Fish-Friendly Hydroelectric Turbine

Alden Turbine Showing Cutaway View of Distributor and Runner
Alden Turbine Showing Cutaway View of
Distributor and Runner
Photo courtesy of Voith Hydro Inc.


Hydroelectric plants make about 18% of New York State’s power. Unfortunately, they also impede the passage of migrating fish, and can lead to high mortality of other organisms moving through the system. Current methodologies to pass fish downstream using bypasses and water spilled over the dam reduce water flow through the turbine and reduce the site’s power output by an average of 6,000 MW hours per year. They are also expensive to build and maintain. Recognizing the need for a more “fish-friendly” solution, a new hydropower turbine has been designed to reduce injury and mortality to downstream moving aquatic life.

Alden Research Laboratory, Inc., with support from the U.S. Department of Energy (DOE), developed the initial concept for the new turbine system that includes a three-bladed runner with sufficient clearances to avoid fish entrapment, and, with the exception of some small areas around the blade leading edges, has pressure and velocity (shear) gradients that meet established bio-criteria for safe fish passage. Computer models and pilot scale laboratory research confirmed high fish passage survival. Electric Power Research Institute (EPRI) continued conceptual development work and focused on optimization of the system as well as investigations of the relationship between turbine leading edge blade shape and fish injury and mortality. The investigation demonstrated that thick, rounded leading edge blade shapes reduce fish injury and increase survival rates. Results of this research were incorporated into a final design of the turbine by Voith Hydro Inc. to further improve biological performance. After the most recent R&D, the Alden turbine is predicted to allow high (≥98 percent) fish passage survival while maintaining high energy efficiency.


The hydraulic development, performance testing on a physical model, mechanical design, and balance of plant investigation has been completed for pilot installation. This project will help prepare the technology for large-scale deployment. The NYSERDA-specific task estimated application potential for sites in New York State (NYS).


The Alden hydroelectric turbine is in late-stage development and has not been deployed in New York State. Existing hydroelectric sites may benefit from the innovative turbine design, but also, the new turbine design allows for new and previously uneconomical sites to be developed. The purpose of NYSERDA funding was to locate and evaluate potential users of the turbine and determine the potential New York State benefit.

Project researchers used various state and federal databases to identify existing projects where unused capacity could be developed with this turbine. This included the hydroelectric sites in the state along with a comprehensive review of the 7,107 unpowered dams throughout the state.

Benefits and Metrics

Because water spillage over dams and through bypasses for fish passage can be eliminated or reduced, the turbine has the potential to create more power than traditional systems with dramatically improved (≥98%) survival for fish, improving fishing and ecosystem benefits. Public funding would decrease compliance costs for interested parties.

Of those sites with sufficient vertical drop and water flow rates, 33 were found acceptable for the turbine. If fully developed, there could be an estimated 120 MW of power generated from installed Alden turbines, enough to power 120,000 homes. This is equivalent to expanding New York State hydropower capacity by approximately two percent. Adding to the benefit is many of these sites are widely distributed, which reduces the power transmission distances and increases security of the utility grid.

Staff Contact

Jennifer L. Harvey
Sr. Project Manager
518-862-1090, Ext. 3264

Last Updated: 07/01/2014