from the Federal Energy Regulatory Commission to replace the 10 turbines at Wanapum Dam with advanced hydropower turbines that are designed to improve survival for fish passing through the turbines while improving operation efficiency and increasing power generation. The U.S. Department of Energy Office of Energy Efficiency and Renewable Energy provided co-funding to Grant PUD for aspects of performance testing that supported the application. As an additional measure to the primary evaluation measure of direct injury and mortality rates of juvenile Chinook salmon using balloon tag-recapture methodology, this study used an autonomous sensor device to provide insight into the specific hydraulic conditions or physical stresses that the fish experienced or the specific causes of the biological response. We found that the new blade shape and the corresponding reduction of turbulence in the advanced hydropower turbine were effective. The frequency of severe events based on Sensor Fish pressure and acceleration measurements showed trends similar to those of fish survival determined by balloon tag-recapture tests. In addition, the new turbine provided a better pressure and rate of change environment for fish passage. Overall, the Sensor Fish data indicated that the advanced hydro turbine design met the desired fish passage goals for Wanapum Dam.