Letter #1

June 14, 2001

Dear Mr. Walker,

Thank you for the opportunity to offer comments to the NWPPC’s mainstem amendment to the Columbia River Basin Fish and Wildlife Program. In your solicitation for comments dated March 14, 2001, you ask respondents to address several areas of concern to the basin as it struggles to balance issues of power generation, habitat enhancement, recreation, and river system stewardship.

Having led the industry for the last decade in improving the mechanical and operational characteristics of hydroturbines to target environmental concerns, Voith Siemens Hydro Power Generation (VSH) would like to point out features of existing technical solutions that can be brought to bear immediately to mitigate some of these concerns.

Upgrading existing turbines to use the same water more efficiently, or uprating them to be both more efficient and to use more water to produce additional power from the existing embedded turbine structures is feasible. Uprating / Upgrading using VSH’s internally developed technologies and those technologies developed by the VSH-led team for DOE’s Advanced Hydro Turbine System (AHTS) technology can provide significant reductions in fish passage injury and mortality as well. Upgrading / Uprating can be accomplished to generate more energy, reduce maintenance, and extend life of existing equipment, all of which assist plant owners in paying for the Upgrading/Uprating. The environmental benefits accrue for minimal incremental cost. The fish passage survival characteristics of the VSH team’s AHTS turbines are anticipated to be about the same as the survival of fish passing the plants in spill. Water, currently spilled to avoid passing fish through turbines can therefore be used to produce needed energy efficiently and in an environmentally friendly manner.

Minimum Gap Runner (MGR) technology, already installed, tested, and proven at Bonneville Dam, enhances both power generation capabilities and fish passage survival in the following ways:

• Elimination of gaps present at both the inner diameter (hub) and outer diameter (discharge ring) of Kaplan turbine runners decreases the likelihood that fish, large or small, can be injured by these gaps.
• Elimination of these gaps increases the efficiency of the turbine across its operating range, thereby better utilizing the water that flows through the machine.
• Improvements in Kaplan runner blade design result in better distribution of pressures found in the flow patterns through the runner, decreasing the likelihood of fish mortality associated with rapid pressure changes.
• Blade design improvements also include the use of blades that are more blunt at the inlet edge, so fish are more likely to be diverted around the inlet edge of the blade rather than to strike the blade directly.
• Tests showed that fish passing similar paths in Unit 5 (old generation design) and Unit 6 (MGR design) through the turbine runner, draft tube and tailrace had 40% less injury in the MGR design.

A design using many of the AHTS concepts has been developed for Grant County Public Utility District for uprating the turbines at Wanapum Dam. This design, when applied to uprate the 10 Unit Wanapum Dam with new turbine components, would provide an additional 300 MW of power to meet peak load needs and 180,000,000 kWh – per year - of additional energy, enough to supply 21,000 homes.

New advances in the understanding of the correlation between the turbine operation point and fish survivability can also contribute to improved utilization of flows through the mainstem dams. Some of the turbines (Wanapum Dam) have been demonstrated to have characteristics providing increased fish survival at increased flow rates (beyond their "best efficiency" points), thereby increasing available generation capacity while also improving fish passage survival. Technology is available to estimate the survival probability as a function of turbine design and turbine discharge, enabling the possibility to operate turbines more effectively for survival. Computer aided operational optimization methodologies exist to enable existing plants to produce more energy from existing water which is passing through the turbines. These two methodologies can be combined to boost both survival and energy generation even without Upgrading/Uprating.

Running water through turbines, rather than over spillways, has two benefits: increased energy production during times of high energy demand, and a reduction of the dissolved gas problem that faces both the Lower Snake and Lower Columbia River systems. Spill is costly in terms of lost generation opportunity, and is detrimental to the health of fish sensitive to high levels of dissolved gases.

We at Voith Siemens acknowledge the need for further study in the area of environmental enhancement of hydroturbine technology. We applaud and support DOE’s on going research to develop improved biological turbine design criteria. Having said that, we also acknowledge the opportunity that currently exists to pursue a win-win strategy that immediately increases generation reliability, efficiency, and capacity while at the same time benefiting the environment to the greatest extent possible. We will continue to support efforts to promote technological advancements that result in even more environmentally friendly turbines, and we would encourage the establishment of a timetable to identify, develop, and implement these longer range goals. In the meantime, we strongly urge the NWPPC to recommend the usage of proven existing technology to advance the above-mentioned win-win strategy. Now is the time to proactively pursue conversion of old technologies in favor of new ones, optimizing our existing resources

We thank you again for the chance to comment. Please feel free to contact me at (717) 792-7848 should you have any questions.

Sincerely,

Richard K. Fisher, Jr.
Vice President, Technology
Voith Siemens HydroPower Generation, Inc.
PO Box 712
York, PA, 17405
Email Richard.Fisher@VS-Hydro.com
Phone 717-792-7209
Fax 717-792-7209
 

Letter #2

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